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      3 <title>Android 6.0 Compatibility Definition</title>
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      8 <h1>Android 6.0 Compatibility Definition</h1>
      9 
     10 <h6>Table of Contents</h6>
     11 
     12 <div id="toc">
     13 
     14 <div id="toc_left">
     15 
     16 <p class="toc_h1"><a href="#1_introduction">1. Introduction</a></p>
     17 
     18 <p class="toc_h1"><a href="#2_device_types">2. Device Types</a></p>
     19 
     20 <p class="toc_h2"><a href="#2_1_device_configurations">2.1 Device Configurations</a></p>
     21 
     22 <p class="toc_h1"><a href="#3_software">3. Software</a></p>
     23 
     24 <p class="toc_h2"><a href="#3_1_managed_api_compatibility">3.1. Managed API Compatibility</a></p>
     25 
     26 <p class="toc_h2"><a href="#3_2_soft_api_compatibility">3.2. Soft API Compatibility</a></p>
     27 
     28 <p class="toc_h3"><a href="#3_2_1_permissions">3.2.1. Permissions</a></p>
     29 
     30 <p class="toc_h3"><a href="#3_2_2_build_parameters">3.2.2. Build Parameters</a></p>
     31 
     32 <p class="toc_h3"><a href="#3_2_3_intent_compatibility">3.2.3. Intent Compatibility</a></p>
     33 
     34 <p class="toc_h4"><a href="#3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</a></p>
     35 
     36 <p class="toc_h4"><a href="#3_2_3_2_intent_resolution">3.2.3.2. Intent Resolution</a></p>
     37 
     38 <p class="toc_h4"><a href="#3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</a></p>
     39 
     40 <p class="toc_h4"><a href="#3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</a></p>
     41 
     42 <p class="toc_h4"><a href="#3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</a></p>
     43 
     44 <p class="toc_h2"><a href="#3_3_native_api_compatibility">3.3. Native API Compatibility</a></p>
     45 
     46 <p class="toc_h3"><a href="#3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</a></p>
     47 
     48 <p class="toc_h3"><a href="#3_3_2_32-bit_arm_native_code_compatibility">3.3.2. 32-bit ARM Native Code Compatibility</a></p>
     49 
     50 <p class="toc_h2"><a href="#3_4_web_compatibility">3.4. Web Compatibility</a></p>
     51 
     52 <p class="toc_h3"><a href="#3_4_1_webview_compatibility">3.4.1. WebView Compatibility</a></p>
     53 
     54 <p class="toc_h3"><a href="#3_4_2_browser_compatibility">3.4.2. Browser Compatibility</a></p>
     55 
     56 <p class="toc_h2"><a href="#3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</a></p>
     57 
     58 <p class="toc_h2"><a href="#3_6_api_namespaces">3.6. API Namespaces</a></p>
     59 
     60 <p class="toc_h2"><a href="#3_7_runtime_compatibility">3.7. Runtime Compatibility</a></p>
     61 
     62 <p class="toc_h2"><a href="#3_8_user_interface_compatibility">3.8. User Interface Compatibility</a></p>
     63 
     64 <p class="toc_h3"><a href="#3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</a></p>
     65 
     66 <p class="toc_h3"><a href="#3_8_2_widgets">3.8.2. Widgets</a></p>
     67 
     68 <p class="toc_h3"><a href="#3_8_3_notifications">3.8.3. Notifications</a></p>
     69 
     70 <p class="toc_h3"><a href="#3_8_4_search">3.8.4. Search</a></p>
     71 
     72 <p class="toc_h3"><a href="#3_8_5_toasts">3.8.5. Toasts</a></p>
     73 
     74 <p class="toc_h3"><a href="#3_8_6_themes">3.8.6. Themes</a></p>
     75 
     76 <p class="toc_h3"><a href="#3_8_7_live_wallpapers">3.8.7. Live Wallpapers</a></p>
     77 
     78 <p class="toc_h3"><a href="#3_8_8_activity_switching">3.8.8. Activity Switching</a></p>
     79 
     80 <p class="toc_h3"><a href="#3_8_9_input_management">3.8.9. Input Management</a></p>
     81 
     82 <p class="toc_h3"><a href="#3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</a></p>
     83 
     84 <p class="toc_h3"><a href="#3_8_11_dreams">3.8.11. Dreams</a></p>
     85 
     86 <p class="toc_h3"><a href="#3_8_12_location">3.8.12. Location</a></p>
     87 
     88 </div>
     89 
     90 <div id="toc_right">
     91 
     92 
     93 <p class="toc_h3"><a href="#3_8_13_unicode_and_font">3.8.13. Unicode and Font</a></p>
     94 
     95 <p class="toc_h2"><a href="#3_9_device_administration">3.9. Device Administration</a></p>
     96 
     97 <p class="toc_h3"><a href="#3_9_1_device_provisioning">3.9.1 Device Provisioning</a></p>
     98 
     99 <p class="toc_h4"><a href="#3_9_1_2_device_owner_provisioning">3.9.1.1 Device Owner provisioning</a></p>
    100 
    101 <p class="toc_h4"><a href="#3_9_1_2_managed_profile_provisioning">3.9.1.2 Managed profile provisioning</a></p>
    102 
    103 <p class="toc_h3"><a href="#3_9_2_managed_profile_support">3.9.2. Managed Profile Support</a></p>
    104 
    105 
    106 <p class="toc_h2"><a href="#3_10_accessibility">3.10. Accessibility</a></p>
    107 
    108 <p class="toc_h2"><a href="#3_11_text-to-speech">3.11. Text-to-Speech</a></p>
    109 
    110 <p class="toc_h2"><a href="#3_12_tv_input_framework">3.12. TV Input Framework</a></p>
    111 
    112 <p class="toc_h3"><a href="#3_12_1_tv_app">3.12.1. TV App</a></p>
    113 
    114 <p class="toc_h4"><a href="#3_12_1_1_electronic_program_guide">3.12.1.1. Electronic Program Guide</a></p>
    115 
    116 <p class="toc_h4"><a href="#3_12_1_2_navigation">3.12.1.2. Navigation</a></p>
    117 
    118 <p class="toc_h4"><a href="#3_12_1_3_tv_input_app_linking">3.12.1.3. TV input app linking</a></p>
    119 
    120 <p class="toc_h1"><a href="#4_application_packaging_compatibility">4. Application Packaging Compatibility</a></p>
    121 
    122 <p class="toc_h1"><a href="#5_multimedia_compatibility">5. Multimedia Compatibility</a></p>
    123 
    124 <p class="toc_h2"><a href="#5_1_media_codecs">5.1. Media Codecs</a></p>
    125 
    126 <p class="toc_h3"><a href="#5_1_1_audio_codecs">5.1.1. Audio Codecs</a></p>
    127 
    128 <p class="toc_h3"><a href="#5_1_2_image_codecs">5.1.2. Image Codecs</a></p>
    129 
    130 <p class="toc_h3"><a href="#5_1_3_video_codecs">5.1.3. Video Codecs</a></p>
    131 
    132 <p class="toc_h2"><a href="#5_2_video_encoding">5.2. Video Encoding</a></p>
    133 
    134 <p class="toc_h2"><a href="#5_3_video_decoding">5.3. Video Decoding</a></p>
    135 
    136 <p class="toc_h2"><a href="#5_4_audio_recording">5.4. Audio Recording</a></p>
    137 
    138 <p class="toc_h3"><a href="#5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</a></p>
    139 
    140 <p class="toc_h3"><a href="#5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</a></p>
    141 
    142 <p class="toc_h3"><a href="#5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</a></p>
    143 
    144 <p class="toc_h2"><a href="#5_5_audio_playback">5.5. Audio Playback</a></p>
    145 
    146 <p class="toc_h3"><a href="#5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</a></p>
    147 
    148 <p class="toc_h3"><a href="#5_5_2_audio_effects">5.5.2. Audio Effects</a></p>
    149 
    150 <p class="toc_h3"><a href="#5_5_3_audio_output_volume">5.5.3. Audio Output Volume</a></p>
    151 
    152 <p class="toc_h2"><a href="#5_6_audio_latency">5.6. Audio Latency</a></p>
    153 
    154 <p class="toc_h2"><a href="#5_7_network_protocols">5.7. Network Protocols</a></p>
    155 
    156 <p class="toc_h2"><a href="#5_8_secure_media">5.8. Secure Media</a></p>
    157 
    158 <p class="toc_h2"><a href="#5_9_midi">5.9. Musical Instrument Digital Interface (MIDI)</a></p>
    159 
    160 <p class="toc_h2"><a href="#5_10_pro_audio">5.10. Professional Audio</a></p>
    161 
    162 </div>
    163 
    164 <div style="clear: both; page-break-after:always; height:1px"></div>
    165 
    166 <div id="toc_left">
    167 
    168 <p class="toc_h1"><a href="#6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</a></p>
    169 
    170 <p class="toc_h2"><a href="#6_1_developer_tools">6.1. Developer Tools</a></p>
    171 
    172 <p class="toc_h2"><a href="#6_2_developer_options">6.2. Developer Options</a></p>
    173 
    174 <p class="toc_h1"><a href="#7_hardware_compatibility">7. Hardware Compatibility</a></p>
    175 
    176 <p class="toc_h2"><a href="#7_1_display_and_graphics">7.1. Display and Graphics</a></p>
    177 
    178 <p class="toc_h3"><a href="#7_1_1_screen_configuration">7.1.1. Screen Configuration</a></p>
    179 
    180 <p class="toc_h4"><a href="#7_1_1_1_screen_size">7.1.1.1. Screen Size</a></p>
    181 
    182 <p class="toc_h4"><a href="#7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</a></p>
    183 
    184 <p class="toc_h4"><a href="#7_1_1_3_screen_density">7.1.1.3. Screen Density</a></p>
    185 
    186 <p class="toc_h3"><a href="#7_1_2_display_metrics">7.1.2. Display Metrics</a></p>
    187 
    188 <p class="toc_h3"><a href="#7_1_3_screen_orientation">7.1.3. Screen Orientation</a></p>
    189 
    190 <p class="toc_h3"><a href="#7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</a></p>
    191 
    192 <p class="toc_h3"><a href="#7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</a></p>
    193 
    194 <p class="toc_h3"><a href="#7_1_6_screen_technology">7.1.6. Screen Technology</a></p>
    195 
    196 <p class="toc_h3"><a href="#7_1_7_external_displays">7.1.7. Secondary Displays</a></p>
    197 
    198 <p class="toc_h2"><a href="#7_2_input_devices">7.2. Input Devices</a></p>
    199 
    200 <p class="toc_h3"><a href="#7_2_1_keyboard">7.2.1. Keyboard</a></p>
    201 
    202 <p class="toc_h3"><a href="#7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</a></p>
    203 
    204 <p class="toc_h3"><a href="#7_2_3_navigation_keys">7.2.3. Navigation Keys</a></p>
    205 
    206 <p class="toc_h3"><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen Input</a></p>
    207 
    208 <p class="toc_h3"><a href="#7_2_5_fake_touch_input">7.2.5. Fake Touch Input</a></p>
    209 
    210 <p class="toc_h3"><a href="#7_2_6_game_controller_support">7.2.6. Game Controller Support</a></p>
    211 
    212 <p class="toc_h4"><a href="#7_2_6_1_button_mapping">7.2.6.1. Button Mappings</a></p>
    213 
    214 <p class="toc_h3"><a href="#7_2_7_remote_control">7.2.7. Remote Control</a></p>
    215 
    216 <p class="toc_h2"><a href="#7_3_sensors">7.3. Sensors</a></p>
    217 
    218 <p class="toc_h3"><a href="#7_3_1_accelerometer">7.3.1. Accelerometer</a></p>
    219 
    220 <p class="toc_h3"><a href="#7_3_2_magnetometer">7.3.2. Magnetometer</a></p>
    221 
    222 <p class="toc_h3"><a href="#7_3_3_gps">7.3.3. GPS</a></p>
    223 
    224 </div>
    225 
    226 <div id="toc_right">
    227 
    228 <p class="toc_h3"><a href="#7_3_4_gyroscope">7.3.4. Gyroscope</a></p>
    229 
    230 <p class="toc_h3"><a href="#7_3_5_barometer">7.3.5. Barometer</a></p>
    231 
    232 <p class="toc_h3"><a href="#7_3_6_thermometer">7.3.6. Thermometer</a></p>
    233 
    234 <p class="toc_h3"><a href="#7_3_7_photometer">7.3.7. Photometer</a></p>
    235 
    236 <p class="toc_h3"><a href="#7_3_8_proximity_sensor">7.3.8. Proximity Sensor</a></p>
    237 
    238 <p class="toc_h3"><a href="#7_3_9_hifi_sensors">7.3.9. High Fidelity Sensors</a></p>
    239 
    240 <p class="toc_h3"><a href="#7_3_10_fingerprint">7.3.10. Fingerprint Sensor</a></p>
    241 
    242 <p class="toc_h2"><a href="#7_4_data_connectivity">7.4. Data Connectivity</a></p>
    243 
    244 <p class="toc_h3"><a href="#7_4_1_telephony">7.4.1. Telephony</a></p>
    245 
    246 <p class="toc_h3"><a href="#7_4_2_ieee_80211_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</a></p>
    247 
    248 <p class="toc_h4"><a href="#7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</a></p>
    249 
    250 <p class="toc_h4"><a href="#7_4_2_2_wi-fi-tunneled-direct-link-setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</a></p>
    251 
    252 <p class="toc_h3"><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></p>
    253 
    254 <p class="toc_h3"><a href="#7_4_4_near-field_communications">7.4.4. Near-Field Communications</a></p>
    255 
    256 <p class="toc_h3"><a href="#7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</a></p>
    257 
    258 <p class="toc_h3"><a href="#7_4_6_sync_settings">7.4.6. Sync Settings</a></p>
    259 
    260 <p class="toc_h2"><a href="#7_5_cameras">7.5. Cameras</a></p>
    261 
    262 <p class="toc_h3"><a href="#7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</a></p>
    263 
    264 <p class="toc_h3"><a href="#7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</a></p>
    265 
    266 <p class="toc_h3"><a href="#7_5_3_external_camera">7.5.3. External Camera</a></p>
    267 
    268 <p class="toc_h3"><a href="#7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</a></p>
    269 
    270 <p class="toc_h3"><a href="#7_5_5_camera_orientation">7.5.5. Camera Orientation</a></p>
    271 
    272 <p class="toc_h2"><a href="#7_6_memory_and_storage">7.6. Memory and Storage</a></p>
    273 
    274 <p class="toc_h3"><a href="#7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</a></p>
    275 
    276 <p class="toc_h3"><a href="#7_6_2_application_shared_storage">7.6.2. Application Shared Storage</a></p>
    277 
    278 <p class="toc_h3"><a href="#7_6_3_adoptable_storage">7.6.3. Adoptable Storage</a></p>
    279 
    280 <p class="toc_h2"><a href="#7_7_usb">7.7. USB</a></p>
    281 
    282 <p class="toc_h2"><a href="#7_8_audio">7.8. Audio</a></p>
    283 
    284 <p class="toc_h3"><a href="#7_8_1_microphone">7.8.1. Microphone</a></p>
    285 
    286 <p class="toc_h3"><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></p>
    287 
    288 <p class="toc_h4"><a href="#7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</a></p>
    289 
    290 <p class="toc_h3"><a href="#7_8_3_near_ultrasound">7.8.3. Near-Ultrasound</a></p>
    291 
    292 <p class="toc_h1"><a href="#8_performance_power">8. Performance and Power</a></p>
    293 
    294 <p class="toc_h2"><a href="#8_1_user_experience_consistency">8.1. User Experience Consistency</a></p>
    295 
    296 <p class="toc_h2"><a href="#8_2_file_i_o_access_performance">8.2. File I/O Access Performance</a></p>
    297 
    298 <p class="toc_h2"><a href="#8_3_power_saving_modes">8.3. Power-Saving Modes</a></p>
    299 
    300 <p class="toc_h2"><a href="#8_4_power_consumption_accounting">8.4. Power Consumption Accounting</a></p>
    301 
    302 </div>
    303 
    304 <div style="clear: both; page-break-after:always; height:1px"></div>
    305 
    306 <div id="toc_left">
    307 
    308 <p class="toc_h1"><a href="#9_security_model_compatibility">9. Security Model Compatibility</a></p>
    309 
    310 <p class="toc_h2"><a href="#9_1_permissions">9.1. Permissions</a></p>
    311 
    312 <p class="toc_h2"><a href="#9_2_uid_and_process_isolation">9.2. UID and Process Isolation</a></p>
    313 
    314 <p class="toc_h2"><a href="#9_3_filesystem_permissions">9.3. Filesystem Permissions</a></p>
    315 
    316 <p class="toc_h2"><a href="#9_4_alternate_execution_environments">9.4. Alternate Execution Environments</a></p>
    317 
    318 <p class="toc_h2"><a href="#9_5_multi-user_support">9.5. Multi-User Support</a></p>
    319 
    320 <p class="toc_h2"><a href="#9_6_premium_sms_warning">9.6. Premium SMS Warning</a></p>
    321 
    322 <p class="toc_h2"><a href="#9_7_kernel_security_features">9.7. Kernel Security Features</a></p>
    323 
    324 <p class="toc_h2"><a href="#9_8_privacy">9.8. Privacy</a></p>
    325 
    326 <p class="toc_h2"><a href="#9_9_full-disk-encryption">9.9. Full-Disk Encryption</a></p>
    327 
    328 <p class="toc_h2"><a href="#9_10_verified_boot">9.10. Verified Boot</a></p>
    329 
    330 <p class="toc_h2"><a href="#9_11_keys_and_credentials">9.11. Keys and Credentials</a></p>
    331 
    332 <p class="toc_h2"><a href="#9_12_data_deletion">9.12. Data Deletion</a></p>
    333 
    334 <p class="toc_h1"><a href="#10_software_compatibility_testing">10. Software Compatibility Testing</a></p>
    335 
    336 <p class="toc_h2"><a href="#10_1_compatibility_test_suite">10.1. Compatibility Test Suite</a></p>
    337 
    338 <p class="toc_h2"><a href="#10_2_cts_verifier">10.2. CTS Verifier</a></p>
    339 
    340 <p class="toc_h1"><a href="#11_updatable_software">11. Updatable Software</a></p>
    341 
    342 <p class="toc_h1"><a href="#12_document_changelog">12. Document Changelog</a></p>
    343 
    344 <p class="toc_h1"><a href="#13_contact_us">13. Contact Us</a></p>
    345 
    346 <p class="toc_h1"><a href="#14_resources">14. Resources</a></p>
    347 
    348 </div>
    349 
    350 </div>
    351 
    352 <div style="clear: both"></div>
    353 
    354 <div id="main">
    355 
    356 <h1 id="1_introduction">1. Introduction</h1>
    357 
    358 
    359 <p>This document enumerates the requirements that must be met in order for devices
    360 to be compatible with Android 6.0.</p>
    361 
    362 <p>The use of &ldquo;MUST&rdquo;, &ldquo;MUST NOT&rdquo;, &ldquo;REQUIRED&rdquo;, &ldquo;SHALL&rdquo;, &ldquo;SHALL NOT&rdquo;, &ldquo;SHOULD&rdquo;, &ldquo;SHOULD NOT&rdquo;, &ldquo;RECOMMENDED&rdquo;, &ldquo;MAY&rdquo;, and &ldquo;OPTIONAL&rdquo; is per the IETF standard
    363 defined in RFC2119 [<a href="http://www.ietf.org/rfc/rfc2119.txt">Resources, 1</a>].</p>
    364 
    365 <p>As used in this document, a &ldquo;device implementer&rdquo; or &ldquo;implementer&rdquo; is a person
    366 or organization developing a hardware/software solution running Android 6.0. A
    367 &ldquo;device implementation&rdquo; or &ldquo;implementation is the hardware/software solution
    368 so developed.</p>
    369 
    370 <p>To be considered compatible with Android 6.0, device implementations MUST meet
    371 the requirements presented in this Compatibility Definition, including any
    372 documents incorporated via reference.</p>
    373 
    374 <p>Where this definition or the software tests described in <a href="#10_software_compatibility_testing">section 10</a> is silent, ambiguous, or incomplete, it is the responsibility of the device
    375 implementer to ensure compatibility with existing implementations.</p>
    376 
    377 <p>For this reason, the Android Open Source Project [<a href="http://source.android.com/">Resources, 2</a>] is both the reference and preferred implementation of Android. Device
    378 implementers are STRONGLY RECOMMENDED to base their implementations to the
    379 greatest extent possible on the &ldquo;upstream&rdquo; source code available from the
    380 Android Open Source Project. While some components can hypothetically be
    381 replaced with alternate implementations, it is STRONGLY RECOMMENDED to not follow this practice,
    382 as passing the software tests will become substantially more difficult. It is
    383 the implementer&rsquo;s responsibility to ensure full behavioral compatibility with
    384 the standard Android implementation, including and beyond the Compatibility
    385 Test Suite. Finally, note that certain component substitutions and
    386 modifications are explicitly forbidden by this document.</p>
    387 
    388 <p>Many of the resources listed in <a href="#14_resources">section 14</a> are derived directly or indirectly from the Android SDK, and will be
    389 functionally identical to the information in that SDK&rsquo;s documentation. For any
    390 case where this Compatibility Definition or the Compatibility Test Suite
    391 disagrees with the SDK documentation, the SDK documentation is considered
    392 authoritative. Any technical details provided in the references included in <a href="#14_resources">section 14</a> are considered by inclusion to be part of this Compatibility Definition. </p>
    393 
    394 <h1 id="2_device_types">2. Device Types</h1>
    395 
    396 
    397 <p>While the Android Open Source Project has been used in the implementation of a
    398 variety of device types and form factors, many aspects of the architecture and
    399 compatibility requirements were optimized for handheld devices. Starting from
    400 Android 5.0, the Android Open Source Project aims to embrace a wider variety of
    401 device types as described in this section.</p>
    402 
    403 <p><strong>Android Handheld device</strong> refers to an Android device implementation that is typically used by holding
    404 it in the hand, such as mp3 players, phones, and tablets. Android Handheld
    405 device implementations:</p>
    406 
    407 <ul>
    408   <li>MUST have a touchscreen embedded in the device.</li>
    409   <li>MUST have a power source that provides mobility, such as a battery.</li>
    410 </ul>
    411 
    412 <p><strong>Android Television device</strong> refers to an Android device implementation that is an entertainment interface
    413 for consuming digital media, movies, games, apps, and/or live TV for users
    414 sitting about ten feet away (a &ldquo;lean back&rdquo; or &ldquo;10-foot user interface&rdquo;).
    415 Android Television devices:</p>
    416 
    417 <ul>
    418   <li>MUST have an embedded screen OR include a video output port, such as VGA, HDMI,
    419 or a wireless port for display.</li>
    420   <li>MUST declare the features android.software.leanback and
    421 android.hardware.type.television [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">Resources, 3</a>].</li>
    422 </ul>
    423 
    424 <p><strong>Android Watch device</strong> refers to an Android device implementation intended to be worn on the body,
    425 perhaps on the wrist, and:</p>
    426 
    427 <ul>
    428   <li>MUST have a screen with the physical diagonal length in the range from 1.1 to
    429 2.5 inches.</li>
    430   <li>MUST declare the feature android.hardware.type.watch.</li>
    431   <li>MUST support uiMode = UI_MODE_TYPE_WATCH [<a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH">Resources, 4</a>].</li>
    432 </ul>
    433 
    434 <p><strong>Android Automotive implementation</strong> refers to a vehicle head
    435 unit running Android as an operating system for part or all of the system and/or
    436 infotainment functionality. Android Automotive implementations:</p>
    437 
    438 <ul>
    439   <li>MUST declare the feature android.hardware.type.automotive.</li>
    440   <li>MUST support
    441 uiMode = UI_MODE_TYPE_CAR [<a
    442 href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">Resources,
    443     5</a>].</li>
    444 </ul>
    445 
    446 <p>All Android device implementations that do not fit into any of the above device
    447 types still MUST meet all requirements in this document to be Android 6.0
    448 compatible, unless the requirement is explicitly described to be only
    449 applicable to a specific Android device type from above.</p>
    450 
    451 <h2 id="2_1_device_configurations">2.1 Device Configurations</h2>
    452 
    453 
    454 <p>This is a summary of major differences in hardware configuration by device
    455 type. (Empty cells denote a &ldquo;MAY&rdquo;). Not all configurations are covered in this
    456 table; see relevant hardware sections for more detail.</p>
    457 <table>
    458  <tr>
    459     <th>Category</th>
    460     <th>Feature</th>
    461     <th>Section</th>
    462     <th>Handheld</th>
    463     <th>Television</th>
    464     <th>Watch</th>
    465     <th>Automotive</th>
    466     <th>Other</th>
    467  </tr>
    468  <tr>
    469     <td rowspan="3">Input</td>
    470     <td>D-pad</td>
    471     <td><a href="#7_2_2_non-touch-navigation">7.2.2. Non-touch Navigation</a></td>
    472     <td></td>
    473     <td>MUST</td>
    474     <td></td>
    475     <td></td>
    476     <td></td>
    477  </tr>
    478  <tr>
    479     <td>Touchscreen </td>
    480     <td><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen input</a></td>
    481     <td>MUST</td>
    482     <td></td>
    483     <td>MUST</td>
    484     <td></td>
    485     <td>SHOULD</td>
    486  </tr>
    487  <tr>
    488     <td>Microphone </td>
    489     <td><a href="#7_8_1_microphone">7.8.1. Microphone</a></td>
    490     <td>MUST</td>
    491     <td>SHOULD </td>
    492     <td>MUST</td>
    493     <td>MUST</td>
    494     <td>SHOULD</td>
    495  </tr>
    496  <tr>
    497     <td rowspan="2">Sensors</td>
    498     <td>Accelerometer </td>
    499     <td><a href="#7_3_1_accelerometer">7.3.1 Accelerometer</a></td>
    500     <td>SHOULD</td>
    501     <td></td>
    502     <td>SHOULD</td>
    503     <td></td>
    504     <td>SHOULD</td>
    505  </tr>
    506  <tr>
    507     <td>GPS</td>
    508     <td><a href="#7_3_3_gps">7.3.3. GPS</a></td>
    509     <td>SHOULD</td>
    510     <td></td>
    511     <td></td>
    512     <td>SHOULD</td>
    513     <td></td>
    514  </tr>
    515  <tr>
    516     <td rowspan="5">Connectivity</td>
    517     <td>Wi-Fi</td>
    518     <td><a href="#7_4_2_ieee_802.11">7.4.2. IEEE 802.11</a></td>
    519     <td>SHOULD</td>
    520     <td> MUST</td>
    521     <td></td>
    522     <td>SHOULD</td>
    523     <td>SHOULD</td>
    524  </tr>
    525  <tr>
    526     <td>Wi-Fi Direct</td>
    527     <td><a href="#7_4_2_1_wi-fi-direct">7.4.2.1. Wi-Fi Direct</a></td>
    528     <td>SHOULD</td>
    529     <td>SHOULD</td>
    530     <td></td>
    531     <td></td>
    532     <td>SHOULD</td>
    533  </tr>
    534  <tr>
    535     <td>Bluetooth</td>
    536     <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td>
    537     <td>SHOULD</td>
    538     <td>MUST</td>
    539     <td>MUST</td>
    540     <td>MUST</td>
    541     <td>SHOULD</td>
    542  </tr>
    543  <tr>
    544     <td>Bluetooth Low Energy</td>
    545     <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td>
    546     <td>SHOULD</td>
    547     <td>MUST</td>
    548     <td>SHOULD</td>
    549     <td>SHOULD</td>
    550     <td>SHOULD</td>
    551  </tr>
    552  <tr>
    553     <td>USB peripheral/host mode</td>
    554     <td><a href="#7_7_usb">7.7. USB</a></td>
    555     <td>SHOULD</td>
    556     <td></td>
    557     <td></td>
    558     <td>SHOULD</td>
    559     <td>SHOULD</td>
    560  </tr>
    561  <tr>
    562     <td>Output</td>
    563     <td>Speaker and/or Audio output ports</td>
    564     <td><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></td>
    565     <td>MUST</td>
    566     <td>MUST</td>
    567     <td></td>
    568     <td>MUST</td>
    569     <td>MUST</td>
    570  </tr>
    571 </table>
    572 
    573 
    574 <h1 id="3_software">3. Software</h1>
    575 
    576 
    577 <h2 id="3_1_managed_api_compatibility">3.1. Managed API Compatibility</h2>
    578 
    579 
    580 <p>The managed Dalvik bytecode execution environment is the primary vehicle for
    581 Android applications. The Android application programming interface (API) is
    582 the set of Android platform interfaces exposed to applications running in the
    583 managed runtime environment. Device implementations MUST provide complete
    584 implementations, including all documented behaviors, of any documented API
    585 exposed by the Android SDK [<a href="http://developer.android.com/reference/packages.html">Resources, 6</a>] or any API decorated with the &ldquo;@SystemApi&rdquo; marker in the upstream Android
    586 source code. </p>
    587 
    588 <p>Device implementations MUST NOT omit any managed APIs, alter API interfaces or
    589 signatures, deviate from the documented behavior, or include no-ops, except
    590 where specifically allowed by this Compatibility Definition.</p>
    591 
    592 <p>This Compatibility Definition permits some types of hardware for which Android
    593 includes APIs to be omitted by device implementations. In such cases, the APIs
    594 MUST still be present and behave in a reasonable way. See <a href="#7_hardware_compatibility">section 7</a> for specific requirements for this scenario.</p>
    595 
    596 <h2 id="3_2_soft_api_compatibility">3.2. Soft API Compatibility</h2>
    597 
    598 
    599 <p>In addition to the managed APIs from <a href="#3_1_managed_api_compatibility">section 3.1</a>, Android also includes a significant runtime-only &ldquo;soft&rdquo; API, in the form of
    600 such things as intents, permissions, and similar aspects of Android
    601 applications that cannot be enforced at application compile time.</p>
    602 
    603 <h3 id="3_2_1_permissions">3.2.1. Permissions</h3>
    604 
    605 
    606 <p>Device implementers MUST support and enforce all permission constants as
    607 documented by the Permission reference page [<a href="http://developer.android.com/reference/android/Manifest.permission.html">Resources, 7</a>]. Note that <a href="#9_security_model_compatibility">section 9</a> lists additional requirements related to the Android security model.</p>
    608 
    609 <h3 id="3_2_2_build_parameters">3.2.2. Build Parameters</h3>
    610 
    611 
    612 <p>The Android APIs include a number of constants on the android.os.Build class [<a href="http://developer.android.com/reference/android/os/Build.html">Resources, 8</a>] that are intended to describe the current device. To provide consistent,
    613 meaningful values across device implementations, the table below includes
    614 additional restrictions on the formats of these values to which device
    615 implementations MUST conform.</p>
    616 <table>
    617  <tr>
    618     <th>Parameter</th>
    619     <th>Details</th>
    620  </tr>
    621  <tr>
    622     <td>VERSION.RELEASE</td>
    623     <td>The version of the currently-executing Android system, in human-readable
    624 format. This field MUST have one of the string values defined in [<a href="http://source.android.com/compatibility/6.0/versions.html">Resources, 9</a>].</td>
    625  </tr>
    626  <tr>
    627     <td>VERSION.SDK</td>
    628     <td>The version of the currently-executing Android system, in a format accessible
    629 to third-party application code. For Android 6.0, this field MUST have the
    630 integer value 23.</td>
    631  </tr>
    632  <tr>
    633     <td>VERSION.SDK_INT</td>
    634     <td>The version of the currently-executing Android system, in a format accessible
    635 to third-party application code. For Android 6.0, this field MUST have the
    636 integer value 23.</td>
    637  </tr>
    638  <tr>
    639     <td>VERSION.INCREMENTAL</td>
    640     <td>A value chosen by the device implementer designating the specific build of the
    641 currently-executing Android system, in human-readable format. This value MUST
    642 NOT be reused for different builds made available to end users. A typical use
    643 of this field is to indicate which build number or source-control change
    644 identifier was used to generate the build. There are no requirements on the
    645 specific format of this field, except that it MUST NOT be null or the empty
    646 string ("").</td>
    647  </tr>
    648  <tr>
    649     <td>BOARD</td>
    650     <td>A value chosen by the device implementer identifying the specific internal
    651 hardware used by the device, in human-readable format. A possible use of this
    652 field is to indicate the specific revision of the board powering the device.
    653 The value of this field MUST be encodable as 7-bit ASCII and match the regular
    654 expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
    655  </tr>
    656  <tr>
    657     <td>BRAND</td>
    658     <td>A value reflecting the brand name associated with the device as known to the
    659 end users. MUST be in human-readable format and SHOULD represent the
    660 manufacturer of the device or the company brand under which the device is
    661 marketed. The value of this field MUST be encodable as 7-bit ASCII and match
    662 the regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
    663  </tr>
    664  <tr>
    665     <td>SUPPORTED_ABIS</td>
    666     <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
    667  </tr>
    668  <tr>
    669     <td>SUPPORTED_32_BIT_ABIS</td>
    670     <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
    671  </tr>
    672  <tr>
    673     <td>SUPPORTED_64_BIT_ABIS</td>
    674     <td>The name of the second instruction set (CPU type + ABI convention) of native
    675 code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
    676  </tr>
    677  <tr>
    678     <td>CPU_ABI</td>
    679     <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
    680  </tr>
    681  <tr>
    682     <td>CPU_ABI2</td>
    683     <td>The name of the second instruction set (CPU type + ABI convention) of native
    684 code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td>
    685  </tr>
    686  <tr>
    687     <td>DEVICE</td>
    688     <td>A value chosen by the device implementer containing the development name or
    689 code name identifying the configuration of the hardware features and industrial
    690 design of the device. The value of this field MUST be encodable as 7-bit ASCII
    691 and match the regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
    692  </tr>
    693  <tr>
    694     <td>FINGERPRINT</td>
    695     <td>A string that uniquely identifies this build. It SHOULD be reasonably
    696 human-readable. It MUST follow this template:
    697 <p class="small">$(BRAND)/$(PRODUCT)/<br>
    698 	&nbsp;&nbsp;&nbsp;&nbsp;$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</p>
    699 <p>For example:</p>
    700 <p class="small">acme/myproduct/<br>
    701 	&nbsp;&nbsp;&nbsp;&nbsp;mydevice:6.0/LMYXX/3359:userdebug/test-keys</p>
    702 <p>The fingerprint MUST NOT include whitespace characters. If other fields
    703 included in the template above have whitespace characters, they MUST be
    704 replaced in the build fingerprint with another character, such as the
    705 underscore ("_") character. The value of this field MUST be encodable as 7-bit
    706 ASCII.</p></td>
    707  </tr>
    708  <tr>
    709     <td>HARDWARE</td>
    710     <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be
    711 reasonably human-readable. The value of this field MUST be encodable as 7-bit
    712 ASCII and match the regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;. </td>
    713  </tr>
    714  <tr>
    715     <td>HOST</td>
    716     <td>A string that uniquely identifies the host the build was built on, in
    717 human-readable format. There are no requirements on the specific format of this
    718 field, except that it MUST NOT be null or the empty string ("").</td>
    719  </tr>
    720  <tr>
    721     <td>ID</td>
    722     <td>An identifier chosen by the device implementer to refer to a specific release,
    723 in human-readable format. This field can be the same as
    724 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently
    725 meaningful for end users to distinguish between software builds. The value of
    726 this field MUST be encodable as 7-bit ASCII and match the regular expression &ldquo;^[a-zA-Z0-9._-]+$&rdquo;.</td>
    727  </tr>
    728  <tr>
    729     <td>MANUFACTURER</td>
    730     <td>The trade name of the Original Equipment Manufacturer (OEM) of the product.
    731 There are no requirements on the specific format of this field, except that it
    732 MUST NOT be null or the empty string ("").</td>
    733  </tr>
    734  <tr>
    735     <td>MODEL</td>
    736     <td>A value chosen by the device implementer containing the name of the device as
    737 known to the end user. This SHOULD be the same name under which the device is
    738 marketed and sold to end users. There are no requirements on the specific
    739 format of this field, except that it MUST NOT be null or the empty string ("").</td>
    740  </tr>
    741  <tr>
    742     <td>PRODUCT</td>
    743     <td>A value chosen by the device implementer containing the development name or
    744 code name of the specific product (SKU) that MUST be unique within the same
    745 brand. MUST be human-readable, but is not necessarily intended for view by end
    746 users. The value of this field MUST be encodable as 7-bit ASCII and match the
    747 regular expression &ldquo;^[a-zA-Z0-9_-]+$&rdquo;.</td>
    748  </tr>
    749  <tr>
    750     <td>SERIAL</td>
    751     <td>A hardware serial number, which MUST be available and unique across
    752 devices with the same MODEL and MANUFACTURER. The value of this field MUST
    753 be encodable as 7-bit ASCII and match the regular expression &ldquo;^([a-zA-Z0-9]{6,20})$&rdquo;.</td>
    754  </tr>
    755  <tr>
    756     <td>TAGS</td>
    757     <td>A comma-separated list of tags chosen by the device implementer that further
    758 distinguishes the build. This field MUST have one of the values corresponding
    759 to the three typical Android platform signing configurations: release-keys,
    760 dev-keys, test-keys. </td>
    761  </tr>
    762  <tr>
    763     <td>TIME</td>
    764     <td>A value representing the timestamp of when the build occurred.</td>
    765  </tr>
    766  <tr>
    767     <td>TYPE</td>
    768     <td>A value chosen by the device implementer specifying the runtime configuration
    769 of the build. This field MUST have one of the values corresponding to the three
    770 typical Android runtime configurations: user, userdebug, or eng.</td>
    771  </tr>
    772  <tr>
    773     <td>USER</td>
    774     <td>A name or user ID of the user (or automated user) that generated the build.
    775 There are no requirements on the specific format of this field, except that it
    776 MUST NOT be null or the empty string ("").</td>
    777  </tr>
    778  <tr>
    779     <td>SECURITY_PATCH</td>
    780     <td>A value indicating the security patch level of a build. It MUST signify that the
    781 build includes all security patches issued up through the designated Android Public
    782 Security Bulletin. It MUST be in the format, [YYYY-MM-DD], matching one of the Android
    783 Security Patch Level strings of the <a href="source.android.com/security/bulletin"> Public
    784 Security Bulletins</a>, for example "2015-11-01".</td>
    785  </tr>
    786  <tr>
    787     <td>BASE_OS</td>
    788     <td>A value representing the FINGERPRINT parameter of the build that is otherwise
    789       identical to this build except for the patches provided in the Android Public
    790       Security Bulletin. It MUST report the correct value and if such a build does not
    791       exist, report an emtpy string ("").</td>
    792  </tr>
    793 </table>
    794 
    795 
    796 <h3 id="3_2_3_intent_compatibility">3.2.3. Intent Compatibility</h3>
    797 
    798 
    799 <p>Device implementations MUST honor Android&rsquo;s loose-coupling intent system, as
    800 described in the sections below. By&ldquo;honored &rdquo; it is meant that the device
    801 implementer MUST provide an Android Activity or Service that specifies a
    802 matching intent filter that binds to and implements correct behavior for each
    803 specified intent pattern.</p>
    804 
    805 <h4 id="3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</h4>
    806 
    807 
    808 <p>Android intents allow application components to request functionality from
    809 other Android components. The Android upstream project includes a list of
    810 applications considered core Android applications, which implements several
    811 intent patterns to perform common actions. The core Android applications are:</p>
    812 
    813 <ul>
    814   <li>Desk Clock</li>
    815   <li>Browser</li>
    816   <li>Calendar</li>
    817   <li>Contacts</li>
    818   <li>Gallery</li>
    819   <li>GlobalSearch</li>
    820   <li>Launcher</li>
    821   <li>Music</li>
    822   <li>Settings</li>
    823 </ul>
    824 
    825 <p>Device implementations SHOULD include the core Android applications as
    826 appropriate but MUST include a component implementing the same intent patterns
    827 defined by all the &ldquo;public&rdquo; Activity or Service components of these core
    828 Android applications. Note that Activity or Service components are considered
    829 &ldquo;public&rdquo; when the attribute android:exported is absent or has the value true.</p>
    830 
    831 <h4 id="3_2_3_2_intent_resolution">3.2.3.2. Intent Resolution</h4>
    832 
    833 
    834 <p>As Android is an extensible platform, device implementations MUST allow each
    835 intent pattern referenced in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>
    836 to be overridden by third-party applications. The upstream Android open source
    837 implementation allows this by default; device implementers MUST NOT attach
    838 special privileges to system applications' use of these intent patterns, or
    839 prevent third-party applications from binding to and assuming control of these
    840 patterns. This prohibition specifically includes but is not limited to
    841 disabling the&ldquo;Chooser&rdquo; user interface that allows the user to select between
    842 multiple applications that all handle the same intent pattern.</p>
    843 
    844 <p>Device implementations MUST provide a user interface for users to modify the default
    845 activity for intents.</p>
    846 
    847 <p>However, device implementations MAY provide default activities for specific URI
    848 patterns (eg. http://play.google.com) when the default activity provides a more
    849 specific attribute for the data URI. For example, an intent filter pattern specifying
    850 the data URI &ldquo;http://www.android.com&rdquo; is more specific than the browser's
    851 core intent pattern for &ldquo;http://&rdquo;.</p>
    852   
    853 <p>Android also includes a mechanism for third-party apps to declare an authoritative
    854 default app linking behavior for certain types of web URI intents [<a
    855 href="https://developer.android.com/training/app-links">Resources, 140</a>]. When such
    856 authoritative declarations are defined in an app's intent filter patterns, device
    857 implementations:</p>
    858 
    859 <ul>
    860 <li>MUST attempt to validate any intent filters by performing the validation steps 
    861 defined in the Digital Asset Links specification [<a
    862 href="https://developers.google.com/digital-asset-links">Resources, 141</a>] as implemented
    863 by the Package Manager in the upstream Android Open Source Project.</li>
    864 <li>MUST attempt validation of the intent filters during the installation of the
    865 application and set all successfully validated UIR intent filters as default app handlers
    866 for their UIRs.</li>
    867 <li>MAY set specific URI intent filters as default app handlers for their URIs, if they
    868 are successfully verified but other candidate URI filters fail verification. If a device
    869 implementation does this, it MUST provide the user appropriate per-URI pattern overrides
    870 in the settings menu.</li>
    871 <li>MUST provide the user with per-app App Links controls in Settings as follows:
    872   <ul>
    873   <li>The user MUST be able to override holistically the default app links behavior for
    874   an app to be: always open, always ask, or never open, which must apply to all candidate
    875   URI intent filters equally.</li>
    876   <li>The user MUST be able to see a list of the candidate URI intent filters.</li>
    877   <li>The device implementation MAY provide the user with the ability to override specific
    878   candidate URI intent filters that were successfully verified, on a per-intent filter basis.
    879   </li>
    880   <li>The device implementation MUST provide users with the ability to view and override
    881   specific candidate URI intent filters if the device implementation lets some candidate
    882   URI intent filters succeed verification while some others can fail.</li>
    883   </ul>
    884 </li>
    885 </ul>
    886 
    887 <h4 id="3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</h4>
    888 
    889 
    890 <p>Device implementations MUST NOT include any Android component that honors any
    891 new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key
    892 string in the android.* or com.android.* namespace. Device implementers MUST
    893 NOT include any Android components that honor any new intent or broadcast
    894 intent patterns using an ACTION, CATEGORY, or other key string in a package
    895 space belonging to another organization. Device implementers MUST NOT alter or
    896 extend any of the intent patterns used by the core apps listed in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. Device implementations MAY include intent patterns using namespaces clearly
    897 and obviously associated with their own organization. This prohibition is
    898 analogous to that specified for Java language classes in <a href="#3_6_api_namespaces">section 3.6</a>.</p>
    899 
    900 <h4 id="3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</h4>
    901 
    902 
    903 <p>Third-party applications rely on the platform to broadcast certain intents to
    904 notify them of changes in the hardware or software environment.
    905 Android-compatible devices MUST broadcast the public broadcast intents in
    906 response to appropriate system events. Broadcast intents are described in the
    907 SDK documentation.</p>
    908 
    909 <h4 id="3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</h4>
    910 
    911 
    912 <p>Android includes settings that provide users an easy way to select their
    913 default applications, for example for Home screen or SMS. Where it makes sense,
    914 device implementations MUST provide a similar settings menu and be compatible
    915 with the intent filter pattern and API methods described in the SDK
    916 documentation as below.</p>
    917 
    918 <p>Device implementations:</p>
    919 
    920 <ul>
    921   <li>MUST honor the android.settings.HOME_SETTINGS intent to show a default app
    922 settings menu for Home Screen, if the device implementation reports
    923 android.software.home_screen [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10</a>]</li>
    924   <li>MUST provide a settings menu that will call the
    925 android.provider.Telephony.ACTION_CHANGE_DEFAULT intent to show a dialog to
    926 change the default SMS application, if the device implementation reports
    927 android.hardware.telephony [<a href="http://developer.android.com/reference/android/provider/Telephony.Sms.Intents.html">Resources, 11</a>]</li>
    928   <li>MUST honor the android.settings.NFC_PAYMENT_SETTINGS intent to show a default
    929 app settings menu for Tap and Pay, if the device implementation reports
    930 android.hardware.nfc.hce [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10</a>]</li>
    931 </ul>
    932 
    933 <h2 id="3_3_native_api_compatibility">3.3. Native API Compatibility</h2>
    934 
    935 
    936 <h3 id="3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</h3>
    937 
    938 
    939 <p>Managed Dalvik bytecode can call into native code provided in the application
    940 .apk file as an ELF .so file compiled for the appropriate device hardware
    941 architecture. As native code is highly dependent on the underlying processor
    942 technology, Android defines a number of Application Binary Interfaces (ABIs) in
    943 the Android NDK. Device implementations MUST be compatible with one or more
    944 defined ABIs, and MUST implement compatibility with the Android NDK, as below.</p>
    945 
    946 <p>If a device implementation includes support for an Android ABI, it:</p>
    947 
    948 <ul>
    949   <li>MUST include support for code running in the managed environment to call into
    950 native code, using the standard Java Native Interface (JNI) semantics</li>
    951   <li>MUST be source-compatible (i.e. header compatible) and binary-compatible (for
    952 the ABI) with each required library in the list below</li>
    953   <li>MUST support the equivalent 32-bit ABI if any 64-bit ABI is supported</li>
    954   <li>MUST accurately report the native Application Binary Interface (ABI) supported
    955 by the device, via the android.os.Build.SUPPORTED_ABIS,
    956 android.os.Build.SUPPORTED_32_BIT_ABIS, and
    957 android.os.Build.SUPPORTED_64_BIT_ABIS parameters, each a comma separated list
    958 of ABIs ordered from the most to the least preferred one</li>
    959   <li>MUST report, via the above parameters, only those ABIs documented and
    960 described in the latest version of the Android NDK ABI Management documentation
    961 [<a href="https://developer.android.com/ndk/guides/abis.html">Resources, 12</a>],
    962 and MUST include support for the Advanced SIMD (a.k.a. NEON)
    963 [<a href="http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html">Resources, 13</a>]
    964 extension
    965   </li>
    966   <li>SHOULD be built using the source code and header files available in the
    967 upstream Android Open Source Project</li>
    968 </ul>
    969 
    970 <p>The following native code APIs MUST be available to apps that include native
    971 code:</p>
    972 
    973 <ul>
    974   <li>libc (C library)</li>
    975   <li>libm (math library)</li>
    976   <li>Minimal support for C++</li>
    977   <li>JNI interface</li>
    978   <li>liblog (Android logging)</li>
    979   <li>libz (Zlib compression)</li>
    980   <li>libdl (dynamic linker)</li>
    981   <li>libGLESv1_CM.so (OpenGL ES 1.x)</li>
    982   <li>libGLESv2.so (OpenGL ES 2.0)</li>
    983   <li>libGLESv3.so (OpenGL ES 3.x)</li>
    984   <li>libEGL.so (native OpenGL surface management)</li>
    985   <li>libjnigraphics.so</li>
    986   <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li>
    987   <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li>
    988   <li>libandroid.so (native Android activity support)</li>
    989   <li>libmediandk.so (native media APIs support)</li>
    990   <li>Support for OpenGL, as described below</li>
    991 </ul>
    992 
    993 <p>Note that future releases of the Android NDK may introduce support for
    994 additional ABIs. If a device implementation is not compatible with an existing
    995 predefined ABI, it MUST NOT report support for any ABIs at all.</p>
    996 
    997 <p>Note that device implementations MUST include libGLESv3.so and it MUST symlink
    998 (symbolic link) to libGLESv2.so. in turn, MUST export all the OpenGL ES 3.1 and
    999 Android Extension Pack [<a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">Resources, 14</a>] function symbols as defined in the NDK release android-21. Although all the
   1000 symbols must be present, only the corresponding functions for OpenGL ES
   1001 versions and extensions actually supported by the device must be fully
   1002 implemented.</p>
   1003 
   1004 <p>Device implementations, if including a native library with the name libvulkan.so,
   1005 MUST export function symbols and provide an implementation of the Vulkan 1.0 API
   1006 and the VK_KHR_surface, VK_KHR_swapchain, and VK_KHR_android_surface extensions
   1007 as defined by the Khronos Group and passing the Khronos conformance tests.</p>
   1008 
   1009 <p>Native code compatibility is challenging. For this reason, device implementers
   1010 are <strong>STRONGLY RECOMMENDED</strong> to use the implementations of the libraries listed above from the upstream
   1011 Android Open Source Project. </p>
   1012 
   1013 <h3 id="3_3_2_32-bit_arm_native_code_compatibility">
   1014 3.3.2. 32-bit ARM Native Code Compatibility
   1015 </h3>
   1016 
   1017 <p>The ARMv8 architecture deprecates several CPU operations, including some
   1018 operations used in existing native code.  On 64-bit ARM devices, the following
   1019 deprecated operations MUST remain available to 32-bit native ARM code, either
   1020 through native CPU support or through software emulation:</p>
   1021 
   1022 <ul>
   1023 <li>SWP and SWPB instructions</li>
   1024 <li>SETEND instruction</li>
   1025 <li>CP15ISB, CP15DSB, and CP15DMB barrier operations</li>
   1026 </ul>
   1027 
   1028 <p>Legacy versions of the Android NDK used /proc/cpuinfo to discover CPU features
   1029 from 32-bit ARM native code. For compatibility with applications built using this
   1030 NDK, devices MUST include the following lines in /proc/cpuinfo when it is read
   1031 by 32-bit ARM applications:</p>
   1032 
   1033 <ul>
   1034 <li>&quot;Features: &quot;, followed by a list of any optional ARMv7 CPU features
   1035 supported by the device</li>
   1036 <li>&quot;CPU architecture: &quot;, followed by an integer describing the device's
   1037 highest supported ARM architecture (e.g., &quot;8&quot; for ARMv8 devices)</li>
   1038 </ul>
   1039 
   1040 <p>These requirements only apply when /proc/cpuinfo is read by 32-bit ARM
   1041 applications. Devices SHOULD not alter /proc/cpuinfo when read by 64-bit ARM or
   1042 non-ARM applications.</p>
   1043 
   1044 <h2 id="3_4_web_compatibility">3.4. Web Compatibility</h2>
   1045 
   1046 
   1047 <h3 id="3_4_1_webview_compatibility">3.4.1. WebView Compatibility</h3>
   1048 
   1049 <div class="note">
   1050 <p>Android Watch devices MAY, but all other device implementations MUST provide
   1051 a complete implementation of the android.webkit.Webview API.</p>
   1052 </div>
   1053 
   1054 
   1055 <p>The platform feature android.software.webview MUST be reported on any device
   1056 that provides a complete implementation of the android.webkit.WebView API, and
   1057 MUST NOT be reported on devices without a complete implementation of the API.
   1058 The Android Open Source implementation uses code from the Chromium Project to
   1059 implement the android.webkit.WebView [<a href="http://developer.android.com/reference/android/webkit/WebView.html">Resources, 15</a>]. Because it is not feasible to develop a comprehensive test suite for a web
   1060 rendering system, device implementers MUST use the specific upstream build of
   1061 Chromium in the WebView implementation. Specifically:</p>
   1062 
   1063 <ul>
   1064   <li>Device android.webkit.WebView implementations MUST be based on the Chromium
   1065 build from the upstream Android Open Source Project for Android 6.0. This build
   1066 includes a specific set of functionality and security fixes for the WebView [<a href="http://www.chromium.org/">Resources, 16</a>].</li>
   1067   <li>The user agent string reported by the WebView MUST be in this format:
   1068 <p>Mozilla/5.0 (Linux; Android $(VERSION); $(MODEL) Build/$(BUILD); wv)
   1069 AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 $(CHROMIUM_VER) Mobile
   1070 Safari/537.36</p>
   1071   <ul>
   1072     <li>The value of the $(VERSION) string MUST be the same as the value for
   1073 android.os.Build.VERSION.RELEASE.</li>
   1074     <li>The value of the $(MODEL) string MUST be the same as the value for
   1075 android.os.Build.MODEL.</li>
   1076     <li>The value of the $(BUILD) string MUST be the same as the value for
   1077 android.os.Build.ID.</li>
   1078     <li>The value of the $(CHROMIUM_VER) string MUST be the version of Chromium in the
   1079 upstream Android Open Source Project.</li>
   1080     <li>Device implementations MAY omit Mobile in the user agent string.</li>
   1081   </ul></li></ul>
   1082 
   1083 <p>The WebView component SHOULD include support for as many HTML5 features as
   1084 possible and if it supports the feature SHOULD conform to the HTML5
   1085 specification [<a href="http://html.spec.whatwg.org/multipage/">Resources, 17</a>].</p>
   1086 
   1087 <h3 id="3_4_2_browser_compatibility">3.4.2. Browser Compatibility</h3>
   1088 
   1089 <div class="note">
   1090 <p>Android Television, Watch, and Android Automotive implementations MAY omit a
   1091 browser application, but MUST support the public intent patterns as described in
   1092 <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. All other types
   1093 of device implementations MUST include a standalone Browser application for
   1094 general user web browsing.</p>
   1095 </div>
   1096 
   1097 <p>The standalone Browser MAY be based on a browser technology other than WebKit.
   1098 However, even if an alternate Browser application is used, the
   1099 android.webkit.WebView component provided to third-party applications MUST be
   1100 based on WebKit, as described in <a href="#3_4_1_webview_compatibility">section 3.4.1</a>.</p>
   1101 
   1102 <p>Implementations MAY ship a custom user agent string in the standalone Browser
   1103 application.</p>
   1104 
   1105 <p>The standalone Browser application (whether based on the upstream WebKit
   1106 Browser application or a third-party replacement) SHOULD include support for as
   1107 much of HTML5 [<a href="http://html.spec.whatwg.org/multipage/">Resources, 17</a>] as possible. Minimally, device implementations MUST support each of these
   1108 APIs associated with HTML5:</p>
   1109 
   1110 <ul>
   1111   <li>application cache/offline operation [<a href="http://www.w3.org/html/wg/drafts/html/master/browsers.html#offline">Resources, 18</a>]</li>
   1112   <li>the &#60;video&#62; tag [<a href="http://www.w3.org/html/wg/drafts/html/master/semantics.html#video">Resources, 19</a>]</li>
   1113   <li>geolocation [<a href="http://www.w3.org/TR/geolocation-API/">Resources, 20</a>]</li>
   1114 </ul>
   1115 
   1116 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage API
   1117 [<a href="http://www.w3.org/TR/webstorage/">Resources, 21</a>], and SHOULD support the HTML5/W3C IndexedDB API [<a href="http://www.w3.org/TR/IndexedDB/">Resources, 22</a>]. Note that as the web development standards bodies are transitioning to favor
   1118 IndexedDB over webstorage, IndexedDB is expected to become a required component
   1119 in a future version of Android.</p>
   1120 
   1121 <h2 id="3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</h2>
   1122 
   1123 
   1124 <p>The behaviors of each of the API types (managed, soft, native, and web) must be
   1125 consistent with the preferred implementation of the upstream Android Open
   1126 Source Project [<a href="http://source.android.com/">Resources, 2</a>]. Some specific areas of compatibility are:</p>
   1127 
   1128 <ul>
   1129   <li>Devices MUST NOT change the behavior or semantics of a standard intent.</li>
   1130   <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular
   1131 type of system component (such as Service, Activity, ContentProvider, etc.).</li>
   1132   <li>Devices MUST NOT change the semantics of a standard permission.</li>
   1133 </ul>
   1134 
   1135 <p>The above list is not comprehensive. The Compatibility Test Suite (CTS) tests
   1136 significant portions of the platform for behavioral compatibility, but not all.
   1137 It is the responsibility of the implementer to ensure behavioral compatibility
   1138 with the Android Open Source Project. For this reason, device implementers
   1139 SHOULD use the source code available via the Android Open Source Project where
   1140 possible, rather than re-implement significant parts of the system.</p>
   1141 
   1142 <h2 id="3_6_api_namespaces">3.6. API Namespaces</h2>
   1143 
   1144 
   1145 <p>Android follows the package and class namespace conventions defined by the Java
   1146 programming language. To ensure compatibility with third-party applications,
   1147 device implementers MUST NOT make any prohibited modifications (see below) to
   1148 these package namespaces:</p>
   1149 
   1150 <ul>
   1151   <li>java.*</li>
   1152   <li>javax.*</li>
   1153   <li>sun.*</li>
   1154   <li>android.*</li>
   1155   <li>com.android.*</li>
   1156 </ul>
   1157 
   1158 <p><strong>Prohibited modifications include</strong>:</p>
   1159 
   1160 <ul>
   1161   <li>Device implementations MUST NOT modify the publicly exposed APIs on the Android
   1162 platform by changing any method or class signatures, or by removing classes or
   1163 class fields.</li>
   1164   <li>Device implementers MAY modify the underlying implementation of the APIs, but
   1165 such modifications MUST NOT impact the stated behavior and Java-language
   1166 signature of any publicly exposed APIs.</li>
   1167   <li>Device implementers MUST NOT add any publicly exposed elements (such as classes
   1168 or interfaces, or fields or methods to existing classes or interfaces) to the
   1169 APIs above.</li>
   1170 </ul>
   1171 
   1172 <p>A &ldquo;publicly exposed element&rdquo; is any construct which is not decorated with the&ldquo;@hide&rdquo; marker as used in the upstream Android source code. In other words,
   1173 device implementers MUST NOT expose new APIs or alter existing APIs in the
   1174 namespaces noted above. Device implementers MAY make internal-only
   1175 modifications, but those modifications MUST NOT be advertised or otherwise
   1176 exposed to developers.</p>
   1177 
   1178 <p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a
   1179 namespace owned by or referring to another organization. For instance, device
   1180 implementers MUST NOT add APIs to the com.google.* or similar namespace: only
   1181 Google may do so. Similarly, Google MUST NOT add APIs to other companies'
   1182 namespaces. Additionally, if a device implementation includes custom APIs
   1183 outside the standard Android namespace, those APIs MUST be packaged in an
   1184 Android shared library so that only apps that explicitly use them (via the
   1185 lt;uses-librarygt; mechanism) are affected by the increased memory usage of such
   1186 APIs.</p>
   1187 
   1188 <p>If a device implementer proposes to improve one of the package namespaces above
   1189 (such as by adding useful new functionality to an existing API, or adding a new
   1190 API), the implementer SHOULD visit <a href="http://source.android.com/">source.android.com</a> and begin the process for contributing changes and code, according to the
   1191 information on that site.</p>
   1192 
   1193 <p>Note that the restrictions above correspond to standard conventions for naming
   1194 APIs in the Java programming language; this section simply aims to reinforce
   1195 those conventions and make them binding through inclusion in this Compatibility
   1196 Definition.</p>
   1197 
   1198 <h2 id="3_7_runtime_compatibility">3.7. Runtime Compatibility</h2>
   1199 
   1200 
   1201 <p>Device implementations MUST support the full Dalvik Executable (DEX) format and
   1202 Dalvik bytecode specification and semantics [<a href="https://android.googlesource.com/platform/dalvik/">Resources, 23</a>]. Device implementers SHOULD use ART, the reference upstream implementation of
   1203 the Dalvik Executable Format, and the reference implementation&rsquo;s package
   1204 management system.</p>
   1205 
   1206 <p>Device implementations MUST configure Dalvik runtimes to allocate memory in
   1207 accordance with the upstream Android platform, and as specified by the
   1208 following table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and screen density definitions.)</p>
   1209 
   1210 <p>Note that memory values specified below are considered minimum values and
   1211 device implementations MAY allocate more memory per application.</p>
   1212 
   1213 <table>
   1214  <tr>
   1215     <th>Screen Layout</th>
   1216     <th>Screen Density</th>
   1217     <th>Minimum Application Memory</th>
   1218  </tr>
   1219  <tr>
   1220     <td rowspan="12">Android Watch</td>
   1221     <td>120 dpi (ldpi)</td>
   1222     <td rowspan="3">32MB</td>
   1223  </tr>
   1224  <tr>
   1225     <td>160 dpi (mdpi)</td>
   1226  </tr>
   1227  <tr>
   1228     <td>213 dpi (tvdpi)</td>
   1229  </tr>
   1230  <tr>
   1231     <td>240 dpi (hdpi)</td>
   1232     <td rowspan="2">36MB</td>
   1233  </tr>
   1234  <tr>
   1235     <td>280 dpi (280dpi)</td>
   1236  </tr>
   1237  <tr>
   1238     <td>320 dpi (xhdpi)</td>
   1239     <td rowspan="2">48MB</td>
   1240  </tr>
   1241  <tr>
   1242     <td>360 dpi (360dpi)</td>
   1243  </tr>
   1244  <tr>
   1245     <td>400 dpi (400dpi)</td>
   1246     <td>56MB</td>
   1247  </tr>
   1248  <tr>
   1249     <td>420 dpi (420dpi)</td>
   1250     <td>64MB</td>
   1251  </tr>
   1252  <tr>
   1253     <td>480 dpi (xxhdpi)</td>
   1254     <td>88MB</td>
   1255  </tr>
   1256  <tr>
   1257     <td>560 dpi (560dpi)</td>
   1258     <td>112MB</td>
   1259  </tr>
   1260  <tr>
   1261     <td>640 dpi (xxxhdpi)</td>
   1262     <td>154MB</td>
   1263  </tr>
   1264  <tr>
   1265     <td rowspan="12">small/normal</td>
   1266     <td>120 dpi (ldpi)</td>
   1267     <td rowspan="2">32MB</td>
   1268  </tr>
   1269  <tr>
   1270     <td>160 dpi (mdpi)</td>
   1271  </tr>
   1272  <tr>
   1273     <td>213 dpi (tvdpi)</td>
   1274     <td rowspan="3">48MB</td>
   1275  </tr>
   1276  <tr>
   1277     <td>240 dpi (hdpi)</td>
   1278  </tr>
   1279  <tr>
   1280     <td>280 dpi (280dpi)</td>
   1281  </tr>
   1282  <tr>
   1283     <td>320 dpi (xhdpi)</td>
   1284     <td rowspan="2">80MB</td>
   1285  </tr>
   1286  <tr>
   1287     <td>360 dpi (360dpi)</td>
   1288  </tr>
   1289  <tr>
   1290     <td>400 dpi (400dpi)</td>
   1291     <td>96MB</td>
   1292  </tr>
   1293  <tr>
   1294     <td>420 dpi (420dpi)</td>
   1295     <td>112MB</td>
   1296  </tr>
   1297  <tr>
   1298     <td>480 dpi (xxhdpi)</td>
   1299     <td>128MB</td>
   1300  </tr>
   1301  <tr>
   1302     <td>560 dpi (560dpi)</td>
   1303     <td>192MB</td>
   1304  </tr>
   1305  <tr>
   1306     <td>640 dpi (xxxhdpi)</td>
   1307     <td>256MB</td>
   1308  </tr>
   1309  <tr>
   1310     <td rowspan="12">large</td>
   1311     <td>120 dpi (ldpi)</td>
   1312     <td>32MB</td>
   1313  </tr>
   1314  <tr>
   1315     <td>160 dpi (mdpi)</td>
   1316     <td>48MB</td>
   1317  </tr>
   1318  <tr>
   1319     <td>213 dpi (tvdpi)</td>
   1320     <td rowspan="2">80MB</td>
   1321  </tr>
   1322  <tr>
   1323     <td>240 dpi (hdpi)</td>
   1324  </tr>
   1325  <tr>
   1326     <td>280 dpi (280dpi)</td>
   1327     <td>96MB</td>
   1328  </tr>
   1329  <tr>
   1330     <td>320 dpi (xhdpi)</td>
   1331     <td>128MB</td>
   1332  </tr>
   1333  <tr>
   1334     <td>360 dpi (360dpi)</td>
   1335     <td>160MB</td>
   1336  </tr>
   1337  <tr>
   1338     <td>400 dpi (400dpi)</td>
   1339     <td>192MB</td>
   1340  </tr>
   1341  <tr>
   1342     <td>420 dpi (420dpi)</td>
   1343     <td>228MB</td>
   1344  </tr>
   1345  <tr>
   1346     <td>480 dpi (xxhdpi)</td>
   1347     <td>256MB</td>
   1348  </tr>
   1349  <tr>
   1350     <td>560 dpi (560dpi)</td>
   1351     <td>384MB</td>
   1352  </tr>
   1353  <tr>
   1354     <td>640 dpi (xxxhdpi)</td>
   1355     <td>512MB</td>
   1356  </tr>
   1357  <tr>
   1358     <td rowspan="12">xlarge</td>
   1359     <td>120 dpi (ldpi)</td>
   1360     <td>48MB</td>
   1361  </tr>
   1362  <tr>
   1363     <td>160 dpi (mdpi)</td>
   1364     <td>80MB</td>
   1365  </tr>
   1366  <tr>
   1367     <td>213 dpi (tvdpi)</td>
   1368     <td rowspan="2">96MB</td>
   1369  </tr>
   1370  <tr>
   1371     <td>240 dpi (hdpi)</td>
   1372  </tr>
   1373  <tr>
   1374     <td>280 dpi (280dpi)</td>
   1375     <td>144MB</td>
   1376  </tr>
   1377  <tr>
   1378     <td>320 dpi (xhdpi)</td>
   1379     <td>192MB</td>
   1380  </tr>
   1381  <tr>
   1382     <td>360 dpi (360dpi)</td>
   1383     <td>240MB</td>
   1384  </tr>
   1385  <tr>
   1386     <td>400 dpi (400dpi)</td>
   1387     <td>288MB</td>
   1388  </tr>
   1389  <tr>
   1390     <td>420 dpi (420dpi)</td>
   1391     <td>336MB</td>
   1392  </tr>
   1393  <tr>
   1394     <td>480 dpi (xxhdpi)</td>
   1395     <td>384MB</td>
   1396  </tr>
   1397  <tr>
   1398     <td>560 dpi (560dpi)</td>
   1399     <td>576MB</td>
   1400  </tr>
   1401  <tr>
   1402     <td>640 dpi (xxxhdpi)</td>
   1403     <td>768MB</td>
   1404  </tr>
   1405 </table>
   1406 
   1407 
   1408 <h2 id="3_8_user_interface_compatibility">3.8. User Interface Compatibility</h2>
   1409 
   1410 
   1411 <h3 id="3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</h3>
   1412 
   1413 
   1414 <p>Android includes a launcher application (home screen) and support for
   1415 third-party applications to replace the device launcher (home screen). Device
   1416 implementations that allow third-party applications to replace the device home
   1417 screen MUST declare the platform feature android.software.home_screen.</p>
   1418 
   1419 <h3 id="3_8_2_widgets">3.8.2. Widgets</h3>
   1420 
   1421 <div class="note">
   1422 <p>Widgets are optional for all Android device implementations, but SHOULD be
   1423 supported on Android Handheld devices.</p>
   1424 </div>
   1425 
   1426 
   1427 <p>Android defines a component type and corresponding API and lifecycle that
   1428 allows applications to expose an &ldquo;AppWidget&rdquo; to the end user [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 24</a>] a feature that is STRONGLY RECOMMENDED to be supported on Handheld Device
   1429 implementations. Device implementations that support embedding widgets on the
   1430 home screen MUST meet the following requirements and declare support for
   1431 platform feature android.software.app_widgets.</p>
   1432 
   1433 <ul>
   1434   <li>Device launchers MUST include built-in support for AppWidgets, and expose user
   1435 interface affordances to add, configure, view, and remove AppWidgets directly
   1436 within the Launcher.</li>
   1437   <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in
   1438 the standard grid size. See the App Widget Design Guidelines in the Android SDK
   1439 documentation [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 24</a>] for details.</li>
   1440   <li>Device implementations that include support for lock screen MAY support
   1441 application widgets on the lock screen.</li>
   1442 </ul>
   1443 
   1444 <h3 id="3_8_3_notifications">3.8.3. Notifications</h3>
   1445 
   1446 
   1447 <p>Android includes APIs that allow developers to notify users of notable events [<a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">Resources, 25</a>], using hardware and software features of the device.</p>
   1448 
   1449 <p>Some APIs allow applications to perform notifications or attract attention
   1450 using hardware&#8212;specifically sound, vibration, and light. Device implementations
   1451 MUST support notifications that use hardware features, as described in the SDK
   1452 documentation, and to the extent possible with the device implementation
   1453 hardware. For instance, if a device implementation includes a vibrator, it MUST
   1454 correctly implement the vibration APIs. If a device implementation lacks
   1455 hardware, the corresponding APIs MUST be implemented as no-ops. This behavior
   1456 is further detailed in <a href="#7_hardware_compatibility">section 7</a>.</p>
   1457 
   1458 <p>Additionally, the implementation MUST correctly render all resources (icons, animation files
   1459 etc.) provided for in the APIs
   1460 [<a href="https://developer.android.com/guide/topics/resources/available-resources.html">Resources, 26</a>],
   1461 or in the Status/System Bar icon style guide
   1462 [<a href="http://developer.android.com/design/style/iconography.html">Resources, 27</a>],
   1463 which in the case of an Android Television device includes the possibility to not display the
   1464 notifications. Device implementers MAY provide an alternative user experience for
   1465 notifications than that provided by the reference Android Open Source
   1466 implementation; however, such alternative notification systems MUST support
   1467 existing notification resources, as above. </p>
   1468 
   1469 <p>Android includes support for various notifications, such as:</p>
   1470 
   1471 <ul>
   1472   <li><strong>Rich notifications</strong>. Interactive Views for ongoing notifications.</li>
   1473   <li><strong>Heads-up notifications</strong>. Interactive Views users can act on or dismiss without leaving the current app.</li>
   1474   <li><strong>Lockscreen notifications</strong>. Notifications shown over a lock screen with granular control on visibility.</li>
   1475 </ul>
   1476 
   1477 <p>Android device implementations, when such notifications are made visible, MUST properly execute
   1478 Rich and Heads-up notifications and include the title/name, icon, text as documented in the Android
   1479 APIs [<a href="https://developer.android.com/design/patterns/notifications.html">Resources, 28</a>].
   1480 </p>
   1481 
   1482 <p>Android includes Notification Listener Service APIs that allow apps (once
   1483 explicitly enabled by the user) to receive a copy of all notifications as they
   1484 are posted or updated. Device implementations MUST correctly and promptly send
   1485 notifications in their entirety to all such installed and user-enabled listener
   1486 services, including any and all metadata attached to the Notification object.</p>
   1487 
   1488 <h3 id="3_8_4_search">3.8.4. Search</h3>
   1489 
   1490 
   1491 <p>Android includes APIs [<a href="http://developer.android.com/reference/android/app/SearchManager.html">Resources, 29</a>] that allow developers to incorporate search into their applications, and
   1492 expose their application&rsquo;s data into the global system search. Generally
   1493 speaking, this functionality consists of a single, system-wide user interface
   1494 that allows users to enter queries, displays suggestions as users type, and
   1495 displays results. The Android APIs allow developers to reuse this interface to
   1496 provide search within their own apps, and allow developers to supply results to
   1497 the common global search user interface.</p>
   1498 
   1499 <p>Android device implementations SHOULD include global search, a single, shared,
   1500 system-wide search user interface capable of real-time suggestions in response
   1501 to user input. Device implementations SHOULD implement the APIs that allow
   1502 developers to reuse this user interface to provide search within their own
   1503 applications. Device implementations that implement the global search interface
   1504 MUST implement the APIs that allow third-party applications to add suggestions
   1505 to the search box when it is run in global search mode. If no third-party
   1506 applications are installed that make use of this functionality, the default
   1507 behavior SHOULD be to display web search engine results and suggestions.</p>
   1508 
   1509 <p>Android device implementations SHOULD implement an assistant on the device
   1510 to handle the Assist action [<a
   1511 href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">Resources,
   1512 30</a>].</p>
   1513 
   1514 <p>Android also includes the Assist APIs to allow applications to elect how much
   1515 information of the current context is shared with the assistant on the device [<a
   1516 href="https://developer.android.com/reference/android/app/assist/package-summary.html">Resources,
   1517 31</a>]. Device implementations supporting the Assist action MUST indicate clearly to
   1518 the end user when the the context is shared by displaying a white light around
   1519 the edges of the screen. To ensure clear visibility to the end user, the indication MUST
   1520 meet or exceed the duration and brightness of the Android Open Source Project
   1521 implementation.</p>
   1522 
   1523 <h3 id="3_8_5_toasts">3.8.5. Toasts</h3>
   1524 
   1525 
   1526 <p>Applications can use the &ldquo;Toast&rdquo; API to display short non-modal strings to the
   1527 end user, that disappear after a brief period of time [<a href="http://developer.android.com/reference/android/widget/Toast.html">Resources, 32</a>]. Device implementations MUST display Toasts from applications to end users in
   1528 some high-visibility manner.</p>
   1529 
   1530 <h3 id="3_8_6_themes">3.8.6. Themes</h3>
   1531 
   1532 
   1533 <p>Android provides &ldquo;themes&rdquo; as a mechanism for applications to apply styles
   1534 across an entire Activity or application.</p>
   1535 
   1536 <p>Android includes a &ldquo;Holo&rdquo; theme family as a set of defined styles for
   1537 application developers to use if they want to match the Holo theme look and
   1538 feel as defined by the Android SDK [<a href="http://developer.android.com/guide/topics/ui/themes.html">Resources, 33</a>]. Device implementations MUST NOT alter any of the Holo theme attributes
   1539 exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 34</a>].</p>
   1540 
   1541 <p>Android includes a &ldquo;Material&rdquo; theme family as a set of defined styles for
   1542 application developers to use if they want to match the design theme&rsquo;s look and
   1543 feel across the wide variety of different Android device types. Device
   1544 implementations MUST support the &ldquo;Material&rdquo; theme family and MUST NOT alter any
   1545 of the Material theme attributes or their assets exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">Resources, 35</a>].</p>
   1546 
   1547 <p>Android also includes a &ldquo;Device Default&rdquo; theme family as a set of defined
   1548 styles for application developers to use if they want to match the look and
   1549 feel of the device theme as defined by the device implementer. Device
   1550 implementations MAY modify the Device Default theme attributes exposed to
   1551 applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 34</a>].</p>
   1552 
   1553 <p>Android supports a variant theme with translucent system bars, which allows
   1554 application developers to fill the area behind the status and navigation bar
   1555 with their app content. To enable a consistent developer experience in this
   1556 configuration, it is important the status bar icon style is maintained across
   1557 different device implementations. Therefore, Android device implementations
   1558 MUST use white for system status icons (such as signal strength and battery
   1559 level) and notifications issued by the system, unless the icon is indicating a
   1560 problematic status or an app requests a light status bar using the
   1561 SYSTEM_UI_FLAG_LIGHT_STATUS_BAR flag. When an app requests a light status bar,
   1562 Android device implementations MUST change the color of the system status icons
   1563 to black [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 34</a>].</p>
   1564 
   1565 <h3 id="3_8_7_live_wallpapers">3.8.7. Live Wallpapers</h3>
   1566 
   1567 
   1568 <p>Android defines a component type and corresponding API and lifecycle that
   1569 allows applications to expose one or more &ldquo;Live Wallpapers&rdquo; to the end user [<a href="http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html">Resources, 36</a>]. Live wallpapers are animations, patterns, or similar images with limited
   1570 input capabilities that display as a wallpaper, behind other applications.</p>
   1571 
   1572 <p>Hardware is considered capable of reliably running live wallpapers if it can
   1573 run all live wallpapers, with no limitations on functionality, at a reasonable
   1574 frame rate with no adverse effects on other applications. If limitations in the
   1575 hardware cause wallpapers and/or applications to crash, malfunction, consume
   1576 excessive CPU or battery power, or run at unacceptably low frame rates, the
   1577 hardware is considered incapable of running live wallpaper. As an example, some
   1578 live wallpapers may use an OpenGL 2.0 or 3.x context to render their content.
   1579 Live wallpaper will not run reliably on hardware that does not support multiple
   1580 OpenGL contexts because the live wallpaper use of an OpenGL context may
   1581 conflict with other applications that also use an OpenGL context.</p>
   1582 
   1583 <p>Device implementations capable of running live wallpapers reliably as described
   1584 above SHOULD implement live wallpapers, and when implemented MUST report the
   1585 platform feature flag android.software.live_wallpaper.</p>
   1586 
   1587 <h3 id="3_8_8_activity_switching">3.8.8. Activity Switching</h3>
   1588 
   1589 <div class="note">
   1590 <p>As the Recent function navigation key is OPTIONAL, the requirements to
   1591 implement the overview screen is OPTIONAL for Android Television devices and
   1592 Android Watch devices.</p>
   1593 </div>
   1594 
   1595 
   1596 <p>The upstream Android source code includes the overview screen [<a href="http://developer.android.com/guide/components/recents.html">Resources, 37</a>], a system-level user interface for task switching and displaying recently
   1597 accessed activities and tasks using a thumbnail image of the application&rsquo;s
   1598 graphical state at the moment the user last left the application. Device
   1599 implementations including the recents function navigation key as detailed in <a href="#7_2_3_navigation_keys">section 7.2.3</a>, MAY alter the interface but MUST meet the following requirements:</p>
   1600 
   1601 <ul>
   1602   <li>MUST display affiliated recents as a group that moves together.</li>
   1603   <li>MUST support at least up to 20 displayed activities.</li>
   1604   <li>MUST at least display the title of 4 activities at a time.</li>
   1605   <li>SHOULD display highlight color, icon, screen title in recents.</li>
   1606   <li>MUST implement the screen pinning behavior [<a href="http://developer.android.com/about/versions/android-5.0.html#ScreenPinning">Resources, 38</a>] and provide the user with a settings menu to toggle the feature.</li>
   1607   <li>SHOULD display a closing affordance ("x") but MAY delay this until user
   1608 interacts with screens.</li>
   1609 </ul>
   1610 
   1611 <p>Device implementations are STRONGLY RECOMMENDED to use the upstream Android user
   1612 interface (or a similar thumbnail-based interface) for the overview screen.</p>
   1613 
   1614 <h3 id="3_8_9_input_management">3.8.9. Input Management</h3>
   1615 
   1616 
   1617 <p>Android includes support for Input Management and support for third-party input
   1618 method editors [<a href="http://developer.android.com/guide/topics/text/creating-input-method.html">Resources, 39</a>]. Device implementations that allow users to use third-party input methods on
   1619 the device MUST declare the platform feature android.software.input_methods and
   1620 support IME APIs as defined in the Android SDK documentation.</p>
   1621 
   1622 <p>Device implementations that declare the android.software.input_methods feature
   1623 MUST provide a user-accessible mechanism to add and configure third-party input
   1624 methods. Device implementations MUST display the settings interface in response
   1625 to the android.settings.INPUT_METHOD_SETTINGS intent.</p>
   1626 
   1627 <h3 id="3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</h3>
   1628 
   1629 
   1630 <p>The Remote Control Client API is deprecated from Android 5.0 in favor of the
   1631 Media Notification Template that allows media applications to integrate with
   1632 playback controls that are displayed on the lock screen [<a href="http://developer.android.com/reference/android/app/Notification.MediaStyle.html">Resources, 40</a>].
   1633 Device implementations that support a lock screen, unless an Android Automotive or Watch
   1634 implementation, MUST display the Lockscreen Notifications including the Media Notification
   1635 Template.</p>
   1636 
   1637 <h3 id="3_8_11_dreams">3.8.11. Dreams</h3>
   1638 
   1639 
   1640 <p>Android includes support for interactive screensavers called Dreams [<a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">Resources, 41</a>]. Dreams allows users to interact with applications when a device connected to
   1641 a power source is idle or docked in a desk dock. Android Watch devices MAY
   1642 implement Dreams, but other types of device implementations SHOULD include
   1643 support for Dreams and provide a settings option for users to configure Dreams
   1644 in response to the android.settings.DREAM_SETTINGS intent.</p>
   1645 
   1646 <h3 id="3_8_12_location">3.8.12. Location</h3>
   1647 
   1648 
   1649 <p>When a device has a hardware sensor (e.g. GPS) that is capable of providing the
   1650 location coordinates, location modes MUST be displayed in the Location menu
   1651 within Settings [<a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">Resources, 42</a>].</p>
   1652 
   1653 <h3 id="3_8_13_unicode_and_font">3.8.13. Unicode and Font</h3>
   1654 
   1655 
   1656 <p>Android includes support for color emoji characters. When Android device
   1657 implementations include an IME, devices SHOULD provide an input method to the
   1658 user for the Emoji characters defined in Unicode 6.1 [<a href="http://www.unicode.org/versions/Unicode6.1.0/">Resources, 43</a>]. All devices MUST be capable of rendering these emoji characters in color glyph.</p>
   1659 
   1660 <p>Android includes support for Roboto 2 font with different
   1661 weights&mdash;sans-serif-thin, sans-serif-light, sans-serif-medium, sans-serif-black,
   1662 sans-serif-condensed, sans-serif-condensed-light&mdash;which MUST all be included for
   1663 the languages available on the device and full Unicode 7.0 coverage of Latin,
   1664 Greek, and Cyrillic, including the Latin Extended A, B, C, and D ranges, and
   1665 all glyphs in the currency symbols block of Unicode 7.0.</p>
   1666 
   1667 <h2 id="3_9_device_administration">3.9. Device Administration</h2>
   1668 
   1669 <p>Android includes features that allow security-aware applications to perform
   1670 device administration functions at the system level, such as enforcing password
   1671 policies or performing remote wipe, through the Android Device Administration
   1672 API [<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 44</a>].
   1673 Device implementations MUST provide an implementation of the DevicePolicyManager class
   1674 [<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">Resources, 45</a>].
   1675 Device implementations that include support for PIN (numeric) or PASSWORD
   1676 (alphanumeric) based lock screens MUST support the full range of device
   1677 administration policies defined in the Android SDK documentation
   1678 [<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 44</a>]
   1679 and report the platform feature android.software.device_admin.</p>
   1680 
   1681 <h3 id="3_9_1_device_provisioning">3.9.1 Device Provisioning</h3>
   1682 <h4 id="3_9_1_1_device_owner_provisioning">3.9.1.1 Device owner provisioning</h4>
   1683 <p>If a device implementation declares the android.software.device_admin feature,
   1684 the out of box setup flow MUST make it possible to enroll a Device Policy
   1685 Controller (DPC) application as the Device Owner app
   1686 [<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">
   1687 Resources, 46</a>]. Device implementations MAY have a preinstalled application
   1688 performing device administration functions but this application MUST NOT be set
   1689 as the Device Owner app without explicit consent or action from the user or the
   1690 administrator of the device.</p>
   1691 
   1692 <p>The device owner provisioning process (the flow initiated by
   1693 android.app.action.PROVISION_MANAGED_DEVICE
   1694 [<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE">
   1695 Resources, 47</a>]) user experience MUST align with the AOSP implementation</p>
   1696 
   1697 <p>If the device implementation reports android.hardware.nfc, it MUST have NFC
   1698 enabled, even during the out-of-box setup flow, in order to allow for NFC
   1699 provisioning of Device owners
   1700 [<a href="https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc">Resources, 48</a>].
   1701 </p>
   1702 
   1703 <h4 id="3_9_1_2_managed_profile_provisioning">3.9.1.2 Managed profile provisioning</h4>
   1704 <p>If a device implementation declares the android.software.managed_users,
   1705 it MUST be possible to enroll a Device Policy Controller (DPC) application
   1706 as the owner of a new Managed Profile
   1707 [<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)">
   1708 Resources, 49</a>]</p>
   1709 
   1710 <p>The managed profile provisioning process (the flow initiated by
   1711 android.app.action.PROVISION_MANAGED_PROFILE
   1712 [<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">
   1713 Resources, 50</a>]) user experience MUST align with the AOSP implementation
   1714 </p>
   1715 
   1716 
   1717 <h2 id="3_9_2_managed_profile_support">3.9.2 Managed Profile Support</h2>
   1718 
   1719 <p>Managed profile capable devices are those devices that:</p>
   1720 <ul>
   1721   <li>Declare android.software.device_admin (see <a href="#3_9_device_administration">section 3.9 Device Administration)</a></li>
   1722   <li>Are not low RAM devices (see <a href="#7_6_1_minimum_memory_and_storage">section 7.6.1</a></li>
   1723   <li>Allocate internal (non-removable) storage as shared storage (see
   1724     <a href="#7_6_2_application_shared_storage">section 7.6.2</a>)</li>
   1725 </ul>
   1726 <p>Managed profile capable devices MUST:</p>
   1727 <ul>
   1728   <li>Declare the platform feature flag android.software.managed_users.</li>
   1729   <li>Support managed profiles via the android.app.admin.DevicePolicyManager APIs</li>
   1730   <li>Allow one and only one managed profile to be created [<a
   1731 href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">Resources,
   1732 50</a>]</li>
   1733   <li>Use an icon badge (similar to the AOSP upstream work badge) to represent
   1734 the managed applications and widgets and other badged UI elements like Recents
   1735 &amp; Notifications</li>
   1736   <li>Display a notification icon (similar to the AOSP upstream work badge) to
   1737 indicate when user is within a managed profile application</li>
   1738   <li>Display a toast indicating that the user is in the managed profile if and when the
   1739 device wakes up (ACTION_USER_PRESENT) and the foreground application is within
   1740 the managed profile</li>
   1741   <li>Where a managed profile exists, show a visual affordance in the Intent
   1742 'Chooser' to allow the user to forward the intent from the managed profile to
   1743 the primary user or vice versa, if enabled by the Device Policy Controller</li>
   1744   <li>Where a managed profile exists, expose the following user affordances for both
   1745 the primary user and the managed profile:
   1746     <ul>
   1747       <li>Separate accounting for battery, location, mobile data and storage usage
   1748       for the primary user and managed profile.</li>
   1749       <li>Independent management of VPN Applications installed within the primary
   1750       user or managed profile.</li>
   1751       <li>Independent management of applications installed within the primary user
   1752       user or managed profile.</li>
   1753       <li>Independent management of accounts within the primary user or managed
   1754       profile.</li>
   1755     </ul>
   1756   </li>
   1757   <li>Ensure the default dialer can look up caller information from the managed
   1758 profile (if one exists) alongside those from the primary profile, if the Device
   1759 Policy Controller permits it.</li>
   1760   <li>MUST ensure that it satisfies all the security requirements applicable for a device
   1761     with multiple users enabled (see <a href="#9_5_multi-user_support">section 9.5</a>),
   1762     even though the managed profile is not counted as another user in addition to the
   1763     primary user.</li>
   1764 </ul>
   1765 
   1766 <h2 id="3_10_accessibility">3.10. Accessibility</h2>
   1767 
   1768 
   1769 <p>Android provides an accessibility layer that helps users with disabilities to
   1770 navigate their devices more easily. In addition, Android provides platform APIs
   1771 that enable accessibility service implementations to receive callbacks for user
   1772 and system events and generate alternate feedback mechanisms, such as
   1773 text-to-speech, haptic feedback, and trackball/d-pad navigation [<a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">Resources, 51</a>].</p>
   1774 
   1775 <p>Device implementations include the following requirements:</p>
   1776 
   1777 <ul>
   1778 <li>Android Automotive implementations SHOULD provide an implementation of the
   1779 Android accessibility framework consistent with the default Android
   1780 implementation.</li>
   1781 <li>Device implementations (Android Automotive excluded) MUST provide an
   1782 implementation of the Android accessibility framework consistent with the
   1783 default Android implementation.</li>
   1784 <li>Device implementations (Android Automotive excluded) MUST support
   1785 third-party accessibility service implementations through the
   1786 android.accessibilityservice APIs
   1787 [<a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">Resources, 52</a>]</li>
   1788 <li>Device implementations (Android Automotive excluded) MUST generate
   1789 AccessibilityEvents and deliver these events to all registered
   1790 AccessibilityService implementations in a manner consistent with the default
   1791 Android implementation</li>
   1792 <li> Device implementations (Android Automotive and Android Watch devices with
   1793 no audio output excluded), MUST provide a user-accessible mechanism to enable
   1794 and disable accessibility services, and MUST display this interface in response
   1795 to the android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS intent.</li>
   1796 </ul>
   1797 
   1798 <p>Additionally, device implementations SHOULD provide an implementation of an
   1799 accessibility service on the device, and SHOULD provide a mechanism for users
   1800 to enable the accessibility service during device setup. An open source
   1801 implementation of an accessibility service is available from the Eyes Free
   1802 project [<a href="http://code.google.com/p/eyes-free/">Resources, 53</a>].</p>
   1803 
   1804 <h2 id="3_11_text-to-speech">3.11. Text-to-Speech</h2>
   1805 
   1806 
   1807 <p>Android includes APIs that allow applications to make use of text-to-speech
   1808 (TTS) services and allows service providers to provide implementations of TTS
   1809 services [<a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">Resources, 54</a>]. Device implementations reporting the feature android.hardware.audio.output
   1810 MUST meet these requirements related to the Android TTS framework. </p>
   1811 
   1812 <p>Android Automotive implementations:</p>
   1813 <ul>
   1814 <li>MUST support the Android TTS framework APIs.</li>
   1815 <li>MAY support installation of third-party TTS engines. If supported, partners
   1816 MUST provide a user-accessible interface that allows the user to select a TTS
   1817 engine for use at system level.</li>
   1818 </ul>
   1819 
   1820 <p>All other device implementations:</p>
   1821 
   1822 <ul>
   1823   <li> MUST support the Android TTS framework APIs and SHOULD include a TTS engine
   1824 supporting the languages available on the device. Note that the upstream
   1825 Android open source software includes a full-featured TTS engine
   1826 implementation.
   1827   <li> MUST support installation of third-party TTS engines
   1828   <li> MUST provide a user-accessible interface that allows users to select a TTS
   1829 engine for use at the system level
   1830 </ul>
   1831 
   1832 <h2 id="3_12_tv_input_framework">3.12. TV Input Framework</h2>
   1833 
   1834 
   1835 <p>The Android Television Input Framework (TIF) simplifies the delivery of live
   1836 content to Android Television devices. TIF provides a standard API to create
   1837 input modules that control Android Television devices. Android Television
   1838 device implementations MUST support TV Input Framework
   1839 [<a href="http://source.android.com/devices/tv/index.html">Resources, 55</a>].</p>
   1840 
   1841 <p>Device implementations that support TIF MUST declare the platform feature
   1842 android.software.live_tv.</p>
   1843 
   1844 <h3 id="3_12_1_tv_app">3.12.1. TV App</h3>
   1845 
   1846 <p>Any device implementation that declares support for Live TV MUST have an
   1847 installed TV application (TV App). The Android Open Source Project provides an implementation of the TV
   1848 App.</p>
   1849 
   1850 The default TV app must provide accesss to channels from installed inputs and third-party inputs.
   1851 Note that the installed inputs encompass all the inputs provided by default, whether they are TIF-based or not.
   1852 
   1853 <p>The TV App MUST provide facilities to install and use TV Channels
   1854 [<a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html">Resources, 56</a>]
   1855  and meet the following requirements:</p>
   1856 
   1857 <ul>
   1858   <li>Device implementations MUST allow third-party TIF-based inputs (third-party inputs)
   1859 [<a href="https://source.android.com/devices/tv/index.html#third-party_input_example">Resources, 57</a>]
   1860  to be installed and managed.
   1861   <li>Device implementations MAY provide visual separation between pre-installed
   1862  TIF-based inputs (installed inputs)
   1863 [<a href="https://source.android.com/devices/tv/index.html#tv_inputs">Resources, 58</a>]
   1864  and third-party inputs.
   1865   <li>The device implementations MUST NOT display the third-party inputs more than a
   1866 single navigation action away from the TV App (i.e. expanding a list of
   1867 third-party inputs from the TV App).
   1868 </ul>
   1869 
   1870 <h4 id="3_12_1_1_electronic_program_guide">3.12.1.1. Electronic Program Guide</h4>
   1871 
   1872 <p>Android Television device implementations MUST show an informational and
   1873 interactive overlay, which MUST include an electronic program guide (EPG)
   1874 generated from the values in the TvContract.Programs fields
   1875 [<a href="https://developer.android.com/reference/android/media/tv/TvContract.Programs.html">Resources, 59</a>].
   1876  The EPG MUST meet the following requirements:</p>
   1877 
   1878 <ul>
   1879   <li>The EPG MUST display information from all installed inputs and third-party
   1880 inputs.
   1881   <li>The EPG MAY provide visual separation between the installed inputs and
   1882 third-party inputs.
   1883   <li>The EPG is STRONGLY RECOMMENDED to display installed inputs and third-party
   1884 inputs with equal prominence. The EPG MUST NOT display the third-party inputs
   1885 more than a single navigation action away from the installed inputs on the EPG.
   1886   <li>On channel change, device implementations MUST display EPG data for the
   1887 currently playing program.
   1888 </ul>
   1889 
   1890 <h4 id="3_12_1_2_navigation">3.12.1.2. Navigation</h4>
   1891 
   1892 <p>Android Television device input devices (i.e. remote control, remote control
   1893 application, or game controller) MUST allow navigation to all actionable
   1894 sections of the screen via the D-pad. D-pad up and down MUST be used to change
   1895 live TV channels when there is no actionable section on the screen.</p>
   1896 
   1897 <p>The TV App SHOULD pass key events to HDMI inputs through CEC.</p>
   1898 
   1899 <h4 id="3_12_1_3_tv_input_app_linking">3.12.1.3. TV input app linking</h4>
   1900 
   1901 <p>Android Television device implementations MUST support TV input app linking,
   1902 which allows all inputs to provide activity links from the current activity to
   1903 another activity (i.e. a link from live programming to related content)
   1904 [<a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html#COLUMN_APP_LINK_INTENT_URI">Resources, 60</a>].
   1905  The TV App MUST show TV input app linking when it is provided.</p>
   1906 
   1907 <h1 id="4_application_packaging_compatibility">4. Application Packaging Compatibility</h1>
   1908 
   1909 
   1910 <p>Device implementations MUST install and run Android &ldquo;.apk&rdquo; files as generated
   1911 by the &ldquo;aapt&rdquo; tool included in the official Android SDK [<a href="http://developer.android.com/tools/help/index.html">Resources, 61</a>].</p>
   1912 
   1913 <p>Devices implementations MUST NOT extend either the .apk [<a href="http://developer.android.com/guide/components/fundamentals.html">Resources, 62</a>], Android Manifest [<a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">Resources, 49</a>], Dalvik bytecode [<a href="https://android.googlesource.com/platform/dalvik/">Resources, 23</a>], or RenderScript bytecode formats in such a way that would prevent those
   1914 files from installing and running correctly on other compatible devices.</p>
   1915 
   1916 <h1 id="5_multimedia_compatibility">5. Multimedia Compatibility</h1>
   1917 
   1918 
   1919 <h2 id="5_1_media_codecs">5.1. Media Codecs</h2>
   1920 
   1921 
   1922 <p>Device implementations MUST support the core media formats specified in the
   1923 Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 64</a>]
   1924 except where explicitly permitted in this document. Specifically, device
   1925 implementations MUST support the media formats, encoders, decoders, file types,
   1926 and container formats defined in the tables below and reported via MediaCodecList
   1927 [<a href="http://developer.android.com/reference/android/media/MediaCodecList.html">Resources, 65</a>].
   1928 Device implementations MUST also be able to decode all profiles reported in its CamcorderProfile
   1929 [<a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">Resources,
   1930 66</a>] and MUST be able to decode all formats it can encode.
   1931 
   1932 All of these codecs are
   1933 provided as software implementations in the preferred Android implementation
   1934 from the Android Open Source Project.</p>
   1935 
   1936 <p>Please note that neither Google nor the Open Handset Alliance make any
   1937 representation that these codecs are free from third-party patents. Those
   1938 intending to use this source code in hardware or software products are advised
   1939 that implementations of this code, including in open source software or
   1940 shareware, may require patent licenses from the relevant patent holders.</p>
   1941 
   1942 <h3 id="5_1_1_audio_codecs">5.1.1. Audio Codecs</h3>
   1943 
   1944 <table>
   1945  <tr>
   1946     <th>Format/Codec</th>
   1947     <th>Encoder</th>
   1948     <th>Decoder</th>
   1949     <th>Details</th>
   1950     <th>Supported File Types/Container Formats</th>
   1951  </tr>
   1952  <tr>
   1953     <td>MPEG-4 AAC Profile<br />
   1954 
   1955 (AAC LC)</td>
   1956     <td>REQUIRED<sup>1</sup></td>
   1957     <td>REQUIRED</td>
   1958     <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 8 to
   1959 48 kHz.</td>
   1960     <td>
   1961     <ul>
   1962     <li class="table_list">3GPP (.3gp)</li>
   1963     <li class="table_list">MPEG-4 (.mp4, .m4a)</li>
   1964     <li class="table_list">ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not
   1965 supported)</li>
   1966     <li class="table_list">MPEG-TS (.ts, not seekable, Android 3.0+)</li></ul></td>
   1967  </tr>
   1968  <tr>
   1969     <td>MPEG-4 HE AAC Profile (AAC+)</td>
   1970     <td>REQUIRED<sup>1</sup><br>(Android 4.1+)</td>
   1971     <td>REQUIRED</td>
   1972     <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16
   1973 to 48 kHz.</td>
   1974     <td></td>
   1975  </tr>
   1976  <tr>
   1977     <td>MPEG-4 HE AACv2<br />
   1978 
   1979 Profile (enhanced AAC+)</td>
   1980     <td> </td>
   1981     <td>REQUIRED</td>
   1982     <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16
   1983 to 48 kHz.</td>
   1984     <td></td>
   1985  </tr>
   1986  <tr>
   1987     <td>AAC ELD (enhanced low delay AAC)</td>
   1988     <td>REQUIRED<sup>1</sup> <br />
   1989 
   1990 (Android 4.1+)</td>
   1991     <td>REQUIRED<br />
   1992 
   1993 (Android 4.1+)</td>
   1994     <td>Support for mono/stereo content with standard sampling rates from 16 to 48 kHz.</td>
   1995     <td></td>
   1996  </tr>
   1997  <tr>
   1998     <td>AMR-NB</td>
   1999     <td>REQUIRED<sup>3</sup></td>
   2000     <td>REQUIRED<sup>3</sup></td>
   2001     <td>4.75 to 12.2 kbps sampled @ 8 kHz</td>
   2002     <td>3GPP (.3gp)</td>
   2003  </tr>
   2004  <tr>
   2005     <td>AMR-WB</td>
   2006     <td>REQUIRED<sup>3</sup></td>
   2007     <td>REQUIRED<sup>3</sup></td>
   2008     <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16 kHz</td>
   2009     <td></td>
   2010  </tr>
   2011  <tr>
   2012     <td>FLAC</td>
   2013     <td></td>
   2014     <td>REQUIRED <br>(Android 3.1+)</td>
   2015     <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 kHz is
   2016 RECOMMENDED on devices with 44.1 kHz output, as the 48 to 44.1 kHz downsampler
   2017 does not include a low-pass filter). 16-bit RECOMMENDED; no dither applied for
   2018 24-bit.</td>
   2019     <td>FLAC (.flac) only</td>
   2020  </tr>
   2021  <tr>
   2022     <td>MP3</td>
   2023     <td></td>
   2024     <td>REQUIRED</td>
   2025     <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bitrate (VBR)</td>
   2026     <td>MP3 (.mp3)</td>
   2027  </tr>
   2028  <tr>
   2029     <td>MIDI</td>
   2030     <td></td>
   2031     <td>REQUIRED</td>
   2032     <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for
   2033 ringtone formats RTTTL/RTX, OTA, and iMelody</td>
   2034     <td><ul>
   2035     <li class="table_list">Type 0 and 1 (.mid, .xmf, .mxmf)</li>
   2036     <li class="table_list">RTTTL/RTX (.rtttl, .rtx)</li>
   2037     <li class="table_list">OTA (.ota)</li>
   2038     <li class="table_list">iMelody (.imy)</li></ul></td>
   2039  </tr>
   2040  <tr>
   2041     <td>Vorbis</td>
   2042     <td></td>
   2043     <td>REQUIRED</td>
   2044     <td></td>
   2045     <td><ul>
   2046     <li class="table_list">Ogg (.ogg)</li>
   2047     <li class="table_list">Matroska (.mkv, Android 4.0+)</li></ul></td>
   2048  </tr>
   2049  <tr>
   2050     <td>PCM/WAVE</td>
   2051     <td>REQUIRED<sup>4</sup><br> (Android 4.1+)</td>
   2052     <td>REQUIRED</td>
   2053     <td>16-bit linear PCM (rates up to limit of hardware). Devices MUST support
   2054 sampling rates for raw PCM recording at 8000, 11025, 16000, and 44100 Hz
   2055 frequencies.</td>
   2056     <td>WAVE (.wav)</td>
   2057  </tr>
   2058  <tr>
   2059     <td>Opus</td>
   2060     <td></td>
   2061     <td>REQUIRED<br> (Android 5.0+)</td>
   2062     <td></td>
   2063     <td>Matroska (.mkv)</td>
   2064  </tr>
   2065 </table>
   2066 
   2067 
   2068 <p class="table_footnote"> 1 Required for device implementations that define android.hardware.microphone
   2069 but optional for Android Watch device implementations.</p>
   2070 
   2071 <p class="table_footnote">2 Only downmix of 5.0/5.1 content is required; recording or rendering more than
   2072 2 channels is optional.</p>
   2073 
   2074 <p class="table_footnote">3 Required for Android Handheld device implementations. </p>
   2075 
   2076 <p class="table_footnote">4 Required for device implementations that define android.hardware.microphone,
   2077 including Android Watch device implementations.</p>
   2078 
   2079 <h3 id="5_1_2_image_codecs">5.1.2. Image Codecs</h3>
   2080 
   2081 <table>
   2082  <tr>
   2083     <th>Format/Codec</th>
   2084     <th>Encoder</th>
   2085     <th>Decoder</th>
   2086     <th>Details</th>
   2087     <th>Supported File Types/Container Formats</th>
   2088  </tr>
   2089  <tr>
   2090     <td>JPEG</td>
   2091     <td>REQUIRED</td>
   2092     <td>REQUIRED</td>
   2093     <td>Base+progressive</td>
   2094     <td>JPEG (.jpg)</td>
   2095  </tr>
   2096  <tr>
   2097     <td>GIF</td>
   2098     <td></td>
   2099     <td>REQUIRED</td>
   2100     <td></td>
   2101     <td>GIF (.gif)</td>
   2102  </tr>
   2103  <tr>
   2104     <td>PNG</td>
   2105     <td>REQUIRED</td>
   2106     <td>REQUIRED</td>
   2107     <td></td>
   2108     <td>PNG (.png)</td>
   2109  </tr>
   2110  <tr>
   2111     <td>BMP</td>
   2112     <td></td>
   2113     <td>REQUIRED</td>
   2114     <td></td>
   2115     <td>BMP (.bmp)</td>
   2116  </tr>
   2117  <tr>
   2118     <td>WebP</td>
   2119     <td>REQUIRED</td>
   2120     <td>REQUIRED</td>
   2121     <td></td>
   2122     <td>WebP (.webp)</td>
   2123  </tr>
   2124 </table>
   2125 
   2126 
   2127 <h3 id="5_1_3_video_codecs">5.1.3. Video Codecs</h3>
   2128 
   2129 <table>
   2130  <tr>
   2131     <th>Format/Codec</th>
   2132     <th>Encoder</th>
   2133     <th>Decoder</th>
   2134     <th>Details</th>
   2135     <th>Supported File Types/<br>Container Formats</th>
   2136  </tr>
   2137  <tr>
   2138     <td>H.263</td>
   2139     <td>REQUIRED<sup>1</sup></td>
   2140     <td>REQUIRED<sup>2</sup></td>
   2141     <td></td>
   2142     <td><ul>
   2143     <li class="table_list">3GPP (.3gp)</li>
   2144     <li class="table_list">MPEG-4 (.mp4)</li></ul></td>
   2145  </tr>
   2146  <tr>
   2147     <td>H.264 AVC</td>
   2148     <td>REQUIRED<sup>2</sup></td>
   2149     <td>REQUIRED<sup>2</sup></td>
   2150     <td>See <a href="#5_2_video_encoding">section 5.2 </a>and <a href="#5_3_video_decoding">5.3</a> for details</td>
   2151     <td><ul>
   2152     <li class="table_list">3GPP (.3gp)</li>
   2153     <li class="table_list">MPEG-4 (.mp4)</li>
   2154     <li class="table_list">MPEG-2 TS (.ts, AAC audio only, not seekable, Android 3.0+)</li></ul></td>
   2155  </tr>
   2156  <tr>
   2157     <td>H.265 HEVC</td>
   2158     <td></td>
   2159     <td>REQUIRED<sup>5</sup></td>
   2160     <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td>
   2161     <td>MPEG-4 (.mp4)</td>
   2162  </tr>
   2163 <tr>
   2164   <td>MPEG-2</td>
   2165   <td></td>  
   2166   <td>STRONGLY RECOMMENDED<sup>6</sup></td>
   2167   <td>Main Profile</td>
   2168   <td>MPEG2-TS</td>
   2169 </tr>
   2170  <tr>
   2171     <td>MPEG-4 SP</td>
   2172     <td></td>
   2173     <td>REQUIRED<sup>2</sup></td>
   2174     <td></td>
   2175     <td>3GPP (.3gp)</td>
   2176  </tr>
   2177  <tr>
   2178     <td>VP8<sup>3</sup></td>
   2179     <td>REQUIRED<sup>2</sup><br />
   2180 
   2181 (Android 4.3+)</td>
   2182     <td>REQUIRED<sup>2</sup><br />
   2183 
   2184 (Android 2.3.3+)</td>
   2185     <td>See <a href="#5_2_video_encoding">section 5.2</a> and <a href="#5_3_video_decoding">5.3</a> for details</td>
   2186     <td><ul>
   2187     <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 67</a></li>
   2188     <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td>
   2189  </tr>
   2190  <tr>
   2191     <td>VP9</td>
   2192     <td></td>
   2193     <td>REQUIRED<sup>2</sup><br> (Android 4.4+)</td>
   2194     <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td>
   2195     <td><ul>
   2196     <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 67</a>]</li>
   2197     <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td>
   2198  </tr>
   2199 </table>
   2200 
   2201 
   2202 <p class="table_footnote">1 Required for device implementations that include camera hardware and define
   2203 android.hardware.camera or android.hardware.camera.front.</p>
   2204 
   2205 <p class="table_footnote">2 Required for device implementations except Android Watch devices. </p>
   2206 
   2207 <p class="table_footnote">3 For acceptable quality of web video streaming and video-conference services,
   2208 device implementations SHOULD use a hardware VP8 codec that meets the
   2209 requirements in [<a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">Resources, 68</a>].</p>
   2210 
   2211 <p class="table_footnote">4 Device implementations SHOULD support writing Matroska WebM files.</p>
   2212 
   2213 <p class="table_footnote">5 STRONGLY RECOMMENDED for Android Automotive, optional for Android Watch, and required for all other device types.</p>
   2214 
   2215 <p class="table_footnote">6 Applies only to Android Television device implementations.</p>
   2216 
   2217 <h2 id="5_2_video_encoding">5.2. Video Encoding</h2>
   2218 
   2219 <div class="note">
   2220 <p>Video codecs are optional for Android Watch device implementations.</p>
   2221 </div>
   2222 
   2223 <p>Android device implementations with H.263 encoders, MUST support Baseline Profile Level 45.</p>
   2224 
   2225 <p>Android device implementations with H.264 codec support, MUST support Baseline
   2226 Profile Level 3 and the following SD (Standard Definition) video encoding
   2227 profiles and SHOULD support Main Profile Level 4 and the following HD (High
   2228 Definition) video encoding profiles. Android Television devices are STRONGLY RECOMMENDED
   2229 to encode HD 1080p video at 30 fps.</p>
   2230 <table>
   2231  <tr>
   2232     <th></th>
   2233     <th>SD (Low quality)</th>
   2234     <th>SD (High quality)</th>
   2235     <th>HD 720p<sup>1</sup></th>
   2236     <th>HD 1080p<sup>1</sup></th>
   2237  </tr>
   2238  <tr>
   2239     <th>Video resolution</th>
   2240     <td>320 x 240 px</td>
   2241     <td>720 x 480 px</td>
   2242     <td>1280 x 720 px</td>
   2243     <td>1920 x 1080 px</td>
   2244  </tr>
   2245  <tr>
   2246     <th>Video frame rate</th>
   2247     <td>20 fps</td>
   2248     <td>30 fps</td>
   2249     <td>30 fps</td>
   2250     <td>30 fps</td>
   2251  </tr>
   2252  <tr>
   2253     <th>Video bitrate</th>
   2254     <td>384 Kbps</td>
   2255     <td>2 Mbps</td>
   2256     <td>4 Mbps</td>
   2257     <td>10 Mbps</td>
   2258  </tr>
   2259 </table>
   2260 
   2261 
   2262 <p class="table_footnote">1 When supported by hardware, but STRONGLY RECOMMENDED for Android Television
   2263 devices.</p>
   2264 
   2265 <p>Android device implementations with VP8 codec support MUST support the SD video
   2266 encoding profiles and SHOULD support the following HD (High Definition) video
   2267 encoding profiles.</p>
   2268 <table>
   2269  <tr>
   2270     <th></th>
   2271     <th>SD (Low quality)</th>
   2272     <th>SD (High quality)</th>
   2273     <th>HD 720p<sup>1</sup></th>
   2274     <th>HD 1080p<sup>1</sup></th>
   2275  </tr>
   2276  <tr>
   2277     <th>Video resolution</th>
   2278     <td>320 x 180 px</td>
   2279     <td>640 x 360 px</td>
   2280     <td>1280 x 720 px</td>
   2281     <td>1920 x 1080 px</td>
   2282  </tr>
   2283  <tr>
   2284     <th>Video frame rate</th>
   2285     <td>30 fps</td>
   2286     <td>30 fps</td>
   2287     <td>30 fps</td>
   2288     <td>30 fps</td>
   2289  </tr>
   2290  <tr>
   2291     <th>Video bitrate</th>
   2292     <td>800 Kbps </td>
   2293     <td>2 Mbps</td>
   2294     <td>4 Mbps</td>
   2295     <td>10 Mbps</td>
   2296  </tr>
   2297 </table>
   2298 
   2299 <p class="table_footnote">1 When supported by hardware.</p>
   2300 
   2301 <h2 id="5_3_video_decoding">5.3. Video Decoding</h2>
   2302 
   2303 <div class="note">
   2304 <p>Video codecs are optional for Android Watch device implementations.</p>
   2305 </div>
   2306 
   2307 <p>Device implementations MUST support dynamic video resolution and frame rate
   2308 switching through the standard Android APIs within the same stream for all VP8,
   2309 VP9, H.264, and H.265 codecs in real time and up to the maximum resolution
   2310 supported by each codec on the device.</p>
   2311 
   2312 <p>Android device implementations with H.263 decoders, MUST support Baseline
   2313 Profile Level 30.</p>
   2314 
   2315 <p>Android device implementations with MPEG-4 decoders, MUST support Simple
   2316 Profile Level 3.</p>
   2317 
   2318 <p>Android device implementations with H.264 decoders, MUST support Main Profile
   2319 Level 3.1 and the following SD video decoding profiles and SHOULD support the
   2320 HD decoding profiles. Android Television devices MUST support High Profile
   2321 Level 4.2 and the HD 1080p decoding profile.</p>
   2322 <table>
   2323  <tr>
   2324     <th></th>
   2325     <th>SD (Low quality)</th>
   2326     <th>SD (High quality)</th>
   2327     <th>HD 720p<sup>1</sup></th>
   2328     <th>HD 1080p<sup>1</sup></th>
   2329  </tr>
   2330  <tr>
   2331     <th>Video resolution</th>
   2332     <td>320 x 240 px</td>
   2333     <td>720 x 480 px</td>
   2334     <td>1280 x 720 px</td>
   2335     <td>1920 x 1080 px</td>
   2336  </tr>
   2337  <tr>
   2338     <th>Video frame rate</th>
   2339     <td>30 fps</td>
   2340     <td>30 fps</td>
   2341     <td>60 fps</td>
   2342     <td>30 fps / 60 fps<sup>2</sup></td>
   2343  </tr>
   2344  <tr>
   2345     <th>Video bitrate</th>
   2346     <td>800 Kbps </td>
   2347     <td>2 Mbps</td>
   2348     <td>8 Mbps</td>
   2349     <td>20 Mbps</td>
   2350  </tr>
   2351 </table>
   2352 
   2353 
   2354 <p class="table_footnote">1 REQUIRED for when the height as reported by the
   2355 Display.getSupportedModes() method is equal or greater than the video resolution.</p>
   2356 
   2357 <p class="table_footnote">2 REQUIRED for Android Television device implementations.</p>
   2358 
   2359 <p>Android device implementations when supporting VP8 codec as described in <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the following SD decoding profiles and SHOULD support the HD
   2360 decoding profiles. Android Television devices MUST support the HD 1080p
   2361 decoding profile.  </p>
   2362 <table>
   2363  <tr>
   2364     <th></th>
   2365     <th>SD (Low quality)</th>
   2366     <th>SD (High quality)</th>
   2367     <th>HD 720p<sup>1</sup></th>
   2368     <th>HD 1080p<sup>1</sup></th>
   2369  </tr>
   2370  <tr>
   2371     <th>Video resolution</th>
   2372     <td>320 x 180 px</td>
   2373     <td>640 x 360 px</td>
   2374     <td>1280 x 720 px</td>
   2375     <td>1920 x 1080 px</td>
   2376  </tr>
   2377  <tr>
   2378     <th>Video frame rate</th>
   2379     <td>30 fps</td>
   2380     <td>30 fps</td>
   2381     <td>30 fps / 60 fps<sup>2</sup></td>
   2382     <td>30 / 60 fps<sup>2</sup></td>
   2383  </tr>
   2384  <tr>
   2385     <th>Video bitrate</th>
   2386     <td>800 Kbps </td>
   2387     <td>2 Mbps</td>
   2388     <td>8 Mbps</td>
   2389     <td>20 Mbps</td>
   2390  </tr>
   2391 </table>
   2392 
   2393 <p class="table_footnote">1 REQUIRED for when the height as reported by the
   2394 Display.getSupportedModes() method is equal or greater than the video resolution.</p>
   2395 
   2396 <p class="table_footnote">2 REQUIRED for Android Television device implementations.</p>
   2397 
   2398 <p>Android device implementations, when supporting VP9 codec as described in <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the following SD video decoding profiles and SHOULD support the
   2399 HD decoding profiles. Android Television devices are STRONGLY RECOMMENDED to
   2400 support the HD 1080p decoding profile and SHOULD support the UHD decoding
   2401 profile. When the UHD video decoding profile is supported, it MUST support 8-bit
   2402 color depth and SHOULD support VP9 Profile 2 (10-bit).</p>
   2403 <table>
   2404  <tr>
   2405     <th></th>
   2406     <th>SD (Low quality)</th>
   2407     <th>SD (High quality)</th>
   2408     <th>HD 720p<sup>1</sup></th>
   2409     <th>HD 1080p<sup>2</sup></th>
   2410     <th>UHD<sup>2</sup></th>
   2411  </tr>
   2412  <tr>
   2413     <th>Video resolution</th>
   2414     <td>320 x 180 px</td>
   2415     <td>640 x 360 px</td>
   2416     <td>1280 x 720 px</td>
   2417     <td>1920 x 1080 px</td>
   2418     <td>3840 x 2160 px</td>
   2419  </tr>
   2420  <tr>
   2421     <th>Video frame rate</th>
   2422     <td>30 fps</td>
   2423     <td>30 fps</td>
   2424     <td>30 fps</td>
   2425     <td>60 fps</td>
   2426     <td>60 fps</td>
   2427  </tr>
   2428  <tr>
   2429     <th>Video bitrate</th>
   2430     <td>600 Kbps</td>
   2431     <td>1.6 Mbps</td>
   2432     <td>4 Mbps</td>
   2433     <td>5 Mbps</td>
   2434     <td>20 Mbps</td>
   2435  </tr>
   2436 </table>
   2437 
   2438 
   2439 <p class="table_footnote">1 Required for Android Television device implementations, but for other type of
   2440 devices only when supported by hardware.</p>
   2441 
   2442 <p class="table_footnote">2 STRONGLY RECOMMENDED for existing Android Television device implementations when
   2443 supported by hardware.</p>
   2444 
   2445 <p>Android device implementations, when supporting H.265 codec as described in
   2446 <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the Main Profile
   2447 Level 3 Main tier and the following SD video decoding profiles and SHOULD
   2448 support the HD decoding profiles.
   2449 Android Television devices MUST support the Main Profile Level 4.1 Main tier and
   2450 the HD 1080p decoding profile and is STRONGLY RECOMMENDED to support the UHD
   2451 decoding profile. If UHD decoding is supported, then it MUST support Main10
   2452 Level 5 Main Tier profile.</p>
   2453 <table>
   2454  <tr>
   2455     <th></th>
   2456     <th>SD (Low quality)</th>
   2457     <th>SD (High quality)</th>
   2458     <th>HD 720p<sup>1</sup></th>
   2459     <th>HD 1080p<sup>1</sup></th>
   2460     <th>UHD<sup>2</sup></th>
   2461  </tr>
   2462  <tr>
   2463     <th>Video resolution</th>
   2464     <td>352 x 288 px</td>
   2465     <td>640 x 360 px</td>
   2466     <td>1280 x 720 px</td>
   2467     <td>1920 x 1080 px</td>
   2468     <td>3840 x 2160 px</td>
   2469  </tr>
   2470  <tr>
   2471     <th>Video frame rate</th>
   2472     <td>30 fps</td>
   2473     <td>30 fps</td>
   2474     <td>30 fps</td>
   2475     <td>60 fps<sup>2</sup></td>
   2476     <td>60 fps</td>
   2477  </tr>
   2478  <tr>
   2479     <th>Video bitrate</th>
   2480     <td>600 Kbps </td>
   2481     <td>1.6 Mbps</td>
   2482     <td>4 Mbps</td>
   2483     <td>10 Mbps</td>
   2484     <td>20 Mbps</td>
   2485  </tr>
   2486 </table>
   2487 
   2488 
   2489 <p class="table_footnote">1 Required for Android Television device implementations, but for other type of
   2490 devices only when supported by hardware.</p>
   2491 
   2492 <p class="table_footnote">2 STRONGLY RECOMMENDED
   2493 for existing Android Television device implementations when supported by hardware.</p>
   2494 
   2495 <h2 id="5_4_audio_recording">5.4. Audio Recording</h2>
   2496 
   2497 
   2498 <p>While some of the requirements outlined in this section are stated as SHOULD
   2499 since Android 4.3, the Compatibility Definition for a future version is planned
   2500 to change these to MUST. Existing and new Android devices are <strong>STRONGLY RECOMMENDED</strong>
   2501 to meet these requirements that are stated as SHOULD, or they will not be able to attain
   2502 Android compatibility when upgraded to the future version.</p>
   2503 
   2504 <h3 id="5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</h3>
   2505 
   2506 
   2507 <p>Device implementations that declare android.hardware.microphone MUST allow
   2508 capture of raw audio content with the following characteristics:</p>
   2509 
   2510 <ul>
   2511   <li><strong>Format</strong>: Linear PCM, 16-bit
   2512   <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 44100
   2513   <li><strong>Channels</strong>: Mono
   2514 </ul>
   2515 
   2516 <p>The capture for the above sample rates MUST be done without up-sampling, and
   2517 any down-sampling MUST include an appropriate anti-aliasing filter.</p>
   2518 
   2519 <p>Device implementations that declare android.hardware.microphone SHOULD allow
   2520 capture of raw audio content with the following characteristics:</p>
   2521 
   2522 <ul>
   2523   <li><strong>Format</strong>: Linear PCM, 16-bit
   2524   <li><strong>Sampling rates</strong>: 22050, 48000
   2525   <li><strong>Channels</strong>: Stereo
   2526 </ul>
   2527 
   2528 <p>If capture for the above sample rates is supported,
   2529 then the capture MUST be done without up-sampling at any ratio higher than 16000:22050
   2530 or 44100:48000.
   2531 Any up-sampling or down-sampling MUST include an appropriate anti-aliasing filter.</p>
   2532 
   2533 <h3 id="5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</h3>
   2534 
   2535 
   2536 <p>In addition to the above recording specifications, when an application has
   2537 started recording an audio stream using the
   2538 android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source:</p>
   2539 
   2540 <ul>
   2541   <li>The device SHOULD exhibit approximately flat amplitude versus frequency
   2542 characteristics: specifically, &plusmn;3 dB, from 100 Hz to 4000 Hz.
   2543   <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level (SPL)
   2544 source at 1000 Hz yields RMS of 2500 for 16-bit samples.
   2545   <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least a 30
   2546 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.
   2547   <li>Total harmonic distortion SHOULD be less than 1% for 1 kHz at 90 dB SPL input
   2548 level at the microphone.
   2549   <li>Noise reduction processing, if present, MUST be disabled.
   2550   <li>Automatic gain control, if present, MUST be disabled
   2551 </ul>
   2552 
   2553 <p>If the platform supports noise suppression technologies tuned for speech
   2554 recognition, the effect MUST be controllable from the
   2555 android.media.audiofx.NoiseSuppressor API. Moreover, the UUID field for the
   2556 noise suppressor&rsquo;s effect descriptor MUST uniquely identify each implementation
   2557 of the noise suppression technology.</p>
   2558 
   2559 <h3 id="5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</h3>
   2560 
   2561 
   2562 <p>The android.media.MediaRecorder.AudioSource class includes the REMOTE_SUBMIX
   2563 audio source. Devices that declare android.hardware.audio.output MUST properly
   2564 implement the REMOTE_SUBMIX audio source so that when an application uses the
   2565 android.media.AudioRecord API to record from this audio source, it can capture
   2566 a mix of all audio streams except for the following:</p>
   2567 
   2568 <ul>
   2569   <li>STREAM_RING
   2570   <li>STREAM_ALARM
   2571   <li>STREAM_NOTIFICATION
   2572 </ul>
   2573 
   2574 <h2 id="5_5_audio_playback">5.5. Audio Playback</h2>
   2575 
   2576 
   2577 <p>Device implementations that declare android.hardware.audio.output MUST conform
   2578 to the requirements in this section.</p>
   2579 
   2580 <h3 id="5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</h3>
   2581 
   2582 
   2583 <p>The device MUST allow playback of raw audio content with the following
   2584 characteristics:</p>
   2585 
   2586 <ul>
   2587   <li><strong>Format</strong>: Linear PCM, 16-bit</li>
   2588   <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 22050, 32000, 44100</li>
   2589   <li><strong>Channels</strong>: Mono, Stereo</li>
   2590 </ul>
   2591 
   2592 <p>The device SHOULD allow playback of raw audio content with the following
   2593 characteristics:</p>
   2594 
   2595 <ul>
   2596   <li><strong>Sampling rates</strong>: 24000, 48000</li>
   2597 </ul>
   2598 
   2599 <h3 id="5_5_2_audio_effects">5.5.2. Audio Effects</h3>
   2600 
   2601 
   2602 <p>Android provides an API for audio effects for device implementations [<a href="http://developer.android.com/reference/android/media/audiofx/AudioEffect.html">Resources, 69</a>]. Device implementations that declare the feature
   2603 android.hardware.audio.output:</p>
   2604 
   2605 <ul>
   2606   <li>MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER
   2607 implementations controllable through the AudioEffect subclasses Equalizer,
   2608 LoudnessEnhancer.</li>
   2609   <li>MUST support the visualizer API implementation, controllable through the
   2610 Visualizer class.</li>
   2611   <li>SHOULD support the EFFECT_TYPE_BASS_BOOST, EFFECT_TYPE_ENV_REVERB,
   2612 EFFECT_TYPE_PRESET_REVERB, and EFFECT_TYPE_VIRTUALIZER implementations
   2613 controllable through the AudioEffect sub-classes BassBoost,
   2614 EnvironmentalReverb, PresetReverb, and Virtualizer.</li>
   2615 </ul>
   2616 
   2617 <h3 id="5_5_3_audio_output_volume">5.5.3. Audio Output Volume</h3>
   2618 
   2619 
   2620 <p>Android Television device implementations MUST include support for system
   2621 Master Volume and digital audio output volume attenuation on supported outputs,
   2622 except for compressed audio passthrough output (where no audio decoding is done
   2623 on the device).</p>
   2624 
   2625 <h2 id="5_6_audio_latency">5.6. Audio Latency</h2>
   2626 
   2627 
   2628 <p>Audio latency is the time delay as an audio signal passes through a system.
   2629 Many classes of applications rely on short latencies, to achieve real-time
   2630 sound effects.</p>
   2631 
   2632 <p>For the purposes of this section, use the following definitions:</p>
   2633 
   2634 <ul>
   2635   <li><strong>output latency</strong>. The interval between when an application writes a frame of PCM-coded data and
   2636 when the corresponding sound can be heard by an external listener or observed
   2637 by a transducer.</li>
   2638   <li><strong>cold output latency</strong>. The output latency for the first frame, when the audio output system has been
   2639 idle and powered down prior to the request.</li>
   2640   <li><strong>continuous output latency</strong>. The output latency for subsequent frames, after the device is playing audio.</li>
   2641   <li><strong>input latency</strong>. The interval between when an external sound is presented to the device and
   2642 when an application reads the corresponding frame of PCM-coded data.</li>
   2643   <li><strong>cold input latency</strong>. The sum of lost input time and the input latency for the first frame, when the
   2644 audio input system has been idle and powered down prior to the request.</li>
   2645   <li><strong>continuous input latency</strong>. The input latency for subsequent frames, while the device is capturing audio.</li>
   2646   <li><strong>cold output jitter</strong>. The variance among separate measurements of cold output latency values.</li>
   2647   <li><strong>cold input jitter</strong>. The variance among separate measurements of cold input latency values.</li>
   2648   <li><strong>continuous round-trip latency</strong>. The sum of continuous input latency plus continuous output latency plus
   2649   one buffer period.
   2650   The buffer period term allows processing time for the app and for the app to
   2651   mitigate phase difference between input and output streams.
   2652   </li>
   2653   <li><strong>OpenSL ES PCM buffer queue API</strong>. The set of PCM-related OpenSL ES APIs within Android NDK; see
   2654 NDK_root/docs/opensles/index.html.</li>
   2655 </ul>
   2656 
   2657 <p>Device implementations that declare android.hardware.audio.output are STRONGLY RECOMMENDED to meet
   2658 or exceed these audio output requirements:</p>
   2659 
   2660 <ul>
   2661   <li>cold output latency of 100 milliseconds or less</li>
   2662   <li>continuous output latency of 45 milliseconds or less</li>
   2663   <li>minimize the cold output jitter</li>
   2664 </ul>
   2665 
   2666 <p>If a device implementation meets the requirements of this section after any
   2667 initial calibration when using the OpenSL ES PCM buffer queue API, for
   2668 continuous output latency and cold output latency over at least one supported
   2669 audio output device, it is STRONGLY RECOMMENDED to report support for low-latency audio, by reporting
   2670 the feature android.hardware.audio.low_latency via the
   2671 android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]. Conversely, if the device implementation does not meet these requirements it
   2672 MUST NOT report support for low-latency audio.</p>
   2673 
   2674 <p>Device implementations that include android.hardware.microphone are STRONGLY RECOMMENDED to meet
   2675 these input audio requirements:</p>
   2676 
   2677 <ul>
   2678   <li>cold input latency of 100 milliseconds or less</li>
   2679   <li>continuous input latency of 30 milliseconds or less</li>
   2680   <li>continuous round-trip latency of 50 milliseconds or less</li>
   2681   <li>minimize the cold input jitter</li>
   2682 </ul>
   2683 
   2684 <h2 id="5_7_network_protocols">5.7. Network Protocols</h2>
   2685 
   2686 
   2687 <p>Devices MUST support the media network protocols for audio and video playback
   2688 as specified in the Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 64</a>]. Specifically, devices MUST support the following media network protocols:</p>
   2689 
   2690 <ul>
   2691   <li>RTSP (RTP, SDP)</li>
   2692   <li>HTTP(S) progressive streaming</li>
   2693   <li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-03">Resources, 71</a>]</li>
   2694 </ul>
   2695 
   2696 <h2 id="5_8_secure_media">5.8. Secure Media</h2>
   2697 
   2698 
   2699 <p>Device implementations that support secure video output and are capable of
   2700 supporting secure surfaces MUST declare support for Display.FLAG_SECURE. Device
   2701 implementations that declare support for Display.FLAG_SECURE, if they support a
   2702 wireless display protocol, MUST secure the link with a cryptographically strong
   2703 mechanism such as HDCP 2.x or higher for Miracast wireless displays. Similarly
   2704 if they support a wired external display, the device implementations MUST
   2705 support HDCP 1.2 or higher. Android Television device implementations MUST
   2706 support HDCP 2.2 for devices supporting 4K resolution and HDCP 1.4 or above for
   2707 lower resolutions. The upstream Android open source implementation includes
   2708 support for wireless (Miracast) and wired (HDMI) displays that satisfies this
   2709 requirement.</p>
   2710 
   2711 <h2 id="5_9_midi">5.9. Musical Instrument Digital Interface (MIDI)</h2>
   2712 
   2713 <p>
   2714 If a device implementation supports the inter-app MIDI software transport
   2715 (virtual MIDI devices), and it supports MIDI over
   2716 <em>all</em> of the following MIDI-capable hardware transports
   2717 for which it provides generic non-MIDI connectivity, it is STRONGLY RECOMMENDED to report
   2718 support for feature android.software.midi via the
   2719 android.content.pm.PackageManager class
   2720 [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>].
   2721 </p>
   2722 
   2723 <p>The MIDI-capable hardware transports are:</p>
   2724 <ul>
   2725   <li>USB host mode (section 7.7 USB)</li>
   2726   <li>USB peripheral mode (section 7.7 USB)</li>
   2727 </ul>
   2728 
   2729 <p>
   2730 Conversely, if the device implementation provides generic non-MIDI connectivity over a particular
   2731 MIDI-capable hardware transport listed above, but does not support MIDI over that hardware transport,
   2732 it MUST NOT report support for feature android.software.midi.
   2733 </p>
   2734 
   2735 <p>
   2736 MIDI over Bluetooth LE acting in central role (section 7.4.3 Bluetooth)
   2737 is in trial use status.  A device implementation that reports
   2738 feature android.software.midi, and which provides generic non-MIDI connectivity
   2739 over Bluetooth LE, SHOULD support MIDI over Bluetooth LE.
   2740 </p>
   2741 
   2742 <h2 id="5_10_pro_audio">5.10. Professional Audio</h2>
   2743 
   2744 <p>
   2745 If a device implementation meets <em>all</em> of the following requirements,
   2746 it is STRONGLY RECOMMENDED to report support for feature android.hardware.audio.pro via the
   2747 android.content.pm.PackageManager class
   2748 [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>].
   2749 </p>
   2750 
   2751 <ul>
   2752 
   2753 <li>
   2754 The device implementation MUST report support for feature android.hardware.audio.low_latency.
   2755 </li>
   2756 
   2757 <li> The continuous round-trip audio latency, as defined in section 5.6 Audio Latency,
   2758 MUST be 20 milliseconds or less and SHOULD be 10 milliseconds or less over at least one
   2759 supported path.
   2760 </li>
   2761 
   2762 <li>
   2763 If the device includes a 4 conductor 3.5mm audio jack,
   2764 the continuous round-trip audio latency MUST be 20 milliseconds or less over the audio jack path,
   2765 and SHOULD be 10 milliseconds or less over the audio jack path.
   2766 </li>
   2767 
   2768 <li>
   2769 The device implementation MUST include a USB port(s) supporting USB host mode and
   2770 USB peripheral mode.
   2771 </li>
   2772 
   2773 <li>
   2774 The USB host mode MUST implement the USB audio class.
   2775 </li>
   2776 
   2777 <li>
   2778 If the device includes an HDMI port, the device implementation
   2779 MUST support output in stereo and eight channels
   2780 at 20-bit or 24-bit depth and 192 kHz without bit-depth loss or resampling.
   2781 </li>
   2782 
   2783 <li>
   2784 The device implementation MUST report support for feature android.software.midi.
   2785 </li>
   2786 
   2787 <li>
   2788 If the device includes a 4 conductor 3.5mm audio jack,
   2789 the device implementation is STRONGLY RECOMMENDED to comply with section
   2790 <a href="https://source.android.com/accessories/headset/specification.html#mobile_device_jack_specifications">Mobile device (jack) specifications</a>
   2791 of the
   2792 <a href="https://source.android.com/accessories/headset/specification.html">Wired Audio Headset Specification (v1.1)</a>.
   2793 </li>
   2794 
   2795 </ul>
   2796 
   2797 <h1 id="6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</h1>
   2798 
   2799 <h2 id="6_1_developer_tools">6.1. Developer Tools</h2>
   2800 
   2801 <p>Device implementations MUST support the Android Developer Tools provided in the
   2802 Android SDK. Android compatible devices MUST be compatible with:</p>
   2803 
   2804 <ul>
   2805   <li><strong>Android Debug Bridge (adb)</strong> [<a href="http://developer.android.com/tools/help/adb.html">Resources, 72</a>]</li>
   2806 </ul>
   2807 
   2808 <p>Device implementations MUST support all adb functions as documented in the
   2809 Android SDK including dumpsys [<a href="https://source.android.com/devices/input/diagnostics.html">Resources, 73</a>]. The device-side adb daemon MUST be inactive by default and there MUST be a
   2810 user-accessible mechanism to turn on the Android Debug Bridge. If a device
   2811 implementation omits USB peripheral mode, it MUST implement the Android Debug
   2812 Bridge via local-area network (such as Ethernet or 802.11). </p>
   2813 
   2814 <p>Android includes support for secure adb. Secure adb enables adb on known
   2815 authenticated hosts. Device implementations MUST support secure adb.</p>
   2816 
   2817 <ul>
   2818   <li><strong>Dalvik Debug Monitor Service (ddms)</strong> [<a href="http://developer.android.com/tools/debugging/ddms.html">Resources, 74</a>]</li>
   2819 </ul>
   2820 
   2821 <p>Device implementations MUST support all ddms features as documented in the
   2822 Android SDK. As ddms uses adb, support for ddms SHOULD be inactive by default,
   2823 but MUST be supported whenever the user has activated the Android Debug Bridge,
   2824 as above.</p>
   2825 
   2826 <ul>
   2827   <li><strong>Monkey</strong> [<a href="http://developer.android.com/tools/help/monkey.html">Resources, 75</a>]</li>
   2828 </ul>
   2829 
   2830 <p>Device implementations MUST include the Monkey framework, and make it available
   2831 for applications to use.</p>
   2832 
   2833 <ul>
   2834   <li><strong>SysTrace</strong> [<a href="http://developer.android.com/tools/help/systrace.html">Resources, 76</a>]</li>
   2835 </ul>
   2836 
   2837 <p>Device implementations MUST support systrace tool as documented in the Android
   2838 SDK. Systrace must be inactive by default, and there MUST be a user-accessible
   2839 mechanism to turn on Systrace.</p>
   2840 
   2841 <p>Most Linux-based systems and Apple Macintosh systems recognize Android devices
   2842 using the standard Android SDK tools, without additional support; however
   2843 Microsoft Windows systems typically require a driver for new Android devices.
   2844 (For instance, new vendor IDs and sometimes new device IDs require custom USB
   2845 drivers for Windows systems.) If a device implementation is unrecognized by the
   2846 adb tool as provided in the standard Android SDK, device implementers MUST
   2847 provide Windows drivers allowing developers to connect to the device using the
   2848 adb protocol. These drivers MUST be provided for Windows XP, Windows Vista,
   2849 Windows 7, Windows 8 and Windows 10 in both 32-bit and 64-bit versions.
   2850 </p>
   2851 
   2852 <h2 id="6_2_developer_options">6.2. Developer Options</h2>
   2853 
   2854 
   2855 <p>Android includes support for developers to configure application
   2856 development-related settings. Device implementations MUST honor the
   2857 android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show application
   2858 development-related settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">Resources, 77</a>]. The upstream Android implementation hides the Developer Options menu by
   2859 default and enables users to launch Developer Options after pressing seven (7)
   2860 times on the <strong>Settings</strong> > <strong>About Device</strong> > <strong>Build Number</strong> menu item. Device implementations MUST provide a consistent experience for
   2861 Developer Options. Specifically, device implementations MUST hide Developer
   2862 Options by default and MUST provide a mechanism to enable Developer Options
   2863 that is consistent with the upstream Android implementation.</p>
   2864 
   2865 <h1 id="7_hardware_compatibility">7. Hardware Compatibility</h1>
   2866 
   2867 
   2868 <p>If a device includes a particular hardware component that has a corresponding
   2869 API for third-party developers, the device implementation MUST implement that
   2870 API as described in the Android SDK documentation. If an API in the SDK
   2871 interacts with a hardware component that is stated to be optional and the
   2872 device implementation does not possess that component:</p>
   2873 
   2874 <ul>
   2875   <li>Complete class definitions (as documented by the SDK) for the component APIs
   2876 MUST still be presented.
   2877   <li>The API&rsquo;s behaviors MUST be implemented as no-ops in some reasonable fashion.
   2878   <li>API methods MUST return null values where permitted by the SDK documentation.
   2879   <li>API methods MUST return no-op implementations of classes where null values are
   2880 not permitted by the SDK documentation.
   2881   <li>API methods MUST NOT throw exceptions not documented by the SDK documentation.
   2882 </ul>
   2883 
   2884 <p>A typical example of a scenario where these requirements apply is the telephony
   2885 API: even on non-phone devices, these APIs must be implemented as reasonable
   2886 no-ops.</p>
   2887 
   2888 <p>Device implementations MUST consistently report accurate hardware configuration
   2889 information via the getSystemAvailableFeatures() and hasSystemFeature(String)
   2890 methods on the android.content.pm.PackageManager class for the same build
   2891 fingerprint. [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]</p>
   2892 
   2893 <h2 id="7_1_display_and_graphics">7.1. Display and Graphics</h2>
   2894 
   2895 
   2896 <p>Android includes facilities that automatically adjust application assets and UI
   2897 layouts appropriately for the device, to ensure that third-party applications
   2898 run well on a variety of hardware configurations [<a href="http://developer.android.com/guide/practices/screens_support.html">Resources, 78</a>]. Devices MUST properly implement these APIs and behaviors, as detailed in
   2899 this section.</p>
   2900 
   2901 <p>The units referenced by the requirements in this section are defined as
   2902 follows:</p>
   2903 
   2904 <ul>
   2905   <li><strong>physical diagonal size</strong>. The distance in inches between two opposing corners of the illuminated portion
   2906 of the display.</li>
   2907   <li><strong>dots per inch (dpi)</strong>. The number of pixels encompassed by a linear horizontal or vertical span of
   2908 1&rdquo;. Where dpi values are listed, both horizontal and vertical dpi must fall
   2909 within the range.</li>
   2910   <li><strong>aspect ratio</strong>. The ratio of the pixels of the longer dimension
   2911   to the shorter dimension of the screen. For example, a display of 480x854 pixels
   2912   would be 854/480 = 1.779, or roughly &ldquo;16:9&rdquo;.</li>
   2913   <li><strong>density-independent pixel (dp)</strong> The virtual pixel unit normalized to a 160 dpi screen, calculated as: pixels =
   2914 dps * (density/160).</li>
   2915 </ul>
   2916 
   2917 <h3 id="7_1_1_screen_configuration">7.1.1. Screen Configuration</h3>
   2918 
   2919 
   2920 <h4 id="7_1_1_1_screen_size">7.1.1.1. Screen Size</h4>
   2921 
   2922 <div class="note">
   2923 <p>Android Watch devices (detailed in <a href="#2_device_types">section 2</a>) MAY have smaller screen sizes as described in this section.</p>
   2924 </div>
   2925 
   2926 <p>The Android UI framework supports a variety of different screen sizes, and
   2927 allows applications to query the device screen size (aka &ldquo;screen layout") via
   2928 android.content.res.Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK.
   2929 Device implementations MUST report the correct screen size as defined in the
   2930 Android SDK documentation [<a href="http://developer.android.com/guide/practices/screens_support.html">Resources, 78</a>] and determined by the upstream Android platform. Specifically, device
   2931 implementations MUST report the correct screen size according to the following
   2932 logical density-independent pixel (dp) screen dimensions.</p>
   2933 
   2934 <ul>
   2935   <li>Devices MUST have screen sizes of at least 426 dp x 320 dp (&lsquo;small&rsquo;), unless it
   2936 is an Android Watch device.</li>
   2937   <li>Devices that report screen size &lsquo;normal&rsquo; MUST have screen sizes of at least 480
   2938 dp x 320 dp.</li>
   2939   <li>Devices that report screen size &lsquo;large&rsquo; MUST have screen sizes of at least 640
   2940 dp x 480 dp.</li>
   2941   <li>Devices that report screen size &lsquo;xlarge&rsquo; MUST have screen sizes of at least 960
   2942 dp x 720 dp.</li>
   2943 </ul>
   2944 
   2945 <p>In addition, </p>
   2946 
   2947 <ul>
   2948   <li>Android Watch devices MUST have a screen with the physical diagonal size in the
   2949 range from 1.1 to 2.5 inches.</li>
   2950   <li>Other types of Android device implementations, with a physically integrated
   2951 screen, MUST have a screen at least 2.5 inches in physical diagonal size.</li>
   2952 </ul>
   2953 
   2954 <p>Devices MUST NOT change their reported screen size at any time.</p>
   2955 
   2956 <p>Applications optionally indicate which screen sizes they support via the
   2957 &lt;supports-screens&gt; attribute in the AndroidManifest.xml file. Device
   2958 implementations MUST correctly honor applications' stated support for small,
   2959 normal, large, and xlarge screens, as described in the Android SDK
   2960 documentation.</p>
   2961 
   2962 <h4 id="7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</h4>
   2963 
   2964 <div class="note">
   2965 <p>Android Watch devices MAY have an aspect ratio of 1.0 (1:1).</p>
   2966 </div>
   2967 
   2968 
   2969 <p>The screen aspect ratio MUST be a value from 1.3333 (4:3) to 1.86 (roughly
   2970 16:9), but Android Watch devices MAY have an aspect ratio of 1.0 (1:1) because
   2971 such a device implementation will use a UI_MODE_TYPE_WATCH as the
   2972 android.content.res.Configuration.uiMode.</p>
   2973 
   2974 <h4 id="7_1_1_3_screen_density">7.1.1.3. Screen Density</h4>
   2975 
   2976 
   2977 <p>The Android UI framework defines a set of standard logical densities to help
   2978 application developers target application resources. Device implementations
   2979 MUST report only one of the following logical Android framework densities
   2980 through the android.util.DisplayMetrics APIs, and MUST execute applications at
   2981 this standard density and MUST NOT change the value at at any time for the
   2982 default display.</p>
   2983 
   2984 <ul>
   2985   <li>120 dpi (ldpi)</li>
   2986   <li>160 dpi (mdpi)</li>
   2987   <li>213 dpi (tvdpi)</li>
   2988   <li>240 dpi (hdpi)</li>
   2989   <li>280 dpi (280dpi)</li>
   2990   <li>320 dpi (xhdpi)</li>
   2991   <li>360 dpi (360dpi)</li>
   2992   <li>400 dpi (400dpi)</li>
   2993   <li>420 dpi (420dpi)</li>
   2994   <li>480 dpi (xxhdpi)</li>
   2995   <li>560 dpi (560dpi)</li>
   2996   <li>640 dpi (xxxhdpi)</li>
   2997 </ul>
   2998 
   2999 <p>Device implementations SHOULD define the standard Android framework density
   3000 that is numerically closest to the physical density of the screen, unless that
   3001 logical density pushes the reported screen size below the minimum supported. If
   3002 the standard Android framework density that is numerically closest to the
   3003 physical density results in a screen size that is smaller than the smallest
   3004 supported compatible screen size (320 dp width), device implementations SHOULD
   3005 report the next lowest standard Android framework density.</p>
   3006 
   3007 <h3 id="7_1_2_display_metrics">7.1.2. Display Metrics</h3>
   3008 
   3009 
   3010 <p>Device implementations MUST report correct values for all display metrics
   3011 defined in android.util.DisplayMetrics [<a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">Resources, 79</a>] and MUST report the same values regardless of whether the embedded or
   3012 external screen is used as the default display.</p>
   3013 
   3014 <h3 id="7_1_3_screen_orientation">7.1.3. Screen Orientation</h3>
   3015 
   3016 
   3017 <p>Devices MUST report which screen orientations they support
   3018 (android.hardware.screen.portrait and/or android.hardware.screen.landscape) and
   3019 MUST report at least one supported orientation. For example, a device with a
   3020 fixed orientation landscape screen, such as a television or laptop, SHOULD only
   3021 report android.hardware.screen.landscape.</p>
   3022 
   3023 <p>Devices that report both screen orientations MUST support dynamic orientation
   3024 by applications to either portrait or landscape screen orientation. That is,
   3025 the device must respect the application&rsquo;s request for a specific screen
   3026 orientation. Device implementations MAY select either portrait or landscape
   3027 orientation as the default.</p>
   3028 
   3029 <p>Devices MUST report the correct value for the device&rsquo;s current orientation,
   3030 whenever queried via the android.content.res.Configuration.orientation,
   3031 android.view.Display.getOrientation(), or other APIs.</p>
   3032 
   3033 <p>Devices MUST NOT change the reported screen size or density when changing
   3034 orientation.</p>
   3035 
   3036 <h3 id="7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</h3>
   3037 
   3038 
   3039 <p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied and
   3040 detailed in the Android SDK documentations. Device implementations SHOULD
   3041 support OpenGL ES 3.0 or 3.1 on devices capable of supporting it. Device
   3042 implementations MUST also support Android RenderScript, as detailed in the
   3043 Android SDK documentation [<a href="http://developer.android.com/guide/topics/renderscript/">Resources, 80</a>].</p>
   3044 
   3045 <p>Device implementations MUST also correctly identify themselves as supporting
   3046 OpenGL ES 1.0, OpenGL ES 2.0, OpenGL ES 3.0 or OpenGL 3.1. That is:</p>
   3047 
   3048 <ul>
   3049   <li>The managed APIs (such as via the GLES10.getString() method) MUST report support
   3050 for OpenGL ES 1.0 and OpenGL ES 2.0.</li>
   3051   <li>The native C/C++ OpenGL APIs (APIs available to apps via libGLES_v1CM.so,
   3052 libGLES_v2.so, or libEGL.so) MUST report support for OpenGL ES 1.0 and OpenGL
   3053 ES 2.0.</li>
   3054   <li>Device implementations that declare support for OpenGL ES 3.0 or 3.1 MUST
   3055 support the corresponding managed APIs and include support for native C/C++
   3056 APIs. On device implementations that declare support for OpenGL ES 3.0 or 3.1,
   3057 libGLESv2.so MUST export the corresponding function symbols in addition to the
   3058 OpenGL ES 2.0 function symbols.</li>
   3059 </ul>
   3060 
   3061 <p>In addition to OpenGL ES 3.1, Android provides an extension pack with Java
   3062 interfaces [<a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">Resources, 81</a>] and native support for advanced graphics functionality such as tessellation
   3063 and the ASTC texture compression format. Android device implementations MAY
   3064 support this extension pack, and&mdash;only if fully implemented&mdash;MUST identify the
   3065 support through the android.hardware.opengles.aep feature flag.</p>
   3066 
   3067 <p>Also, device implementations MAY implement any desired OpenGL ES extensions.
   3068 However, device implementations MUST report via the OpenGL ES managed and
   3069 native APIs all extension strings that they do support, and conversely MUST NOT
   3070 report extension strings that they do not support.</p>
   3071 
   3072 <p>Note that Android includes support for applications to optionally specify that
   3073 they require specific OpenGL texture compression formats. These formats are
   3074 typically vendor-specific. Device implementations are not required by Android
   3075 to implement any specific texture compression format. However, they SHOULD
   3076 accurately report any texture compression formats that they do support, via the
   3077 getString() method in the OpenGL API.</p>
   3078 
   3079 <p>Android includes a mechanism for applications to declare that they want to
   3080 enable hardware acceleration for 2D graphics at the Application, Activity,
   3081 Window, or View level through the use of a manifest tag
   3082 android:hardwareAccelerated or direct API calls [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 82</a>].</p>
   3083 
   3084 <p>Device implementations MUST enable hardware acceleration by default, and MUST
   3085 disable hardware acceleration if the developer so requests by setting
   3086 android:hardwareAccelerated="false&rdquo; or disabling hardware acceleration directly
   3087 through the Android View APIs.</p>
   3088 
   3089 <p>In addition, device implementations MUST exhibit behavior consistent with the
   3090 Android SDK documentation on hardware acceleration [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 82</a>].</p>
   3091 
   3092 <p>Android includes a TextureView object that lets developers directly integrate
   3093 hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy.
   3094 Device implementations MUST support the TextureView API, and MUST exhibit
   3095 consistent behavior with the upstream Android implementation.</p>
   3096 
   3097 <p>Android includes support for EGL_ANDROID_RECORDABLE, an EGLConfig attribute
   3098 that indicates whether the EGLConfig supports rendering to an ANativeWindow
   3099 that records images to a video. Device implementations MUST support
   3100 EGL_ANDROID_RECORDABLE extension [<a href="https://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">Resources, 83</a>].</p>
   3101 
   3102 <h3 id="7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</h3>
   3103 
   3104 
   3105 <p>Android specifies a &ldquo;compatibility mode&rdquo; in which the framework operates in a
   3106 'normal' screen size equivalent (320dp width) mode for the benefit of legacy
   3107 applications not developed for old versions of Android that pre-date
   3108 screen-size independence.</p>
   3109 
   3110 <ul>
   3111 <li>Android Automotive does not support legacy compatibility mode.</li>
   3112 <li>All other device implementations MUST include support for legacy application
   3113 compatibility mode as implemented by the upstream Android open source code. That
   3114 is, device implementations MUST NOT alter the triggers or thresholds at which
   3115 compatibility mode is activated, and MUST NOT alter the behavior of the
   3116 compatibility mode itself.</li>
   3117 </ul>
   3118 
   3119 <h3 id="7_1_6_screen_technology">7.1.6. Screen Technology</h3>
   3120 
   3121 
   3122 <p>The Android platform includes APIs that allow applications to render rich
   3123 graphics to the display. Devices MUST support all of these APIs as defined by
   3124 the Android SDK unless specifically allowed in this document. </p>
   3125 
   3126 <ul>
   3127   <li>Devices MUST support displays capable of rendering 16-bit color graphics and
   3128 SHOULD support displays capable of 24-bit color graphics.</li>
   3129   <li>Devices MUST support displays capable of rendering animations.</li>
   3130   <li>The display technology used MUST have a pixel aspect ratio (PAR) between 0.9
   3131 and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 10 ~
   3132 15% tolerance.</li>
   3133 </ul>
   3134 
   3135 <h3 id="7_1_7_external_displays">7.1.7. Secondary Displays</h3>
   3136 
   3137 
   3138 <p>Android includes support for secondary display to enable media sharing
   3139 capabilities and developer APIs for accessing external displays. If a device
   3140 supports an external display either via a wired, wireless, or an embedded
   3141 additional display connection then the device implementation MUST implement the
   3142 display manager API as described in the Android SDK documentation [<a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html">Resources, 84</a>].</p>
   3143 
   3144 <h2 id="7_2_input_devices">7.2. Input Devices</h2>
   3145 
   3146 <p>Devices MUST support a touchscreen or meet the requirements listed in 7.2.2
   3147 for non-touch navigation.</p>
   3148 
   3149 <h3 id="7_2_1_keyboard">7.2.1. Keyboard</h3>
   3150 
   3151 <div class="note">
   3152 <p>Android Watch and Android Automotive implementations MAY implement a soft
   3153 keyboard. All other device implementations MUST implement a soft keyboard and:</p>
   3154 </div>
   3155 
   3156 
   3157 <p>Device implementations:</p>
   3158 
   3159 <ul>
   3160   <li>MUST include support for the Input Management Framework (which allows
   3161 third-party developers to create Input Method Editors&mdash;i.e. soft keyboard) as
   3162 detailed at <a href="http://developer.android.com">http://developer.android.com</a>.</li>
   3163   <li>MUST provide at least one soft keyboard implementation (regardless of whether a
   3164 hard keyboard is present) except for Android Watch devices where the screen
   3165 size makes it less reasonable to have a soft keyboard.</li>
   3166   <li>MAY include additional soft keyboard implementations.</li>
   3167   <li>MAY include a hardware keyboard.</li>
   3168   <li>MUST NOT include a hardware keyboard that does not match one of the formats
   3169 specified in android.content.res.Configuration.keyboard [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 85</a>] (QWERTY or 12-key).</li>
   3170 </ul>
   3171 
   3172 <h3 id="7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</h3>
   3173 
   3174 <div class="note">
   3175 <p>Android Television devices MUST support D-pad.</p>
   3176 </div>
   3177 
   3178 <p>Device implementations:</p>
   3179 
   3180 <ul>
   3181   <li>MAY omit a non-touch navigation option (trackball, d-pad, or wheel) if the
   3182 device implementation is not an Android Television device.</li>
   3183   <li>MUST report the correct value for android.content.res.Configuration.navigation
   3184 [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 85</a>].</li>
   3185   <li>MUST provide a reasonable alternative user interface mechanism for the
   3186 selection and editing of text, compatible with Input Management Engines. The
   3187 upstream Android open source implementation includes a selection mechanism
   3188 suitable for use with devices that lack non-touch navigation inputs.</li>
   3189 </ul>
   3190 
   3191 <h3 id="7_2_3_navigation_keys">7.2.3. Navigation Keys</h3>
   3192 
   3193 <div class="note">
   3194 <p>The availability and visibility requirement of the Home, Recents, and Back
   3195 functions differ between device types as described in this section.</p>
   3196 </div>
   3197 
   3198 <p>The Home, Recents, and Back functions (mapped to the key events KEYCODE_HOME,
   3199 KEYCODE_APP_SWITCH, KEYCODE_BACK, respectively) are essential to the Android
   3200 navigation paradigm and therefore:</p>
   3201 
   3202 <ul>
   3203   <li>Android Handheld device implementations MUST provide the Home, Recents, and
   3204 Back functions.</li>
   3205   <li>Android Television device implementations MUST provide the Home and Back
   3206 functions.</li>
   3207   <li>Android Watch device implementations MUST have the Home function available to
   3208 the user, and the Back function except for when it is in UI_MODE_TYPE_WATCH.</li>
   3209   <li>Android Automotive implementations MUST provide the Home function and MAY
   3210 provide Back and Recent functions.</li>
   3211   <li>All other types of device implementations MUST provide the Home and Back
   3212 functions.</li>
   3213 </ul>
   3214 
   3215 <p>These functions MAY be implemented via dedicated physical buttons (such as
   3216 mechanical or capacitive touch buttons), or MAY be implemented using dedicated
   3217 software keys on a distinct portion of the screen, gestures, touch panel, etc.
   3218 Android supports both implementations. All of these functions MUST be
   3219 accessible with a single action (e.g. tap, double-click or gesture) when
   3220 visible.</p>
   3221 
   3222 <p>Recents function, if provided, MUST have a visible button or icon unless hidden
   3223 together with other navigation functions in full-screen mode. This does not
   3224 apply to devices upgrading from earlier Android versions that have physical
   3225 buttons for navigation and no recents key.</p>
   3226 
   3227 <p> The Home and Back functions, if provided, MUST each have a visible button or
   3228 icon unless hidden together with other navigation functions in full-screen mode
   3229 or when the uiMode UI_MODE_TYPE_MASK is set to UI_MODE_TYPE_WATCH.</p>
   3230 
   3231 <p>The Menu function is deprecated in favor of action bar since Android 4.0.
   3232 Therefore the new device implementations shipping with Android 6.0 and later MUST NOT
   3233 implement a dedicated physical button for the Menu function. Older device
   3234 implementations SHOULD NOT implement a dedicated physical button for the Menu
   3235 function, but if the physical Menu button is implemented and the device is
   3236 running applications with targetSdkVersion > 10, the device implementation:</p>
   3237 
   3238 <ul>
   3239   <li>MUST display the action overflow button on the action bar when it is visible
   3240 and the resulting action overflow menu popup is not empty. For a device
   3241 implementation launched before Android 4.4 but upgrading to Android 6.0, this
   3242 is RECOMMENDED.</li>
   3243   <li>MUST NOT modify the position of the action overflow popup displayed by
   3244 selecting the overflow button in the action bar.</li>
   3245   <li>MAY render the action overflow popup at a modified position on the screen when
   3246 it is displayed by selecting the physical menu button.</li>
   3247 </ul>
   3248 
   3249 <p>For backwards compatibility, device implementations MUST make the Menu function
   3250 available to applications when targetSdkVersion is less than 10, either by a physical
   3251 button, a software key, or gestures. This Menu function should be presented
   3252 unless hidden together with other navigation functions.</p>
   3253 
   3254 <p>Android device implementations with the support of the Assist action [<a
   3255 href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">Resources,
   3256 30</a>] MUST make this accessible with a single action (e.g. tap, double-click,
   3257 or gesture) when other navigation keys are visible, and are STRONGLY RECOMMENDED to
   3258 use the long-press on the Home button or software key as the single action.</p>
   3259 
   3260 <p>Device implementations MAY use a distinct portion of the screen to display the
   3261 navigation keys, but if so, MUST meet these requirements:</p>
   3262 
   3263 <ul>
   3264   <li>Device implementation navigation keys MUST use a distinct portion of the
   3265 screen, not available to applications, and MUST NOT obscure or otherwise
   3266 interfere with the portion of the screen available to applications.</li>
   3267   <li>Device implementations MUST make available a portion of the display to
   3268 applications that meets the requirements defined in <a href="#7_1_1_screen_configuration">section 7.1.1</a>.</li>
   3269   <li>Device implementations MUST display the navigation keys when applications do
   3270 not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE.</li>
   3271   <li>Device implementations MUST present the navigation keys in an unobtrusive &ldquo;low
   3272 profile&rdquo; (eg. dimmed) mode when applications specify
   3273 SYSTEM_UI_FLAG_LOW_PROFILE.</li>
   3274   <li>Device implementations MUST hide the navigation keys when applications specify
   3275 SYSTEM_UI_FLAG_HIDE_NAVIGATION.</li>
   3276 </ul>
   3277 
   3278 <h3 id="7_2_4_touchscreen_input">7.2.4. Touchscreen Input</h3>
   3279 
   3280 <div class="note">
   3281 <p>Android Handhelds and Watch Devices MUST support touchscreen input.</p>
   3282 </div>
   3283 
   3284 
   3285 <p>Device implementations SHOULD have a pointer input system of some kind (either
   3286 mouse-like or touch). However, if a device implementation does not support a
   3287 pointer input system, it MUST NOT report the android.hardware.touchscreen or
   3288 android.hardware.faketouch feature constant. Device implementations that do
   3289 include a pointer input system:</p>
   3290 
   3291 <ul>
   3292   <li>SHOULD support fully independently tracked pointers, if the device input system
   3293 supports multiple pointers.</li>
   3294   <li>MUST report the value of android.content.res.Configuration.touchscreen [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 85</a>] corresponding to the type of the specific touchscreen on the device.</li>
   3295 </ul>
   3296 
   3297 <p>Android includes support for a variety of touchscreens, touch pads, and fake
   3298 touch input devices. Touchscreen based device implementations are associated
   3299 with a display [<a href="http://source.android.com/devices/tech/input/touch-devices.html">Resources, 86</a>] such that the user has the impression of directly manipulating items on
   3300 screen. Since the user is directly touching the screen, the system does not
   3301 require any additional affordances to indicate the objects being manipulated.
   3302 In contrast, a fake touch interface provides a user input system that
   3303 approximates a subset of touchscreen capabilities. For example, a mouse or
   3304 remote control that drives an on-screen cursor approximates touch, but requires
   3305 the user to first point or focus then click. Numerous input devices like the
   3306 mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and multi-touch
   3307 trackpad can support fake touch interactions. Android includes the feature
   3308 constant android.hardware.faketouch, which corresponds to a high-fidelity
   3309 non-touch (pointer-based) input device such as a mouse or trackpad that can
   3310 adequately emulate touch-based input (including basic gesture support), and
   3311 indicates that the device supports an emulated subset of touchscreen
   3312 functionality. Device implementations that declare the fake touch feature MUST
   3313 meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p>
   3314 
   3315 <p>Device implementations MUST report the correct feature corresponding to the
   3316 type of input used. Device implementations that include a touchscreen
   3317 (single-touch or better) MUST report the platform feature constant
   3318 android.hardware.touchscreen. Device implementations that report the platform
   3319 feature constant android.hardware.touchscreen MUST also report the platform
   3320 feature constant android.hardware.faketouch. Device implementations that do not
   3321 include a touchscreen (and rely on a pointer device only) MUST NOT report any
   3322 touchscreen feature, and MUST report only android.hardware.faketouch if they
   3323 meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p>
   3324 
   3325 <h3 id="7_2_5_fake_touch_input">7.2.5. Fake Touch Input</h3>
   3326 
   3327 
   3328 <p>Device implementations that declare support for android.hardware.faketouch:</p>
   3329 
   3330 <ul>
   3331   <li>MUST report the absolute X and Y screen positions of the pointer location and
   3332 display a visual pointer on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>].</li>
   3333   <li>MUST report touch event with the action code that specifies the state change
   3334 that occurs on the pointer going down or up on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>].</li>
   3335   <li>MUST support pointer down and up on an object on the screen, which allows users
   3336 to emulate tap on an object on the screen.</li>
   3337   <li>MUST support pointer down, pointer up, pointer down then pointer up in the same
   3338 place on an object on the screen within a time threshold, which allows users to
   3339 emulate double tap on an object on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>].</li>
   3340   <li>MUST support pointer down on an arbitrary point on the screen, pointer move to
   3341 any other arbitrary point on the screen, followed by a pointer up, which allows
   3342 users to emulate a touch drag.</li>
   3343   <li>MUST support pointer down then allow users to quickly move the object to a
   3344 different position on the screen and then pointer up on the screen, which
   3345 allows users to fling an object on the screen.</li>
   3346 </ul>
   3347 
   3348 <p>Devices that declare support for android.hardware.faketouch.multitouch.distinct
   3349 MUST meet the requirements for faketouch above, and MUST also support distinct
   3350 tracking of two or more independent pointer inputs.</p>
   3351 
   3352 <h3 id="7_2_6_game_controller_support">7.2.6. Game Controller Support</h3>
   3353 
   3354 
   3355 <p>Android Television device implementations MUST support button mappings for game
   3356 controllers as listed below. The upstream Android implementation includes
   3357 implementation for game controllers that satisfies this requirement. </p>
   3358 
   3359 <h4 id="7_2_6_1_button_mappings">7.2.6.1. Button Mappings</h4>
   3360 
   3361 
   3362 <p>Android Television device implementations MUST support the following key
   3363 mappings:</p>
   3364 <table>
   3365  <tr>
   3366     <th>Button</th>
   3367     <th>HID Usage<sup>2</sup></th>
   3368     <th>Android Button</th>
   3369  </tr>
   3370  <tr>
   3371     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_A">A</a><sup>1</sup></td>
   3372     <td>0x09 0x0001</td>
   3373     <td>KEYCODE_BUTTON_A (96)</td>
   3374  </tr>
   3375  <tr>
   3376     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_B">B</a><sup>1</sup></td>
   3377     <td>0x09 0x0002</td>
   3378     <td>KEYCODE_BUTTON_B (97)</td>
   3379  </tr>
   3380  <tr>
   3381     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_X">X</a><sup>1</sup></td>
   3382     <td>0x09 0x0004</td>
   3383     <td>KEYCODE_BUTTON_X (99)</td>
   3384  </tr>
   3385  <tr>
   3386     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_Y">Y</a><sup>1</sup></td>
   3387     <td>0x09 0x0005</td>
   3388     <td>KEYCODE_BUTTON_Y (100)</td>
   3389  </tr>
   3390  <tr>
   3391     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_UP">D-pad up</a><sup>1</sup><br />
   3392 
   3393 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_DOWN">D-pad down</a><sup>1</sup></td>
   3394     <td>0x01 0x0039<sup>3</sup></td>
   3395     <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_Y">AXIS_HAT_Y</a><sup>4</sup></td>
   3396  </tr>
   3397  <tr>
   3398     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_LEFT">D-pad left</a>1<br />
   3399 
   3400 <a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_RIGHT">D-pad right</a><sup>1</sup></td>
   3401     <td>0x01 0x0039<sup>3</sup></td>
   3402     <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_X">AXIS_HAT_X</a><sup>4</sup></td>
   3403  </tr>
   3404  <tr>
   3405     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_L1">Left shoulder button</a><sup>1</sup></td>
   3406     <td>0x09 0x0007</td>
   3407     <td>KEYCODE_BUTTON_L1 (102)</td>
   3408  </tr>
   3409  <tr>
   3410     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_R1">Right shoulder button</a><sup>1</sup></td>
   3411     <td>0x09 0x0008</td>
   3412     <td>KEYCODE_BUTTON_R1 (103)</td>
   3413  </tr>
   3414  <tr>
   3415     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBL">Left stick click</a><sup>1</sup></td>
   3416     <td>0x09 0x000E</td>
   3417     <td>KEYCODE_BUTTON_THUMBL (106)</td>
   3418  </tr>
   3419  <tr>
   3420     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBR">Right stick click</a><sup>1</sup></td>
   3421     <td>0x09 0x000F</td>
   3422     <td>KEYCODE_BUTTON_THUMBR (107)</td>
   3423  </tr>
   3424  <tr>
   3425     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_HOME">Home</a><sup>1</sup></td>
   3426     <td>0x0c 0x0223</td>
   3427     <td>KEYCODE_HOME (3)</td>
   3428  </tr>
   3429  <tr>
   3430     <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BACK">Back</a><sup>1</sup></td>
   3431     <td>0x0c 0x0224</td>
   3432     <td>KEYCODE_BACK (4)</td>
   3433  </tr>
   3434 </table>
   3435 
   3436 
   3437 <p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 88</a>]</p>
   3438 
   3439 <p class="table_footnote">2 The above HID usages must be declared within a Game pad CA (0x01 0x0005).</p>
   3440 
   3441 <p class="table_footnote">3 This usage must have a Logical Minimum of 0, a Logical Maximum of 7, a
   3442 Physical Minimum of 0, a Physical Maximum of 315, Units in Degrees, and a
   3443 Report Size of 4. The logical value is defined to be the clockwise rotation
   3444 away from the vertical axis; for example, a logical value of 0 represents no
   3445 rotation and the up button being pressed, while a logical value of 1 represents
   3446 a rotation of 45 degrees and both the up and left keys being pressed.</p>
   3447 
   3448 <p class="table_footnote">4 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>]</p>
   3449 
   3450 <table>
   3451  <tr>
   3452     <th>Analog Controls<sup>1</sup></th>
   3453     <th>HID Usage</th>
   3454     <th>Android Button</th>
   3455  </tr>
   3456  <tr>
   3457     <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_LTRIGGER">Left Trigger</a></td>
   3458     <td>0x02 0x00C5</td>
   3459     <td>AXIS_LTRIGGER </td>
   3460  </tr>
   3461  <tr>
   3462     <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_THROTTLE">Right Trigger</a></td>
   3463     <td>0x02 0x00C4</td>
   3464     <td>AXIS_RTRIGGER </td>
   3465  </tr>
   3466  <tr>
   3467     <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Y">Left Joystick</a></td>
   3468     <td>0x01 0x0030<br />
   3469 
   3470 0x01 0x0031</td>
   3471     <td>AXIS_X<br />
   3472 
   3473 AXIS_Y</td>
   3474  </tr>
   3475  <tr>
   3476     <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Z">Right Joystick</a></td>
   3477     <td>0x01 0x0032<br />
   3478 
   3479 0x01 0x0035</td>
   3480     <td>AXIS_Z<br />
   3481 
   3482 AXIS_RZ</td>
   3483  </tr>
   3484 </table>
   3485 
   3486 
   3487 <p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 87</a>]</p>
   3488 
   3489 <h3 id="7_2_7_remote_control">7.2.7. Remote Control</h3>
   3490 
   3491 
   3492 <p>Android Television device implementations SHOULD provide a remote control to
   3493 allow users to access the TV interface. The remote control MAY be a physical
   3494 remote or can be a software-based remote that is accessible from a mobile phone
   3495 or tablet. The remote control MUST meet the requirements defined below.</p>
   3496 
   3497 <ul>
   3498   <li><strong>Search affordance</strong>. Device implementations MUST fire KEYCODE_SEARCH when the user invokes voice search either on the physical or software-based remote.</li>
   3499   <li><strong>Navigation</strong>. All Android Television remotes MUST include Back, Home, and Select buttons and
   3500 support for D-pad events [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 88</a>].</li>
   3501 </ul>
   3502 
   3503 <h2 id="7_3_sensors">7.3. Sensors</h2>
   3504 
   3505 
   3506 <p>Android includes APIs for accessing a variety of sensor types. Devices
   3507 implementations generally MAY omit these sensors, as provided for in the
   3508 following subsections. If a device includes a particular sensor type that has a
   3509 corresponding API for third-party developers, the device implementation MUST
   3510 implement that API as described in the Android SDK documentation and the
   3511 Android Open Source documentation on sensors [<a href="http://source.android.com/devices/sensors/">Resources, 89</a>]. For example, device implementations:</p>
   3512 
   3513 <ul>
   3514   <li>MUST accurately report the presence or absence of sensors per the
   3515 android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70]</a>.</li>
   3516   <li>MUST return an accurate list of supported sensors via the
   3517 SensorManager.getSensorList() and similar methods.</li>
   3518   <li>MUST behave reasonably for all other sensor APIs (for example, by returning
   3519 true or false as appropriate when applications attempt to register listeners,
   3520 not calling sensor listeners when the corresponding sensors are not present;
   3521 etc.).</li>
   3522   <li>MUST report all sensor measurements using the relevant International System of
   3523 Units (metric) values for each sensor type as defined in the Android SDK
   3524 documentation [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 90</a>].</li>
   3525   <li>SHOULD report the event time in nanoseconds as defined in the Android SDK
   3526 documentation, representing the time the event happened and synchronized with
   3527 the SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices
   3528 are <strong>STRONGLY RECOMMENDED</strong> to meet these requirement so they will be able to upgrade to the future
   3529 platform releases where this might become a REQUIRED component. The
   3530 synchronization error SHOULD be below 100 milliseconds [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">Resources, 91</a>].</li>
   3531   <li>MUST report sensor data with a maximum latency of 100 milliseconds + 2 * sample_time for the case of a sensor streamed
   3532     with a minimum required latency of 5 ms + 2 * sample_time when the application processor is active. This delay does not include any filtering delays.</li>
   3533   <li>MUST report the first sensor sample within 400 milliseconds + 2 * sample_time of the sensor being activated. It is acceptable for this sample to have an accuracy of 0.</li>
   3534 </ul>
   3535 
   3536 <p>The list above is not comprehensive; the documented behavior of the Android SDK
   3537 and the Android Open Source Documentations on Sensors [<a href="http://source.android.com/devices/sensors/">Resources, 89</a>] is to be considered authoritative.</p>
   3538 
   3539 <p>Some sensor types are composite, meaning they can be derived from data provided
   3540 by one or more other sensors. (Examples include the orientation sensor, and the
   3541 linear acceleration sensor.) Device implementations SHOULD implement these
   3542 sensor types, when they include the prerequisite physical sensors as described
   3543 in [<a href="https://source.android.com/devices/sensors/sensor-types.html">Resources, 92</a>].
   3544 If a device implementation includes a composite sensor it MUST implement the
   3545 sensor as described in the Android Open Source documentation on composite
   3546 sensors [<a href="https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">Resources, 92</a>].</p>
   3547 
   3548 <p>Some Android sensors support a &ldquo;continuous&rdquo; trigger mode, which returns data
   3549 continuously [<a href="https://source.android.com/devices/sensors/report-modes.html#continuous">Resources, 93</a>]. For any API indicated by the Android SDK documentation to be a continuous
   3550 sensor, device implementations MUST continuously provide periodic data samples
   3551 that SHOULD have a jitter below 3%, where jitter is defined as the standard
   3552 deviation of the difference of the reported timestamp values between
   3553 consecutive events.</p>
   3554 
   3555 <p>Note that the device implementations MUST ensure that the sensor event stream
   3556 MUST NOT prevent the device CPU from entering a suspend state or waking up from
   3557 a suspend state.</p>
   3558 
   3559 <p>Finally, when several sensors are activated, the power consumption SHOULD NOT
   3560 exceed the sum of the individual sensor&rsquo;s reported power consumption.</p>
   3561 
   3562 <h3 id="7_3_1_accelerometer">7.3.1. Accelerometer</h3>
   3563 
   3564 
   3565 <p>Device implementations SHOULD include a 3-axis accelerometer. Android Handheld
   3566 devices and Android Watch devices are STRONGLY RECOMMENDED to include this
   3567 sensor. If a device implementation does include a 3-axis accelerometer, it:</p>
   3568 
   3569 <ul>
   3570   <li>MUST implement and report TYPE_ACCELEROMETER sensor [<a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER">Resources, 94</a>].</li>
   3571   <li>MUST be able to report events up to a frequency of at least 50 Hz for
   3572   Android Watch devices as such devices have a stricter power constraint and
   3573   100 Hz for all other device types.</li>
   3574   <li>SHOULD report events up to at least 200 Hz.</li>
   3575   <li>MUST comply with the Android sensor coordinate system as detailed in the
   3576 Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 90</a>].</li>
   3577   <li>MUST be capable of measuring from freefall up to four times the gravity (4g) or
   3578 more on any axis.</li>
   3579   <li>MUST have a resolution of at least 12-bits and SHOULD have a resolution of at
   3580 least 16-bits.</li>
   3581   <li>SHOULD be calibrated while in use if the characteristics changes over the life
   3582 cycle and compensated, and preserve the compensation parameters between device
   3583 reboots.</li>
   3584   <li>SHOULD be temperature compensated.</li>
   3585   <li>MUST have a standard deviation no greater than 0.05 m/s^, where the standard
   3586 deviation should be calculated on a per axis basis on samples collected over a
   3587 period of at least 3 seconds at the fastest sampling rate.</li>
   3588   <li>SHOULD implement the TYPE_SIGNIFICANT_MOTION, TYPE_TILT_DETECTOR,
   3589 TYPE_STEP_DETECTOR, TYPE_STEP_COUNTER composite sensors as described in the
   3590 Android SDK document. Existing and new Android devices are <strong>STRONGLY RECOMMENDED</strong> to implement the TYPE_SIGNIFICANT_MOTION composite sensor. If any of these
   3591 sensors are implemented, the sum of their power consumption MUST always be less
   3592 than 4 mW and SHOULD each be below 2 mW and 0.5 mW for when the device is in a
   3593 dynamic or static condition.</li>
   3594   <li>If a gyroscope sensor is included, MUST implement the TYPE_GRAVITY and
   3595 TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the
   3596 TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices
   3597 are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li>
   3598   <li>MUST implement a TYPE_ROTATION_VECTOR composite sensor, if a gyroscope sensor
   3599 and a magnetometer sensor is also included.</li>
   3600 </ul>
   3601 
   3602 <h3 id="7_3_2_magnetometer">7.3.2. Magnetometer</h3>
   3603 
   3604 
   3605 <p>Device implementations SHOULD include a 3-axis magnetometer (compass). If a
   3606 device does include a 3-axis magnetometer, it:</p>
   3607 
   3608 <ul>
   3609   <li>MUST implement the TYPE_MAGNETIC_FIELD sensor and SHOULD also implement
   3610 TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. Existing and new Android devices are
   3611 STRONGLY RECOMMENDED to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.</li>
   3612   <li>MUST be able to report events up to a frequency of at least 10 Hz and SHOULD
   3613 report events up to at least 50 Hz.</li>
   3614   <li>MUST comply with the Android sensor coordinate system as detailed in the
   3615 Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 90</a>].</li>
   3616   <li>MUST be capable of measuring between -900 &micro;T and +900 &micro;T on each axis before
   3617 saturating.</li>
   3618   <li>MUST have a hard iron offset value less than 700 &micro;T and SHOULD have a value
   3619 below 200 &micro;T, by placing the magnetometer far from dynamic (current-induced)
   3620 and static (magnet-induced) magnetic fields.</li>
   3621   <li>MUST have a resolution equal or denser than 0.6 &micro;T and SHOULD have a resolution
   3622 equal or denser than 0.2 &micro;.</li>
   3623   <li>SHOULD be temperature compensated.</li>
   3624   <li>MUST support online calibration and compensation of the hard iron bias, and
   3625 preserve the compensation parameters between device reboots.</li>
   3626   <li>MUST have the soft iron compensation applied&mdash;the calibration can be done either
   3627 while in use or during the production of the device.</li>
   3628   <li>SHOULD have a standard deviation, calculated on a per axis basis on samples
   3629 collected over a period of at least 3 seconds at the fastest sampling rate, no
   3630 greater than 0.5 &micro;T.</li>
   3631   <li>MUST implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer
   3632 sensor and a gyroscope sensor is also included.</li>
   3633   <li>MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor if an accelerometer
   3634 sensor is also implemented. However if implemented, it MUST consume less than
   3635 10 mW and SHOULD consume less than 3 mW when the sensor is registered for batch
   3636 mode at 10 Hz.</li>
   3637 </ul>
   3638 
   3639 <h3 id="7_3_3_gps">7.3.3. GPS</h3>
   3640 
   3641 
   3642 <p>Device implementations SHOULD include a GPS receiver. If a device
   3643 implementation does include a GPS receiver, it SHOULD include some form of&ldquo;assisted GPS&rdquo; technique to minimize GPS lock-on time.</p>
   3644 
   3645 <h3 id="7_3_4_gyroscope">7.3.4. Gyroscope</h3>
   3646 
   3647 
   3648 <p>Device implementations SHOULD include a gyroscope (angular change sensor).
   3649 Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is
   3650 also included. If a device implementation includes a gyroscope, it:</p>
   3651 
   3652 <ul>
   3653   <li>MUST implement the TYPE_GYROSCOPE sensor and SHOULD also implement
   3654 TYPE_GYROSCOPE_UNCALIBRATED sensor. Existing and new Android devices are
   3655 STRONGLY RECOMMENDED to implement the SENSOR_TYPE_GYROSCOPE_UNCALIBRATED sensor.</li>
   3656   <li>MUST be capable of measuring orientation changes up to 1,000 degrees per second.</li>
   3657   <li>MUST be able to report events up to a frequency of at least 50 Hz for
   3658   Android Watch devices as such devices have a stricter power constraint and 
   3659   100 Hz for all other device types.</li>
   3660   <li>SHOULD report events up to at least 200 Hz.</li>
   3661   <li>MUST have a resolution of 12-bits or more and SHOULD have a resolution of
   3662 16-bits or more.</li>
   3663   <li>MUST be temperature compensated.</li>
   3664   <li>MUST be calibrated and compensated while in use, and preserve the compensation
   3665 parameters between device reboots.</li>
   3666   <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz,
   3667 or rad^2 / s). The variance is allowed to vary with the sampling rate, but must
   3668 be constrained by this value. In other words, if you measure the variance of
   3669 the gyro at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2.</li>
   3670   <li>MUST implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer
   3671 sensor and a magnetometer sensor is also included.</li>
   3672   <li>If an accelerometer sensor is included, MUST implement the TYPE_GRAVITY and
   3673 TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the
   3674 TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices
   3675 are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li>
   3676 </ul>
   3677 
   3678 <h3 id="7_3_5_barometer">7.3.5. Barometer</h3>
   3679 
   3680 
   3681 <p>Device implementations SHOULD include a barometer (ambient air pressure
   3682 sensor). If a device implementation includes a barometer, it:</p>
   3683 
   3684 <ul>
   3685   <li>MUST implement and report TYPE_PRESSURE sensor.</li>
   3686   <li>MUST be able to deliver events at 5 Hz or greater.</li>
   3687   <li>MUST have adequate precision to enable estimating altitude.</li>
   3688   <li>MUST be temperature compensated.</li>
   3689 </ul>
   3690 
   3691 <h3 id="7_3_6_thermometer">7.3.6. Thermometer</h3>
   3692 
   3693 
   3694 <p>Device implementations MAY include an ambient thermometer (temperature sensor).
   3695 If present, it MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and it MUST
   3696 measure the ambient (room) temperature in degrees Celsius.</p>
   3697 
   3698 <p>Device implementations MAY but SHOULD NOT include a CPU temperature sensor. If
   3699 present, it MUST be defined as SENSOR_TYPE_TEMPERATURE, it MUST measure the
   3700 temperature of the device CPU, and it MUST NOT measure any other temperature.
   3701 Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0.</p>
   3702 
   3703 <h3 id="7_3_7_photometer">7.3.7. Photometer</h3>
   3704 
   3705 
   3706 <p>Device implementations MAY include a photometer (ambient light sensor).</p>
   3707 
   3708 <h3 id="7_3_8_proximity_sensor">7.3.8. Proximity Sensor</h3>
   3709 
   3710 
   3711 <p>Device implementations MAY include a proximity sensor. Devices that can make a
   3712 voice call and indicate any value other than PHONE_TYPE_NONE in getPhoneType
   3713 SHOULD include a proximity sensor. If a device implementation does include a
   3714 proximity sensor, it:</p>
   3715 
   3716 <ul>
   3717   <li>MUST measure the proximity of an object in the same direction as the screen.
   3718 That is, the proximity sensor MUST be oriented to detect objects close to the
   3719 screen, as the primary intent of this sensor type is to detect a phone in use
   3720 by the user. If a device implementation includes a proximity sensor with any
   3721 other orientation, it MUST NOT be accessible through this API.</li>
   3722   <li>MUST have 1-bit of accuracy or more.</li>
   3723 </ul>
   3724 
   3725 
   3726 <h3 id="7_3_9_hifi_sensors">7.3.9. High Fidelity Sensors</h3>
   3727 
   3728 <p>Device implementations supporting a set of higher quality sensors that can meet all
   3729 the requirements listed in this section MUST identify the support through the
   3730 <code>android.hardware.sensor.hifi_sensors</code> feature flag.</p>
   3731 
   3732 <p>A device declaring android.hardware.sensor.hifi_sensors MUST support all of the following
   3733 sensor types meeting the quality requirements as below:</p>
   3734 
   3735 <ul>
   3736   <li>SENSOR_TYPE_ACCELEROMETER
   3737   <ul>
   3738     <li>MUST have a measurement range between at least -8g and +8g</li>
   3739     <li>MUST have a measurement resolution of at least 1024 LSB/G</li>
   3740     <li>MUST have a minimum measurement frequency of 12.5 Hz or lower</li>
   3741     <li>MUST have a maxmium measurement frequency of 200 Hz or higher</li>
   3742     <li>MUST have a measurement noise not above 400uG/&radic;Hz</li>
   3743     <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 3000 sensor events</li>
   3744     <li>MUST have a batching power consumption not worse than 3 mW</li>
   3745   </ul>
   3746   </li>
   3747   <li>SENSOR_TYPE_GYROSCOPE
   3748   <ul>
   3749     <li>MUST have a measurement range between at least -1000 and +1000 dps</li>
   3750     <li>MUST have a measurement resolution of at least 16 LSB/dps</li>
   3751     <li>MUST have a minimum measurement frequency of 12.5 Hz or lower</li>
   3752     <li>MUST have a maxmium measurement frequency of 200 Hz or higher</li>
   3753     <li>MUST have a measurement noise not above 0.014&deg;/s/&radic;Hz</li>
   3754   </ul>
   3755   </li>
   3756   <li>SENSOR_TYPE_GYROSCOPE_UNCALIBRATED with the same quality requirements as
   3757     SENSOR_TYPE_GYROSCOPE</li>
   3758   <li>SENSOR_TYPE_GEOMAGNETIC_FIELD
   3759   <ul>
   3760     <li>MUST have a measurement range between at least -900 and +900 uT</li>
   3761     <li>MUST have a measurement resolution of at least 5 LSB/uT</li>
   3762     <li>MUST have a minimum measurement frequency of 5 Hz or lower</li>
   3763     <li>MUST have a maxmium measurement frequency of 50 Hz or higher</li>
   3764     <li>MUST have a measurement noise not above 0.5 uT</li>
   3765   </ul>
   3766   </li>
   3767   <li>SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED with the same quality requirements as
   3768     SENSOR_TYPE_GEOMAGNETIC_FIELD and in addition:
   3769   <ul>
   3770     <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 600 sensor events</li>
   3771   </ul>
   3772   </li>
   3773   <li>SENSOR_TYPE_PRESSURE
   3774   <ul>
   3775     <li>MUST have a measurement range between at least 300 and 1100 hPa</li>
   3776     <li>MUST have a measurement resolution of at least 80 LSB/hPa</li>
   3777     <li>MUST have a minimum measurement frequency of 1 Hz or lower</li>
   3778     <li>MUST have a maximum measurement frequency of 10 Hz or higher</li>
   3779     <li>MUST have a measurement noise not above 2 Pa/&radic;Hz</li>
   3780     <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 300 sensor events</li>
   3781     <li>MUST have a batching power consumption not worse than 2 mW</li>
   3782   </ul>
   3783   </li>
   3784   <li>SENSOR_TYPE_ROTATION_VECTOR
   3785   <ul>
   3786     <li>MUST have a batching power consumption not worse than 4 mW</li>
   3787   </ul>
   3788   </li>
   3789   <li>SENSOR_TYPE_GAME_ROTATION_VECTOR MUST implement a non-wake-up form of this sensor with a buffering capability of at least 300 sensor events</li>
   3790   <li>SENSOR_TYPE_SIGNIFICANT_MOTION
   3791   <ul>
   3792     <li>MUST have a power consumption not worse than 0.5 mW when device is static
   3793       and 1.5 mW when device is moving</li>
   3794   </ul>
   3795   </li>
   3796   <li>SENSOR_TYPE_STEP_DETECTOR
   3797   <ul>
   3798     <li>MUST implement a non-wake-up form of this sensor with a buffering capability of at least 100 sensor events</li>
   3799     <li>MUST have a power consumption not worse than 0.5 mW when device is static
   3800       and 1.5 mW when device is moving</li>
   3801     <li>MUST have a batching power consumption not worse than 4 mW</li>
   3802   </ul>
   3803   </li>
   3804   <li>SENSOR_TYPE_STEP_COUNTER
   3805   <ul>
   3806     <li>MUST have a power consumption not worse than 0.5 mW when device is static
   3807       and 1.5 mW when device is moving</li>
   3808   </ul>
   3809   </li>
   3810   <li>SENSOR_TILT_DETECTOR
   3811   <ul>
   3812     <li>MUST have a power consumption not worse than 0.5 mW when device is static
   3813       and 1.5 mW when device is moving</li>
   3814   </ul>
   3815   </li>
   3816 </ul>
   3817 
   3818 <p>Also such a device MUST meet the following sensor subsystem requirements:</p>
   3819 
   3820 <ul>
   3821   <li>The event timestamp of the same physical event reported by the Accelerometer, Gyroscope
   3822     sensor and Magnetometer MUST be within 2.5 milliseconds of each other.</li>
   3823   <li>The Gyroscope sensor event timestamps MUST be on the same time base as the camera
   3824     subsystem and within 1 millisconds of error.</li>
   3825   <li>The latency of delivery of samples to the HAL SHOULD be below 5 milliseconds from
   3826     the instant the data is available on the physical sensor hardware.</li>
   3827   <li>The power consumption MUST not be higher than 0.5 mW when device is static and 2.0 mW
   3828     when device is moving when any combination of the following sensors are enabled:
   3829   <ul>
   3830     <li>SENSOR_TYPE_SIGNIFICANT_MOTION</li>
   3831     <li>SENSOR_TYPE_STEP_DETECTOR</li>
   3832     <li>SENSOR_TYPE_STEP_COUNTER</li>
   3833     <li>SENSOR_TILT_DETECTORS</li>
   3834   </ul>
   3835   </li>
   3836 </ul>
   3837 
   3838 <p>Note that all power consumption requirements in this section do not include the power
   3839   consumption of the Application Processor. It is inclusive of the power drawn by the entire
   3840   sensor chain - the sensor, any supporting circuitry, any dedicated sensor processing system,
   3841   etc.</p>
   3842 
   3843 <p>The following sensor types MAY also be supported on a device implementation declaring
   3844   android.hardware.sensor.hifi_sensors, but if these sensor types are present they MUST meet the
   3845   following minimum buffering capability requirement:</p>
   3846 
   3847 <ul>
   3848   <li>SENSOR_TYPE_PROXIMITY: 100 sensor events</li>
   3849 </ul>
   3850 
   3851 <h3 id="7_3_10_fingeprint">7.3.10. Fingerprint Sensor</h3>
   3852 
   3853 <p>Device implementations with a secure lock screen SHOULD include a fingerprint sensor.
   3854 If a device implementation includes a fingerprint sensor and has a corresponding API for
   3855 third-party developers, it:</p>
   3856 
   3857 <ul>
   3858   <li>MUST declare support for the android.hardware.fingerprint feature.</li>
   3859   <li>MUST fully implement the corresponding API as described in the Android SDK documentation
   3860 [<a href="https://developer.android.com/reference/android/hardware/fingerprint/package-summary.html">Resources, 95</a>].
   3861   </li>
   3862   <li>MUST have a false acceptance rate not higher than 0.002%.</li>
   3863   <li>Is STRONGLY RECOMMENDED to have a false rejection rate of less than 10%, as measured
   3864     on the device</li>
   3865   <li>Is STRONGLY RECOMMENDED to have a latency below 1 second, measured from when the fingerprint
   3866 sensor is touched until the screen is unlocked, for one enrolled finger.</li>
   3867   <li>MUST rate limit attempts for at least 30 seconds after five false trials for fingerprint
   3868     verification.</li>
   3869   <li>MUST have a hardware-backed keystore implementation, and perform the fingerprint matching
   3870     in a Trusted Execution Environment (TEE) or on a chip with a secure channel to the TEE.
   3871   </li>
   3872   <li>MUST have all identifiable fingerprint data encrypted and cryptographically
   3873     authenticated such that they cannot be acquired, read or altered outside of the
   3874     Trusted Execution Environment (TEE) as documented in the implementation guidelines
   3875     on the Android Open Source Project site
   3876     [<a href="https://source.android.com/devices/tech/security/authentication/fingerprint-hal.html">Resources, 96</a>].
   3877   </li>
   3878   <li>MUST prevent adding a fingerprint without first establishing a chain of trust by
   3879     having the user confirm existing or add a new device credential (PIN/pattern/password)
   3880     using the TEE as implemented in the Android Open Source project.</li>
   3881   <li>MUST NOT enable 3rd-party applications to distinguish between individual fingerprints.
   3882   </li>
   3883   <li>MUST honor the DevicePolicyManager.KEYGUARD_DISABLE_FINGERPRINT flag.</li>
   3884   <li>MUST, when upgraded from a version earlier than Android 6.0, have the fingerprint
   3885     data securely migrated to meet the above requirements or removed.</li>
   3886   <li>SHOULD use the Android Fingerprint icon provided in the Android Open Source Project.</li>
   3887 </ul>
   3888 
   3889 <h2 id="7_4_data_connectivity">7.4. Data Connectivity</h2>
   3890 
   3891 
   3892 <h3 id="7_4_1_telephony">7.4.1. Telephony</h3>
   3893 
   3894 
   3895 <p>&ldquo;Telephony&rdquo; as used by the Android APIs and this document refers specifically
   3896 to hardware related to placing voice calls and sending SMS messages via a GSM
   3897 or CDMA network. While these voice calls may or may not be packet-switched,
   3898 they are for the purposes of Android considered independent of any data
   3899 connectivity that may be implemented using the same network. In other words,
   3900 the Android &ldquo;telephony&rdquo; functionality and APIs refer specifically to voice
   3901 calls and SMS. For instance, device implementations that cannot place calls or
   3902 send/receive SMS messages MUST NOT report the android.hardware.telephony
   3903 feature or any subfeatures, regardless of whether they use a cellular network
   3904 for data connectivity.</p>
   3905 
   3906 <p>Android MAY be used on devices that do not include telephony hardware. That is,
   3907 Android is compatible with devices that are not phones. However, if a device
   3908 implementation does include GSM or CDMA telephony, it MUST implement full
   3909 support for the API for that technology. Device implementations that do not
   3910 include telephony hardware MUST implement the full APIs as no-ops.</p>
   3911 
   3912 <h3 id="7_4_2_ieee_802_11_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</h3>
   3913 
   3914 <div class="note">
   3915 <p>Android Television device implementations MUST include Wi-Fi support.</p>
   3916 </div>
   3917 
   3918 
   3919 <p>Android Television device implementations MUST include support for one or more
   3920 forms of 802.11 (b/g/a/n, etc.) and other types of Android device
   3921 implementation SHOULD include support for one or more forms of 802.11. If a
   3922 device implementation does include support for 802.11 and exposes the
   3923 functionality to a third-party application, it MUST implement the corresponding
   3924 Android API and:</p>
   3925 
   3926 <ul>
   3927   <li>MUST report the hardware feature flag android.hardware.wifi.</li>
   3928   <li>MUST implement the multicast API as described in the SDK documentation [<a href="http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html">Resources, 97</a>].</li>
   3929   <li>MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets
   3930 (224.0.0.251) at any time of operation including:
   3931     <ul>
   3932       <li>Even when the screen is not in an active state.</li>
   3933       <li>For Android Television device implementations, even when in standby power states.</li>
   3934     </ul>
   3935 </ul>
   3936 
   3937 <h4 id="7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</h4>
   3938 
   3939 
   3940 <p>Device implementations SHOULD include support for Wi-Fi Direct (Wi-Fi
   3941 peer-to-peer). If a device implementation does include support for Wi-Fi
   3942 Direct, it MUST implement the corresponding Android API as described in the SDK
   3943 documentation [<a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">Resources, 98</a>]. If a device implementation includes support for Wi-Fi Direct, then it:</p>
   3944 
   3945 <ul>
   3946   <li>MUST report the hardware feature android.hardware.wifi.direct.</li>
   3947   <li>MUST support regular Wi-Fi operation.</li>
   3948   <li>SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation.</li>
   3949 </ul>
   3950 
   3951 <h4 id="7_4_2_2_wi-fi_tunneled_direct_link_setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</h4>
   3952 
   3953 <div class="note">
   3954 <p>Android Television device implementations MUST include support for Wi-Fi
   3955 Tunneled Direct Link Setup (TDLS).</p>
   3956 </div>
   3957 
   3958 
   3959 <p>Android Television device implementations MUST include support for Wi-Fi
   3960 Tunneled Direct Link Setup (TDLS) and other types of Android device
   3961 implementations SHOULD include support for Wi-Fi TDLS as described in the
   3962 Android SDK Documentation [<a href="http://developer.android.com/reference/android/net/wifi/WifiManager.html">Resources, 99</a>]. If a device implementation does include support for TDLS and TDLS is enabled
   3963 by the WiFiManager API, the device:</p>
   3964 
   3965 <ul>
   3966   <li>SHOULD use TDLS only when it is possible AND beneficial.</li>
   3967   <li>SHOULD have some heuristic and NOT use TDLS when its performance might be worse
   3968 than going through the Wi-Fi access point.</li>
   3969 </ul>
   3970 
   3971 <h3 id="7_4_3_bluetooth">7.4.3. Bluetooth</h3>
   3972 
   3973 <div class="note">
   3974 <p>Android Watch and Automotive implementations MUST support Bluetooth. Android
   3975 Television implementations MUST support Bluetooth and Bluetooth LE.</p>
   3976 </div>
   3977 
   3978 
   3979 <p>Android includes support for Bluetooth and Bluetooth Low Energy [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 100</a>]. Device implementations that include support for Bluetooth and Bluetooth Low
   3980 Energy MUST declare the relevant platform features (android.hardware.bluetooth
   3981 and android.hardware.bluetooth_le respectively) and implement the platform
   3982 APIs. Device implementations SHOULD implement relevant Bluetooth profiles such
   3983 as A2DP, AVCP, OBEX, etc. as appropriate for the device. Android Television
   3984 device implementations MUST support Bluetooth and Bluetooth LE. </p>
   3985 
   3986 <p>Device implementations including support for Bluetooth Low Energy:</p>
   3987 
   3988 <ul>
   3989   <li>MUST declare the hardware feature android.hardware.bluetooth_le.</li>
   3990   <li>MUST enable the GATT (generic attribute profile) based Bluetooth APIs as
   3991 described in the SDK documentation and [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 100</a>].</li>
   3992   <li>are STRONGLY RECOMMMENDED to implement a Resolvable Private Address (RPA)
   3993 timeout no longer than 15 minutes and rotate the address at timeout to protect
   3994 user privacy.</li>
   3995   <li>SHOULD support offloading of the filtering logic to the bluetooth chipset when
   3996 implementing the ScanFilter API [<a href="https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html">Resources, 101</a>], and MUST report the correct value of where the filtering logic is implemented whenever queried via the
   3997 android.bluetooth.BluetoothAdapter.isOffloadedFilteringSupported() method.</li>
   3998   <li>SHOULD support offloading of the batched scanning to the bluetooth chipset, but
   3999 if not supported, MUST report &lsquo;false&rsquo; whenever queried via the
   4000 android.bluetooth.BluetoothAdapater.isOffloadedScanBatchingSupported() method.</li>
   4001   <li>SHOULD support multi advertisement with at least 4 slots, but if not supported,
   4002 MUST report &lsquo;false&rsquo; whenever queried via the
   4003 android.bluetooth.BluetoothAdapter.isMultipleAdvertisementSupported() method.</li>
   4004 </ul>
   4005 
   4006 <h3 id="7_4_4_near-field_communications">7.4.4. Near-Field Communications</h3>
   4007 
   4008 
   4009 <p>Device implementations SHOULD include a transceiver and related hardware for
   4010 Near-Field Communications (NFC). If a device implementation does include NFC
   4011 hardware and plans to make it available to third-party apps, then it:</p>
   4012 
   4013 <ul>
   4014   <li>MUST report the android.hardware.nfc feature from the
   4015 android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>].</li>
   4016   <li>MUST be capable of reading and writing NDEF messages via the following NFC
   4017 standards:
   4018   <ul>
   4019     <li>MUST be capable of acting as an NFC Forum reader/writer (as defined by the NFC
   4020 Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the
   4021 following NFC standards:
   4022     <ul>
   4023       <li>NfcA (ISO14443-3A)</li>
   4024       <li>NfcB (ISO14443-3B)</li>
   4025       <li>NfcF (JIS X 6319-4)</li>
   4026       <li>IsoDep (ISO 14443-4)</li>
   4027       <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li>
   4028     </ul>
   4029   <li>STRONGLY RECOMMENDED to be capable of reading and writing NDEF messages as well
   4030       as raw data via the following NFC standards. Note that while the NFC standards
   4031       below are stated as STRONGLY RECOMMENDED, the Compatibility Definition for a
   4032       future version is planned to change these to MUST. These standards are optional
   4033       in this version but will be required in future versions. Existing and new devices
   4034       that run this version of Android are very strongly encouraged to meet these
   4035       requirements now so they will be able to upgrade to the future platform releases.
   4036   <ul>
   4037     <li>NfcV (ISO 15693)</li>
   4038   </ul></li>
   4039   <li>SHOULD be capable of reading the barcode and URL (if encoded) of
   4040       Thinfilm NFC Barcode
   4041       [<a href="http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html">Resources, 102</a>] products.
   4042   </li>
   4043   <li>MUST be capable of transmitting and receiving data via the following
   4044 peer-to-peer standards and protocols:
   4045   <ul>
   4046     <li>ISO 18092</li>
   4047     <li>LLCP 1.2 (defined by the NFC Forum)</li>
   4048     <li>SDP 1.0 (defined by the NFC Forum)</li>
   4049     <li>NDEF Push Protocol [<a href="http://static.googleusercontent.com/media/source.android.com/en/us/compatibility/ndef-push-protocol.pdf">Resources, 103</a>]</li>
   4050     <li>SNEP 1.0 (defined by the NFC Forum)</li>
   4051   </ul></li>
   4052   <li>MUST include support for Android Beam [<a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">Resources, 104</a>]:
   4053   <ul>
   4054     <li>MUST implement the SNEP default server. Valid NDEF messages received by the
   4055 default SNEP server MUST be dispatched to applications using the
   4056 android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam in settings
   4057 MUST NOT disable dispatch of incoming NDEF message.</li>
   4058     <li>MUST honor the android.settings.NFCSHARING_SETTINGS intent to show NFC sharing
   4059 settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">Resources, 105</a>].</li>
   4060     <li>MUST implement the NPP server. Messages received by the NPP server MUST be
   4061 processed the same way as the SNEP default server.</li>
   4062     <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to the
   4063 default SNEP server when Android Beam is enabled. If no default SNEP server is
   4064 found then the client MUST attempt to send to an NPP server.</li>
   4065     <li>MUST allow foreground activities to set the outbound P2P NDEF message using
   4066 android.nfc.NfcAdapter.setNdefPushMessage, and
   4067 android.nfc.NfcAdapter.setNdefPushMessageCallback, and
   4068 android.nfc.NfcAdapter.enableForegroundNdefPush.</li>
   4069     <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', before
   4070 sending outbound P2P NDEF messages.</li>
   4071     <li>SHOULD enable Android Beam by default and MUST be able to send and receive
   4072 using Android Beam, even when another proprietary NFC P2p mode is turned on.</li>
   4073     <li>MUST support NFC Connection handover to Bluetooth when the device supports
   4074 Bluetooth Object Push Profile. Device implementations MUST support connection
   4075 handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, by
   4076 implementing the &ldquo;Connection Handover version 1.2&rdquo; [<a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">Resources, 106</a>] and &ldquo;Bluetooth Secure Simple Pairing Using NFC version 1.0&rdquo; [<a href="http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf">Resources, 107</a>] specs from the NFC Forum. Such an implementation MUST implement the handover
   4077 LLCP service with service name &ldquo;urn:nfc:sn:handover&rdquo; for exchanging the
   4078 handover request/select records over NFC, and it MUST use the Bluetooth Object
   4079 Push Profile for the actual Bluetooth data transfer. For legacy reasons (to
   4080 remain compatible with Android 4.1 devices), the implementation SHOULD still
   4081 accept SNEP GET requests for exchanging the handover request/select records
   4082 over NFC. However an implementation itself SHOULD NOT send SNEP GET requests
   4083 for performing connection handover.</li>
   4084   </ul></li>
   4085   <li>MUST poll for all supported technologies while in NFC discovery mode.</li>
   4086   <li>SHOULD be in NFC discovery mode while the device is awake with the screen
   4087 active and the lock-screen unlocked.</li>
   4088 </ul>
   4089 </ul>
   4090 
   4091 <p>(Note that publicly available links are not available for the JIS, ISO, and NFC
   4092 Forum specifications cited above.)</p>
   4093 
   4094 <p>Android includes support for NFC Host Card Emulation (HCE) mode. If a
   4095 device implementation does include an NFC controller chipset capable of HCE and
   4096 Application ID (AID) routing, then it:</p>
   4097 
   4098 <ul>
   4099   <li>MUST report the android.hardware.nfc.hce feature constant.</li>
   4100   <li>MUST support NFC HCE APIs as defined in the Android SDK [<a href="http://developer.android.com/guide/topics/connectivity/nfc/hce.html">Resources, 108</a>].</li>
   4101 </ul>
   4102 
   4103 <p>Additionally, device implementations MAY include reader/writer support for the
   4104 following MIFARE technologies.</p>
   4105 
   4106 <ul>
   4107   <li>MIFARE Classic</li>
   4108   <li>MIFARE Ultralight</li>
   4109   <li>NDEF on MIFARE Classic</li>
   4110 </ul>
   4111 
   4112 <p>Note that Android includes APIs for these MIFARE types. If a device
   4113 implementation supports MIFARE in the reader/writer role, it:</p>
   4114 
   4115 <ul>
   4116   <li>MUST implement the corresponding Android APIs as documented by the Android SDK.</li>
   4117   <li>MUST report the feature com.nxp.mifare from the
   4118 android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>]. Note that this is not a standard Android feature and as such does not appear
   4119 as a constant in the android.content.pm.PackageManager class.</li>
   4120   <li>MUST NOT implement the corresponding Android APIs nor report the com.nxp.mifare
   4121 feature unless it also implements general NFC support as described in this
   4122 section.</li>
   4123 </ul>
   4124 
   4125 <p>If a device implementation does not include NFC hardware, it MUST NOT declare
   4126 the android.hardware.nfc feature from the
   4127 android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 70</a>], and MUST implement the Android NFC API as a no-op.</p>
   4128 
   4129 <p>As the classes android.nfc.NdefMessage and android.nfc.NdefRecord represent a
   4130 protocol-independent data representation format, device implementations MUST
   4131 implement these APIs even if they do not include support for NFC or declare the
   4132 android.hardware.nfc feature.</p>
   4133 
   4134 <h3 id="7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</h3>
   4135 
   4136 
   4137 <p>Device implementations MUST include support for one or more forms of data
   4138 networking. Specifically, device implementations MUST include support for at
   4139 least one data standard capable of 200Kbit/sec or greater. Examples of
   4140 technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g,
   4141 Ethernet, Bluetooth PAN, etc.</p>
   4142 
   4143 <p>Device implementations where a physical networking standard (such as Ethernet)
   4144 is the primary data connection SHOULD also include support for at least one
   4145 common wireless data standard, such as 802.11 (Wi-Fi).</p>
   4146 
   4147 <p>Devices MAY implement more than one form of data connectivity.</p>
   4148 
   4149 <p>Devices MUST include an IPv6 networking stack and support IPv6 communication
   4150 using the managed APIs, such as <code>java.net.Socket</code> and
   4151 <code>java.net.URLConnection</code>, as well as the native APIs, such as
   4152 <code>AF_INET6</code> sockets. The required level of IPv6 support depends on
   4153 the network type, as follows:</p>
   4154 <ul>
   4155   <li>Devices that support Wi-Fi networks MUST support dual-stack and IPv6-only
   4156   operation on Wi-Fi.</li>
   4157   <li>Devices that support Ethernet networks MUST support dual-stack operation
   4158   on Ethernet.</li>
   4159   <li>Devices that support cellular data SHOULD support IPv6 operation
   4160   (IPv6-only and possibly dual-stack) on cellular data.</li>
   4161   <li>When a device is simultaneously connected to more than one network (e.g.,
   4162   Wi-Fi and cellular data), it MUST simultaneously meet these requirements on
   4163   each network to which it is connected.</li>
   4164 </ul>
   4165 
   4166 <p>IPv6 MUST be enabled by default.</p>
   4167 
   4168 <p>In order to ensure that IPv6 communication is as reliable as IPv4, unicast
   4169 IPv6 packets sent to the device MUST NOT be dropped, even when the screen is
   4170 not in an active state. Redundant multicast IPv6 packets, such as repeated
   4171 identical Router Advertisements, MAY be rate-limited in hardware or firmware
   4172 if doing so is necessary to save power. In such cases, rate-limiting MUST NOT
   4173 cause the device to lose IPv6 connectivity on any IPv6-compliant network that
   4174 uses RA lifetimes of at least 180 seconds.</p>
   4175 
   4176 <p>IPv6 connectivity MUST be maintained in doze mode.</p>
   4177 
   4178 <h3 id="7_4_6_sync_settings">7.4.6. Sync Settings</h3>
   4179 
   4180 
   4181 <p>Device implementations MUST have the master auto-sync setting on by default so
   4182 that the method getMasterSyncAutomatically() returns &ldquo;true&rdquo; [<a href="http://developer.android.com/reference/android/content/ContentResolver.html">Resources, 109</a>].</p>
   4183 
   4184 <h2 id="7_5_cameras">7.5. Cameras</h2>
   4185 
   4186 
   4187 <p>Device implementations SHOULD include a rear-facing camera and MAY include a
   4188 front-facing camera. A rear-facing camera is a camera located on the side of
   4189 the device opposite the display; that is, it images scenes on the far side of
   4190 the device, like a traditional camera. A front-facing camera is a camera
   4191 located on the same side of the device as the display; that is, a camera
   4192 typically used to image the user, such as for video conferencing and similar
   4193 applications.</p>
   4194 
   4195 <p>If a device implementation includes at least one camera, it SHOULD be possible
   4196 for an application to simultaneously allocate 3 bitmaps equal to the size of
   4197 the images produced by the largest-resolution camera sensor on the device.</p>
   4198 
   4199 <h3 id="7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</h3>
   4200 
   4201 
   4202 <p>Device implementations SHOULD include a rear-facing camera. If a device
   4203 implementation includes at least one rear-facing camera, it:</p>
   4204 
   4205 <ul>
   4206   <li>MUST report the feature flag android.hardware.camera and
   4207 android.hardware.camera.any.</li>
   4208   <li>MUST have a resolution of at least 2 megapixels.</li>
   4209   <li>SHOULD have either hardware auto-focus or software auto-focus implemented in
   4210 the camera driver (transparent to application software).</li>
   4211   <li>MAY have fixed-focus or EDOF (extended depth of field) hardware.</li>
   4212   <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST NOT be
   4213 lit while an android.hardware.Camera.PreviewCallback instance has been
   4214 registered on a Camera preview surface, unless the application has explicitly
   4215 enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes
   4216 of a Camera.Parameters object. Note that this constraint does not apply to the
   4217 device&rsquo;s built-in system camera application, but only to third-party
   4218 applications using Camera.PreviewCallback.</li>
   4219 </ul>
   4220 
   4221 <h3 id="7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</h3>
   4222 
   4223 
   4224 <p>Device implementations MAY include a front-facing camera. If a device
   4225 implementation includes at least one front-facing camera, it:</p>
   4226 
   4227 <ul>
   4228   <li>MUST report the feature flag android.hardware.camera.any and
   4229 android.hardware.camera.front.</li>
   4230   <li>MUST have a resolution of at least VGA (640x480 pixels).</li>
   4231   <li>MUST NOT use a front-facing camera as the default for the Camera API. The
   4232 camera API in Android has specific support for front-facing cameras and device
   4233 implementations MUST NOT configure the API to to treat a front-facing camera as
   4234 the default rear-facing camera, even if it is the only camera on the device.</li>
   4235   <li>MAY include features (such as auto-focus, flash, etc.) available to rear-facing
   4236 cameras as described in <a href="#7_5_1_rear-facing_camera">section 7.5.1</a>.</li>
   4237   <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a
   4238 CameraPreview, as follows:
   4239   <ul>
   4240     <li>If the device implementation is capable of being rotated by user (such as
   4241 automatically via an accelerometer or manually via user input), the camera
   4242 preview MUST be mirrored horizontally relative to the device&rsquo;s current
   4243 orientation.</li>
   4244     <li>If the current application has explicitly requested that the Camera display be
   4245 rotated via a call to the android.hardware.Camera.setDisplayOrientation()[<a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">Resources, 110</a>] method, the camera preview MUST be mirrored horizontally relative to the
   4246 orientation specified by the application.</li>
   4247     <li>Otherwise, the preview MUST be mirrored along the device&rsquo;s default horizontal
   4248 axis.</li>
   4249   </ul></li>
   4250   <li>MUST mirror the image displayed by the postview in the same manner as the
   4251 camera preview image stream. If the device implementation does not support
   4252 postview, this requirement obviously does not apply.</li>
   4253   <li>MUST NOT mirror the final captured still image or video streams returned to
   4254 application callbacks or committed to media storage.</li>
   4255 </ul>
   4256 
   4257 <h3 id="7_5_3_external_camera">7.5.3. External Camera</h3>
   4258 
   4259 
   4260 <p>Device implementations with USB host mode MAY include support for an external
   4261 camera that connects to the USB port. If a device includes support for an
   4262 external camera, it:</p>
   4263 
   4264 <ul>
   4265   <li>MUST declare the platform feature android.hardware.camera.external and
   4266 android.hardware camera.any.</li>
   4267   <li>MUST support USB Video Class (UVC 1.0 or higher).</li>
   4268   <li>MAY support multiple cameras.</li>
   4269 </ul>
   4270 
   4271 <p>Video compression (such as MJPEG) support is RECOMMENDED to enable transfer of
   4272 high-quality unencoded streams (i.e. raw or independently compressed picture
   4273 streams). Camera-based video encoding MAY be supported. If so, a simultaneous
   4274 unencoded/ MJPEG stream (QVGA or greater resolution) MUST be accessible to the
   4275 device implementation.</p>
   4276 
   4277 <h3 id="7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</h3>
   4278 
   4279 
   4280 <p>Android includes two API packages to access the camera, the newer
   4281 android.hardware.camera2 API expose lower-level camera control to the app,
   4282 including efficient zero-copy burst/streaming flows and per-frame controls of
   4283 exposure, gain, white balance gains, color conversion, denoising, sharpening,
   4284 and more.</p>
   4285 
   4286 <p>The older API package, android.hardware.Camera, is marked as deprecated in
   4287 Android 5.0 but as it should still be available for apps to use Android device
   4288 implementations MUST ensure the continued support of the API as described in
   4289 this section and in the Android SDK.</p>
   4290 
   4291 <p>Device implementations MUST implement the following behaviors for the
   4292 camera-related APIs, for all available cameras:</p>
   4293 
   4294 <ul>
   4295   <li>If an application has never called
   4296 android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST
   4297 use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to
   4298 application callbacks.</li>
   4299   <li>If an application registers an android.hardware.Camera.PreviewCallback instance
   4300 and the system calls the onPreviewFrame() method when the preview format is
   4301 YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() must further
   4302 be in the NV21 encoding format. That is, NV21 MUST be the default.</li>
   4303   <li>For android.hardware.Camera, device implementations MUST support the YV12
   4304 format (as denoted by the android.graphics.ImageFormat.YV12 constant) for
   4305 camera previews for both front- and rear-facing cameras. (The hardware video
   4306 encoder and camera may use any native pixel format, but the device
   4307 implementation MUST support conversion to YV12.)</li>
   4308   <li>For android.hardware.camera2, device implementations must support the
   4309 android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG
   4310 formats as outputs through the android.media.ImageReader API.</li>
   4311 </ul>
   4312 
   4313 <p>Device implementations MUST still implement the full Camera API included in the
   4314 Android SDK documentation [<a href="http://developer.android.com/reference/android/hardware/Camera.html">Resources, 111</a>],
   4315 regardless of whether the device includes hardware autofocus or other
   4316 capabilities. For instance, cameras that lack autofocus MUST still call any
   4317 registered android.hardware.Camera.AutoFocusCallback instances (even though
   4318 this has no relevance to a non-autofocus camera.) Note that this does apply to
   4319 front-facing cameras; for instance, even though most front-facing cameras do
   4320 not support autofocus, the API callbacks must still be &ldquo;faked&rdquo; as described.</p>
   4321 
   4322 <p>Device implementations MUST recognize and honor each parameter name defined as
   4323 a constant on the android.hardware.Camera.Parameters class, if the underlying
   4324 hardware supports the feature. If the device hardware does not support a
   4325 feature, the API must behave as documented. Conversely, device implementations
   4326 MUST NOT honor or recognize string constants passed to the
   4327 android.hardware.Camera.setParameters() method other than those documented as
   4328 constants on the android.hardware.Camera.Parameters. That is, device
   4329 implementations MUST support all standard Camera parameters if the hardware
   4330 allows, and MUST NOT support custom Camera parameter types. For instance,
   4331 device implementations that support image capture using high dynamic range
   4332 (HDR) imaging techniques MUST support camera parameter Camera.SCENE_MODE_HDR [<a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">Resources, 112</a>].</p>
   4333 
   4334 <p>Because not all device implementations can fully support all the features of
   4335 the android.hardware.camera2 API, device implementations MUST report the proper
   4336 level of support with the android.info.supportedHardwareLevel property as
   4337 described in the Android SDK [<a href="https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL">Resources, 113</a>] and report the appropriate framework feature flags [<a href="http://source.android.com/devices/camera/versioning.html">Resources, 114</a>].</p>
   4338 
   4339 <p>Device implementations MUST also declare its Individual camera capabilities of
   4340 android.hardware.camera2 via the android.request.availableCapabilities property
   4341 and declare the appropriate feature flags [<a href="http://source.android.com/devices/camera/versioning.html">Resources, 114</a>]; a device must define the feature flag if any of its attached camera devices supports the feature.</p>
   4342 
   4343 <p>Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent
   4344 whenever a new picture is taken by the camera and the entry of the picture has
   4345 been added to the media store.</p>
   4346 
   4347 <p>Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent
   4348 whenever a new video is recorded by the camera and the entry of the picture has
   4349 been added to the media store.</p>
   4350 
   4351 <h3 id="7_5_5_camera_orientation">7.5.5. Camera Orientation</h3>
   4352 
   4353 
   4354 <p>Both front- and rear-facing cameras, if present, MUST be oriented so that the
   4355 long dimension of the camera aligns with the screen&rsquo;s long dimension. That is,
   4356 when the device is held in the landscape orientation, cameras MUST capture
   4357 images in the landscape orientation. This applies regardless of the device&rsquo;s
   4358 natural orientation; that is, it applies to landscape-primary devices as well
   4359 as portrait-primary devices.</p>
   4360 
   4361 <h2 id="7_6_memory_and_storage">7.6. Memory and Storage</h2>
   4362 
   4363 
   4364 <h3 id="7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</h3>
   4365 
   4366 <div class="note">
   4367 <p>Android Television devices MUST have at least 5GB of non-volatile storage
   4368 available for application private data.</p>
   4369 </div>
   4370 
   4371 
   4372 <p>The memory available to the kernel and userspace on device implementations MUST
   4373 be at least equal or larger than the minimum values specified by the following
   4374 table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and density definitions.)</p>
   4375 <table>
   4376  <tr>
   4377     <th>Density and screen size</th>
   4378     <th>32-bit device</th>
   4379     <th>64-bit device</th>
   4380  </tr>
   4381  <tr>
   4382     <td>Android Watch devices (due to smaller screens)</td>
   4383     <td>416MB</td>
   4384     <td>Not applicable</td>
   4385  </tr>
   4386  <tr>
   4387     <td><ul>
   4388     <li class="table_list">280dpi or lower on small/normal screens</li>
   4389     <li class="table_list">mdpi or lower on large screens</li>
   4390     <li class="table_list">ldpi or lower on extra large screens</li>
   4391     </ul></td>
   4392     <td>424MB</td>
   4393     <td>704MB</td>
   4394  </tr>
   4395  <tr>
   4396     <td><ul>
   4397     <li class="table_list">xhdpi or higher on small/normal screens</li>
   4398     <li class="table_list">hdpi or higher on large screens</li>
   4399     <li class="table_list">mdpi or higher on extra large screens</li></ul></td>
   4400     <td>512MB</td>
   4401     <td>832MB</td>
   4402  </tr>
   4403  <tr>
   4404     <td><ul>
   4405     <li class="table_list">400dpi or higher on small/normal screens</li>
   4406     <li class="table_list">xhdpi or higher on large screens</li>
   4407      <li class="table_list">tvdpi or higher on extra large screens</li></ul></td>
   4408     <td>896MB</td>
   4409     <td>1280MB</td>
   4410  </tr>
   4411  <tr>
   4412     <td><ul>
   4413     <li class="table_list">560dpi or higher on small/normal screens</li>
   4414     <li class="table_list">400dpi or higher on large screens</li>
   4415     <li class="table_list">xhdpi or higher on extra large screens</li></ul></td>
   4416     <td>1344MB</td>
   4417     <td>1824MB</td>
   4418  </tr>
   4419 </table>
   4420 
   4421 
   4422 <p>The minimum memory values MUST be in addition to any memory space already
   4423 dedicated to hardware components such as radio, video, and so on that is not
   4424 under the kernel&rsquo;s control.</p>
   4425 
   4426 <p>Device implementations with less than 512MB of memory available to the kernel
   4427 and userspace, unless an Android Watch, MUST return the value "true" for
   4428 ActivityManager.isLowRamDevice().</p>
   4429 
   4430 <p>Android Television devices MUST have at least 5GB and other device
   4431 implementations MUST have at least 1.5GB of non-volatile storage available for
   4432 application private data. That is, the /data partition MUST be at least 5GB for
   4433 Android Television devices and at least 1.5GB for other device implementations.
   4434 Device implementations that run Android are <strong>STRONGLY RECOMMENDED</strong> to have at least 3GB of non-volatile storage for application private data so
   4435 they will be able to upgrade to the future platform releases.</p>
   4436 
   4437 <p>The Android APIs include a Download Manager that applications MAY use to
   4438 download data files [<a href="http://developer.android.com/reference/android/app/DownloadManager.html">Resources, 115</a>]. The device implementation of the Download Manager MUST be capable of
   4439 downloading individual files of at least 100MB in size to the default &ldquo;cache"
   4440 location.</p>
   4441 
   4442 <h3 id="7_6_2_application_shared_storage">7.6.2. Application Shared Storage</h3>
   4443 
   4444 
   4445 <p>Device implementations MUST offer shared storage for applications also often
   4446 referred as &ldquo;shared external storage&rdquo;. </p>
   4447 
   4448 <p>Device implementations MUST be configured with shared storage mounted by
   4449 default, &ldquo;out of the box&rdquo;. If the shared storage is not mounted on the Linux
   4450 path /sdcard, then the device MUST include a Linux symbolic link from /sdcard
   4451 to the actual mount point.</p>
   4452 
   4453 <p>Device implementations MAY have hardware for user-accessible removable storage,
   4454 such as a Secure Digital (SD) card slot. If this slot is used to satisfy the
   4455 shared storage requirement, the device implementation:</p>
   4456 
   4457 <ul>
   4458   <li>MUST implement a toast or pop-up user interface warning the user when there is
   4459 no SD card.</li>
   4460   <li>MUST include a FAT-formatted SD card 1GB in size or larger OR show on the box
   4461 and other material available at time of purchase that the SD card has to be
   4462 separately purchased.</li>
   4463   <li>MUST mount the SD card by default.</li>
   4464 </ul>
   4465 
   4466 <p>Alternatively, device implementations MAY allocate internal (non-removable)
   4467 storage as shared storage for apps as included in the upstream Android Open
   4468 Source Project; device implementations SHOULD use this configuration and
   4469 software implementation. If a device implementation uses internal
   4470 (non-removable) storage to satisfy the shared storage requirement, while that
   4471 storage MAY share space with the application private data, it MUST be at least
   4472 1GB in size and mounted on /sdcard (or /sdcard MUST be a
   4473 symbolic link to the physical location if it is mounted elsewhere).</p>
   4474 
   4475 <p>Device implementations MUST enforce as documented the
   4476 android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage.
   4477 Shared storage MUST otherwise be writable by any application that obtains that
   4478 permission.</p>
   4479 
   4480 <p>Device implementations that include multiple shared storage paths (such as both
   4481 an SD card slot and shared internal storage) MUST allow only pre-installed &amp;
   4482 privileged Android applications with the WRITE_EXTERNAL_STORAGE permission to
   4483 write to the secondary external storage, except when writing to their
   4484 package-specific directories or within the <code>URI</code> returned by firing
   4485 the <code>ACTION_OPEN_DOCUMENT_TREE</code> intent.</p>
   4486 
   4487 <p>However, device implementations SHOULD expose content from
   4488 both storage paths transparently through Android&rsquo;s media scanner service
   4489 and android.provider.MediaStore.</p>
   4490 
   4491 <p>Regardless of the form of shared storage used, if the device implementation
   4492 has a USB port with USB peripheral mode support, it MUST provide some mechanism
   4493 to access the contents of shared storage from a host computer. Device
   4494 implementations MAY use USB mass storage, but SHOULD use Media Transfer Protocol
   4495 to satisfy this requirement. If the device implementation supports Media
   4496 Transfer Protocol, it:</p>
   4497 
   4498 <ul>
   4499   <li>SHOULD be compatible with the reference Android MTP host, Android File Transfer
   4500 [<a href="http://www.android.com/filetransfer">Resources, 116</a>].</li>
   4501   <li>SHOULD report a USB device class of 0x00.</li>
   4502   <li>SHOULD report a USB interface name of 'MTP'.</li>
   4503 </ul>
   4504 
   4505 <h3 id="7_6_3_adoptable_storage">7.6.3. Adoptable Storage</h3>
   4506 
   4507 <p>Device implementations are STRONGLY RECOMMENDED to implement adoptable
   4508 storage if the removable storage device port is in a long-term stable location,
   4509 such as within the battery compartment or other protective cover
   4510 [<a
   4511 href="http://source.android.com/devices/storage/adoptable.html">Resources,
   4512 117</a>].</p>
   4513 
   4514 <p>Device implementations such as a television, MAY enable adoption through USB
   4515 ports as the device is expected to be static and not mobile. But for other
   4516 device implementations that are mobile in nature, it is STRONGLY RECOMMENDED to
   4517 implement the adoptable storage in a long-term stable location, since accidentally
   4518 disconnecting them can cause data loss/corruption.</p>
   4519 
   4520 <h2 id="7_7_usb">7.7. USB</h2>
   4521 
   4522 
   4523 <p>Device implementations SHOULD support USB peripheral mode and SHOULD support
   4524 USB host mode.</p>
   4525 
   4526 <p>If a device implementation includes a USB port supporting peripheral mode:</p>
   4527 
   4528 <ul>
   4529   <li>The port MUST be connectable to a USB host that has a standard type-A or type
   4530 -C USB port.</li>
   4531   <li>The port SHOULD use micro-B, micro-AB or Type-C USB form factor. Existing and
   4532 new Android devices are <strong>STRONGLY RECOMMENDED to meet these requirements</strong>
   4533 so they will be able to upgrade to future platform releases.</li>
   4534   <li>The port SHOULD either be located on the bottom of the device (according to natural
   4535 orientation) or enable software screen rotation for all apps (including home
   4536 screen), so that the display draws correctly when the device is oriented with
   4537 the port at bottom. Existing and new Android devices are <strong>STRONGLY RECOMMENDED
   4538 to meet these requirements</strong> so they will be able to upgrade to future platform
   4539 releases.</li>
   4540   <li>It SHOULD implement the Android Open Accessory (AOA) API and specification as
   4541 documented in the Android SDK documentation, and if it is an Android Handheld
   4542 device it MUST implement the AOA API. Device implementations implementing the
   4543 AOA specification:
   4544   <ul>
   4545     <li>MUST declare support for the hardware feature android.hardware.usb.accessory [<a href="http://developer.android.com/guide/topics/connectivity/usb/accessory.html">Resources, 118</a>].</li>
   4546     <li>MUST support establishing an
   4547 <a href="http://source.android.com/devices/accessories/aoa.html">AOA protocol based communication</a>
   4548 on first time connection with a USB host machine that acts as an accessory, without the need for the
   4549 user to change the default USB mode.</li>
   4550     <li>MUST implement the USB audio class as documented in the Android SDK
   4551 documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 119</a>].</li>
   4552     <li>And also the USB mass storage class, MUST include the string "android"
   4553 at the end of the interface description <code>iInterface</code> string of the
   4554 USB mass storage</li>
   4555   </ul>
   4556   </li>
   4557   <li>It SHOULD implement support to draw 1.5 A current during HS chirp and traffic
   4558 as specified in the USB Battery Charging Specification, Revision 1.2 [<a href="http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip">Resources, 120</a>]. Existing and new Android devices are <strong>STRONGLY RECOMMENDED to meet these requirements</strong> so they will be able to upgrade to the future platform releases.</li>
   4559 the Type-C resistor standard.</li>
   4560   <li>The value of iSerialNumber in USB standard device descriptor MUST be equal to
   4561 the value of android.os.Build.SERIAL.</li>
   4562 </ul>
   4563 
   4564 <p>If a device implementation includes a USB port supporting host mode, it:</p>
   4565 
   4566 <ul>
   4567   <li>SHOULD use a type-C USB port, if the device implementation supports USB 3.1.</li>
   4568   <li>MAY use a non-standard port form factor, but if so MUST ship with a cable or
   4569 cables adapting the port to a standard type-A or type-C USB port.</li>
   4570   <li>MAY use a micro-AB USB port, but if so SHOULD ship with a cable or cables
   4571 adapting the port to a standard type-A or type-C USB port.</li>
   4572   <li>is <strong>STRONGLY RECOMMENDED</strong> to implement the USB audio class as documented in the Android SDK
   4573 documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 119</a>].</li>
   4574   <li>MUST implement the Android USB host API as documented in the Android SDK, and
   4575 MUST declare support for the hardware feature android.hardware.usb.host [<a href="http://developer.android.com/guide/topics/connectivity/usb/host.html">Resources, 121</a>].</li>
   4576   <li>SHOULD support the Charging Downstream Port output current range of 1.5 A ~ 5 A
   4577 as specified in the USB Battery Charging Specification, Revision 1.2 [<a href="http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip">Resources, 120</a>].</li>
   4578 </ul>
   4579 
   4580 <h2 id="7_8_audio">7.8. Audio</h2>
   4581 
   4582 
   4583 <h3 id="7_8_1_microphone">7.8.1. Microphone</h3>
   4584 
   4585 <div class="note">
   4586 <p>Android Handheld, Watch, and Automotive implementations MUST include a
   4587 microphone.</p>
   4588 </div>
   4589 
   4590 
   4591 <p>Device implementations MAY omit a microphone. However, if a device
   4592 implementation omits a microphone, it MUST NOT report the
   4593 android.hardware.microphone feature constant, and MUST implement the audio
   4594 recording API at least as no-ops, per <a href="#7_hardware_compatibility">section 7</a>.
   4595 Conversely, device implementations that do possess a microphone:</p>
   4596 
   4597 <ul>
   4598   <li>MUST report the android.hardware.microphone feature constant</li>
   4599   <li>MUST meet the audio recording requirements in <a href="#5_4_audio_recording">section 5.4</a></li>
   4600   <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a></li>
   4601   <li>STRONGLY RECOMMENDED to support near-ultrasound recording as described in
   4602     <a href="#7_8_3_near_ultrasound">section 7.8.3</a></li>
   4603 </ul>
   4604 
   4605 <h3 id="7_8_2_audio_output">7.8.2. Audio Output</h3>
   4606 
   4607 <div class="note">
   4608 <p>Android Watch devices MAY include an audio output.</p>
   4609 </div>
   4610 
   4611 <p>Device implementations including a speaker or with an audio/multimedia output
   4612 port for an audio output peripheral as a headset or an external speaker:</p>
   4613 
   4614 <ul>
   4615   <li>MUST report the android.hardware.audio.output feature constant.</li>
   4616   <li>MUST meet the audio playback requirements in <a href="#5_5_audio_playback">section 5.5</a>.</li>
   4617   <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a>.</li>
   4618   <li>STRONGLY RECOMMENDED to support near-ultrasound playback as described in
   4619     <a href="#7_8_3_near_ultrasound">section 7.8.3</a></li>
   4620 </ul>
   4621 
   4622 <p>Conversely, if a device implementation does not include a speaker or audio
   4623 output port, it MUST NOT report the android.hardware.audio output feature, and
   4624 MUST implement the Audio Output related APIs as no-ops at least. </p>
   4625 
   4626 <p>Android Watch device implementation MAY but SHOULD NOT have audio output, but
   4627 other types of Android device implementations MUST have an audio output and
   4628 declare android.hardware.audio.output.</p>
   4629 
   4630 <h4 id="7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</h4>
   4631 
   4632 
   4633 <p>In order to be compatible with the headsets and other audio accessories using
   4634 the 3.5mm audio plug across the Android ecosystem [<a href="http://source.android.com/accessories/headset-spec.html">Resources, 122</a>], if a device implementation includes one or more analog audio ports, at least
   4635 one of the audio port(s) SHOULD be a 4 conductor 3.5mm audio jack. If a device
   4636 implementation has a 4 conductor 3.5mm audio jack, it:</p>
   4637 
   4638 <ul>
   4639   <li>MUST support audio playback to stereo headphones and stereo headsets with a
   4640 microphone, and SHOULD support audio recording from stereo headsets with a
   4641 microphone.</li>
   4642   <li>MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD support
   4643 audio plugs with the OMTP pin-out order.</li>
   4644   <li>MUST support the detection of microphone on the plugged in audio accessory, if
   4645 the device implementation supports a microphone, and broadcast the
   4646 android.intent.action.HEADSET_PLUG with the extra value microphone set as 1.</li>
   4647   <li>SHOULD support the detection and mapping to the keycodes for the following 3
   4648 ranges of equivalent impedance between the microphone and ground conductors on
   4649 the audio plug:
   4650   <ul>
   4651     <li><strong>70 ohm or less</strong>: KEYCODE_HEADSETHOOK</li>
   4652     <li><strong>210&#45;290 Ohm</strong>: KEYCODE_VOLUME_UP</li>
   4653     <li><strong>360&#45;680 Ohm</strong>: KEYCODE_VOLUME_DOWN</li>
   4654   </ul></li>
   4655   <li>SHOULD support the detection and mapping to the keycode for the following range
   4656 of equivalent impedance between the microphone and ground conductors on the
   4657 audio plug:
   4658   <ul>
   4659     <li><strong>110&#45;180 Ohm: </strong>KEYCODE_VOICE_ASSIST</li>
   4660   </ul></li>
   4661   <li>MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all
   4662 contacts on plug are touching their relevant segments on the jack.</li>
   4663   <li>MUST be capable of driving at least 150mV &plusmn; 10% of output voltage on a 32 Ohm
   4664 speaker impedance.</li>
   4665   <li>MUST have a microphone bias voltage between 1.8V ~ 2.9V.</li>
   4666 </ul>
   4667 
   4668 <h3 id="7_8_3_near_ultrasound">7.8.3. Near-Ultrasound </h3>
   4669 
   4670 <p>Near-Ultrasound audio is the 18.5 kHz to 20 kHz band.
   4671 Device implementations MUST correctly report the support
   4672 of near-ultrasound audio capability via the
   4673 <a href="http://developer.android.com/reference/android/media/AudioManager.html#getProperty(java.lang.String)">AudioManager.getProperty</a>
   4674 API as follows:
   4675 </p>
   4676 
   4677 <ul>
   4678   <li>If
   4679   <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND">PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND</a>
   4680   is "true", then
   4681   <ul>
   4682     <li>The microphone's mean power response in the 18.5 kHz to 20 kHz band MUST be no more than
   4683     15 dB below the response at 2 kHz.</li>
   4684     <li>The signal to noise ratio of the microphone MUST be no lower than 80 dB.</li>
   4685   </ul>
   4686   </li>
   4687   <li>If
   4688   <a href="http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND">PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND</a>
   4689   is "true", then the speaker's mean response in 18.5 kHz - 20 kHz MUST be no lower than 40 dB
   4690   below the response at 2 kHz.
   4691   </li>
   4692 </ul>
   4693 
   4694 <h1 id="8_performance_power">8. Performance and Power</h1>
   4695 
   4696 
   4697 <p>Some minimum performance and power criteria are critical to the user experience
   4698 and impact the baseline assumptions developers would have when developing an app.
   4699 Android Watch devices SHOULD and other type of device implementations MUST meet
   4700 the following criteria:</p>
   4701 
   4702 <h2 id="8_1_user_experience_consistency">8.1. User Experience Consistency</h2>
   4703 
   4704 
   4705 <p>Device implementations MUST provide a smooth user interface by ensuring a
   4706 consistent frame rate and response times for applications and games. Device
   4707 implementations MUST meet the following requirements: </p>
   4708 
   4709 <ul>
   4710   <li><strong>Consistent frame latency</strong>. Inconsistent frame latency or a delay to render frames MUST NOT happen more
   4711 often than 5 frames in a second, and SHOULD be below 1 frames in a second.</li>
   4712   <li><strong>User interface latency</strong>. Device implementations MUST ensure low latency user experience by scrolling a
   4713 list of 10K list entries as defined by the Android Compatibility Test Suite
   4714 (CTS) in less than 36 secs.</li>
   4715   <li><strong>Task switching</strong>. When multiple applications have been launched, re-launching an already-running
   4716 application after it has been launched MUST take less than 1 second.</li>
   4717 </ul>
   4718 
   4719 <h2 id="8_2_file_i_o_access_performance">8.2. File I/O Access Performance</h2>
   4720 
   4721 
   4722 <p>Device implementations MUST ensure internal storage file access performance consistency for read
   4723 and write operations. </p>
   4724 
   4725 <ul>
   4726   <li><strong>Sequential write</strong>. Device implementations MUST ensure a sequential write performance of at least 5MB/s
   4727 for a 256MB file using 10MB write buffer.</li>
   4728   <li><strong>Random write</strong>. Device implementations MUST ensure a random write performance of at least 0.5MB/s for a
   4729 256MB file using 4KB write buffer.</li>
   4730   <li><strong>Sequential read</strong>. Device implementations MUST ensure a sequential read performance of at least 15MB/s for
   4731 a 256MB file using 10MB write buffer.</li>
   4732   <li><strong>Random read</strong>. Device implementations MUST ensure a random read performance of at least 3.5MB/s for a
   4733 256MB file using 4KB write buffer.</li>
   4734 </ul>
   4735 
   4736 <h2 id="8_3_power_saving_modes">8.3. Power-Saving Modes</h2>
   4737 
   4738 <p>All apps exempted from App Standby and/or Doze mode MUST be made visible to
   4739 the end user. Further, the triggering, maintenance, wakeup algorithms and
   4740 the use of Global system settings of these power-saving modes MUST not deviate
   4741 from the Android Open Source Project.</p>
   4742 
   4743 <h2 id="8_4_power_consumption_accounting">8.4. Power Consumption Accounting</h2>
   4744 
   4745 <p>A more accurate accounting and reporting of the power consumption provides the
   4746 app developer both the incentives and the tools to optimize the power usage pattern
   4747 of the application. Therefore, device implementations:</p>
   4748 
   4749 <ul>
   4750   <li>MUST be able to track hardware component power usage and attribute that power
   4751     usage to specific applications. Specifically, implementations:
   4752     <ul>
   4753       <li>MUST provide a per-component power profile that defines the current consumption
   4754         value for each hardware component and the approximate battery drain caused by the
   4755         components over time as documented in the Android Open Source Project site [<a
   4756 href="http://source.android.com/devices/tech/power/values.html">Resources, 123</a>].</li>
   4757       <li>MUST report all power consumption values in milliampere hours (mAh)</li>
   4758       <li>SHOULD be attributed to the hardware component itself if unable to
   4759         attribute hardware component power usage to an application.</li>
   4760       <li>MUST report CPU power consumption per each process's UID. The Android Open
   4761         Source Project meets the requirement through the <code>uid_cputime</code>
   4762         kernel module implementation.</li>
   4763     </ul>
   4764   </li>
   4765   <li>MUST make this power usage available via the <code>adb shell dumpsys
   4766     batterystats</code> shell command to the app developer [<a
   4767 href="http://source.android.com/devices/tech/power/batterystats.html">Resources, 124</a>].</li>
   4768   <li>MUST honor the android.intent.action.POWER_USAGE_SUMMARY intent and display
   4769     a settings menu that shows this power usage [<a
   4770 href="http://developer.android.com/reference/android/content/Intent.html#ACTION_POWER_USAGE_SUMMARY">Resources,
   4771 125</a>].</li>
   4772 </ul>
   4773 
   4774 <h1 id="9_security_model_compatibility">9. Security Model Compatibility</h1>
   4775 
   4776 
   4777 <p>Device implementations MUST implement a security model consistent with the
   4778 Android platform security model as defined in Security and Permissions
   4779 reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>] in the Android developer documentation. Device implementations MUST support
   4780 installation of self-signed applications without requiring any additional
   4781 permissions/certificates from any third parties/authorities. Specifically,
   4782 compatible devices MUST support the security mechanisms described in the follow
   4783 subsections.</p>
   4784 
   4785 <h2 id="9_1_permissions">9.1. Permissions</h2>
   4786 
   4787 
   4788 <p>Device implementations MUST support the Android permissions model as defined in
   4789 the Android developer documentation [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>]. Specifically, implementations MUST enforce each permission defined as
   4790 described in the SDK documentation; no permissions may be omitted, altered, or
   4791 ignored. Implementations MAY add additional permissions, provided the new
   4792 permission ID strings are not in the android.* namespace.</p>
   4793 
   4794 <p>Permissions with a protection level of dangerous are runtime permissions. Applications
   4795 with targetSdkVersion > 22 request them at runtime. Device implementations:</p>
   4796 
   4797 <ul>
   4798 <li>MUST show a dedicated interface for the user to decide whether to grant the
   4799 requested runtime permissions and also provide an interface for the user to manage
   4800 runtime permissions.</li>
   4801 <li>MUST have one and only one implementation of both user interfaces.</li>
   4802 <li>MUST NOT grant any runtime permissions to preinstalled apps unless:
   4803   <ul>
   4804     <li>the user's consent can be obtained before the application uses it</li>
   4805     <li>the runtime permissions are associated with an intent pattern for which the preinstalled
   4806     application is set as the default handler</li>
   4807   </ul>
   4808 </li>
   4809 </ul>
   4810 
   4811 <h2 id="9_2_uid_and_process_isolation">9.2. UID and Process Isolation</h2>
   4812 
   4813 
   4814 <p>Device implementations MUST support the Android application sandbox model, in
   4815 which each application runs as a unique Unixstyle UID and in a separate
   4816 process. Device implementations MUST support running multiple applications as
   4817 the same Linux user ID, provided that the applications are properly signed and
   4818 constructed, as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>].</p>
   4819 
   4820 <h2 id="9_3_filesystem_permissions">9.3. Filesystem Permissions</h2>
   4821 
   4822 
   4823 <p>Device implementations MUST support the Android file access permissions model
   4824 as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>].</p>
   4825 
   4826 <h2 id="9_4_alternate_execution_environments">9.4. Alternate Execution Environments</h2>
   4827 
   4828 
   4829 <p>Device implementations MAY include runtime environments that execute
   4830 applications using some other software or technology than the Dalvik Executable
   4831 Format or native code. However, such alternate execution environments MUST NOT
   4832 compromise the Android security model or the security of installed Android
   4833 applications, as described in this section.</p>
   4834 
   4835 <p>Alternate runtimes MUST themselves be Android applications, and abide by the
   4836 standard Android security model, as described elsewhere in <a href="#9_security_model_compatibility">section 9</a>.</p>
   4837 
   4838 <p>Alternate runtimes MUST NOT be granted access to resources protected by
   4839 permissions not requested in the runtime&rsquo;s AndroidManifest.xml file via the
   4840 &lt;uses-permission&gt; mechanism.</p>
   4841 
   4842 <p>Alternate runtimes MUST NOT permit applications to make use of features
   4843 protected by Android permissions restricted to system applications.</p>
   4844 
   4845 <p>Alternate runtimes MUST abide by the Android sandbox model. Specifically,
   4846 alternate runtimes:</p>
   4847 
   4848 <ul>
   4849   <li>SHOULD install apps via the PackageManager into separate Android sandboxes (
   4850 Linux user IDs, etc.).</li>
   4851   <li>MAY provide a single Android sandbox shared by all applications using the
   4852 alternate runtime.</li>
   4853   <li>and installed applications using an alternate runtime, MUST NOT reuse the
   4854 sandbox of any other app installed on the device, except through the standard
   4855 Android mechanisms of shared user ID and signing certificate.</li>
   4856   <li>MUST NOT launch with, grant, or be granted access to the sandboxes
   4857 corresponding to other Android applications.</li>
   4858   <li>MUST NOT be launched with, be granted, or grant to other applications any
   4859 privileges of the superuser (root), or of any other user ID.</li>
   4860 </ul>
   4861 
   4862 <p>The .apk files of alternate runtimes MAY be included in the system image of a
   4863 device implementation, but MUST be signed with a key distinct from the key used
   4864 to sign other applications included with the device implementation.</p>
   4865 
   4866 <p>When installing applications, alternate runtimes MUST obtain user consent for
   4867 the Android permissions used by the application. If an application needs to
   4868 make use of a device resource for which there is a corresponding Android
   4869 permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the
   4870 user that the application will be able to access that resource. If the runtime
   4871 environment does not record application capabilities in this manner, the
   4872 runtime environment MUST list all permissions held by the runtime itself when
   4873 installing any application using that runtime.</p>
   4874 
   4875 <h2 id="9_5_multi-user_support">9.5. Multi-User Support</h2>
   4876 
   4877 <div class="note">
   4878 <p>This feature is optional for all device types.</p>
   4879 </div>
   4880 
   4881 
   4882 <p>Android includes support for multiple users and provides support for full user
   4883 isolation [<a href="http://developer.android.com/reference/android/os/UserManager.html">Resources, 127</a>]. Device implementations MAY enable multiple users, but when enabled MUST meet
   4884 the following requirements related to multi-user support [<a href="http://source.android.com/devices/storage/traditional.html">Resources, 128</a>]:</p>
   4885 
   4886 <ul>
   4887   <li>Device implementations that do not declare the android.hardware.telephony
   4888 feature flag MUST support restricted profiles, a feature that allows device
   4889 owners to manage additional users and their capabilities on the device. With
   4890 restricted profiles, device owners can quickly set up separate environments for
   4891 additional users to work in, with the ability to manage finer-grained
   4892 restrictions in the apps that are available in those environments.</li>
   4893   <li>Conversely device implementations that declare the android.hardware.telephony
   4894 feature flag MUST NOT support restricted profiles but MUST align with the AOSP
   4895 implementation of controls to enable /disable other users from accessing the
   4896 voice calls and SMS.</li>
   4897   <li>Device implementations MUST, for each user, implement a security model
   4898 consistent with the Android platform security model as defined in Security and
   4899 Permissions reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 126</a>].</li>
   4900   <li>Each user instance on an Android device MUST have separate and isolated
   4901 external storage directories. Device implementations MAY store multiple users'
   4902 data on the same volume or filesystem. However, the device implementation MUST
   4903 ensure that applications owned by and running on behalf a given user cannot
   4904 list, read, or write to data owned by any other user. Note that removable
   4905 media, such as SD card slots, can allow one user to access another&rsquo;s data by
   4906 means of a host PC. For this reason, device implementations that use removable
   4907 media for the primary external storage APIs MUST encrypt the contents of the SD
   4908 card if multiuser is enabled using a key stored only on non-removable media accessible
   4909 only to the system. As this will make the media unreadable by a host PC, device
   4910 implementations will be required to switch to MTP or a similar system to
   4911 provide host PCs with access to the current user&rsquo;s data. Accordingly, device
   4912 implementations MAY but SHOULD NOT enable multi-user if they use removable
   4913 media [<a href="http://developer.android.com/reference/android/os/Environment.html">Resources, 129</a>] for primary external storage.</li>
   4914 </ul>
   4915 
   4916 <h2 id="9_6_premium_sms_warning">9.6. Premium SMS Warning</h2>
   4917 
   4918 
   4919 <p>Android includes support for warning users of any outgoing premium SMS message
   4920 [<a href="http://en.wikipedia.org/wiki/Short_code">Resources, 130</a>]. Premium SMS messages are text messages sent to a service registered with a
   4921 carrier that may incur a charge to the user. Device implementations that
   4922 declare support for android.hardware.telephony MUST warn users before sending a
   4923 SMS message to numbers identified by regular expressions defined in
   4924 /data/misc/sms/codes.xml file in the device. The upstream Android Open Source
   4925 Project provides an implementation that satisfies this requirement.</p>
   4926 
   4927 <h2 id="9_7_kernel_security_features">9.7. Kernel Security Features</h2>
   4928 
   4929 
   4930 <p>The Android Sandbox includes features that use the Security-Enhanced Linux
   4931 (SELinux) mandatory access control (MAC) system and other security features in
   4932 the Linux kernel. SELinux or any other security features implemented below
   4933 the Android framework:</p>
   4934 
   4935 <ul>
   4936   <li>MUST maintain compatibility with existing applications.</li>
   4937   <li>MUST NOT have a visible user interface when a security violation is detected
   4938 and successfully blocked, but MAY have a visible user interface when an
   4939 unblocked security violation occurs resulting in a successful exploit.</li>
   4940   <li>SHOULD NOT be user or developer configurable.</li>
   4941 </ul>
   4942 
   4943 <p>If any API for configuration of policy is exposed to an application that can
   4944 affect another application (such as a Device Administration API), the API MUST
   4945 NOT allow configurations that break compatibility.</p>
   4946 
   4947 <p>Devices MUST implement SELinux or, if using a kernel other than Linux, an
   4948 equivalent mandatory access control system. Devices MUST also meet the
   4949 following requirements, which are satisfied by the reference implementation
   4950 in the upstream Android Open Source Project.</p>
   4951 
   4952 <p>Device implementations:</p>
   4953 
   4954 <ul>
   4955   <li>MUST set SELinux to global enforcing mode.</li>
   4956   <li>MUST configure all domains in enforcing mode. No permissive mode domains
   4957 are allowed, including domains specific to a device/vendor.</li>
   4958   <li>MUST NOT modify, omit, or replace the neverallow rules present within the
   4959 external/sepolicy folder provided in the upstream Android Open Source Project (AOSP) and
   4960 the policy MUST compile with all neverallow rules present, for both AOSP SELinux
   4961 domains as well as device/vendor specific domains.</li>
   4962 </ul>
   4963 
   4964 <p>Device implementations SHOULD retain the default SELinux policy provided in the
   4965 external/sepolicy folder of the upstream Android Open Source Project and only
   4966 further add to this policy for their own device-specific configuration. Device
   4967 implementations MUST be compatible with the upstream Android Open Source Project.
   4968 </p>
   4969 
   4970 <h2 id="9_8_privacy">9.8. Privacy</h2>
   4971 
   4972 <p>If the device implements functionality in the system that captures the contents
   4973 displayed on the screen and/or records the audio stream played on the device,
   4974 it MUST continuously notify the user whenever this functionality is enabled and
   4975 actively capturing/recording.</p>
   4976 
   4977 <p>If a device implementation has a mechanism that routes network data traffic
   4978 through a proxy server or VPN gateway by default (for example, preloading a VPN
   4979 service with android.permission.CONTROL_VPN granted), the device implementation
   4980 MUST ask for the user's consent before enabling that mechanism.</p>
   4981 
   4982 <p>If a device implementation has a USB port with USB peripheral mode support,
   4983 it MUST present a user interface asking for the user's consent before allowing
   4984 access to the contents of the shared storage over the USB port.</p>
   4985 
   4986 <h2 id="9_9_full-disk_encryption">9.9. Full-Disk Encryption</h2>
   4987 
   4988 <div class="note">
   4989 <p>Optional for Android device implementations without a lock screen.</p>
   4990 </div>
   4991 
   4992 <p>If the device implementation supports a secure lock screen reporting "<code>true</code>"
   4993 for KeyguardManager.isDeviceSecure()
   4994 [<a href="http://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceSecure()">Resources, 131</a>],
   4995 and is not a device with restricted memory as reported through the
   4996 ActivityManager.isLowRamDevice() method, then the device MUST support full-disk encryption
   4997 [<a href="http://source.android.com/devices/tech/security/encryption/index.html">Resources, 132</a>]
   4998 of the application private data (/data partition), as well as the application
   4999 shared storage partition (/sdcard partition) if it is a permanent, non-removable
   5000 part of the device.</p>
   5001 
   5002 <p>For device implementations supporting full-disk encryption and with Advanced
   5003 Encryption Standard (AES) crypto performance above 50MiB/sec, the full-disk
   5004 encryption MUST be enabled by default at the time the user has completed the out-of-box
   5005 setup experience. If a device implementation is already launched on an earlier Android
   5006 version with full-disk encryption disabled by default, such a device cannot
   5007 meet the requirement through a system software update and thus MAY be exempted.</p>
   5008 
   5009 <p>Encryption MUST use AES with a key of 128-bits (or greater) and a mode designed
   5010 for storage (for example, AES-XTS, AES-CBC-ESSIV). The encryption key MUST NOT
   5011 be written to storage at any time without being encrypted. Other than when in
   5012 active use, the encryption key SHOULD be AES encrypted with the lockscreen
   5013 passcode stretched using a slow stretching algorithm (e.g. PBKDF2 or scrypt).
   5014 If the user has not specified a lockscreen passcode or has disabled use of the
   5015 passcode for encryption, the system SHOULD use a default passcode to wrap the
   5016 encryption key. If the device provides a hardware-backed keystore, the password
   5017 stretching algorithm MUST be cryptographically bound to that keystore. The
   5018 encryption key MUST NOT be sent off the device (even when wrapped with the user
   5019 passcode and/or hardware bound key). The upstream Android Open Source project
   5020 provides a preferred implementation of this feature based on the Linux kernel
   5021 feature dm-crypt.</p>
   5022 
   5023 <h2 id="9_10_verified_boot">9.10. Verified Boot</h2>
   5024 
   5025 <p>
   5026 Verified boot is a feature that guarantees the integrity of the device software.
   5027 If a device implementation supports the feature, it MUST:
   5028 </p>
   5029 <ul>
   5030 <li>Declare the platform feature flag android.software.verified_boot</li>
   5031 <li>Perform verification on every boot sequence</li>
   5032 <li>Start verification from an immutable hardware key that is the root of trust, 
   5033 and go all the way up to the system partition</li>
   5034 <li>Implement each stage of verification to check the integrity and authenticity
   5035 of all the bytes in the next stage before executing the code in the next stage</li>
   5036 <li>Use verification algorithms as strong as current recommendations
   5037 from NIST for hashing algorithms (SHA-256) and public key sizes (RSA-2048)</li>
   5038 </ul>
   5039 
   5040 <p>The upstream Android Open Source Project provides a preferred implementation of this 
   5041 feature based on the Linux kernel feature dm-verity.</p>
   5042 
   5043 <p>Starting from Android 6.0, device implementations with Advanced Encryption Standard (AES)
   5044 crypto perfomance above 50MiB/seconds MUST support verified boot for device integrity.
   5045 If a device implementation is already launched without supporting verified boot on an earlier
   5046 version of Android, such a device can not add support for this feature with a system software
   5047 update and thus are exempted from the requirement.</p>
   5048 
   5049 <h2 id="9_11_keys_and_credentials">9.11. Keys and Credentials</h2>
   5050 
   5051 <p>The Android Keystore System
   5052 [<a href="https://developer.android.com/training/articles/keystore.html">Resources, 133</a>]
   5053 allows app developers to store cryptographic keys in a container and use them in cryptographic
   5054 operations through the KeyChain API
   5055 [<a href="https://developer.android.com/reference/android/security/KeyChain.html">Resources, 134</a>]
   5056 or the Keystore API
   5057   [<a href="https://developer.android.com/reference/java/security/KeyStore.html">Resources, 135</a>].
   5058 </p>
   5059 
   5060 <p>All Android device implementations MUST meet the following requirements:</p>
   5061 
   5062 <ul>
   5063 <li>SHOULD not limit the number of keys that can be generated, and MUST at least allow more
   5064 than 8,192 keys to be imported.</li>
   5065 <li>The lock screen authentication MUST rate limit attempts and SHOULD have an exponential
   5066   backoff algorithm as implemented in the Android Open Source Project.</li>
   5067 <li>When the device implementation supports a secure lock screen and has a secure hardware
   5068   such as a Secure Element (SE) where a Trusted Execution Environment (TEE) can be implemented,
   5069   then it:
   5070   <ul>
   5071   <li>Is STRONGLY RECOMMENDED to back up the keystore implementation with the secure hardware.
   5072     The upstream Android Open Source Project provides the Keymaster Hardware Abstraction Layer
   5073     (HAL) implementation that can be used to satisfy this requirement.</li>
   5074   <li>MUST perform the lock screen authentication in the secure hardware if the device has a
   5075     hardware-backed keystore implementation and only when successful allow the authentication-bound
   5076     keys to be used. The upstream Android Open Source Project provides the Gatekeeper Hardware
   5077     Abstraction Layer (HAL) that can be used to satisfy this requirement
   5078     [<a href="http://source.android.com/devices/tech/security/authentication/gatekeeper.html">Resources, 136</a>].</li>
   5079   </ul>
   5080 </li>
   5081 </ul>
   5082 
   5083 <p>Note that while the above TEE-related requirements are stated as STRONGLY RECOMMENDED, the
   5084   Compatibility Definition for the next API version is planned to changed these to REQIUIRED. If a
   5085   device implementation is already launched on an earlier Android version and has not implemented a
   5086   trusted operating system on the secure hardware, such a device might not be able to meet the
   5087   requirements through a system software update and thus is STRONGLY RECOMMENDED to implement a
   5088   TEE.</p>
   5089 
   5090 <h2 id="9_12_data_deletion">9.12. Data Deletion</h2>
   5091 
   5092 <p>Devices MUST provide users with a mechanism to perform a "Factory Data Reset"
   5093 that allows logical and physical deletion of all data except for the system image
   5094 and data in other partitions that can be regarded as part of the sytem image.
   5095 This MUST satisfy relevant industry standards for data deletion such as NIST SP800-88.
   5096 This MUST be used for the implementation of the wipeData() API (part of the Android Device
   5097 Administration API) described in <a href="#3_9_device_administration">section 3.9 Device
   5098 Administration</a>.</p>
   5099 
   5100 <p>Devices MAY provide a fast data wipe that conducts a logical data erase.</p>
   5101 
   5102 <h1 id="10_software_compatibility_testing">10. Software Compatibility Testing</h1>
   5103 
   5104 
   5105 <p>Device implementations MUST pass all tests described in this section.</p>
   5106 
   5107 <p>However, note that no software test package is fully comprehensive. For this
   5108 reason, device implementers are <strong>STRONGLY RECOMMENDED</strong> to make the minimum number of changes as possible to the reference and
   5109 preferred implementation of Android available from the Android Open Source
   5110 Project. This will minimize the risk of introducing bugs that create
   5111 incompatibilities requiring rework and potential device updates.</p>
   5112 
   5113 <h2 id="10_1_compatibility_test_suite">10.1. Compatibility Test Suite</h2>
   5114 
   5115 
   5116 <p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) [<a href="http://source.android.com/compatibility/index.html">Resources, 137</a>] available from the Android Open Source Project, using the final shipping
   5117 software on the device. Additionally, device implementers SHOULD use the
   5118 reference implementation in the Android Open Source tree as much as possible,
   5119 and MUST ensure compatibility in cases of ambiguity in CTS and for any
   5120 reimplementations of parts of the reference source code.</p>
   5121 
   5122 <p>The CTS is designed to be run on an actual device. Like any software, the CTS
   5123 may itself contain bugs. The CTS will be versioned independently of this
   5124 Compatibility Definition, and multiple revisions of the CTS may be released for
   5125 Android 6.0. Device implementations MUST pass the latest CTS version available
   5126 at the time the device software is completed.</p>
   5127 
   5128 <h2 id="10_2_cts_verifier">10.2. CTS Verifier</h2>
   5129 
   5130 
   5131 <p>Device implementations MUST correctly execute all applicable cases in the CTS
   5132 Verifier. The CTS Verifier is included with the Compatibility Test Suite, and
   5133 is intended to be run by a human operator to test functionality that cannot be
   5134 tested by an automated system, such as correct functioning of a camera and
   5135 sensors.</p>
   5136 
   5137 <p>The CTS Verifier has tests for many kinds of hardware, including some hardware
   5138 that is optional. Device implementations MUST pass all tests for hardware that
   5139 they possess; for instance, if a device possesses an accelerometer, it MUST
   5140 correctly execute the Accelerometer test case in the CTS Verifier. Test cases
   5141 for features noted as optional by this Compatibility Definition Document MAY be
   5142 skipped or omitted.</p>
   5143 
   5144 <p>Every device and every build MUST correctly run the CTS Verifier, as noted
   5145 above. However, since many builds are very similar, device implementers are not
   5146 expected to explicitly run the CTS Verifier on builds that differ only in
   5147 trivial ways. Specifically, device implementations that differ from an
   5148 implementation that has passed the CTS Verifier only by the set of included
   5149 locales, branding, etc. MAY omit the CTS Verifier test.</p>
   5150 
   5151 <h1 id="11_updatable_software">11. Updatable Software</h1>
   5152 
   5153 
   5154 <p>Device implementations MUST include a mechanism to replace the entirety of the
   5155 system software. The mechanism need not perform &ldquo;live&rdquo; upgrades&mdash;that is, a
   5156 device restart MAY be required.</p>
   5157 
   5158 <p>Any method can be used, provided that it can replace the entirety of the
   5159 software preinstalled on the device. For instance, any of the following
   5160 approaches will satisfy this requirement:</p>
   5161 
   5162 <ul>
   5163   <li>&ldquo;Over-the-air (OTA)&rdquo; downloads with offline update via reboot</li>
   5164   <li>&ldquo;Tethered&rdquo; updates over USB from a host PC</li>
   5165   <li>&ldquo;Offline&rdquo; updates via a reboot and update from a file on removable storage</li>
   5166 </ul>
   5167 
   5168 <p>However, if the device implementation includes support for an unmetered data
   5169 connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile:</p>
   5170 
   5171 <ul>
   5172 <li>Android Automotive implementations SHOULD support OTA downloads with offline
   5173 update via reboot.</li>
   5174 <li>All other device implementations MUST support OTA downloads with offline
   5175 update via reboot.</li>
   5176 </ul>
   5177 
   5178 <p>The update mechanism used MUST support updates without wiping user data. That
   5179 is, the update mechanism MUST preserve application private data and application
   5180 shared data. Note that the upstream Android software includes an update
   5181 mechanism that satisfies this requirement.</p>
   5182 
   5183 <p>For device implementations that are launching with Android 6.0 and later, the
   5184 update mechanism SHOULD support verifying that the system image is binary
   5185 identical to expected result following an OTA. The block-based OTA
   5186 implementation in the upstream Android Open Source Project, added since Android
   5187 5.1, satisfies this requirement.</p>
   5188 
   5189 <p>If an error is found in a device implementation after it has been released but
   5190 within its reasonable product lifetime that is determined in consultation with
   5191 the Android Compatibility Team to affect the compatibility of third-party
   5192 applications, the device implementer MUST correct the error via a software
   5193 update available that can be applied per the mechanism just described.</p>
   5194 
   5195 <p>Android includes features that allow the Device Owner app (if present) to control the
   5196 installation of system updates. To facilitate this, the system update subsystem
   5197 for devices that report android.software.device_admin MUST implement the behavior
   5198 described in the SystemUpdatePolicy class
   5199 [<a href="http://developer.android.com/reference/android/app/admin/SystemUpdatePolicy.html">
   5200 Resources, 138</a>].</p>
   5201 
   5202 <h1 id="12_document_changelog">12. Document Changelog</h1>
   5203 
   5204 <p>The following table contains a summary of the changes to the Compatibility
   5205 Definition in this release.</p>
   5206 <table>
   5207  <tr>
   5208     <th>Section</th>
   5209     <th>Summary of changes</th>
   5210  </tr>
   5211  <tr>
   5212     <td>Various</td>
   5213     <td>Replaced instances of the "encouraged" term with "RECOMMENDED"</td>
   5214  </tr>
   5215  <tr>
   5216     <td>2. Device Types</td>
   5217     <td>Update for Android Automotive implementations</td>
   5218  </tr>
   5219  <tr>
   5220     <td>3.2.2. Build Parameters</td>
   5221     <td>Additions for the hardware serial number and for the security patch level of a build</td>
   5222  </tr>
   5223  <tr>
   5224     <td>3.2.3.2. Intent Resolution</td>
   5225     <td>Section renamed from "Intent Overrides" to "Intent Resolution," with new requirements related to authoritative default app linking</td>
   5226  </tr>
   5227  <tr>
   5228     <td>3.3.1. Application Binary Interfaces</td>
   5229     <td>Additions for Android ABI support; change related to Vulkan library name</td>
   5230  </tr>
   5231  <tr>
   5232     <td>3.4.1. WebView Compatibility</td>
   5233     <td>Change for the user agent string reported by the WebView</td>
   5234  </tr>
   5235  <tr>
   5236     <td>3.7. Runtime Compatibility</td>
   5237     <td>Updates to memory allocation table</td>
   5238  </tr>
   5239  <tr>
   5240     <td>3.8.4. Search</td>
   5241     <td>Updates regarding Assistant requirements</td>
   5242  </tr>
   5243  <tr>
   5244     <td>3.8.6. Themes</td>
   5245     <td>Added requirement to support black system icons when requested by the SYSTEM_UI_FLAG_LIGHT_STATUS_BAR flag</td>
   5246  </tr>
   5247  <tr>
   5248     <td>3.9.1. Device Provisioning</td>
   5249     <td>Contains new sections for device owner provisioning and managed profile provisioning</td>
   5250  </tr>
   5251  <tr>
   5252     <td>3.9.2. Managed Profile Support</td>
   5253     <td>New section with requirements for device support of managed profile functionality</td>
   5254  </tr>
   5255 <tr>
   5256     <td>3.12.1. TV App</td>
   5257     <td>Added section to clarify TV App requirements for Android Television devices</td>
   5258  </tr>
   5259  <tr>
   5260     <td>3.12.1.1. Electronic Program Guide</td>
   5261     <td>Added section to clarify EPG requirements for Android Television devices</td>
   5262  </tr>
   5263  <tr>
   5264     <td>3.12.1.2. Navigation</td>
   5265     <td>Added section to clarify TV App navigation requirements for Android Television devices</td>
   5266  </tr>
   5267     <td>3.12.1.3. TV input app linking</td>
   5268     <td>Added section to clarify TV input app linking support requirements for Android Television devices</td>
   5269  </tr>
   5270  <tr>
   5271     <td>5.1. Media Codecs</td>
   5272     <td>Updates regarding support for core media formats and decoding.</td>
   5273  </tr>
   5274  <tr>
   5275     <td>5.1.3. Video Codecs</td>
   5276     <td>Changes and additions related to Android Televisions</td>
   5277  </tr>
   5278  <tr>
   5279     <td>5.2. Video Encoding</td>
   5280     <td>Changes for encoders</td>
   5281  </tr>
   5282  <tr>
   5283     <td>5.3. Video Decoding</td>
   5284     <td>Changes for decoders, including regarding support for dynamic video resolution, frame rate
   5285 switching, and more</td>
   5286  </tr>
   5287  <tr>
   5288     <td>5.4. Audio Recording</td>
   5289     <td>Additions related to audio capture</td>
   5290  </tr>
   5291  <tr>
   5292     <td>5.6. Audio Latency</td>
   5293     <td>Update regarding reporting of support for low-latency audio</td>
   5294  </tr>
   5295  <tr>
   5296     <td>5.10. Professional Audio</td>
   5297     <td>General updates for professional audio support; updates for mobile device (jack) specifications, USB audio host mode, and other updates</td>
   5298  </tr>
   5299  <tr>
   5300     <td>5.9. Musical Instrument Digital Interface (MIDI)</td>
   5301     <td>Added new section on optional Musical Instrument Digital Interface (MIDI) support</td>
   5302  </tr>
   5303 <tr>
   5304     <td>6.1. Developer Tools</td>
   5305     <td>Update for drivers supporting Windows 10</td>
   5306  </tr>
   5307  <tr>
   5308     <td>7.1.1.3. Screen Density</td>
   5309     <td>Updates for screen density, for example related to an Android watch</td>
   5310  </tr>
   5311  <tr>
   5312     <td>7.2.3. Navigation Keys</td>
   5313     <td>Updated requirements for device implementations that include the Assist action</td>
   5314  </tr>
   5315  <tr>
   5316     <td>7.3. Sensors (and subsections)</td>
   5317     <td>New requirements for some sensor types</td>
   5318  </tr>
   5319  <tr>
   5320     <td>7.3.9. High Fidelity Sensors</td>
   5321     <td>New section with requirements for devices supporting high fidelity sensors</td>
   5322  </tr>
   5323  <tr>
   5324     <td>7.3.10. Fingerprint Sensor</td>
   5325     <td>New section on requirements related to fingerprint sensors</td>
   5326  </tr>
   5327  <tr>
   5328     <td>7.4.2. IEEE 802.11 (Wi-Fi)</td>
   5329     <td>Updates regarding support for multicast DNS (mDNS)</td>
   5330  </tr>
   5331  <tr>
   5332     <td>7.4.3. Bluetooth</td>
   5333     <td>Addition related to Resolvable Private Address (RPA) for Bluetooth Low Energy (BLE)</td>
   5334  </tr>
   5335  <tr>
   5336     <td>7.4.4. Near-Field Communications</td>
   5337     <td>Additions to requirements for Near-Field Communications (NFC)</td>
   5338  </tr>
   5339  <tr>
   5340     <td>7.4.5. Minimum Network Capability</td>
   5341     <td>Added requirements for IPv6 support</td>
   5342  </tr>
   5343  <tr>
   5344     <td>7.6.3. Adoptable Storage</td>
   5345     <td>New section for implementation of adoptable storage</td>
   5346  </tr>
   5347  <tr>
   5348     <td>7.7. USB</td>
   5349     <td>Requirement related to implementing the AOA specification</td>
   5350  </tr>
   5351  <tr>
   5352     <td>7.8.3. Near-Ultrasound</td>
   5353     <td>Additions related to near-ultrasound recording, playback, and audio</td>
   5354  </tr>
   5355  <tr>
   5356     <td>8.3. Power-Saving Modes</td>
   5357     <td>New section with requirements regarding the App Standby and Doze modes</td>
   5358  </tr>
   5359 <tr>
   5360     <td>8.4. Power Consumption Accounting</td>
   5361     <td>New section with requirements for tracking hardware component power usage and attributing that power usage to specific applications</td>
   5362  </tr>
   5363  <tr>
   5364     <td>9.1. Permissions</td>
   5365     <td>Addition to Permissions requirements</td>
   5366  </tr>
   5367 <tr>
   5368     <td>9.7. Kernel Security Features</td>
   5369     <td>SE Linux updates</td>
   5370  </tr>
   5371 <tr>
   5372     <td>9.8. Privacy</td>
   5373     <td>Addition regarding user's consent for access to shared storage over a USB port</td>
   5374  </tr>
   5375  <tr>
   5376     <td>9.9. Full-Disk Encryption</td>
   5377     <td>Requirements related to full disk encryption</td>
   5378  </tr>
   5379  <tr>
   5380     <td>9.10. Verified Boot</td>
   5381     <td>Additional requirement for verified boot</td>
   5382  </tr>
   5383  <tr>
   5384     <td>9.11. Keys and Credentials</td>
   5385     <td>New section of requirements related to keys and credentials</td>
   5386  </tr>
   5387  <tr>
   5388     <td>9.12. Data Deletion</td>
   5389     <td>New section for "Factory Data Reset"</td>
   5390  </tr>
   5391  <tr>
   5392     <td>11. Updatable Software</td>
   5393     <td>Requirement related to the system update policy set by the device owner</td>
   5394  </tr>
   5395  </table>
   5396 
   5397 
   5398 <h1 id="13_contact_us">13. Contact Us</h1>
   5399 
   5400 
   5401 <p>You can join the android-compatibility forum <a href="https://groups.google.com/forum/#!forum/android-compatibility">[Resources, 139</a>] and ask for clarifications or bring up any issues that you think the document
   5402 does not cover.</p>
   5403 
   5404 <h1 id="14_resources">14. Resources</h1>
   5405 
   5406 <p>1. IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></p>
   5407 
   5408 <p>2. Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></p>
   5409 
   5410 <p>3. Android Television features: <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK</a></p>
   5411 
   5412 <p>4. Android Watch feature: <a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH">http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH</a></p>
   5413 
   5414 <p>5. Android UI_MODE_TYPE_CAR API: <a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR</a></p>
   5415 
   5416 <p>6. API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></p>
   5417 
   5418 <p>7. Android Permissions reference: <a href="http://developer.android.com/reference/android/Manifest.permission.html">http://developer.android.com/reference/android/Manifest.permission.html</a></p>
   5419 
   5420 <p>8. android.os.Build reference: <a href="http://developer.android.com/reference/android/os/Build.html">http://developer.android.com/reference/android/os/Build.html</a></p>
   5421 
   5422 <p>9. Android 6.0 allowed version strings: <a href="http://source.android.com/compatibility/6.0/versions.html">http://source.android.com/compatibility/6.0/versions.html</a></p>
   5423 
   5424 <p>10. Android Developer Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html">http://developer.android.com/reference/android/provider/Settings.html</a></p>
   5425 
   5426 <p>11. Telephony Provider: <a href="http://developer.android.com/reference/android/provider/Telephony.html">http://developer.android.com/reference/android/provider/Telephony.html</a></p>
   5427 
   5428 <p>12. Android NDK ABI Management: <a href="https://developer.android.com/ndk/guides/abis.html">https://developer.android.com/ndk/guides/abis.html</a></p>
   5429 
   5430 <p>13. Advanced SIMD architecture: <a href="http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html">http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0388f/Beijfcja.html</a></p>
   5431 
   5432 <p>14. Android Extension Pack: <a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">http://developer.android.com/guide/topics/graphics/opengl.html#aep</a></p>
   5433 
   5434 <p>15. android.webkit.WebView class: <a href="http://developer.android.com/reference/android/webkit/WebView.html">http://developer.android.com/reference/android/webkit/WebView.html</a></p>
   5435 
   5436 <p>16. WebView compatibility: <a href="http://www.chromium.org/">http://www.chromium.org/</a></p>
   5437 
   5438 <p>17. HTML5: <a href="http://html.spec.whatwg.org/multipage/">http://html.spec.whatwg.org/multipage/</a></p>
   5439 
   5440 <p>18. HTML5 offline capabilities:<a href="http://dev.w3.org/html5/spec/Overview.html#offline"> http://dev.w3.org/html5/spec/Overview.html#offline</a></p>
   5441 
   5442 <p>19. HTML5 video tag: <a href="http://dev.w3.org/html5/spec/Overview.html#video">http://dev.w3.org/html5/spec/Overview.html#video</a></p>
   5443 
   5444 <p>20. HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></p>
   5445 
   5446 <p>21. HTML5/W3C webstorage API: <a href="http://www.w3.org/TR/webstorage/">http://www.w3.org/TR/webstorage/</a></p>
   5447 
   5448 <p>22. HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></p>
   5449 
   5450 <p>23. Dalvik Executable Format and bytecode specification: available in the
   5451 Android source code, at dalvik/docs</p>
   5452 
   5453 <p>24. AppWidgets: <a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">http://developer.android.com/guide/practices/ui_guidelines/widget_design.html</a></p>
   5454 
   5455 <p>25. Notifications: <a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">http://developer.android.com/guide/topics/ui/notifiers/notifications.html</a></p>
   5456 
   5457 <p>26. Application Resources: <a href="https://developer.android.com/guide/topics/resources/available-resources.html">https://developer.android.com/guide/topics/resources/available-resources.html</a></p>
   5458 
   5459 <p>27. Status Bar icon style guide: <a href="http://developer.android.com/design/style/iconography.html">http://developer.android.com/design/style/iconography.html</a></p>
   5460 
   5461 <p>28. Notifications Resources: <a href="https://developer.android.com/design/patterns/notifications.html">https://developer.android.com/design/patterns/notifications.html</a></p>
   5462 
   5463 <p>29. Search Manager: <a href="http://developer.android.com/reference/android/app/SearchManager.html">http://developer.android.com/reference/android/app/SearchManager.html</a></p>
   5464 
   5465 <p>30. Action Assist: <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST</a></p>
   5466 
   5467 <p>31. Android Assist APIs: <a href="https://developer.android.com/reference/android/app/assist/package-summary.html">https://developer.android.com/reference/android/app/assist/package-summary.html</a></p>
   5468 
   5469 <p>32. Toasts: <a href="http://developer.android.com/reference/android/widget/Toast.html">http://developer.android.com/reference/android/widget/Toast.html</a></p>
   5470 
   5471 <p>33. Themes: <a href="http://developer.android.com/guide/topics/ui/themes.html">http://developer.android.com/guide/topics/ui/themes.html</a></p>
   5472 
   5473 <p>34. R.style class: <a href="http://developer.android.com/reference/android/R.style.html">http://developer.android.com/reference/android/R.style.html</a></p>
   5474 
   5475 <p>35. Material design: <a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">http://developer.android.com/reference/android/R.style.html#Theme_Material</a></p>
   5476 
   5477 <p>36. Live Wallpapers: <a href="http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html">http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html</a></p>
   5478 
   5479 <p>37. Overview screen resources: <a href="http://developer.android.com/guide/components/recents.html">http://developer.android.com/guide/components/recents.html</a></p>
   5480 
   5481 <p>38. Screen pinning: <a href="https://developer.android.com/about/versions/android-5.0.html#ScreenPinning">https://developer.android.com/about/versions/android-5.0.html#ScreenPinning</a></p>
   5482 
   5483 <p>39. Input methods: <a href="http://developer.android.com/guide/topics/text/creating-input-method.html">http://developer.android.com/guide/topics/text/creating-input-method.html</a></p>
   5484 
   5485 <p>40. Media Notification: <a href="https://developer.android.com/reference/android/app/Notification.MediaStyle.html">https://developer.android.com/reference/android/app/Notification.MediaStyle.html</a></p>
   5486 
   5487 <p>41. Dreams: <a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">http://developer.android.com/reference/android/service/dreams/DreamService.html</a></p>
   5488 
   5489 <p>42. Settings.Secure LOCATION_MODE: <a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE</a></p>
   5490 
   5491 <p>43. Unicode 6.1.0: <a href="http://www.unicode.org/versions/Unicode6.1.0/">http://www.unicode.org/versions/Unicode6.1.0/</a></p>
   5492 
   5493 <p>44. Android Device Administration: <a href="http://developer.android.com/guide/topics/admin/device-admin.html">http://developer.android.com/guide/topics/admin/device-admin.html</a></p>
   5494 
   5495 <p>45. DevicePolicyManager reference: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html</a></p>
   5496 
   5497 <p>46. Device Owner App: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)</a></p>
   5498 
   5499 
   5500 <p>47. Android Device Owner Provisioning Flow: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_DEVICE</a></p>
   5501 
   5502 <p>48. Device Owner Provisioning via NFC: <a href="https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc">https://source.android.com/devices/tech/admin/provision.html#device_owner_provisioning_via_nfc</a></p>
   5503 
   5504 <p>49. Android Profile Owner App:<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isProfileOwnerApp(java.lang.String)</a></p>
   5505 
   5506 <p>50. Android Managed Profile Provisioning flow: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#ACTION_PROVISION_MANAGED_PROFILE</a></p>
   5507 
   5508 <p>51. Android Accessibility Service APIs: <a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html</a></p>
   5509 
   5510 <p>52. Android Accessibility APIs: <a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">http://developer.android.com/reference/android/view/accessibility/package-summary.html</a></p>
   5511 
   5512 <p>53. Eyes Free project: <a href="http://code.google.com/p/eyes-free/">http://code.google.com/p/eyes-free</a></p>
   5513 
   5514 <p>54. Text-To-Speech APIs: <a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">http://developer.android.com/reference/android/speech/tts/package-summary.html</a></p>
   5515 
   5516 <p>55. Television Input Framework: <a href="https://source.android.com/devices/tv/index.html">https://source.android.com/devices/tv/index.html</a></p>
   5517 
   5518 <p>56. TV App channels: <a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html">http://developer.android.com/reference/android/media/tv/TvContract.Channels.html</a></p>
   5519 
   5520 <p>57. Third-party TV inputs: <a href="https://source.android.com/devices/tv/index.html#third-party_input_example">https://source.android.com/devices/tv/index.html#third-party_input_example</a></p>
   5521 
   5522 <p>58. TV inputs: <a href="https://source.android.com/devices/tv/index.html#tv_inputs">https://source.android.com/devices/tv/index.html#tv_inputs</a></p>
   5523 
   5524 <p>59. TV channel EPG fields: <a href="https://developer.android.com/reference/android/media/tv/TvContract.Programs.html">https://developer.android.com/reference/android/media/tv/TvContract.Programs.html</a></p>
   5525 
   5526 <p>60. TV input app linking: <a href="http://developer.android.com/reference/android/media/tv/TvContract.Channels.html#COLUMN_APP_LINK_INTENT_URI">http://developer.android.com/reference/android/media/tv/TvContract.Channels.html#COLUMN_APP_LINK_INTENT_URI</a></p>
   5527 
   5528 <p>61. Reference tool documentation (for adb, aapt, ddms, systrace): <a href="http://developer.android.com/tools/help/index.html">http://developer.android.com/tools/help/index.html</a></p>
   5529 
   5530 <p>62. Android apk file description: <a href="http://developer.android.com/guide/components/fundamentals.html">http://developer.android.com/guide/components/fundamentals.html</a></p>
   5531 
   5532 <p>63. Manifest files: <a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">http://developer.android.com/guide/topics/manifest/manifest-intro.html</a></p>
   5533 
   5534 <p>64. Android Media Formats: <a href="http://developer.android.com/guide/appendix/media-formats.html">http://developer.android.com/guide/appendix/media-formats.html</a></p>
   5535 
   5536 <p>65. Android MediaCodecList API: <a href="http://developer.android.com/reference/android/media/MediaCodecList.html">http://developer.android.com/reference/android/media/MediaCodecList.html</a></p>
   5537 
   5538 <p>66. Android CamcorderProfile API: <a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">http://developer.android.com/reference/android/media/CamcorderProfile.html</a></p>
   5539 
   5540 <p>67. WebM project: <a href="http://www.webmproject.org/">http://www.webmproject.org/</a></p>
   5541 
   5542 <p>68. RTC Hardware Coding Requirements: <a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">http://www.webmproject.org/hardware/rtc-coding-requirements/</a></p>
   5543 
   5544 <p>69. AudioEffect API: <a href="http://developer.android.com/reference/android/media/audiofx/AudioEffect.html">http://developer.android.com/reference/android/media/audiofx/AudioEffect.html</a></p>
   5545 
   5546 <p>70. Android android.content.pm.PackageManager class and Hardware Features List: <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">http://developer.android.com/reference/android/content/pm/PackageManager.html</a></p>
   5547 
   5548 <p>71. HTTP Live Streaming Draft Protocol: <a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-03">http://tools.ietf.org/html/draft-pantos-http-live-streaming-03</a></p>
   5549 
   5550 <p>72. ADB: <a href="http://developer.android.com/tools/help/adb.html">http://developer.android.com/tools/help/adb.html</a></p>
   5551 
   5552 <p>73. Dumpsys: <a href="https://source.android.com/devices/input/diagnostics.html">https://source.android.com/devices/input/diagnostics.html</a></p>
   5553 
   5554 <p>74. DDMS: <a href="http://developer.android.com/tools/debugging/ddms.html">http://developer.android.com/tools/debugging/ddms.html</a></p>
   5555 
   5556 <p>75. Monkey testing tool: <a href="http://developer.android.com/tools/help/monkey.html">http://developer.android.com/tools/help/monkey.html</a></p>
   5557 
   5558 <p>76. SysyTrace tool: <a href="http://developer.android.com/tools/help/systrace.html">http://developer.android.com/tools/help/systrace.html</a></p>
   5559 
   5560 <p>77. Android Application Development-Related Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS</a></p>
   5561 
   5562 <p>78. Supporting Multiple Screens: <a href="http://developer.android.com/guide/practices/screens_support.html">http://developer.android.com/guide/practices/screens_support.html</a></p>
   5563 
   5564 <p>79. android.util.DisplayMetrics: <a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">http://developer.android.com/reference/android/util/DisplayMetrics.html</a></p>
   5565 
   5566 <p>80. RenderScript: <a href="http://developer.android.com/guide/topics/renderscript/">http://developer.android.com/guide/topics/renderscript/</a></p>
   5567 
   5568 <p>81. Android extension pack for OpenGL ES: <a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">https://developer.android.com/reference/android/opengl/GLES31Ext.html</a></p>
   5569 
   5570 <p>82. Hardware Acceleration: <a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">http://developer.android.com/guide/topics/graphics/hardware-accel.html</a></p>
   5571 
   5572 <p>83. EGL Extension-EGL_ANDROID_RECORDABLE: <a href="http://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">http://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt</a></p>
   5573 
   5574 <p>84. Display Manager: <a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html">http://developer.android.com/reference/android/hardware/display/DisplayManager.html</a></p>
   5575 
   5576 <p>85. android.content.res.Configuration: <a href="http://developer.android.com/reference/android/content/res/Configuration.html">http://developer.android.com/reference/android/content/res/Configuration.html</a></p>
   5577 
   5578 <p>86. Touch Input Configuration: <a href="http://source.android.com/devices/tech/input/touch-devices.html">http://source.android.com/devices/tech/input/touch-devices.html</a></p>
   5579 
   5580 <p>87. Motion Event API: <a href="http://developer.android.com/reference/android/view/MotionEvent.html">http://developer.android.com/reference/android/view/MotionEvent.html</a></p>
   5581 
   5582 <p>88. Key Event API: <a href="http://developer.android.com/reference/android/view/KeyEvent.html">http://developer.android.com/reference/android/view/KeyEvent.html</a></p>
   5583 
   5584 <p>89. Android Open Source sensors: <a href="http://source.android.com/devices/sensors/">http://source.android.com/devices/sensors</a></p>
   5585 
   5586 <p>90. android.hardware.SensorEvent: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">http://developer.android.com/reference/android/hardware/SensorEvent.html</a></p>
   5587 
   5588 <p>91. Timestamp sensor event: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp</a></p>
   5589 
   5590 <p>92. Android Open Source composite sensors: <a href="http://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary</a></p>
   5591 
   5592 <p>93. Continuous trigger mode: <a href="http://source.android.com/devices/sensors/report-modes.html#continuous">https://source.android.com/devices/sensors/report-modes.html#continuous</a></p>
   5593 
   5594 <p>94. Accelerometer sensor: <a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER">http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER</a></p>
   5595 
   5596 <p>95. Android Fingerprint API: <a href="https://developer.android.com/reference/android/hardware/fingerprint/package-summary.html">https://developer.android.com/reference/android/hardware/fingerprint/package-summary.html</a></p>
   5597 
   5598 <p>96. Android Fingerprint HAL: <a href="https://source.android.com/devices/tech/security/authentication/fingerprint-hal.html">https://source.android.com/devices/tech/security/authentication/fingerprint-hal.html</a></p>
   5599 
   5600 <p>97. Wi-Fi Multicast API: <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html">http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html</a></p>
   5601 
   5602 <p>98. Wi-Fi Direct (Wi-Fi P2P): <a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html</a></p>
   5603 
   5604 <p>99. WifiManager API: <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.html">http://developer.android.com/reference/android/net/wifi/WifiManager.html</a></p>
   5605 
   5606 <p>100. Bluetooth API: <a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">http://developer.android.com/reference/android/bluetooth/package-summary.html</a></p>
   5607 
   5608 <p>101. Bluetooth ScanFilter API: <a href="https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html">https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html</a></p>
   5609 
   5610 <p>102. NFC Barcode: <a href="http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html">http://developer.android.com/reference/android/nfc/tech/NfcBarcode.html</a></p>
   5611 
   5612 <p>103. NDEF Push Protocol: <a href="http://source.android.com/compatibility/ndef-push-protocol.pdf">http://source.android.com/compatibility/ndef-push-protocol.pdf</a></p>
   5613 
   5614 <p>104. Android Beam: <a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">http://developer.android.com/guide/topics/connectivity/nfc/nfc.html</a></p>
   5615 
   5616 <p>105. Android NFC Sharing Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS</a></p>
   5617 
   5618 <p>106. NFC Connection Handover: <a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">http://members.nfc-forum.org/specs/spec_list/#conn_handover</a></p>
   5619 
   5620 <p>107. Bluetooth Secure Simple Pairing Using NFC: <a href="http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf">http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf</a></p>
   5621 
   5622 <p>108. Host-based Card Emulation: <a href="http://developer.android.com/guide/topics/connectivity/nfc/hce.html">http://developer.android.com/guide/topics/connectivity/nfc/hce.html</a></p>
   5623 
   5624 <p>109. Content Resolver: <a href="http://developer.android.com/reference/android/content/ContentResolver.html">http://developer.android.com/reference/android/content/ContentResolver.html</a></p>
   5625 
   5626 <p>110. Camera orientation API: <a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)</a></p>
   5627 
   5628 <p>111. Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></p>
   5629 
   5630 <p>112. Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">http://developer.android.com/reference/android/hardware/Camera.Parameters.html</a></p>
   5631 
   5632 <p>113. Camera hardware level: <a href="https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL">https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL</a></p>
   5633 
   5634 <p>114. Camera version support: <a href="http://source.android.com/devices/camera/versioning.html">http://source.android.com/devices/camera/versioning.html</a></p>
   5635 
   5636 <p>115. Android DownloadManager: <a href="http://developer.android.com/reference/android/app/DownloadManager.html">http://developer.android.com/reference/android/app/DownloadManager.html</a></p>
   5637 
   5638 <p>116. Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></p>
   5639 
   5640 <p>117. Adoptable storage: <a href="http://source.android.com/devices/storage/adoptable.html">http://source.android.com/devices/storage/adoptable.html</a></p>
   5641 
   5642 <p>118. Android Open Accessories: <a href="http://developer.android.com/guide/topics/connectivity/usb/accessory.html">http://developer.android.com/guide/topics/connectivity/usb/accessory.html</a></p>
   5643 
   5644 <p>119. Android USB Audio: <a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO</a></p>
   5645 
   5646 <p>120. USB Battery Charging Specification, Revision 1.2: <a href="http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip">http://www.usb.org/developers/docs/devclass_docs/BCv1.2_070312.zip</a></p>
   5647 
   5648 <p>121. USB Host API:<a href="http://developer.android.com/guide/topics/connectivity/usb/host.html"> http://developer.android.com/guide/topics/connectivity/usb/host.html</a></p>
   5649 
   5650 <p>122. Wired audio headset: <a href="http://source.android.com/accessories/headset-spec.html">http://source.android.com/accessories/headset-spec.html</a></p>
   5651 
   5652 <p>123. Power profile components: <a href="http://source.android.com/devices/tech/power/values.html">http://source.android.com/devices/tech/power/values.html</a></p>
   5653 
   5654 <p>124. Batterystats: <a href="http://source.android.com/devices/tech/power/batterystats.html">http://source.android.com/devices/tech/power/batterystats.html</a></p>
   5655 
   5656 <p>125. Power usage summary: <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_POWER_USAGE_SUMMARY">http://developer.android.com/reference/android/content/Intent.html#ACTION_POWER_USAGE_SUMMARY</a></p>
   5657 
   5658 <p>126. Android Security and Permissions reference: <a href="http://developer.android.com/guide/topics/security/permissions.html">http://developer.android.com/guide/topics/security/permissions.html</a></p>
   5659 
   5660 <p>127. UserManager reference: <a href="http://developer.android.com/reference/android/os/UserManager.html">http://developer.android.com/reference/android/os/UserManager.html</a></p>
   5661 
   5662 <p>128. External Storage reference: <a href="http://source.android.com/devices/storage/traditional.html">http://source.android.com/devices/storage</a></p>
   5663 
   5664 <p>129. External Storage APIs: <a href="http://developer.android.com/reference/android/os/Environment.html">http://developer.android.com/reference/android/os/Environment.html</a></p>
   5665 
   5666 <p>130. SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></p>
   5667 
   5668 <p>131. Secure lock screen reporting: <a href="http://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceSecure()">http://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceSecure()</a></p>
   5669 
   5670 <p>132. Android Open Source Encryption: <a href="http://source.android.com/devices/tech/security/encryption/index.html">http://source.android.com/devices/tech/security/encryption/index.html</a></p>
   5671 
   5672 <p>133. Android Keystore System: <a href="https://developer.android.com/training/articles/keystore.html">https://developer.android.com/training/articles/keystore.html</a></p>
   5673 
   5674 <p>134. KeyChain API: <a href="https://developer.android.com/reference/android/security/KeyChain.html">https://developer.android.com/reference/android/security/KeyChain.html</a></p>
   5675 
   5676 <p>135. Keystore API: <a href="https://developer.android.com/reference/java/security/KeyStore.html">https://developer.android.com/reference/java/security/KeyStore.html</a></p>
   5677 
   5678 <p>136. Gatekeeper HAL: <a href="http://source.android.com/devices/tech/security/authentication/gatekeeper.html">http://source.android.com/devices/tech/security/authentication/gatekeeper.html</a></p>
   5679 
   5680 <p>137. Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></p>
   5681 
   5682 <p>138. SystemUpdatePolicy class: <a href="http://developer.android.com/reference/android/app/admin/SystemUpdatePolicy.html">http://developer.android.com/reference/android/app/admin/SystemUpdatePolicy.html</a></p>
   5683 
   5684 <p>139. Android Compatibility forum: <a href="https://groups.google.com/forum/#!forum/android-compatibility">https://groups.google.com/forum/#!forum/android-compatibility</a></p>
   5685 
   5686 <p>140. Handling app links: <a href="https://developer.android.com/training/app-links">https://developer.android.com/training/app-links/index.html</a></p>
   5687 
   5688 <p>141. Google Digital Asset Links: <a href="https://developers.google.com/digital-asset-links">https://developers.google.com/digital-asset-links</a></p>
   5689 
   5690 <p>Many of these resources are derived directly or indirectly from the Android
   5691 SDK, and will be functionally identical to the information in that SDK&rsquo;s
   5692 documentation. In any cases where this Compatibility Definition or the
   5693 Compatibility Test Suite disagrees with the SDK documentation, the SDK
   5694 documentation is considered authoritative. Any technical details provided in
   5695 the references included above are considered by inclusion to be part of this
   5696 Compatibility Definition.</p>
   5697 
   5698 </div>
   5699 </body>
   5700 </html>
   5701