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2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
3<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
4<head>
5<title>Android 4.2Compatibility Definition</title>
6<link rel="stylesheet" type="text/css" href="cdd.css"/>
7</head>
8<body>
9<div><img src="header.jpg" alt="Android logo"/></div>
10<h1>Android 4.2 Compatibility Definition</h1>
11<!--
12<span style="color: red; font-weight: bold;"><h2>Revision 1</h2></span><br/>
13<span style="color: red;">Last updated: October 17, 2012</span>
14-->
15<p><b><font color="red">Revision 2</font></b><br/>
16Last updated: Feb 17, 2013
17</p>
18<p>Copyright &copy; 2012, Google Inc. All rights reserved.<br/>
19<a href="mailto:compatibility@android.com">compatibility@android.com</a>
20</p>
21
22<h2> Table of Contents</h2>
23<div style="margin-left: 2em;">
24 <a href="#section-1">1. Introduction</a><br/>
25 <a href="#section-2">2. Resources</a><br/>
26 <a href="#section-3">3. Software</a><br/>
27 <div style="margin-left: 2em;">
28 <a href="#section-3.1">3.1. Managed API Compatibility</a><br/>
29 <a href="#section-3.2">3.2. Soft API Compatibility</a><br/>
30 <div style="margin-left: 2em;">
31 <a href="#section-3.2.1">3.2.1. Permissions</a><br/>
32 <a href="#section-3.2.2">3.2.2. Build Parameters</a><br/>
33 <a href="#section-3.2.3">3.2.3. Intent Compatibility</a><br/>
34 <div style="margin-left: 2em;">
35 <a href="#section-3.2.3.1">3.2.3.1. Core Application Intents</a><br/>
36 <a href="#section-3.2.3.2">3.2.3.2. Intent Overrides</a><br/>
37 <a href="#section-3.2.3.3">3.2.3.3. Intent Namespaces</a><br/>
38 <a href="#section-3.2.3.4">3.2.3.4. Broadcast Intents</a><br/>
39 </div>
40 </div>
41 <a href="#section-3.3">3.3. Native API Compatibility</a><br/>
42 <div style="margin-left: 2em;">
43 <a href="#section-3.3.1">3.3.1 Application Binary Interfaces</a><br/>
44 </div>
45 <a href="#section-3.4">3.4. Web Compatibility</a><br/>
46 <div style="margin-left: 2em;">
47 <a href="#section-3.4.1">3.4.1. WebView Compatibility</a><br/>
48 <a href="#section-3.4.2">3.4.2. Browser Compatibility</a><br/>
49 </div>
50 <a href="#section-3.5">3.5. API Behavioral Compatibility</a><br/>
51 <a href="#section-3.6">3.6. API Namespaces</a><br/>
52 <a href="#section-3.7">3.7. Virtual Machine Compatibility</a><br/>
53 <a href="#section-3.8">3.8. User Interface Compatibility</a><br/>
54 <div style="margin-left: 2em;">
55 <a href="#section-3.8.1">3.8.1. Widgets</a><br/>
56 <a href="#section-3.8.2">3.8.2. Notifications</a><br/>
57 <a href="#section-3.8.3">3.8.3. Search</a><br/>
58 <a href="#section-3.8.4">3.8.4. Toasts</a><br/>
59 <a href="#section-3.8.5">3.8.5. Themes</a><br/>
60 <a href="#section-3.8.6">3.8.6. Live Wallpapers</a><br/>
61 <a href="#section-3.8.7">3.8.7. Recent Application Display</a><br/>
62 <a href="#section-3.8.8">3.8.8. Input Management Settings</a><br/>
63 <a href="#section-3.8.9">3.8.9. Lock and Home Screen Widgets</a><br/>
64 <a href="#section-3.8.10">3.8.10. Lock Screen Media Remote Control</a><br/>
65 <a href="#section-3.8.11">3.8.11. Dreams</a><br/>
66 </div>
67 <a href="#section-3.9">3.9 Device Administration</a><br/>
68 <a href="#section-3.10">3.10 Accessibility</a><br/>
69 <a href="#section-3.11">3.11 Text-to-Speech</a><br/>
70 </div>
71 <a href="#section-4">4. Application Packaging Compatibility</a><br/>
72 <a href="#section-5">5. Multimedia Compatibility</a><br/>
73 <div style="margin-left: 2em;">
74 <a href="#section-5.1">5.1. Media Codecs</a><br/>
75 <a href="#section-5.2">5.2. Video Encoding</a><br/>
76 <a href="#section-5.3">5.3. Video Decoding</a><br/>
77 <a href="#section-5.4">5.4. Audio Recording</a><br/>
78 <a href="#section-5.5">5.5. Audio Latency</a><br/>
79 <a href="#section-5.6">5.6. Network Protocols</a><br/>
80 </div>
81 <a href="#section-6">6. Developer Tools and Options Compatibility</a><br/>
82 <div style="margin-left: 2em;">
83 <a href="#section-6.1">6.1. Developer Tools</a><br/>
84 <a href="#section-6.2">6.2. Developer Options</a><br/>
85 </div>
86 <a href="#section-7">7. Hardware Compatibility</a><br/>
87 <div style="margin-left: 2em;">
88 <a href="#section-7.1">7.1. Display and Graphics</a><br/>
89 <div style="margin-left: 2em;">
90 <a href="#section-7.1.1">7.1.1. Screen Configuration</a><br/>
91 <a href="#section-7.1.2">7.1.2. Display Metrics</a><br/>
92 <a href="#section-7.1.3">7.1.3. Screen Orientation</a><br/>
93 <a href="#section-7.1.4">7.1.4. 2D and 3D Graphics Accleration</a><br/>
94 <a href="#section-7.1.5">7.1.5. Legacy Application Compatibility Mode</a><br/>
95 <a href="#section-7.1.6">7.1.6. Screen Types</a><br/>
96 <a href="#section-7.1.7">7.1.7. Screen Technology</a><br/>
97 <a href="#section-7.1.8">7.1.8. External Displays</a><br/>
98 </div>
99 <a href="#section-7.2">7.2. Input Devices</a><br/>
100 <div style="margin-left: 2em;">
101 <a href="#section-7.2.1">7.2.1. Keyboard</a><br/>
102 <a href="#section-7.2.2">7.2.2. Non-touch Navigation</a><br/>
103 <a href="#section-7.2.3">7.2.3. Navigation keys</a><br/>
104 <a href="#section-7.2.4">7.2.4. Touchscreen input</a><br/>
105 </div>
106 <a href="#section-7.3">7.3. Sensors</a><br/>
107 <div style="margin-left: 2em;">
108 <a href="#section-7.3.1">7.3.1. Accelerometer</a><br/>
109 <a href="#section-7.3.2">7.3.2. Magnetometer</a><br/>
110 <a href="#section-7.3.3">7.3.3. GPS</a><br/>
111 <a href="#section-7.3.4">7.3.4. Gyroscope</a><br/>
112 <a href="#section-7.3.5">7.3.5. Barometer</a><br/>
113 <a href="#section-7.3.6">7.3.6. Thermometer</a><br/>
114 <a href="#section-7.3.7">7.3.7. Photometer</a><br/>
115 <a href="#section-7.3.8">7.3.8. Proximity Sensor</a><br/>
116 </div>
117 <a href="#section-7.4">7.4. Data Connectivity</a><br/>
118 <div style="margin-left: 2em;">
119 <a href="#section-7.4.1">7.4.1. Telephony</a><br/>
120 <a href="#section-7.4.2">7.4.2. IEEE 802.11 (WiFi)</a><br/>
121 <div style="margin-left: 2em;">
122 <a href="#section-7.4.2.1">7.4.2.1. WiFi Direct</a><br/>
123 </div>
124 <a href="#section-7.4.3">7.4.3. Bluetooth</a><br/>
125 <a href="#section-7.4.4">7.4.4. Near-Field Communications</a><br/>
126 <a href="#section-7.4.5">7.4.5. Minimum Network Capability</a><br/>
127 </div>
128 <a href="#section-7.5">7.5. Cameras</a><br/>
129 <div style="margin-left: 2em;">
130 <a href="#section-7.5.1">7.5.1. Rear-Facing Camera</a><br/>
131 <a href="#section-7.5.2">7.5.2. Front-Facing Camera</a><br/>
132 <a href="#section-7.5.3">7.5.3. Camera API Behavior</a><br/>
133 <a href="#section-7.5.4">7.5.4. Camera Orientation</a><br/>
134 </div>
135 <a href="#section-7.6">7.6. Memory and Storage</a><br/>
136 <div style="margin-left: 2em;">
137 <a href="#section-7.6.1">7.6.1. Minimum Memory and Storage</a><br/>
138 <a href="#section-7.6.2">7.6.2. Application Shared Storage</a><br/>
139 </div>
140 <a href="#section-7.7">7.7. USB</a><br/>
141 </div>
142 <a href="#section-8">8. Performance Compatibility</a><br/>
143 <a href="#section-9">9. Security Model Compatibility</a><br/>
144 <div style="margin-left: 2em;">
145 <a href="#section-9.1">9.1. Permissions</a><br/>
146 <a href="#section-9.2">9.2. UID and Process Isolation</a><br/>
147 <a href="#section-9.3">9.3. Filesystem Permissions</a><br/>
148 <a href="#section-9.4">9.4. Alternate Execution Environments</a><br/>
149 <a href="#section-9.5">9.5. Multi-User Support</a><br/>
150 <a href="#section-9.6">9.6. Premium SMS Warning</a><br/>
151 </div>
152 <a href="#section-10">10. Software Compatibility Testing</a><br/>
153 <div style="margin-left: 2em;">
154 <a href="#section-10.1">10.1. Compatibility Test Suite</a><br/>
155 <a href="#section-10.2">10.2. CTS Verifier</a><br/>
156 <a href="#section-10.3">10.3. Reference Applications</a><br/>
157 </div>
158 <a href="#section-11">11. Updatable Software</a><br/>
159 <a href="#section-12">12. Contact Us</a><br/>
160 <a href="#appendix-A">Appendix A - Bluetooth Test Procedure</a><br/>
161</div>
162
163<div style="page-break-before: always;"></div>
164
165<a name="section-1"></a><h2>1. Introduction</h2>
166<p>This document enumerates the requirements that must be met in order for
167devices to be compatible with Android 4.2.</p>
168<p>The use of "must", "must not", "required", "shall", "shall not", "should",
169"should not", "recommended", "may" and "optional" is per the IETF standard
170defined in RFC2119 [<a href="#resources01">Resources, 1</a>].</p>
171<p>As used in this document, a "device implementer" or "implementer" is a
172person or organization developing a hardware/software solution running Android
1734.2. A "device implementation" or "implementation" is the hardware/software
174solution so developed.</p>
175<p>To be considered compatible with Android 4.2, device implementations
176MUST meet the requirements presented in this Compatibility Definition,
177including any documents incorporated via reference.</p>
178<p>Where this definition or the software tests described in <a
179href="#section-10">Section 10</a> is silent, ambiguous, or incomplete, it is
180the responsibility of the device implementer to ensure compatibility with
181existing implementations.</p>
182<p>For this reason, the Android Open Source Project [<a
183href="#resources03">Resources, 3</a>] is both the reference and preferred
184implementation of Android. Device implementers are strongly encouraged to base
185their implementations to the greatest extent possible on the "upstream" source
186code available from the Android Open Source Project. While some components can
187hypothetically be replaced with alternate implementations this practice is
188strongly discouraged, as passing the software tests will become substantially
189more difficult. It is the implementer's responsibility to ensure full
190behavioral compatibility with the standard Android implementation, including
191and beyond the Compatibility Test Suite. Finally, note that certain component
192substitutions and modifications are explicitly forbidden by this document.</p>
193<a name="section-2"></a><h2>2. Resources</h2>
194<ol>
195<a name="resources01"></a><li>IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></li>
196<a name="resources02"></a><li>Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></li>
197<a name="resources03"></a><li>Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></li>
198<a name="resources04"></a><li>API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></li>
199<a name="resources05"></a><li>Android Permissions reference: <a href="http://developer.android.com/reference/android/Manifest.permission.html">http://developer.android.com/reference/android/Manifest.permission.html</a></li>
200<a name="resources06"></a><li>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></li>
201<a name="resources07"></a><li>Android 4.2 allowed version strings: <a href="http://source.android.com/compatibility/4.2/versions.html">http://source.android.com/compatibility/4.2/versions.html</a></li>
202<a name="resources08"></a><li>Renderscript: <a href="http://developer.android.com/guide/topics/graphics/renderscript.html">http://developer.android.com/guide/topics/graphics/renderscript.html</a></li>
203<a name="resources09"></a><li>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></li>
204<a name="resources10"></a><li>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></li>
205<a name="resources11"></a><li>HTML5: <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/">http://www.whatwg.org/specs/web-apps/current-work/multipage/</a></li>
206<a name="resources12"></a><li>HTML5 offline capabilities: <a href="http://dev.w3.org/html5/spec/Overview.html#offline">http://dev.w3.org/html5/spec/Overview.html#offline</a></li>
207<a name="resources13"></a><li>HTML5 video tag: <a href="http://dev.w3.org/html5/spec/Overview.html#video">http://dev.w3.org/html5/spec/Overview.html#video</a></li>
208<a name="resources14"></a><li>HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></li>
209<a name="resources15"></a><li>HTML5/W3C webdatabase API: <a href="http://www.w3.org/TR/webdatabase/">http://www.w3.org/TR/webdatabase/</a></li>
210<a name="resources16"></a><li>HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></li>
211<a name="resources17"></a><li>Dalvik Virtual Machine specification: available in the Android source code, at dalvik/docs</li>
212<a name="resources18"></a><li>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></li>
213<a name="resources19"></a><li>Notifications: <a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">http://developer.android.com/guide/topics/ui/notifiers/notifications.html</a></li>
214<a name="resources20"></a><li>Application Resources: <a href="http://code.google.com/android/reference/available-resources.html">http://code.google.com/android/reference/available-resources.html</a></li>
215<a name="resources21"></a><li>Status Bar icon style guide: <a href="http://developer.android.com/guide/practices/ui_guidelines/icon_design_status_bar.html">http://developer.android.com/guide/practices/ui_guidelines/icon_design_status_bar.html</a></li>
216<a name="resources22"></a><li>Search Manager: <a href="http://developer.android.com/reference/android/app/SearchManager.html">http://developer.android.com/reference/android/app/SearchManager.html</a></li>
217<a name="resources23"></a><li>Toasts: <a href="http://developer.android.com/reference/android/widget/Toast.html">http://developer.android.com/reference/android/widget/Toast.html</a></li>
218<a name="resources24"></a><li>Themes: <a href="http://developer.android.com/guide/topics/ui/themes.html">http://developer.android.com/guide/topics/ui/themes.html</a></li>
219<a name="resources25"></a><li>R.style class: <a href="http://developer.android.com/reference/android/R.style.html">http://developer.android.com/reference/android/R.style.html</a></li>
220<a name="resources26"></a><li>Live Wallpapers: <a href="http://developer.android.com/resources/articles/live-wallpapers.html">http://developer.android.com/resources/articles/live-wallpapers.html</a></li>
221<a name="resources27"></a><li>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></li>
222<a name="resources28"></a><li>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></li>
223<a name="resources29"></a><li>Android Accessibility Service APIs: <a href="http://developer.android.com/reference/android/accessibilityservice/package-summary.html">http://developer.android.com/reference/android/accessibilityservice/package-summary.html</a></li>
224<a name="resources30"></a><li>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></li>
225<a name="resources31"></a><li>Eyes Free project: <a href="http://http://code.google.com/p/eyes-free">http://code.google.com/p/eyes-free</a></li>
226<a name="resources32"></a><li>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></li>
227<a name="resources33"></a><li>Reference tool documentation (for adb, aapt, ddms, systrace): <a href="http://developer.android.com/guide/developing/tools/index.html">http://developer.android.com/guide/developing/tools/index.html</a></li>
228<a name="resources34"></a><li>Android apk file description: <a href="http://developer.android.com/guide/topics/fundamentals.html">http://developer.android.com/guide/topics/fundamentals.html</a></li>
229<a name="resources35"></a><li>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></li>
230<a name="resources36"></a><li>Monkey testing tool: <a href="http://developer.android.com/guide/developing/tools/monkey.html">http://developer.android.com/guide/developing/tools/monkey.html</a></li>
231<a name="resources37"></a><li>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></li>
232<a name="resources38"></a><li>Supporting Multiple Screens: <a href="http://developer.android.com/guide/practices/screens_support.html">http://developer.android.com/guide/practices/screens_support.html</a></li>
233<a name="resources39"></a><li>android.util.DisplayMetrics: <a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">http://developer.android.com/reference/android/util/DisplayMetrics.html</a></li>
234<a name="resources40"></a><li>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></li>
235<a name="resources41"></a><li>android.hardware.SensorEvent: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">http://developer.android.com/reference/android/hardware/SensorEvent.html</a></li>
236<a name="resources42"></a><li>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></li>
237<a name="resources43"></a><li>NDEF Push Protocol: <a href="http://source.android.com/compatibility/ndef-push-protocol.pdf">http://source.android.com/compatibility/ndef-push-protocol.pdf</a></li>
238<a name="resources44"></a><li>MIFARE MF1S503X: <a href="http://www.nxp.com/documents/data_sheet/MF1S503x.pdf">http://www.nxp.com/documents/data_sheet/MF1S503x.pdf</a></li>
239<a name="resources45"></a><li>MIFARE MF1S703X: <a href="http://www.nxp.com/documents/data_sheet/MF1S703x.pdf">http://www.nxp.com/documents/data_sheet/MF1S703x.pdf</a></li>
240<a name="resources46"></a><li>MIFARE MF0ICU1: <a href="http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf">http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf</a></li>
241<a name="resources47"></a><li>MIFARE MF0ICU2: <a href="http://www.nxp.com/documents/short_data_sheet/MF0ICU2_SDS.pdf">http://www.nxp.com/documents/short_data_sheet/MF0ICU2_SDS.pdf</a></li>
242<a name="resources48"></a><li>MIFARE AN130511: <a href="http://www.nxp.com/documents/application_note/AN130511.pdf">http://www.nxp.com/documents/application_note/AN130511.pdf</a></li>
243<a name="resources49"></a><li>MIFARE AN130411: <a href="http://www.nxp.com/documents/application_note/AN130411.pdf">http://www.nxp.com/documents/application_note/AN130411.pdf</a></li>
244<a name="resources50"></a><li>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></li>
245<a name="resources51"></a><li>Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></li>
246<a name="resources52"></a><li>Android Open Accessories: <a href="http://developer.android.com/guide/topics/usb/accessory.html">http://developer.android.com/guide/topics/usb/accessory.html</a></li>
247<a name="resources53"></a><li>USB Host API: <a href="http://developer.android.com/guide/topics/usb/host.html">http://developer.android.com/guide/topics/usb/host.html</a></li>
248<a name="resources54"></a><li>Android Security and Permissions reference: <a href="http://developer.android.com/guide/topics/security/security.html">http://developer.android.com/guide/topics/security/security.html</a></li>
249<a name="resources55"></a><li>Apps for Android: <a href="http://code.google.com/p/apps-for-android">http://code.google.com/p/apps-for-android</a></li>
250<a name="resources56"></a><li>Android DownloadManager: <a href="http://developer.android.com/reference/android/app/DownloadManager.html">http://developer.android.com/reference/android/app/DownloadManager.html</a></li>
251<a name="resources57"></a><li>Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></li>
252<a name="resources58"></a><li>Android Media Formats: <a href="http://developer.android.com/guide/appendix/media-formats.html">http://developer.android.com/guide/appendix/media-formats.html</a></li>
253<a name="resources59"></a><li>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></li>
254<a name="resources60"></a><li>NFC Connection Handover: <a href="http://www.nfc-forum.org/specs/spec_list/#conn_handover/">http://www.nfc-forum.org/specs/spec_list/#conn_handover</a></li>
255<a name="resources61"></a><li>Bluetooth Secure Simple Pairing Using NFC: <a href="http://www.nfc-forum.org/resources/AppDocs/NFCForum_AD_BTSSP_1_0.pdf">http://www.nfc-forum.org/resources/AppDocs/NFCForum_AD_BTSSP_1_0.pdf</a></li>
256<a name="resources62"></a><li>Wifi 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></li>
257<a name="resources63"></a><li>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></li>
258<a name="resources64"></a><li>USB Charging Specification: <a href="http://www.usb.org/developers/devclass_docs/USB_Battery_Charging_1.2.pdf">http://www.usb.org/developers/devclass_docs/USB_Battery_Charging_1.2.pdf</a></li>
259<a name="resources65"></a><li>Android Beam: <a href="http://developer.android.com/guide/topics/nfc/nfc.html">http://developer.android.com/guide/topics/nfc/nfc.html</a></li>
260<a name="resources66"></a><li>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></li>
261<a name="resources67"></a><li>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></li>
262<a name="resources68"></a><li>Wifi Direct (Wifi 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></li>
263<a name="resources69"></a><li>Lock and Home Screen Widget: <a href="http://developer.android.com/reference/android/appwidget/AppWidgetProviderInfo.html">http://developer.android.com/reference/android/appwidget/AppWidgetProviderInfo.html</a></li>
264<a name="resources70"></a><li>UserManager reference: <a href="http://developer.android.com/reference/android/os/UserManager.html">http://developer.android.com/reference/android/os/UserManager.html</a></li>
265<a name="resources71"></a><li>External Storage reference: <a href="http://source.android.com/tech/storage">http://source.android.com/tech/storage</a></li>
266<a name="resources72"></a><li>External Storage APIs: <a href="http://developer.android.com/reference/android/os/Environment.html">http://developer.android.com/reference/android/os/Environment.html</a></li>
267<a name="resources73"></a><li>SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></li>
268<a name="resources74"></a><li>Media Remote Control Client: <a href="http://developer.android.com/reference/android/media/RemoteControlClient.html">http://developer.android.com/reference/android/media/RemoteControlClient.html</a></li>
269<a name="resources75"></a><li>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></li>
270<a name="resources76"></a><li>Dreams: <a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">http://developer.android.com/reference/android/service/dreams/DreamService.html</a></li>
271<a name="resources77"></a><li>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></li>
272</ol>
273<a name="resources78"></a><li>Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">http://developer.android.com/reference/android/hardware/Camera.Parameters.html</a></li>
274<p>Many of these resources are derived directly or indirectly from the Android
2754.2 SDK, and will be functionally identical to the information in that SDK's
276documentation. In any cases where this Compatibility Definition or the
277Compatibility Test Suite disagrees with the SDK documentation, the SDK
278documentation is considered authoritative. Any technical details provided in
279the references included above are considered by inclusion to be part of this
280Compatibility Definition.</p>
281
282<a name="section-3"></a><h2>3. Software</h2>
283<a name="section-3.1"></a><h3>3.1. Managed API Compatibility</h3>
284<p>The managed (Dalvik-based) execution environment is the primary vehicle for
285Android applications. The Android application programming interface (API) is
286the set of Android platform interfaces exposed to applications running in the
287managed VM environment. Device implementations MUST provide complete
288implementations, including all documented behaviors, of any documented API
289exposed by the Android 4.2 SDK [<a href="#resources04">Resources, 4</a>].</p>
290<p>Device implementations MUST NOT omit any managed APIs, alter API interfaces
291or signatures, deviate from the documented behavior, or include no-ops, except
292where specifically allowed by this Compatibility Definition.</p>
293<p>This Compatibility Definition permits some types of hardware for which
294Android includes APIs to be omitted by device implementations. In such cases,
295the APIs MUST still be present and behave in a reasonable way. See
296<a href="#section-7">Section 7</a> for specific requirements for this scenario.
297</p>
298
299<a name="section-3.2"></a><h3>3.2. Soft API Compatibility</h3>
300<p>In addition to the managed APIs from Section 3.1, Android also includes a
301significant runtime-only "soft" API, in the form of such things such as
302Intents, permissions, and similar aspects of Android applications that cannot
303be enforced at application compile time.</p>
304<a name="section-3.2.1"></a><h4>3.2.1. Permissions</h4>
305<p>Device implementers MUST support and enforce all permission constants as
306documented by the Permission reference page [<a
307href="#resources05">Resources, 5</a>]. Note that Section 10 lists additional
308requirements related to the Android security model.</p>
309<a name="section-3.2.2"></a><h4>3.2.2. Build Parameters</h4>
310<p>The Android APIs include a number of constants on the <code>android.os.Build</code>
311class [<a href="#resources06">Resources, 6</a>] that are intended to describe
312the current device. To provide consistent, meaningful values across device
313implementations, the table below includes additional restrictions on the
314formats of these values to which device implementations MUST conform.</p>
315<table>
316<tbody>
317<tr>
318<td><b>Parameter</b></td>
319<td><b>Comments</b></td>
320</tr>
321<tr>
322<td>android.os.Build.VERSION.RELEASE</td>
323<td>The version of the currently-executing Android system, in human-readable
324format. This field MUST have one of the string values defined in [<a
325href="#resources07">Resources, 7</a>].</td>
326</tr>
327<tr>
328<td>android.os.Build.VERSION.SDK</td>
329<td>The version of the currently-executing Android system, in a format
330accessible to third-party application code. For Android 4.2, this
331field MUST have the integer value 17.</td>
332</tr>
333<tr>
334<td>android.os.Build.VERSION.SDK_INT</td>
335<td>The version of the currently-executing Android system, in a format
336accessible to third-party application code. For Android 4.2, this
337field MUST have the integer value 17.</td>
338</tr>
339<tr>
340<td>android.os.Build.VERSION.INCREMENTAL</td>
341<td>A value chosen by the device implementer designating the specific build of
342the currently-executing Android system, in human-readable format. This value
343MUST NOT be re-used for different builds made available to end users. A typical use
344of this field is to indicate which build number or source-control change
345identifier was used to generate the build. There are no requirements on the
346specific format of this field, except that it MUST NOT be null or the empty
347string ("").</td>
348</tr>
349<tr>
350<td>android.os.Build.BOARD</td>
351<td>A value chosen by the device implementer identifying the specific internal
352hardware used by the device, in human-readable format. A possible use of this
353field is to indicate the specific revision of the board powering the device.
354The value of this field MUST be encodable as 7-bit ASCII and match the regular expression
355<code>"^[a-zA-Z0-9.,_-]+$"</code>.</td>
356</tr>
357<tr>
358<td>android.os.Build.BRAND</td>
359<td>A value chosen by the device implementer identifying the name of the
360company, organization, individual, etc. who produced the device, in
361human-readable format. A possible use of this field is to indicate the OEM
362and/or carrier who sold the device. The value of this field MUST be
363encodable as 7-bit ASCII and match the regular expression
364<code>"^[a-zA-Z0-9.,_-]+$"</code>.
365</td>
366</tr>
367<tr>
368<td>android.os.Build.CPU_ABI</td>
369<td>The name of the instruction set (CPU type + ABI convention) of native code.
370See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>.
371</td>
372</tr>
373<tr>
374<td>android.os.Build.CPU_ABI2</td>
375<td>The name of the second instruction set (CPU type + ABI convention) of native code.
376See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>.
377</td>
378</tr>
379<tr>
380<td>android.os.Build.DEVICE</td>
381<td>A value chosen by the device implementer identifying the specific
382configuration or revision of the body (sometimes called "industrial design")
383of the device. The value of this field MUST be encodable as 7-bit ASCII and
384match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td>
385</tr>
386<tr>
387<td>android.os.Build.FINGERPRINT</td>
388<td>A string that uniquely identifies this build. It SHOULD be reasonably
389human-readable. It MUST follow this template:
390<br/><code>$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</code><br/>
391For example:
392<br/><code>acme/mydevice/generic:4.2/JRN53/3359:userdebug/test-keys</code><br/>
393The fingerprint MUST NOT include whitespace characters. If other fields included in the
394template above have whitespace characters, they MUST be replaced in the build
395fingerprint with another character, such as the underscore ("_") character.
396The value of this field MUST be encodable as 7-bit ASCII.</td>
397</tr>
398<tr>
399<td>android.os.Build.HARDWARE</td>
400<td>The name of the hardware (from the kernel command line or /proc). It SHOULD be
401reasonably human-readable. The value of this field MUST be encodable as 7-bit ASCII and
402match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td>
403</tr>
404<tr>
405<td>android.os.Build.HOST</td>
406<td>A string that uniquely identifies the host the build was built on, in
407human readable format. There are no requirements on the specific format of
408this field, except that it MUST NOT be null or the empty string ("").</td>
409</tr>
410<tr>
411<td>android.os.Build.ID</td>
412<td>An identifier chosen by the device implementer to refer to a specific
413release, in human readable format. This field can be the same as
414android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently
415meaningful for end users to distinguish between software builds. The value of
416this field MUST be encodable as 7-bit ASCII and match the regular expression
417<code>"^[a-zA-Z0-9.,_-]+$"</code>.
418</td>
419</tr>
420<tr>
421<td>android.os.Build.MANUFACTURER</td>
422<td>The trade name of the Original Equipment Manufacturer (OEM) of the product.
423There are no requirements on the specific format of this field, except that it
424MUST NOT be null or the empty string ("").</td>
425</tr>
426<tr>
427<td>android.os.Build.MODEL</td>
428<td>A value chosen by the device implementer containing the name of the device
429as known to the end user. This SHOULD be the same name under which the device
430is marketed and sold to end users. There are no requirements on the specific
431format of this field, except that it MUST NOT be null or the empty string
432("").</td>
433</tr>
434<tr>
435<td>android.os.Build.PRODUCT</td>
436<td>A value chosen by the device implementer containing the development name
437or code name of the product (SKU). MUST be human-readable, but is not necessarily
438intended for view by end users. The value of this field MUST be encodable as 7-bit
439ASCII and match the regular expression
440<code>"^[a-zA-Z0-9.,_-]+$"</code>.</td>
441</tr>
442<tr>
443<td>android.os.Build.SERIAL</td>
444<td>A hardware serial number, if available. The value of this field MUST be encodable
445as 7-bit ASCII and match the regular expression
446<code>"^([a-zA-Z0-9]{0,20})$"</code>.</td>
447</tr>
448<tr>
449<td>android.os.Build.TAGS</td>
450<td>A comma-separated list of tags chosen by the device implementer that
451further distinguish the build. For example, "unsigned,debug". The value of
452this field MUST be encodable as 7-bit ASCII and match the regular expression
453<code>"^[a-zA-Z0-9.,_-]+$"</code>.</td>
454</tr>
455<tr>
456<td>android.os.Build.TIME</td>
457<td>A value representing the timestamp of when the build occurred.</td>
458</tr>
459<tr>
460<td>android.os.Build.TYPE</td>
461<td>A value chosen by the device implementer specifying the runtime
462configuration of the build. This field SHOULD have one of the values
463corresponding to the three typical Android runtime configurations: "user",
464"userdebug", or "eng". The value of this field MUST be
465encodable as 7-bit ASCII and match the regular expression
466<code>"^[a-zA-Z0-9.,_-]+$"</code>.</td>
467</tr>
468<tr>
469<td>android.os.Build.USER</td>
470<td>A name or user ID of the user (or automated user) that generated the
471build. There are no requirements on the specific format of this field, except
472that it MUST NOT be null or the empty string ("").</td>
473</tr>
474</tbody>
475</table>
476<a name="section-3.2.3"></a><h4>3.2.3. Intent Compatibility</h4>
477<p>
478Device implementations MUST honor Android's loose-coupling Intent system, as
479described in the sections below. By "honored", it is meant that the device
480implementer MUST provide an Android Activity or Service that specifies a
481matching Intent filter and binds to and implements correct behavior for each
482specified Intent pattern.</p>
483<a name="section-3.2.3.1"></a><h4>3.2.3.1. Core Application Intents</h4>
484<p>The Android upstream project defines a number of core applications, such as
485contacts, calendar, photo gallery, music player, and so on. Device implementers
486MAY replace these applications with alternative versions.</p>
487<p>However, any such alternative versions MUST honor the same Intent patterns
488provided by the upstream project. For example, if a device contains an
489alternative music player, it must still honor the Intent pattern issued by
490third-party applications to pick a song.</p>
491<p>The following applications are considered core Android system
492applications:</p>
493<ul>
494<li>Desk Clock</li>
495<li>Browser</li>
496<li>Calendar</li>
497<li>Contacts</li>
498<!--<li>Email</li>-->
499<li>Gallery</li>
500<li>GlobalSearch</li>
501<li>Launcher</li>
502<!-- <li>LivePicker (that is, the Live Wallpaper picker application; MAY be omitted
503if the device does not support Live Wallpapers, per Section 3.8.5.)</li> -->
504<!-- <li>Messaging (AKA "Mms")</li> -->
505<li>Music</li>
506<!-- <li>Phone</li> -->
507<li>Settings</li>
508<!-- <li>SoundRecorder</li> -->
509</ul>
510<p>The core Android system applications include various Activity, or Service
511components that are considered "public". That is, the attribute
512"android:exported" may be absent, or may have the value "true".</p>
513<p>For every Activity or Service defined
514in one of the core Android system apps that is not marked as non-public via an
515android:exported attribute with the value "false", device implementations MUST
516include a compontent of the same type implementing the same Intent filter
517patterns as the core Android system app.</p>
518<p>In other words, a device implementation MAY replace core Android system
519apps; however, if it does, the device implementation MUST support all Intent
520patterns defined by each core Android system app being replaced.</p>
521<a name="section-3.2.3.2"></a><h4>3.2.3.2. Intent Overrides</h4>
522<p>As Android is an extensible platform, device implementations MUST allow each
523Intent pattern referenced in Section 3.2.3.2 to be overridden by third-party
524applications. The upstream Android open source implementation allows this by
525default; device implementers MUST NOT attach special privileges to system
526applications' use of these Intent patterns, or prevent third-party
527applications from binding to and assuming control of these patterns. This
528prohibition specifically includes but is not limited to disabling the
529"Chooser" user interface which allows the user to select between multiple
530applications which all handle the same Intent pattern.</p>
531<p>However, device implementations MAY provide default activities for specific
532URI patterns (eg. http://play.google.com) if the default activity provides a
533more specific filter for the data URI. For example, an intent filter specifying
534the data URI "http://www.android.com" is more specific than the browser filter
535for "http://". Device implementations MUST provide a user interface for users
536to modify the default activity for intents.</p>
537
538<a name="section-3.2.3.3"></a><h4>3.2.3.3. Intent Namespaces</h4>
539<p>Device implementations MUST NOT include any Android component that honors any
540new Intent or Broadcast Intent patterns using an ACTION, CATEGORY, or other
541key string in the android.* or com.android.* namespace. Device implementers
542MUST NOT include any Android components that honor any new Intent or Broadcast
543Intent patterns using an ACTION, CATEGORY, or other key string in a package
544space belonging to another organization. Device implementers MUST NOT alter or
545extend any of the Intent patterns used by the core apps listed in Section
5463.2.3.1. Device implementations MAY include Intent patterns using
547namespaces clearly and obviously associated with their own organization.</p>
548<p>This prohibition is analogous to that specified for Java language classes
549in Section 3.6.</p>
550<a name="section-3.2.3.4"></a><h4>3.2.3.4. Broadcast Intents</h4>
551<p>Third-party applications rely on the platform to broadcast certain Intents
552to notify them of changes in the hardware or software environment.
553Android-compatible devices MUST broadcast the public broadcast Intents in
554response to appropriate system events. Broadcast Intents are described in the
555SDK documentation.</p>
556
557<a name="section-3.3"></a><h3>3.3. Native API Compatibility</h3>
558<a name="section-3.3.1"></a><h4>3.3.1 Application Binary Interfaces</h4>
559<p>Managed code running in Dalvik can call into native code provided in the
560application .apk file as an ELF .so file compiled for the appropriate device
561hardware architecture. As native code is highly dependent on the underlying
562processor technology, Android defines a number of Application Binary
563Interfaces (ABIs) in the Android NDK, in the file
564<code>docs/CPU-ARCH-ABIS.html</code>. If a device implementation is compatible
565with one or more defined ABIs, it SHOULD implement compatibility with the
566Android NDK, as below.</p>
567<p>If a device implementation includes support for an Android ABI, it:</p>
568<ul>
569<li>MUST include support for code running in the managed environment to call
570into native code, using the standard Java Native Interface (JNI)
571semantics.</li>
572<li>MUST be source-compatible (i.e. header compatible) and binary-compatible
573(for the ABI) with each required library in the list below</li>
574<li>MUST accurately report the native Application Binary Interface (ABI)
575supported by the device, via the <code>android.os.Build.CPU_ABI</code>
576API</li>
577<li>MUST report only those ABIs documented in the latest version of the
578Android NDK, in the file <code>docs/CPU-ARCH-ABIS.txt</code></li>
579<li>SHOULD be built using the source code and header files available in the
580upstream Android open source project</li>
581</ul>
582<p>The following native code APIs MUST be available to apps that include
583native code:</p>
584<ul>
585<li>libc (C library)</li>
586<li>libm (math library)</li>
587<li>Minimal support for C++</li>
588<li>JNI interface</li>
589<li>liblog (Android logging)</li>
590<li>libz (Zlib compression)</li>
591<li>libdl (dynamic linker)</li>
592<li>libGLESv1_CM.so (OpenGL ES 1.0)</li>
593<li>libGLESv2.so (OpenGL ES 2.0)</li>
594<li>libEGL.so (native OpenGL surface management)</li>
595<li>libjnigraphics.so</li>
596<li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li>
597<li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li>
598<li>libandroid.so (native Android activity support)</li>
599<li>Support for OpenGL, as described below</li>
600</ul>
601<p>Note that future releases of the Android NDK may introduce support for
602additional ABIs. If a device implementation is not compatible with an existing
603predefined ABI, it MUST NOT report support for any ABI at all.</p>
604<p>Native code compatibility is challenging. For this reason, it should be
605repeated that device implementers are VERY strongly encouraged to use the
606upstream implementations of the libraries listed above to help ensure
607compatibility.</p>
608
609<a name="section-3.4"></a><h3>3.4. Web Compatibility</h3>
610<a name="section-3.4.1"></a><h4>3.4.1. WebView Compatibility</h4>
611<p>The Android Open Source implementation uses the WebKit rendering engine to
612implement the <code>android.webkit.WebView</code>. Because it is not feasible
613to develop a comprehensive test suite for a web rendering system, device
614implementers MUST use the specific upstream build of WebKit in the WebView
615implementation. Specifically:</p>
616<ul>
617<li>Device implementations' <code>android.webkit.WebView</code>
618implementations MUST be based on the 534.30 WebKit build from the upstream
619Android Open Source tree for Android 4.2. This build includes a specific set
620of functionality and security fixes for the WebView. Device implementers MAY
621include customizations to the WebKit implementation; however, any such
622customizations MUST NOT alter the behavior of the WebView, including rendering
623behavior.</li>
624<li>The user agent string reported by the WebView MUST be in this format:<br/>
625 <code>Mozilla/5.0 (Linux; U; Android $(VERSION); $(LOCALE); $(MODEL) Build/$(BUILD)) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.2 Mobile Safari/534.30</code>
626 <ul>
627 <li>The value of the $(VERSION) string MUST be the same as the value for <code>android.os.Build.VERSION.RELEASE</code></li>
628 <li>The value of the $(LOCALE) string SHOULD follow the ISO conventions for country code and language, and SHOULD refer to the current configured locale of the device</li>
629 <li>The value of the $(MODEL) string MUST be the same as the value for <code>android.os.Build.MODEL</code></li>
630 <li>The value of the $(BUILD) string MUST be the same as the value for <code>android.os.Build.ID</code></li>
631 <li>Device implementations MAY omit <code>Mobile</code> in the user agent string</li>
632 </ul>
633</li>
634</ul>
635<p>The WebView component SHOULD include support for as much of HTML5 [<a
636href="#resources11">Resources, 11</a>] as possible.
637Minimally, device implementations MUST support each of these APIs associated
638with HTML5 in the WebView:</p>
639<ul>
640<li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li>
641<li>the &lt;video&gt; tag [<a href="#resources13">Resources, 13</a>]</li>
642<li>geolocation [<a href="#resources14">Resources, 14</a>]</li>
643</ul>
644<p>Additionally, device implementations MUST support the HTML5/W3C webstorage
645API [<a href="#resources15">Resources, 15</a>], and SHOULD support the
646HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note
647that as the web development standards bodies are transitioning to favor
648IndexedDB over webstorage, IndexedDB is expected to become a required
649component in a future version of Android.</i></p>
650<p>HTML5 APIs, like all JavaScript APIs, MUST be disabled by default in a
651WebView, unless the developer explicitly enables them via the usual Android
652APIs.</p>
653
654<a name="section-3.4.2"></a><h4>3.4.2. Browser Compatibility</h4>
655<p>Device implementations MUST include a standalone Browser application for
656general user web browsing. The standalone Browser MAY be based on a
657browser technology other than WebKit. However, even if an alternate Browser
658application is used, the <code>android.webkit.WebView</code> component
659provided to third-party applications MUST be based on WebKit, as described in
660Section 3.4.1.</p>
661<p>Implementations MAY ship a custom user agent string in the standalone
662Browser application.</p>
663<p>The standalone Browser application (whether based on the upstream
664WebKit Browser application or a third-party replacement) SHOULD include support
665for as much of HTML5 [<a href="#resources11">Resources, 11</a>] as possible.
666Minimally, device implementations MUST support each of these APIs associated
667with HTML5:</p>
668<ul>
669<li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li>
670<li>the &lt;video&gt; tag [<a href="#resources13">Resources, 13</a>]</li>
671<li>geolocation [<a href="#resources14">Resources, 14</a>]</li>
672</ul>
673<p>Additionally, device implementations MUST support the HTML5/W3C webstorage
674API [<a href="#resources15">Resources, 15</a>], and SHOULD support the
675HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note
676that as the web development standards bodies are transitioning to favor
677IndexedDB over webstorage, IndexedDB is expected to become a required
678component in a future version of Android.</i></p>
679
680<a name="section-3.5"></a><h3>3.5. API Behavioral Compatibility</h3>
681<p>The behaviors of each of the API types (managed, soft, native, and web)
682must be consistent with the preferred implementation of the upstream Android
683open source project [<a href="#resources03">Resources, 3</a>]. Some specific areas
684of compatibility are:</p>
685<ul>
686<li>Devices MUST NOT change the behavior or semantics of a standard Intent</li>
687<li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a
688 particular type of system component (such as Service, Activity,
689 ContentProvider, etc.)</li>
690<li>Devices MUST NOT change the semantics of a standard permission</li>
691</ul>
692<p>The above list is not comprehensive. The Compatibility Test Suite (CTS)
693tests significant portions of the platform for behavioral compatibility, but
694not all. It is the responsibility of the implementer to ensure behavioral
695compatibility with the Android Open Source Project. For this reason, device
696implementers SHOULD use the source code available via the Android Open Source
697Project where possible, rather than re-implement significant parts of the
698system.</p>
699
700
701<a name="section-3.6"></a><h3>3.6. API Namespaces</h3>
702<p>Android follows the package and class namespace conventions defined by the
703Java programming language. To ensure compatibility with third-party
704applications, device implementers MUST NOT make any prohibited modifications
705(see below) to these package namespaces:</p>
706<ul>
707<li>java.*</li>
708<li>javax.*</li>
709<li>sun.*</li>
710<li>android.*</li>
711<li>com.android.*</li>
712</ul>
713<p>Prohibited modifications include:</p>
714<ul>
715<li>Device implementations MUST NOT modify the publicly exposed APIs on the
716Android platform by changing any method or class signatures, or by removing
717classes or class fields.</li>
718<li>Device implementers MAY modify the underlying implementation of the APIs,
719but such modifications MUST NOT impact the stated behavior and Java-language
720signature of any publicly exposed APIs.</li>
721<li>Device implementers MUST NOT add any publicly exposed elements (such as
722classes or interfaces, or fields or methods to existing classes or interfaces)
723to the APIs above.</li>
724</ul>
725<p>A "publicly exposed element" is any construct which is not decorated with
726the "@hide" marker as used in the upstream Android source code. In other
727words, device implementers MUST NOT expose new APIs or alter existing APIs in
728the namespaces noted above. Device implementers MAY make internal-only
729modifications, but those modifications MUST NOT be advertised or otherwise
730exposed to developers.</p>
731<p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a
732namespace owned by or referring to another organization. For instance, device
733implementers MUST NOT add APIs to the com.google.* or similar namespace; only
734Google may do so. Similarly, Google MUST NOT add APIs to other companies'
735namespaces. Additionally, if a device implementation includes custom APIs
736outside the standard Android namespace, those APIs MUST be packaged in an
737Android shared library so that only apps that explicitly use them (via the
738<code>&lt;uses-library&gt;</code> mechanism) are affected by the increased
739memory usage of such APIs.</p>
740<p>If a device implementer proposes to improve one of the package namespaces
741above (such as by adding useful new functionality to an existing API, or
742adding a new API), the implementer SHOULD visit source.android.com and begin
743the process for contributing changes and code, according to the information on
744that site.</p>
745<p>Note that the restrictions above correspond to standard conventions for
746naming APIs in the Java programming language; this section simply aims to
747reinforce those conventions and make them binding through inclusion in this
748compatibility definition.</p>
749
750<a name="section-3.7"></a><h3>3.7. Virtual Machine Compatibility</h3>
751<p>Device implementations MUST support the full Dalvik Executable (DEX)
752bytecode specification and Dalvik Virtual Machine semantics [<a
753href="#resources17">Resources, 17</a>].</p>
754<p>Device implementations MUST configure Dalvik to allocate memory in
755accordance with the upstream Android platform, and as specified by the following
756table. (See <a href="#section-7.1.1">Section 7.1.1</a> for screen size and screen
757density definitions.)</p>
758
759<p>Note that memory values specified below are considered minimum values,
760and device implementations MAY allocate more memory per application.</p>
761<table>
762<tbody>
763<tr>
764<td><b>Screen Size</b></td>
765<td><b>Screen Density</b></td>
766<td><b>Application Memory</b></td>
767</tr>
768<tr>
769<td>small / normal / large</td>
770<td>ldpi / mdpi</td>
771<td>16MB</td>
772</tr>
773<tr>
774<td>small / normal / large</td>
775<td>tvdpi / hdpi</td>
776<td>32MB</td>
777</tr>
778<tr>
779<td>small / normal / large</td>
780<td>xhdpi</td>
781<td>64MB</td>
782</tr>
783<tr>
784<td>xlarge</td>
785<td>mdpi</td>
786<td>32MB</td>
787</tr>
788<tr>
789<td>xlarge</td>
790<td>tvdpi / hdpi</td>
791<td>64MB</td>
792</tr>
793<tr>
794<td>xlarge</td>
795<td>xhdpi</td>
796<td>128MB</td>
797</tr>
798</tbody>
799</table>
800
801<a name="section-3.8"></a><h3>3.8. User Interface Compatibility</h3>
802<a name="section-3.8.1"></a><h4>3.8.1. Widgets</h4>
803<p>Android defines a component type and corresponding API and lifecycle that
804allows applications to expose an "AppWidget" to the end user [<a
805href="#resources18">Resources, 18</a>].
806The Android Open Source reference release includes a Launcher application that
807includes user interface affordances allowing the user to add, view, and remove
808AppWidgets from the home screen.</p>
809<p>Device implementations MAY substitute an alternative to the reference Launcher
810(i.e. home screen). Alternative Launchers SHOULD include built-in support for
811AppWidgets, and expose user interface affordances to add, configure, view, and
812remove AppWidgets directly within the Launcher. Alternative Launchers MAY omit
813these user interface elements; however, if they are omitted, the device
814implementation MUST provide a separate application accessible from the Launcher
815that allows users to add, configure, view, and remove AppWidgets.</p>
816<p>Device implementations MUST be capable of rendering widgets that are 4 x 4
817in the standard grid size. (See the App Widget Design Guidelines in the Android
818SDK documentation [<a href="#resources18">Resources, 18</a>] for details.</p>
819<p>
820<a name="section-3.8.2"></a><h4>3.8.2. Notifications</h4>
821<p>Android includes APIs that allow developers to notify users of notable
822events [<a href="#resources19">Resources, 19</a>], using hardware and software
823features of the device.</p>
824<p>Some APIs allow applications to perform notifications or attract attention
825using hardware, specifically sound, vibration, and light. Device implementations
826MUST support notifications that use hardware features, as described in the SDK
827documentation, and to the extent possible with the device implementation
828hardware. For instance, if a device implementation includes a vibrator, it
829MUST correctly implement the vibration APIs. If a device implementation lacks
830hardware, the corresponding APIs MUST be implemented as no-ops. Note that this
831behavior is further detailed in <a href="#section-7">Section 7.</a></p>
832<p>Additionally, the implementation MUST correctly render all resources
833(icons, sound files, etc.) provided for in the APIs [<a
834href="#resources20">Resources, 20</a>], or in the
835Status/System Bar icon style guide [<a href="#resources21">Resources, 21</a>].
836Device implementers MAY provide an alternative user experience for
837notifications than that provided by the reference Android Open Source
838implementation; however, such alternative notification systems MUST support
839existing notification resources, as above.</p>
840<p>Android 4.2 includes support for rich notifications, such as interactive
841Views for ongoing notifications. Device implementations MUST properly display
842and execute rich notifications, as documented in the Android APIs.</p>
843<a name="section-3.8.3"></a><h4>3.8.3. Search</h4>
844<p>Android includes APIs [<a href="#resources22">Resources, 22</a>] that allow
845developers to incorporate search into their applications, and expose their
846application's data into the global system search. Generally speaking, this
847functionality consists of a single, system-wide user interface that allows users
848to enter queries, displays suggestions as users type, and displays results. The
849Android APIs allow developers to reuse this interface to provide search within
850their own apps, and allow developers to supply results to the common global
851search user interface.</p>
852<p>Device implementations MUST include a single, shared, system-wide search
853user interface capable of real-time suggestions in response to user input.
854Device implementations MUST implement the APIs that allow developers to reuse
855this user interface to provide search within their own applications. Device
856implementations MUST implement the APIs that allow third-party applications to
857add suggestions to the search box when it is run in global search mode. If no
858third-party applications are installed that make use of this functionality,
859the default behavior SHOULD be to display web search engine results and
860suggestions.</p>
861<a name="section-3.8.4"></a><h4>3.8.4. Toasts</h4>
862<p>Applications can use the "Toast" API (defined in [<a
863href="#resources23">Resources, 23</a>]) to
864display short non-modal strings to the end user, that disappear after a brief
865period of time. Device implementations MUST display Toasts from applications
866to end users in some high-visibility manner.</p>
867
868<a name="section-3.8.5"></a><h4>3.8.5. Themes</h4>
869<p>Android provides "themes" as a mechanism for applications to apply styles
870across an entire Activity or application. Android 4.2 includes a "Holo"
871or "holographic" theme as a set of defined styles for application developers to
872use if they want to match the Holo theme look and feel as defined by the Android
873SDK [<a href="#resources24">Resources, 24</a>]. Device implementations MUST NOT
874alter any of the Holo theme attributes exposed to applications
875[<a href="#resources25">Resources, 25</a>].</p>
876<p>Android 4.2 includes a new "Device Default" theme as a set of defined
877styles for application developers to use if they want to match the look and feel
878of the device theme as defined by the device implementer. Device implementations
879MAY modify the DeviceDefault theme attributes exposed to applications
880[<a href="#resources25">Resources, 25</a>].</p>
881
882<a name="section-3.8.6"></a><h4>3.8.6. Live Wallpapers</h4>
883<p>Android defines a component type and corresponding API and lifecycle that
884allows applications to expose one or more "Live Wallpapers" to the end user
885[<a href="#resources26">Resources, 26</a>]. Live Wallpapers are animations,
886patterns, or similar images with limited input capabilities that display as a
887wallpaper, behind other applications.</p>
888<p>Hardware is considered capable of reliably running live wallpapers if it
889can run all live wallpapers, with no limitations on functionality, at a
890reasonable framerate with no adverse affects on other applications. If
891limitations in the hardware cause wallpapers and/or applications to crash,
892malfunction, consume excessive CPU or battery power, or run at unacceptably
893low frame rates, the hardware is considered incapable of running live
894wallpaper. As an example, some live wallpapers may use an Open GL 1.0 or 2.0
895context to render their content. Live wallpaper will not run reliably on
896hardware that does not support multiple OpenGL contexts because the live
897wallpaper use of an OpenGL context may conflict with other applications that
898also use an OpenGL context.</p>
899<p>Device implementations capable of running live wallpapers reliably as
900described above SHOULD implement live wallpapers. Device implementations
901determined to not run live wallpapers reliably as described above MUST NOT
902implement live wallpapers.</p>
903<a name="section-3.8.7"></a><h4>3.8.7. Recent Application Display</h4>
904<p>The upstream Android 4.2 source code includes a user interface for
905displaying recent applications using a thumbnail image of the application's
906graphical state at the moment the user last left the application. Device
907implementations MAY alter or eliminate this user interface; however, a future
908version of Android is planned to make more extensive use of this
909functionality. Device implementations are strongly encouraged to use the
910upstream Android 4.2 user interface (or a similar thumbnail-based interface)
911for recent applications, or else they may not be compatible with a future
912version of Android.</p>
913<a name="section-3.8.8"></a><h4>3.8.8. Input Management Settings</h4>
914<p>Android 4.2 includes support for Input Management Engines. The Android 4.2
915APIs allow custom app IMEs to specify user-tunable settings. Device
916implementations MUST include a way for the user to access IME settings at all
917times when an IME that provides such user settings is displayed.</p>
918
919<a name="section-3.8.9"></a><h4>3.8.9. Lock and Home Screen Widgets</h4>
920<p>Android 4.2 includes support for application widgets that users can embed in the home screen or the lock screen
921(See the App Widget Design Guidelines in the Android SDK documentation [<a href="#resources69">Resources, 69</a>] for details).
922Application widgets allow quick access to application data and services without launching a new activity. Widgets declare support
923for usage on the home screen or the lock screen by declaring the <code>android:widgetCategory</code> manifest tag that tells the system
924where the widget can be placed. Specifically, device implementations MUST meet the following requirements.</p>
925<ul>
926 <li>Device implementations MUST support application widgets on the home screen.</li>
927 <li>Device implementations SHOULD support lock screen. If device implementations include support for lock screen
928 then device implementations MUST support application widgets on the lock screen.</li>
929</ul>
930
931<a name="section-3.8.10"></a><h4>3.8.10. Lock Screen Media Remote Control</h4>
932<p>Android 4.2 includes support for Remote Control API that lets media applications integrate with playback controls
933that are displayed in a remote view like the device lock screen[<a href="#resources74">Resources, 74</a>]. Device implementations MUST
934include support for embedding remote controls in the device lock screen.
935</p>
936<a name="section-3.8.11"></a><h4>3.8.11. Dreams</h4>
937<p>Android 4.2 includes support for interactive screensavers called Dreams [<a href="#resources76">Resources, 76</a>].
938Dreams allows users to interact with applications when a charging device is idle, or docked in a desk dock. Device implementations
939MUST include support for Dreams and provide a settings option for users to configure Dreams.</p>
940
941<a name="section-3.9"></a><h3>3.9 Device Administration</h3>
942<p>Android 4.2 includes features that allow security-aware applications
943to perform device administration functions at the system level, such as enforcing
944password policies or performing remote wipe, through the Android Device
945Administration API [<a href="#resources27">Resources, 27</a>]. Device
946implementations MUST provide an implementation of the <code>DevicePolicyManager
947</code> class [<a href="#resources28">Resources, 28</a>], and SHOULD support
948the full range of device administration policies defined in the Android SDK
949documentation [<a href="#resources27">Resources, 27</a>].
950</p>
951<p><b>Note:</b> while some of the requirements outlined above are stated as "SHOULD"
952for Android 4.2, device implementations that support lock screen MUST support device policies to manage widgets
953on the lock screen as defined in the Android SDK documentation [<a href="#resources27">Resources, 27</a>].
954</p>
955<p><b>Note:</b> while some of the requirements outlined above are stated as "SHOULD"
956for Android 4.2, the Compatibility Definition for a future version is planned
957to change these to "MUST". That is, these requirements are optional in Android
9584.2 but <b>will be required</b> by a future version. Existing and new devices
959that run Android 4.2 are <b>very strongly encouraged to meet
960these requirements in Android 4.2</b>, or they will not be able to attain
961Android compatibility when upgraded to the future version.</p>
962
963<a name="section-3.10"></a><h3>3.10 Accessibility</h3>
964<p>Android 4.2 provides an accessibility layer that helps users with disabilities
965to navigate their devices more easily. In addition, Android 4.2 provides
966platform APIs that enable accessibility service implementations to receive
967callbacks for user and system events and generate alternate feedback mechanisms,
968such as text-to-speech, haptic feedback, and trackball/d-pad navigation
969[<a href="#resources29">Resources, 29</a>]. Device implementations MUST provide an
970implementation of the Android accessibility framework consistent with the
971default Android implementation. Specifically, device implementations MUST meet
972the following requirements.</p>
973<ul>
974 <li>Device implementations MUST support third party accessibility service
975 implementations through the <code>android.accessibilityservice</code>
976 APIs [<a href="#resources30">Resources, 30</a>].</li>
977 <li>Device implementations MUST generate <code>AccessibilityEvents</code>
978 and deliver these events to all registered <code>AccessibilityService
979 </code> implementations in a manner consistent with the default Android
980 implementation.</li>
981 <li>Device implementations MUST provide a user-accessible mechanism to enable
982 and disable accessibility services, and MUST display this interface in
983 response to the
984 <code>android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS</code>
985 intent.</li>
986</ul>
987<p>Additionally, device implementations SHOULD provide an implementation
988of an accessibility service on the device, and SHOULD provide a mechanism
989for users to enable the accessibility service during device setup. An open
990source implementation of an accessibility service is available from the Eyes
991Free project [<a href="#resources31">Resources, 31</a>].</p>
992
993<a name="section-3.11"></a><h3>3.11 Text-to-Speech</h3>
994<p>Android 4.2 includes APIs that allow applications to make use of
995text-to-speech (TTS) services, and allows service providers to provide
996implementations of TTS services [<a href="#resources32">Resources, 32</a>].
997Device implementations MUST meet these requirements related to the Android TTS
998framework:</p>
999<ul>
1000 <li>Device implementations MUST support the Android TTS framework APIs and
1001 SHOULD include a TTS engine supporting the languages available on the
1002 device. Note that the upstream Android open source software includes a
1003 full-featured TTS engine implementation.</li>
1004 <li>Device implementations MUST support installation of third-party TTS
1005 engines.</li>
1006 <li>Device implementations MUST provide a user-accessible interface that allows
1007 users to select a TTS engine for use at the system level.</li>
1008</ul>
1009
1010<a name="section-4"></a><h2>4. Application Packaging Compatibility</h2>
1011<p>Device implementations MUST install and run Android ".apk" files as
1012generated by the "aapt" tool included in the official Android SDK [<a
1013href="#resources33">Resources, 33</a>].</p>
1014<p>Devices implementations MUST NOT extend either the .apk [<a
1015href="#resources34">Resources, 34</a>], Android Manifest [<a
1016href="#resources35">Resources, 35</a>],
1017Dalvik bytecode [<a href="#resources17">Resources, 17</a>], or renderscript
1018bytecode formats in such a way that would prevent those files from installing
1019and running correctly on other compatible devices. Device implementers SHOULD
1020use the reference upstream implementation of Dalvik, and the reference
1021implementation's package management system.</p>
1022
1023<a name="section-5"></a><h2>5. Multimedia Compatibility</h2>
1024<p>Device implementations MUST include at least one form of audio output, such as
1025speakers, headphone jack, external speaker connection, etc.</p>
1026<a name="section-5.1"></a><h3>5.1. Media Codecs</h3>
1027<p>Device implementations MUST support the core media formats specified
1028in the Android SDK documentation [<a href="#resources58">Resources, 58</a>] except
1029where explicitly permitted in this document. Specifically, device implementations
1030MUST support the media formats, encoders, decoders, file types and container
1031formats defined in the tables below. All of these codecs are provided as
1032software implementations in the preferred Android implementation from the Android
1033Open Source Project.</p>
1034
1035<p><strong>Please note that neither Google nor the Open Handset Alliance make any
1036representation that these codecs are unencumbered by third-party patents.
1037Those intending to use this source code in hardware or software products are
1038advised that implementations of this code, including in open source software
1039or shareware, may require patent licenses from the relevant patent
1040holders.</strong></p>
1041
1042<p>Note that these tables do not list specific bitrate requirements for
1043most video codecs because current device hardware does not necessarily support
1044bitrates that map exactly to the required bitrates specified by the relevant
1045standards. Instead, device implementations SHOULD support the highest bitrate
1046practical on the hardware, up to the limits defined by the specifications.</p>
1047<div style="page-break-before: always;"></div>
1048<table>
1049<tbody>
1050
1051<tr>
1052<th>Type</th>
1053<th>Format / Codec</th>
1054<th>Encoder</th>
1055<th>Decoder</th>
1056<th>Details</th>
1057<th>File Type(s) / Container Formats</th>
1058</tr>
1059
1060<tr>
1061<td rowspan="11">Audio</td>
1062<td>MPEG-4 AAC Profile (AAC LC)</td>
1063<td style="text-align: center;">REQUIRED<br/>
1064<small>Required for device implementations that include microphone hardware
1065and define <code>android.hardware.microphone</code>.</small></td>
1066<td style="text-align: center;">REQUIRED</td>
1067<td rowspan="1"> Support for mono/stereo/5.0/5.1* content with standard sampling rates from 8 to 48 kHz.</td>
1068<td rowspan="4">
1069 <ul>
1070 <li>3GPP (.3gp)</li>
1071 <li>MPEG-4 (.mp4, .m4a)</li>
1072 <li>ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not supported)</li>
1073 <li>MPEG-TS (.ts, not seekable, Android 3.0+)</li>
1074 </ul>
1075</td>
1076</tr>
1077
1078<tr>
1079<td>MPEG-4 HE AAC Profile (AAC+)</td>
1080<td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td>
1081<td style="text-align: center;">REQUIRED</td>
1082<td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td>
1083</tr>
1084
1085<tr>
1086<td>MPEG-4 HE AAC v2 Profile (enhanced AAC+)</td>
1087<td>&nbsp;</td>
1088<td style="text-align: center;">REQUIRED</td>
1089<td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td>
1090</tr>
1091
1092<tr>
1093<td>MPEG-4 Audio Object Type ER AAC ELD (Enhanced Low Delay AAC)</td>
1094<td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td>
1095<td style="text-align: center;">REQUIRED</td>
1096<td>Support for mono/stereo content with standard
1097sampling rates from 16 to 48 kHz.</td>
1098</tr>
1099
1100<tr>
1101<td>AMR-NB</td>
1102<td style="text-align: center;">REQUIRED<br/>
1103<small>Required for device implementations that include microphone hardware
1104and define <code>android.hardware.microphone</code>.</small></td>
1105<td style="text-align: center;">REQUIRED</td>
1106<td>4.75 to 12.2 kbps sampled @ 8kHz</td>
1107<td>3GPP (.3gp)
1108</td>
1109</tr>
1110
1111<tr>
1112<td>AMR-WB</td>
1113<td style="text-align: center;">REQUIRED<br/>
1114<small>Required for device implementations that include microphone hardware
1115and define <code>android.hardware.microphone</code>.</small></td>
1116<td style="text-align: center;">REQUIRED</td>
1117<td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td>
1118<td>3GPP (.3gp)</td>
1119</tr>
1120
1121<tr>
1122<td>FLAC</td>
1123<td>&nbsp;</td>
1124<td style="text-align: center;">REQUIRED<br/><small>(Android 3.1+)</small></td>
1125<td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1
1126kHz is recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz
1127downsampler does not include a low-pass filter). 16-bit recommended;
1128no dither applied for 24-bit.
1129</td>
1130<td>FLAC (.flac) only</td>
1131</tr>
1132
1133<tr>
1134<td>MP3</td>
1135<td>&nbsp;</td>
1136<td style="text-align: center;">REQUIRED</td>
1137<td>Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR)
1138</td>
1139<td>MP3 (.mp3)</td>
1140</tr>
1141
1142<tr>
1143<td>MIDI</td>
1144<td>&nbsp;</td>
1145<td style="text-align: center;">REQUIRED</td>
1146<td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for ringtone formats RTTTL/RTX, OTA, and iMelody </td>
1147<td>
1148 <ul>
1149 <li>Type 0 and 1 (.mid, .xmf, .mxmf)</li>
1150 <li>RTTTL/RTX (.rtttl, .rtx)</li>
1151 <li>OTA (.ota)</li>
1152 <li>iMelody (.imy)</li>
1153 </ul>
1154</td>
1155</tr>
1156
1157<tr>
1158<td>Vorbis</td>
1159<td>&nbsp;</td>
1160<td style="text-align: center;">REQUIRED</td>
1161<td>&nbsp;</td>
1162<td>
1163 <ul>
1164 <li>Ogg (.ogg)</li>
1165 <li>Matroska (.mkv)</li>
1166 </ul>
1167</td>
1168</tr>
1169
1170<tr>
1171<td>PCM/WAVE</td>
1172<td style="text-align: center;">REQUIRED</td>
1173<td style="text-align: center;">REQUIRED</td>
1174<td>8-bit and 16-bit linear PCM** (rates up to limit of hardware).Devices MUST support sampling rates
1175for raw PCM recording at 8000,16000 and 44100 Hz frequencies</td>
1176<td>WAVE (.wav)</td>
1177</tr>
1178
1179<tr>
1180<td rowspan="5">Image</td>
1181<td>JPEG</td>
1182<td style="text-align: center;">REQUIRED</td>
1183<td style="text-align: center;">REQUIRED</td>
1184<td>Base+progressive</td>
1185<td>JPEG (.jpg)</td>
1186</tr>
1187
1188<tr>
1189<td>GIF</td>
1190<td>&nbsp;</td>
1191<td style="text-align: center;">REQUIRED</td>
1192<td>&nbsp;</td>
1193<td>GIF (.gif)</td>
1194</tr>
1195
1196<tr>
1197<td>PNG</td>
1198<td style="text-align: center;">REQUIRED</td>
1199<td style="text-align: center;">REQUIRED</td>
1200<td>&nbsp;</td>
1201<td>PNG (.png)</td>
1202</tr>
1203
1204<tr>
1205<td>BMP</td>
1206<td>&nbsp;</td>
1207<td style="text-align: center;">REQUIRED</td>
1208<td>&nbsp;</td>
1209<td>BMP (.bmp)</td>
1210</tr>
1211
1212
1213<tr>
1214<td>WEBP</td>
1215<td style="text-align: center;">REQUIRED</td>
1216<td style="text-align: center;">REQUIRED</td>
1217<td>&nbsp;</td>
1218<td>WebP (.webp)</td>
1219</tr>
1220
1221<tr>
1222<td rowspan="4">Video</td>
1223<td>H.263</td>
1224<td style="text-align: center;">REQUIRED<br/>
1225<small>Required for device implementations that include camera hardware
1226and define <code>android.hardware.camera</code> or
1227<code>android.hardware.camera.front</code>.</small></td>
1228<td style="text-align: center;">REQUIRED</td>
1229<td>&nbsp;</td>
1230<td>
1231 <ul>
1232 <li>3GPP (.3gp)</li>
1233 <li>MPEG-4 (.mp4)</li>
1234 </ul>
1235</td>
1236</tr>
1237
1238<tr>
1239<td>H.264 AVC</td>
1240<td style="text-align: center;">REQUIRED<br/>
1241<small>Required for device implementations that include camera hardware
1242and define <code>android.hardware.camera</code> or
1243<code>android.hardware.camera.front</code>.</small></td>
1244<td style="text-align: center;">REQUIRED</td>
1245<td>Baseline Profile (BP)</td>
1246<td>
1247 <ul>
1248 <li>3GPP (.3gp)</li>
1249 <li>MPEG-4 (.mp4)</li>
1250 <li>MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li>
1251 </ul>
1252</td>
1253</tr>
1254
1255<tr>
1256<td>MPEG-4 SP</td>
1257<td>&nbsp;</td>
1258<td style="text-align: center;">REQUIRED</td>
1259<td>&nbsp;</td>
1260<td>3GPP (.3gp)</td>
1261</tr>
1262
1263<tr>
1264<td>VP8</td>
1265<td>&nbsp;</td>
1266<td style="text-align: center;">REQUIRED<br/><small>(Android 2.3.3+)</small></td>
1267<td>&nbsp;</td>
1268<td><a href="http://www.webmproject.org/">WebM</a> (.webm) and Matroska (.mkv, Android 4.0+)</td>
1269</tr>
1270
1271</tbody></table>
1272*Note: Only downmix of 5.0/5.1 content is required; recording or rendering more than 2 channels is optional.
1273**Note: 16-bit linear PCM capture is mandatory. 8-bit linear PCM capture is not mandatory.
1274
1275<a name="section-5.2"></a><h3>5.2 Video Encoding</h3>
1276<p>Android device implementations that include a rear-facing camera and declare
1277<code>android.hardware.camera</code> SHOULD support the following video encoding
1278profiles.</p>
1279<table>
1280 <thead>
1281 <tr>
1282 <th>&nbsp;</th>
1283 <th>SD (Low quality)</th>
1284 <th>SD (High quality)</th>
1285 <th>HD (When supported by hardware)</th>
1286 </tr>
1287 </thead>
1288 <tbody>
1289 <tr>
1290 <th>Video codec</th>
1291 <td>H.264 Baseline Profile</td>
1292 <td>H.264 Baseline Profile</td>
1293 <td>H.264 Baseline Profile</td>
1294 </tr>
1295 <tr>
1296 <th>Video resolution</th>
1297 <td>176 x 144 px</td>
1298 <td>480 x 360 px</td>
1299 <td>1280 x 720 px</td>
1300 </tr>
1301 <tr>
1302 <th>Video frame rate</th>
1303 <td>12 fps</td>
1304 <td>30 fps</td>
1305 <td>30 fps</td>
1306 </tr>
1307 <tr>
1308 <th>Video bitrate</th>
1309 <td>56 Kbps</td>
1310 <td>500 Kbps or higher</td>
1311 <td>2 Mbps or higher</td>
1312 </tr>
1313 <tr>
1314 <th>Audio codec</th>
1315 <td>AAC-LC</td>
1316 <td>AAC-LC</td>
1317 <td>AAC-LC</td>
1318 </tr>
1319 <tr>
1320 <th>Audio channels</th>
1321 <td>1 (mono)</td>
1322 <td>2 (stereo)</td>
1323 <td>2 (stereo)</td>
1324 </tr>
1325 <tr>
1326 <th>Audio bitrate</th>
1327 <td>24 Kbps</td>
1328 <td>128 Kbps</td>
1329 <td>192 Kbps</td>
1330 </tr>
1331 </tbody>
1332</table>
1333
1334<a name="section-5.3"></a><h3>5.3 Video Decoding</h3>
1335<p>Android device implementations SHOULD support the following VP8 video decoding profiles.</p>
1336<div style="page-break-before: always;"></div>
1337<table>
1338 <thead>
1339 <tr>
1340 <th>&nbsp;</th>
1341 <th>SD (Low quality)</th>
1342 <th>SD (High quality)</th>
1343 <th>HD 720p <br/> (When supported by hardware)</th>
1344 <th>HD 1080p <br/>(When supported by hardware)</th>
1345 </tr>
1346 </thead>
1347 <tbody>
1348 <tr>
1349 <th>Video resolution</th>
1350 <td>320 x 180 px</td>
1351 <td>640 x 360 px</td>
1352 <td>1280 x 720 px</td>
1353 <td>1920 x 1080 px</td>
1354 </tr>
1355 <tr>
1356 <th>Video frame rate</th>
1357 <td>30 fps</td>
1358 <td>30 fps</td>
1359 <td>30 fps</td>
1360 <td>30 fps</td>
1361 </tr>
1362 <tr>
1363 <th>Video bitrate</th>
1364 <td>800 Kbps</td>
1365 <td>2 Mbps</td>
1366 <td>8 Mbps</td>
1367 <td>20 Mbps</td>
1368 </tr>
1369 </tbody>
1370</table>
1371<a name="section-5.4"></a><h3>5.4. Audio Recording</h3>
1372<p>When an application has used the <code>android.media.AudioRecord</code> API to
1373start recording an audio stream, device implementations that include microphone
1374hardware and declare <code>android.hardware.microphone</code> MUST sample and
1375record audio with each of these behaviors:</p>
1376<ul>
1377<li>The device SHOULD exhibit approximately flat amplitude versus frequency
1378 characteristics; specifically, &plusmn;3 dB, from 100 Hz to 4000 Hz</li>
1379<li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level
1380 (SPL) source at 1000 Hz yields RMS of 2500 for 16-bit samples.</li>
1381<li>PCM amplitude levels SHOULD linearly track input SPL changes over at least
1382 a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.</li>
1383<li>Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input level.</li>
1384</ul>
1385<p>In addition to the above recording specifications, when an application has
1386started recording an audio stream using the
1387<code>android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION</code> audio
1388source:</p>
1389<ul>
1390<li>Noise reduction processing, if present, MUST be disabled.</li>
1391<li>Automatic gain control, if present, MUST be disabled.</li>
1392</ul>
1393<p><b>Note:</b> while some of the requirements outlined above are stated as "SHOULD"
1394for Android 4.2, the Compatibility Definition for a future version is planned
1395to change these to "MUST". That is, these requirements are optional in Android
13964.2 but <b>will be required</b> by a future version. Existing and new devices
1397that run Android 4.2 are <b>very strongly encouraged to meet
1398these requirements in Android 4.2</b>, or they will not be able to attain
1399Android compatibility when upgraded to the future version.</p>
1400
1401<a name="section-5.5"></a><h3>5.5. Audio Latency</h3>
1402<p>Audio latency is the time delay as an audio signal passes through a system.
1403Many classes of
1404applications rely on short latencies, to achieve real-time effects such sound
1405effects or VOIP communication.</p>
1406<p>For the purposes of this section:</p>
1407<ul>
1408<li>"output latency" is defined as the interval between when an application
1409writes a frame of PCM-coded data and when the corresponding sound can be heard
1410by an external listener or observed by a transducer</li>
1411<li>"cold output latency" is defined as the output latency for the first frame, when
1412 the audio output system has been idle and powered down prior to the request</li>
1413<li>"continuous output latency" is defined as the output latency for subsequent frames,
1414 after the device is already playing audio</li>
1415<li>"input latency" is the interval between when an external sound is presented
1416to the device and when an application reads the corresponding frame of PCM-coded data</li>
1417<li>"cold input latency" is defined as the sum of lost input time
1418 and the input latency for the first frame, when
1419 the audio input system has been idle and powered down prior to the request</li>
1420<li>"continuous input latency" is defined as the input latency for subsequent frames,
1421 while the device is already capturing audio</li>
1422<li>"OpenSL ES PCM buffer queue API" is the set of PCM-related OpenSL ES APIs within Android NDK;
1423see <i>NDK_root</i><code>/docs/opensles/index.html</code></li>
1424</ul>
1425<p>Per <a href="#section-5">Section 5</a>,
1426all compatible device implementations MUST include at least one form of audio output.
1427Device implementations SHOULD meet or exceed these output latency requirements:</p>
1428<ul>
1429<li>cold output latency of 100 milliseconds or less</li>
1430<li>continuous output latency of 45 milliseconds or less</li>
1431</ul>
1432<p>If a device implementation meets the requirements of this section
1433after any initial calibration
1434when using the OpenSL ES PCM buffer queue API,
1435for continuous output latency and cold output latency
1436over at least one supported audio output device, it MAY
1437report support for low-latency audio, by reporting the feature
1438"android.hardware.audio.low-latency" via the
1439<code>android.content.pm.PackageManager</code> class. [<a
1440href="#resources37">Resources, 37</a>] Conversely, if the device
1441implementation does not meet these requirements it MUST NOT report support for
1442low-latency audio.</p>
1443<p>
1444Per <a href="#section-7.2.5">Section 7.2.5</a>,
1445microphone hardware may be omitted by device implementations.</p>
1446<p>
1447Device implementations that include microphone
1448hardware and declare <code>android.hardware.microphone</code> SHOULD
1449meet these input audio latency requirements:</p>
1450<ul>
1451<li>cold input latency of 100 milliseconds or less</li>
1452<li>continuous input latency of 50 milliseconds or less</li>
1453</ul>
1454
1455<a name="section-5.6"></a><h3>5.6. Network Protocols</h3>
1456<p>Devices MUST support the media network protocols for audio and video playback
1457as specified in the Android SDK documentation
1458[<a href="#resources58">Resources, 58</a>]. Specifically, devices MUST support
1459the following media network protocols:</p>
1460<ul>
1461<li>RTSP (RTP, SDP)</li>
1462<li>HTTP(S) progressive streaming</li>
1463<li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="#resources59">Resources, 59</a>]</li>
1464</ul>
1465<a name="section-6"></a><h2>6. Developer Tools and Options Compatibility</h2>
1466
1467<a name="section-6.1"></a><h3>6.1 Developer Tools</h3>
1468<p>Device implementations MUST support the Android Developer Tools provided in the Android SDK.
1469Specifically, Android-compatible devices MUST be compatible with:</p>
1470<ul>
1471<li><b>Android Debug Bridge (known as adb)</b> [<a href="#resources33">Resources, 33</a>]<br/>
1472Device implementations MUST support all <code>adb</code> functions as
1473documented in the Android SDK. The device-side <code>adb</code> daemon MUST
1474be inactive by default, and there MUST be a user-accessible mechanism to turn
1475on the Android Debug Bridge.</li>
1476<p>Android 4.2.2 includes support for secure adb. Secure adb enables adb on known authenticated hosts.
1477Existing and new devices that run Android 4.2.2 are <b>very strongly encouraged to meet
1478this requirement in Android 4.2</b>, or they will not be able to attain
1479Android compatibility when upgraded to the future version.</p>
1480<li><b>Dalvik Debug Monitor Service (known as ddms)</b> [<a href="#resources33">Resources, 33</a>]<br/>
1481Device implementations MUST support all <code>ddms</code> features as documented in the
1482Android SDK. As <code>ddms</code> uses <code>adb</code>, support for
1483<code>ddms</code> SHOULD be inactive by default,
1484but MUST be supported whenever the user has activated the Android Debug
1485Bridge, as above.</li>
1486<li><b>Monkey</b> [<a href="#resources36">Resources, 36</a>]<br/>
1487Device implementations MUST include the Monkey framework, and make it
1488available for applications to use.</li>
1489<li><b>SysTrace</b> [<a href="#resources33">Resources, 33</a>]<br/>
1490Device implementations MUST support systrace tool as documented in the Android SDK.
1491Systrace must be inactive by default, and there MUST be a user-accessible mechanism to turn
1492on Systrace.</li>
1493</ul>
1494<p>Most Linux-based systems and Apple Macintosh systems recognize Android
1495devices using the standard Android SDK tools, without additional support;
1496however Microsoft Windows systems typically require a driver for new Android
1497devices. (For instance, new vendor IDs and sometimes new device IDs require
1498custom USB drivers for Windows systems.) If a device implementation is
1499unrecognized by the <code>adb</code> tool as provided in the standard Android
1500SDK, device implementers MUST provide Windows drivers allowing developers to
1501connect to the device using the <code>adb</code> protocol. These drivers MUST
1502be provided for Windows XP, Windows Vista, Windows 7, and Windows 8, in both 32-bit and
150364-bit versions.</p>
1504
1505<a name="section-6.2"></a><h3>6.2 Developer Options</h3>
1506<p>Android 4.2 includes support for developers to configure application development-related settings.
1507Device implementations MUST honor the android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show
1508application development-related settings [<a href="#resources77">Resources, 77</a>]. The upstream Android
1509implementation hides the Developer Options menu by default, and enables users to launch Developer Options
1510after pressing seven (7) times on the Settings > About Device > Build Number menu item. Device implementations
1511MUST provide a consistent experience for Developer Options. Specifically, device implementations MUST hide
1512Developer Options by default and MUST provide a mechanism to enable Developer Options that is consistent with
1513the upstream Android implementation.</p>
1514
1515<a name="section-7"></a><h2>7. Hardware Compatibility</h2>
1516<p>If a device includes a particular hardware component that has a
1517corresponding API for third-party developers, the device implementation MUST
1518implement that API as described in the Android SDK documentation. If an API in
1519the SDK interacts with a hardware component that is stated to be optional and
1520the device implementation does not possess that component:</p>
1521<ul>
1522<li>complete class definitions (as documented by the SDK) for the component's
1523APIs MUST still be present</li>
1524<li>the API's behaviors MUST be implemented as no-ops in some reasonable
1525fashion</li>
1526<li>API methods MUST return null values where permitted by the SDK
1527documentation</li>
1528<li>API methods MUST return no-op implementations of classes where null
1529values are not permitted by the SDK documentation</li>
1530<li>API methods MUST NOT throw exceptions not documented by the SDK
1531documentation</li>
1532</ul>
1533<p>A typical example of a scenario where these requirements apply is the
1534telephony API: even on non-phone devices, these APIs must be implemented as
1535reasonable no-ops.</p>
1536<p>Device implementations MUST accurately report accurate hardware configuration
1537information via the <code>getSystemAvailableFeatures()</code> and
1538<code>hasSystemFeature(String)</code> methods on the
1539<code>android.content.pm.PackageManager</code> class. [<a
1540href="#resources37">Resources, 37</a>]</p>
1541
1542<a name="section-7.1"></a><h3>7.1. Display and Graphics</h3>
1543<p>Android 4.2 includes facilities that automatically adjust application
1544assets and UI layouts appropriately for the device, to ensure that third-party
1545applications run well on a variety of hardware configurations [<a
1546href="#resources38">Resources, 38</a>]. Devices MUST properly implement these
1547APIs and behaviors, as detailed in this section.</p>
1548
1549<p>The units referenced by the requirements in this section are defined as follows:</p>
1550<ul>
1551<li>"Physical diagonal size" is the distance in inches between two opposing
1552corners of the illuminated portion of the display.</li>
1553<li>"dpi" (meaning "dots per inch") is the number of pixels encompassed by a
1554linear horizontal or vertical span of 1". Where dpi values are listed, both
1555horizontal and vertical dpi must fall within the range.</li>
1556<li>"Aspect ratio" is the ratio of the longer dimension of the screen to the
1557shorter dimension. For example, a display of 480x854 pixels would be 854 / 480
1558= 1.779, or roughly "16:9".</li>
1559<li>A "density-independent pixel" or ("dp") is the virtual pixel unit normalized to a
1560160 dpi screen, calculated as:
1561<code>pixels = dps * (density / 160)</code>.</li>
1562</ul>
1563
1564
1565<a name="section-7.1.1"></a><h4>7.1.1. Screen Configuration</h4>
1566
1567<p style="font-weight:bold;">Screen Size</p>
1568<p>The Android UI framework supports a variety of different screen sizes, and
1569allows applications to query the device screen size (aka "screen layout") via
1570<code>android.content.res.Configuration.screenLayout</code> with the
1571<code>SCREENLAYOUT_SIZE_MASK</code>. Device implementations MUST report the
1572correct screen size as defined in the Android SDK documentation
1573[<a href="#resources38">Resources, 38</a>] and determined by the upstream
1574Android platform. Specifically, device implementations must report the correct
1575screen size according to the following logical density-independent pixel (dp)
1576screen dimensions.</p>
1577<ul>
1578<li>Devices MUST have screen sizes of at least 426 dp x 320 dp ('small')</li>
1579<li>Devices that report screen size 'normal' MUST have screen sizes of at least
1580480 dp x 320 dp</li>
1581<li>Devices that report screen size 'large' MUST have screen sizes of at least
1582640 dp x 480 dp</li>
1583<li>Devices that report screen size 'xlarge' MUST have screen sizes of at least
1584960 dp x 720 dp</li>
1585</ul>
1586<p>In addition, devices MUST have screen sizes of at least 2.5 inches in
1587physical diagonal size.</p>
1588
1589<p>Devices MUST NOT change their reported screen size at any time.</p>
1590<p>Applications optionally indicate which screen sizes they support via the
1591<code>&lt;supports-screens&gt;</code> attribute in the AndroidManifest.xml
1592file. Device implementations MUST correctly honor applications' stated support
1593for small, normal, large, and xlarge screens, as described in the Android
1594SDK documentation.</p>
1595
1596<p style="font-weight:bold;">Screen Aspect Ratio</p>
1597<p>The aspect ratio MUST be between 1.3333 (4:3) and 1.85 (16:9).</p>
1598
1599<p style="font-weight:bold;">Screen Density</p>
1600<p>The Android UI framework defines a set of standard logical densities to
1601help application developers target application resources. Device
1602implementations MUST report one of the following logical Android framework
1603densities through the <code>android.util.DisplayMetrics</code> APIs, and MUST
1604execute applications at this standard density.
1605<ul>
1606<li>120 dpi, known as 'ldpi'</li>
1607<li>160 dpi, known as 'mdpi'</li>
1608<li>213 dpi, known as 'tvdpi'</li>
1609<li>240 dpi, known as 'hdpi'</li>
1610<li>320 dpi, known as 'xhdpi'</li>
1611<li>480 dpi, known as 'xxhdpi'</li>
1612</ul>
1613Device implementations SHOULD define the standard Android framework density
1614that is numerically closest to the physical density of the screen, unless that
1615logical density pushes the reported screen size below the minimum supported.
1616If the standard Android framework density that is numerically closest to the
1617physical density results in a screen size that is smaller than the smallest
1618supported compatible screen size (320 dp width), device implementations SHOULD
1619report the next lowest standard Android framework density.</p>
1620
1621<a name="section-7.1.2"></a><h4>7.1.2. Display Metrics</h4>
1622<p>Device implementations MUST report correct values for all display metrics
1623defined in <code>android.util.DisplayMetrics</code> [<a
1624href="#resources39">Resources, 39</a>].</p>
1625
1626<a name="section-7.1.3"></a><h4>7.1.3. Screen Orientation</h4>
1627<p>Devices MUST support dynamic orientation by applications to
1628either portrait or landscape screen orientation. That is, the device must
1629respect the application's request for a specific screen orientation. Device
1630implementations MAY select either portrait or landscape orientation as the
1631default.</p>
1632<p>Devices MUST report the correct value for the device's current orientation,
1633whenever queried via the android.content.res.Configuration.orientation,
1634android.view.Display.getOrientation(), or other APIs.</p>
1635<p>Devices MUST NOT change the reported screen size or density when changing
1636orientation.</p>
1637<p>Devices MUST report which screen orientations they support (
1638<code>android.hardware.screen.portrait</code> and/or
1639<code>android.hardware.screen.landscape</code>) and MUST report at least one
1640supported orientation. For example, a device with a fixed-orientation
1641landscape screen, such as a television or laptop, MUST only report
1642<code>android.hardware.screen.landscape</code>.</p>
1643
1644<a name="section-7.1.4"></a><h4>7.1.4. 2D and 3D Graphics Acceleration</h4>
1645<p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied
1646and detailed in the Android SDK documentations. Device implementations MUST
1647also support Android Renderscript, as detailed in the Android SDK
1648documentation [<a href="#resources08">Resources, 8</a>].</p>
1649<p>Device implementations MUST also correctly identify themselves as
1650supporting OpenGL ES 1.0 and 2.0. That is:</p>
1651<ul>
1652<li>The managed APIs (such as via the <code>GLES10.getString()</code> method)
1653MUST report support for OpenGL ES 1.0 and 2.0</li>
1654<li>The native C/C++ OpenGL APIs (that is, those available to apps via
1655libGLES_v1CM.so, libGLES_v2.so, or libEGL.so) MUST report support for
1656OpenGL ES 1.0 and 2.0.</li>
1657</ul>
1658<p>Device implementations MAY implement any desired OpenGL ES extensions.
1659However, device implementations MUST report via the OpenGL ES managed and
1660native APIs all extension strings that they do support, and conversely MUST
1661NOT report extension strings that they do not support.</p>
1662<p>Note that Android 4.2 includes support for applications to optionally
1663specify that they require specific OpenGL texture compression formats. These
1664formats are typically vendor-specific. Device implementations are not required
1665by Android 4.2 to implement any specific texture compression format. However,
1666they SHOULD accurately report any texture compression formats that they do
1667support, via the <code>getString()</code> method in the OpenGL API.</p>
1668
1669<p>Android 4.2 includes a mechanism for applications to declare that they
1670wanted to enable hardware acceleration for 2D graphics at the Application,
1671Activity, Window or View level through the use of a manifest tag
1672<code>android:hardwareAccelerated</code> or direct API calls
1673[<a href="#resources09">Resources, 9</a>].</p>
1674<p>In Android 4.2, device implementations MUST enable hardware acceleration by
1675default, and MUST disable hardware acceleration if the developer so requests
1676by setting <code>android:hardwareAccelerated="false"</code> or disabling
1677hardware acceleration directly through the Android View APIs.</p>
1678<p>In addition, device implementations MUST exhibit behavior consistent with the
1679Android SDK documentation on hardware acceleration
1680[<a href="#resources09">Resources, 9</a>].</p>
1681<p>Android 4.2 includes a <code>TextureView</code> object that lets developers
1682directly integrate hardware-accelerated OpenGL ES textures as rendering targets
1683in a UI hierarchy. Device implementations MUST support the <code>TextureView
1684</code> API, and MUST exhibit consistent behavior with the upstream Android
1685implementation.</p>
1686
1687<a name="section-7.1.5"></a><h4>7.1.5. Legacy Application Compatibility Mode</h4>
1688<p>Android 4.2 specifies a "compatibility mode" in which the framework
1689operates in an 'normal' screen size equivalent (320dp width) mode for the benefit
1690of legacy applications not developed for old versions of Android that pre-date
1691screen-size independence. Device implementations MUST include support for legacy
1692application compatibility mode as implemented by the upstream Android open source
1693code. That is, device implementations MUST NOT alter the triggers or thresholds at
1694which compatibility mode is activated, and MUST NOT alter the behavior of the
1695compatibility mode itself.</p>
1696
1697<a name="section-7.1.6"></a><h4>7.1.6. Screen Types</h4>
1698<p>Device implementation screens are classified as one of two types:</p>
1699<ul>
1700<li>Fixed-pixel display implementations: the screen is a single panel that supports only a
1701single pixel width and height. Typically the screen is physically integrated with
1702the device. Examples include mobile phones, tablets, and so on.</li>
1703<li>Variable-pixel display implementations: the device implementation either has no
1704embedded screen and includes a video output port such as VGA, HDMI or a wireless port
1705for display, or has an embedded screen that can change pixel dimensions. Examples
1706include televisions, set-top boxes, and so on.</li>
1707</ul>
1708<p style="font-weight: bold;">Fixed-Pixel Device Implementations</p>
1709<p>Fixed-pixel device implementations MAY use screens of any pixel dimensions, provided
1710that they meet the requirements defined this Compatibility Definition.</p>
1711<p>Fixed-pixel implementations MAY include a video output port for use with an
1712external display. However, if that display is ever used for running apps, the
1713device MUST meet the following requirements:</p>
1714<ul>
1715<li>The device MUST report the same screen configuration and display metrics, as detailed
1716in Sections 7.1.1 and 7.1.2, as the fixed-pixel display.</li>
1717<li>The device MUST report the same logical density as the fixed-pixel display.</li>
1718<li>The device MUST report screen dimensions that are the same as, or very close to,
1719the fixed-pixel display.</li>
1720</ul>
1721<p>For example, a tablet that is 7" diagonal size with a 1024x600 pixel resolution is
1722considered a fixed-pixel large mdpi display implementation. If it contains a video
1723output port that displays at 720p or 1080p, the device implementation MUST scale the output so that
1724applications are only executed in a large mdpi window, regardless of whether the fixed-pixel display
1725or video output port is in use.</p>
1726
1727<p style="font-weight: bold;">Variable-Pixel Device Implementations</p>
1728<p>Variable-pixel device implementations MUST support one or both of 1280x720,
1729or 1920x1080 (that is, 720p or 1080p). Device implementations with
1730variable-pixel displays MUST NOT support any other screen configuration or
1731mode. Device implementations with variable-pixel screens MAY change screen
1732configuration or mode at runtime or boot-time. For example, a user of a
1733set-top box may replace a 720p display with a 1080p display, and the device
1734implementation may adjust accordingly.</p>
1735
1736<p>Additionally, variable-pixel device implementations MUST report the following
1737configuration buckets for these pixel dimensions:</p>
1738<ul>
1739<li>1280x720 (also known as 720p): 'large' screen size, 'tvdpi' (213 dpi)
1740density</li>
1741<li>1920x1080 (also known as 1080p): 'large' screen size, 'xhdpi' (320 dpi)
1742density</li>
1743</ul>
1744<p>For clarity, device implementations with variable pixel dimensions are
1745restricted to 720p or 1080p in Android 4.2, and MUST be configured to report
1746screen size and density buckets as noted above.</p>
1747
1748<a name="section-7.1.7"></a><h4>7.1.7. Screen Technology</h4>
1749<p>The Android platform includes APIs that allow applications to render rich
1750graphics to the display. Devices MUST support all of these APIs as defined by
1751the Android SDK unless specifically allowed in this document. Specifically:</p>
1752<ul>
1753<li>Devices MUST support displays capable of rendering 16-bit color graphics and
1754SHOULD support displays capable of 24-bit color graphics.</li>
1755<li>Devices MUST support displays capable of rendering animations.</li>
1756<li>The display technology used MUST have a pixel aspect ratio (PAR) between
1757 0.9 and 1.1. That is, the pixel aspect ratio MUST be near square (1.0) with
1758 a 10% tolerance.</li>
1759</ul>
1760<a name="section-7.1.8"></a><h4>7.1.8. External Displays</h4>
1761<p>Android 4.2 includes support for secondary display to enable media sharing capabilities and
1762developer APIs for accessing external displays. If a device supports an external display either via
1763a wired, wireless or an embedded additional display connection then the device implementation MUST
1764implement the display manager API as described in the Android SDK documentation [<a href="#resources75">Resources, 75</a>].
1765Device implementations that support secure video output and are capable of supporting secure surfaces MUST declare support
1766for <code>Display.SECURE_FLAG</code>. Specifically, device implementations that declare support for <code>Display.SECURE_FLAG</code>,
1767MUST support <b>HDCP 2.x or higher</b> for Miracast wireless displays or <b>HDCP 1.2 or higher</b> for wired displays. The upstream
1768Android open source implementation includes support for wireless (Miracast) and wired (HDMI) displays that satisfies this requirement.</p>
1769
1770<a name="section-7.2"></a><h3>7.2. Input Devices</h3>
1771<a name="section-7.2.1"></a><h4>7.2.1. Keyboard</h4>
1772<p>Device implementations:</p>
1773<ul>
1774<li>MUST include support for the Input Management Framework (which allows third
1775party developers to create Input Management Engines - i.e. soft keyboard) as
1776detailed at <a href="http://developer.android.com">http://developer.android.com</a>
1777</li>
1778<li>MUST provide at least one soft keyboard implementation (regardless of whether
1779a hard keyboard is present)</li>
1780<li>MAY include additional soft keyboard implementations</li>
1781<li>MAY include a hardware keyboard</li>
1782<li>MUST NOT include a hardware keyboard that does not match one of the
1783formats specified in <code>android.content.res.Configuration.keyboard</code>
1784[<a href="#resources40">Resources, 40</a>] (that is, QWERTY, or 12-key)</li>
1785</ul>
1786<a name="section-7.2.2"></a><h4>7.2.2. Non-touch Navigation</h4>
1787<p>Device implementations:</p>
1788<ul>
1789<li>MAY omit a non-touch navigation option (that is, may omit a trackball, d-pad,
1790or wheel)</li>
1791<li>MUST report the correct value for
1792<code>android.content.res.Configuration.navigation</code>
1793[<a href="#resources40">Resources, 40</a>]</li>
1794<li>MUST provide a reasonable alternative user interface mechanism for the
1795selection and editing of text, compatible with Input Management Engines. The
1796upstream Android open source implementation includes a selection mechanism suitable
1797for use with devices that lack non-touch navigation inputs.</li>
1798</ul>
1799<a name="section-7.2.3"></a><h4>7.2.3. Navigation keys</h4>
1800<p>The Home, Menu and Back functions are essential to the Android navigation
1801paradigm. Device implementations MUST make these functions available to the
1802user at all times when running applications. These functions MAY be implemented
1803via dedicated physical buttons (such as mechanical or capacitive touch buttons),
1804or MAY be implemented using dedicated software keys, gestures, touch panel, etc.
1805Android 4.2 supports both implementations.</p>
1806
1807<p>Android 4.2 includes support for assist action [<a href="#resources63">Resources, 63</a>].
1808Device implementations MUST make the assist action available to the user at all times when running applications.
1809This function MAY be implemented via hardware or software keys.</p>
1810
1811<p>Device implementations MAY use a distinct portion of the screen to display
1812the navigation keys, but if so, MUST meet these requirements:</p>
1813
1814<ul>
1815 <li>Device implementation navigation keys MUST use a distinct portion of the
1816 screen, not available to applications, and MUST NOT obscure or otherwise
1817 interfere with the portion of the screen available to applications.</li>
1818 <li>Device implementations MUST make available a portion of the display to
1819 applications that meets the requirements defined in
1820 <a href="section-7.1.1">Section 7.1.1</a>.</li>
1821 <li>Device implementations MUST display the navigation keys when applications
1822 do not specify a system UI mode, or specify
1823 <code>SYSTEM_UI_FLAG_VISIBLE</code>.</li>
1824 <li>Device implementations MUST present the navigation keys in an unobtrusive
1825 "low profile" (eg. dimmed) mode when applications specify
1826 <code>SYSTEM_UI_FLAG_LOW_PROFILE</code>.</li>
1827 <li>Device implementations MUST hide the navigation keys when applications
1828 specify <code>SYSTEM_UI_FLAG_HIDE_NAVIGATION</code>.</li>
1829 <li>Device implementation MUST present a Menu key to applications when
1830 targetSdkVersion &lt;= 10 and SHOULD NOT present a Menu key when the
1831 targetSdkVersion &gt; 10.</li>
1832</ul>
1833
1834<a name="section-7.2.4"></a><h4>7.2.4. Touchscreen input</h4>
1835<p>Device implementations:</p>
1836<ul>
1837<li>MUST have a pointer input system of some kind (either mouse-like, or
1838touch)</li>
1839<li>MAY have a touchscreen of any modality (such as capacitive or resistive)</li>
1840<li>SHOULD support fully independently tracked pointers, if a touchscreen
1841supports multiple pointers</li>
1842<li>MUST report the value of <code>android.content.res.Configuration</code>
1843[<a href="#resources40">Resources, 39</a>]
1844reflecting corresponding to the type of the specific touchscreen on the
1845device</li>
1846</ul>
1847<p>Device implementations MUST report the correct feature corresponding to the
1848type of input used. Note that Android 4.2 includes the feature
1849<code>android.hardware.faketouch</code>, which corresponds to a high-fidelity
1850non-touch (that is, pointer-based) input device such as a mouse or trackpad that
1851can adequately emulate touch-based input (including basic gesture support),
1852and indicates that the device supports an emulated subset of touchscreen
1853functionality.
1854Device implementations that include a touchscreen (single-touch or better)
1855MUST also report android.hardware.faketouch. Device implementations that do
1856not include a touchscreen (and rely on a pointer device only) MUST NOT report
1857any touchscreen feature, and MUST report only
1858<code>android.hardware.faketouch</code>.</p>
1859<a name="section-7.2.5"></a><h4>7.2.5. Microphone</h4>
1860<p>Device implementations MAY omit a microphone. However, if a device
1861implementation omits a microphone, it MUST NOT report the
1862<code>android.hardware.microphone</code> feature constant, and must implement
1863the audio recording API as no-ops, per <a href="section-7">Section 7</a>.
1864Conversely, device implementations that do possess a microphone:</p>
1865<ul>
1866<li>MUST report the <code>android.hardware.microphone</code> feature constant</li>
1867<li>SHOULD meet the audio quality requirements in <a href="section-5.4">Section 5.4</a></li>
1868<li>SHOULD meet the audio latency requirements in <a href="section-5.5">Section 5.5</a></li>
1869</ul>
1870
1871<a name="section-7.3"></a><h3>7.3. Sensors</h3>
1872<p>Android 4.2 includes APIs for accessing a variety of sensor types. Devices
1873implementations generally MAY omit these sensors, as provided for in the
1874following subsections. If a device includes a particular sensor type that has a
1875corresponding API for third-party developers, the device implementation MUST
1876implement that API as described in the Android SDK documentation. For example,
1877device implementations:</p>
1878<ul>
1879<li>MUST accurately report the presence or absence of sensors per the
1880<code>android.content.pm.PackageManager</code> class. [<a
1881href="#resources37">Resources, 37</a>]</li>
1882<li>MUST return an accurate list of supported sensors via the
1883<code>SensorManager.getSensorList()</code> and similar methods</li>
1884<li>MUST behave reasonably for all other sensor APIs (for example, by
1885returning true or false as appropriate when applications attempt to register
1886listeners, not calling sensor listeners when the corresponding sensors are not
1887present; etc.)</li>
1888<li>MUST report all sensor measurements using the relevant International System
1889of Units (i.e. metric) values for each sensor type as defined in the Android SDK
1890documentation [<a href="#resources41">Resources, 41</a>]</li>
1891</ul>
1892<p>The list above is not comprehensive; the documented behavior of the Android
1893SDK is to be considered authoritative.</p>
1894<p>Some sensor types are synthetic, meaning they can be derived from data
1895provided by one or more other sensors. (Examples include the orientation
1896sensor, and the linear acceleration sensor.) Device implementations SHOULD
1897implement these sensor types, when they include the prerequisite physical
1898sensors.</p>
1899<p>The Android 4.2 includes a notion of a "streaming" sensor, which is
1900one that returns data continuously, rather than only when the data changes.
1901Device implementations MUST continuously provide periodic data samples for any
1902API indicated by the Android 4.2 SDK documentation to be a streaming
1903sensor. Note that the device implementations MUST ensure that the sensor stream must not
1904prevent the device CPU from entering a suspend state or waking up from a suspend state.</p>
1905
1906<a name="section-7.3.1"></a><h4>7.3.1. Accelerometer</h4>
1907<p>Device implementations SHOULD include a 3-axis accelerometer. If a device
1908implementation does include a 3-axis accelerometer, it:</p>
1909<ul>
1910<li>SHOULD be able to deliver events at 120 Hz or greater. Note that while the
1911accelerometer frequency above is stated as "SHOULD" for Android 4.2, the Compatibility Definition
1912for a future version is planned to change these to "MUST". That is, these standards are
1913optional in Android 4.2 but <b>will be required</b> in future versions. Existing and
1914new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements
1915in Android 4.2</b> so they will be able to upgrade to the future platform releases
1916</li>
1917<li>MUST comply with the Android sensor coordinate system as detailed
1918in the Android APIs (see [<a href="#resources41">Resources, 41</a>])</li>
1919<li>MUST be capable of measuring from freefall up to twice gravity (2g) or
1920more on any three-dimensional vector</li>
1921<li>MUST have 8-bits of accuracy or more</li>
1922<li>MUST have a standard deviation no greater than 0.05 m/s^2</li>
1923</ul>
1924<a name="section-7.3.2"></a><h4>7.3.2. Magnetometer</h4>
1925<p>Device implementations SHOULD include a 3-axis magnetometer (i.e. compass.)
1926If a device does include a 3-axis magnetometer, it:</p>
1927<ul>
1928<li>MUST be able to deliver events at 10 Hz or greater</li>
1929<li>MUST comply with the Android sensor coordinate system as detailed
1930in the Android APIs (see [<a href="#resources41">Resources, 41</a>]).</li>
1931<li>MUST be capable of sampling a range of field strengths adequate to cover the
1932geomagnetic field</li>
1933<li>MUST have 8-bits of accuracy or more</li>
1934<li>MUST have a standard deviation no greater than 0.5 &micro;T</li>
1935</ul>
1936<a name="section-7.3.3"></a><h4>7.3.3. GPS</h4>
1937<p>Device implementations SHOULD include a GPS receiver. If a device
1938implementation does include a GPS receiver, it SHOULD include
1939some form of "assisted GPS" technique to minimize GPS lock-on time.</p>
1940<a name="section-7.3.4"></a><h4>7.3.4. Gyroscope</h4>
1941<p>Device implementations SHOULD include a gyroscope (i.e. angular change
1942sensor.) Devices SHOULD NOT include a gyroscope sensor unless a 3-axis
1943accelerometer is also included. If a device implementation includes a
1944gyroscope, it:</p>
1945<ul>
1946<li>MUST be temperature compensated</li>
1947<li>MUST be capable of measuring orientation changes up to 5.5*Pi
1948radians/second (that is, approximately 1,000 degrees per second)</li>
1949<li>SHOULD be able to deliver events at 200 Hz or greater. Note that while the
1950gyroscope frequency above is stated as "SHOULD" for Android 4.2, the Compatibility Definition
1951for a future version is planned to change these to "MUST". That is, these standards are
1952optional in Android 4.2 but <b>will be required</b> in future versions. Existing and
1953new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements
1954in Android 4.2</b> so they will be able to upgrade to the future platform releases
1955</li>
1956<li>MUST have 12-bits of accuracy or more</li>
1957<li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, or rad^2 / s).
1958The variance is allowed to vary with the sampling rate, but must be constrained by this value.
1959In other words, if you measure the variance of the gyro at 1 Hz sampling rate it should be no
1960greater than 1e-7 rad^2/s^2. </li>
1961<li>MUST have timestamps as close to when the hardware event happened as possible. The constant latency must be removed.</li>
1962</ul>
1963<a name="section-7.3.5"></a><h4>7.3.5. Barometer</h4>
1964<p>Device implementations MAY include a barometer (i.e. ambient air pressure
1965sensor.) If a device implementation includes a barometer, it:</p>
1966<ul>
1967<li>MUST be able to deliver events at 5 Hz or greater</li>
1968<li>MUST have adequate precision to enable estimating altitude</li>
1969<li>MUST be temperature compensated</li>
1970</ul>
1971<a name="section-7.3.6"></a><h4>7.3.7. Thermometer</h4>
1972<p>Device implementations MAY but SHOULD NOT include a thermometer (i.e.
1973temperature sensor.) If a device implementation does include a thermometer, it
1974MUST measure the temperature of the device CPU. It MUST NOT measure any other
1975temperature. (Note that this sensor type is deprecated in the Android 4.2
1976APIs.)</p>
1977<a name="section-7.3.7"></a><h4>7.3.7. Photometer</h4>
1978<p>Device implementations MAY include a photometer (i.e. ambient light
1979sensor.)</p>
1980<a name="section-7.3.8"></a><h4>7.3.8. Proximity Sensor</h4>
1981<p>Device implementations MAY include a proximity sensor. If a device
1982implementation does include a proximity sensor, it MUST measure the proximity
1983of an object in the same direction as the screen. That is, the proximity
1984sensor MUST be oriented to detect objects close to the screen, as the
1985primary intent of this sensor type is to detect a phone in use by the
1986user. If a device implementation includes a proximity sensor with any other
1987orientation, it MUST NOT be accessible through this API. If a device
1988implementation has a proximity sensor, it MUST be have 1-bit of accuracy or
1989more.</p>
1990
1991<a name="section-7.4"></a><h3>7.4. Data Connectivity</h3>
1992<a name="section-7.4.1"></a><h4>7.4.1. Telephony</h4>
1993<p>"Telephony" as used by the Android 4.2 APIs and this document refers
1994specifically to hardware related to placing voice calls and sending SMS
1995messages via a GSM or CDMA network. While these voice calls may or may not be
1996packet-switched, they are for the purposes of Android 4.2 considered
1997independent of any data connectivity that may be implemented using the same
1998network. In other words, the Android "telephony" functionality and APIs refer
1999specifically to voice calls and SMS; for instance, device implementations that
2000cannot place calls or send/receive SMS messages MUST NOT report the
2001"android.hardware.telephony" feature or any sub-features, regardless of
2002whether they use a cellular network for data connectivity.</p>
2003<p>Android 4.2 MAY be used on devices that do not include telephony hardware.
2004That is, Android 4.2 is compatible with devices that are not phones.
2005However, if a device implementation does include GSM or CDMA telephony, it
2006MUST implement full support for the API for that technology. Device
2007implementations that do not include telephony hardware MUST implement the full
2008APIs as no-ops.</p>
2009<a name="section-7.4.2"></a><h4>7.4.2. IEEE 802.11 (WiFi)</h4>
2010<p>Android 4.2 device implementations SHOULD include support for one or more
2011forms of 802.11 (b/g/a/n, etc.) If a device implementation does include
2012support for 802.11, it MUST implement the corresponding Android API.</p>
2013<p>Device implementations MUST implement the multicast API as described in
2014the SDK documentation [<a href="#resources62">Resources, 62</a>]. Device
2015implementations that do include Wifi support MUST support multicast DNS (mDNS).
2016Device implementations MUST not filter mDNS packets (224.0.0.251) at any time
2017of operation including when the screen is not in an active state.</p>
2018
2019<a name="section-7.4.2.1"></a><h4>7.4.2.1. WiFi Direct</h4>
2020<p>Device implementations SHOULD include support for Wifi direct (Wifi peer-to-peer).
2021If a device implementation does include support for Wifi direct, it MUST implement the corresponding
2022Android API as described in the SDK documentation [<a href="#resources68">Resources, 68</a>].
2023If a device implementation includes support for Wifi direct, then it:</p>
2024<ul>
2025 <li>MUST support regular Wifi operation</li>
2026 <li>SHOULD support concurrent wifi and wifi Direct operation</li>
2027</ul>
2028
2029<a name="section-7.4.3"></a><h4>7.4.3. Bluetooth</h4>
2030<p>Device implementations SHOULD include a Bluetooth transceiver. Device
2031implementations that do include a Bluetooth transceiver MUST enable the
2032RFCOMM-based Bluetooth API as described in the SDK documentation [<a
2033href="#resources42">Resources, 42</a>]. Device implementations SHOULD
2034implement relevant Bluetooth profiles, such as A2DP, AVRCP, OBEX, etc. as
2035appropriate for the device.</p>
2036<p>The Compatibility Test Suite includes cases that cover basic operation of
2037the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications
2038protocol between devices, it cannot be fully tested by unit tests running on a
2039single device. Consequently, device implementations MUST also pass the
2040human-driven Bluetooth test procedure described in Appendix A.</p>
2041
2042<a name="section-7.4.4"></a><h4>7.4.4. Near-Field Communications</h4>
2043<p>Device implementations SHOULD include a transceiver and related hardware
2044for Near-Field Communications (NFC). If a device implementation does include
2045NFC hardware, then it:</p>
2046<ul>
2047 <li>MUST report the android.hardware.nfc feature from the
2048 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method.
2049 [<a href="#resources37">Resources, 37</a>]</li>
2050 <li>MUST be capable of reading and writing NDEF messages via the following NFC
2051 standards:
2052 <ul>
2053 <li>MUST be capable of acting as an NFC Forum reader/writer
2054 (as defined by the NFC Forum technical specification
2055 NFCForum-TS-DigitalProtocol-1.0) via the following NFC standards:
2056 <ul>
2057 <li>NfcA (ISO14443-3A)</li>
2058 <li>NfcB (ISO14443-3B) </li>
2059 <li>NfcF (JIS 6319-4)</li>
2060 <li>IsoDep (ISO 14443-4)</li>
2061 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li>
2062 </ul>
2063 </li>
2064 </ul>
2065 </li>
2066 <li>SHOULD be capable of reading and writing NDEF messages via the following
2067 NFC standards. Note that while the NFC standards below are stated as
2068 "SHOULD" for Android 4.2, the Compatibility Definition for a future
2069 version is planned to change these to "MUST". That is, these standards are
2070 optional in Android 4.2 but <b>will be required</b> in future versions.
2071 Existing and new devices that run Android 4.2 are <b>very strongly
2072 encouraged to meet these requirements in Android 4.2</b> so they will be
2073 able to upgrade to the future platform releases.
2074 <ul>
2075 <li>NfcV (ISO 15693)</li>
2076 </ul>
2077 </li>
2078 <li>MUST be capable of transmitting and receiving data via the following
2079 peer-to-peer standards and protocols:
2080 <ul>
2081 <li>ISO 18092</li>
2082 <li>LLCP 1.0 (defined by the NFC Forum)</li>
2083 <li>SDP 1.0 (defined by the NFC Forum)</li>
2084 <li>NDEF Push Protocol [<a href="#resources43">Resources, 43</a>]</li>
2085 <li>SNEP 1.0 (defined by the NFC Forum)</li>
2086 </ul>
2087 </li>
2088 <li>MUST include support for Android Beam [<a href="#resources65">Resources, 65</a>]:
2089 <ul>
2090 <li>MUST implement the SNEP default server. Valid NDEF messages received
2091 by the default SNEP server MUST be dispatched to applications using
2092 the android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam
2093 in settings MUST NOT disable dispatch of incoming NDEF message.</li>
2094 <li>Device implementations MUST honor the android.settings.NFCSHARING_SETTINGS intent
2095 to show NFC sharing settings [<a href="#resources67">Resources, 67</a>].</li>
2096 <li>MUST implement the NPP server. Messages received by the NPP server MUST
2097 be processed the same way as the SNEP default server.</li>
2098 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to
2099 the default SNEP server when Android Beam is enabled. If no default
2100 SNEP server is found then the client MUST attempt to send to an NPP
2101 server.</li>
2102 <li>MUST allow foreground activities to set the outbound P2P NDEF message
2103 using android.nfc.NfcAdapter.setNdefPushMessage, and
2104 android.nfc.NfcAdapter.setNdefPushMessageCallback, and
2105 android.nfc.NfcAdapter.enableForegroundNdefPush.</li>
2106 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam',
2107 before sending outbound P2P NDEF messages.</li>
2108 <li>SHOULD enable Android Beam by default</li>
2109 <li>MUST support NFC Connection handover to Bluetooth when the device supports Bluetooth Object Push Profile.
2110 Device implementations must support connection handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris,
2111 by implementing the "Connection Handover version 1.2" [<a href="#resources60">Resources, 60</a>]
2112 and "Bluetooth Secure Simple Pairing Using NFC version 1.0" [<a href="#resources61">Resources, 61</a>]
2113 specs from the NFC Forum. Such an implementation SHOULD use SNEP GET
2114 requests for exchanging the handover request / select records over NFC, and it MUST
2115 use the Bluetooth Object Push Profile for the actual Bluetooth data transfer.</li>
2116 </ul>
2117 </li>
2118 <li>MUST poll for all supported technologies while in NFC discovery mode.</li>
2119 <li>SHOULD be in NFC discovery mode while the device is awake with the screen active
2120 and the lock-screen unlocked.</li>
2121</ul>
2122
2123<p>(Note that publicly available links are not available for the JIS, ISO, and
2124NFC Forum specifications cited above.)</p>
2125<p>Additionally, device implementations MAY include reader/writer support for
2126the following MIFARE technologies.</p>
2127<ul>
2128 <li>MIFARE Classic (NXP MF1S503x [<a href="#resources44">Resources, 44</a>],
2129 MF1S703x [<a href="#resources44">Resources, 44</a>])</li>
2130 <li>MIFARE Ultralight (NXP MF0ICU1 [<a href="#resources46">Resources, 46</a>],
2131 MF0ICU2 [<a href="#resources46">Resources, 46</a>])</li>
2132 <li>NDEF on MIFARE Classic (NXP AN130511 [<a href="#resources48">Resources, 48</a>],
2133 AN130411 [<a href="#resources49">Resources, 49</a>])</li>
2134</ul>
2135<p>Note that Android 4.2 includes APIs for these MIFARE types. If a
2136device implementation supports MIFARE in the reader/writer role, it:</p>
2137<ul>
2138 <li>MUST implement the corresponding Android APIs as documented by the
2139 Android SDK</li>
2140 <li>MUST report the feature com.nxp.mifare from the
2141 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method.
2142 [<a href="#resources37">Resources, 37</a>] Note that this is not a standard
2143 Android feature, and as such does not appear as a constant on the
2144 <code>PackageManager</code> class.</li>
2145 <li>MUST NOT implement the corresponding Android APIs nor report the
2146 com.nxp.mifare feature unless it also implements general NFC support as
2147 described in this section</li>
2148</ul>
2149<p>If a device implementation does not include NFC hardware, it MUST NOT
2150declare the android.hardware.nfc feature from the
2151<code>android.content.pm.PackageManager.hasSystemFeature()</code> method [<a
2152href="#resources37">Resources, 37</a>], and MUST implement the Android 4.2 NFC
2153API as a no-op.</p>
2154<p>As the classes <code>android.nfc.NdefMessage</code> and
2155<code>android.nfc.NdefRecord</code> represent a protocol-independent data
2156representation format, device implementations MUST implement these APIs even
2157if they do not include support for NFC or declare the android.hardware.nfc
2158feature.</p>
2159<a name="section-7.4.5"></a><h4>7.4.5. Minimum Network Capability</h4>
2160<p>Device implementations MUST include support for one or more forms of data
2161networking. Specifically, device implementations MUST include support for at
2162least one data standard capable of 200Kbit/sec or greater. Examples of
2163technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g,
2164Ethernet, etc.</p>
2165<p>Device implementations where a physical networking standard (such as
2166Ethernet) is the primary data connection SHOULD also include support for at
2167least one common wireless data standard, such as 802.11 (WiFi).</p>
2168<p>Devices MAY implement more than one form of data connectivity.</p>
2169
2170
2171<a name="section-7.5"></a><h3>7.5. Cameras</h3>
2172<p>Device implementations SHOULD include a rear-facing camera, and MAY include
2173a front-facing camera. A rear-facing camera is a camera located on the side of
2174the device opposite the display; that is, it images scenes on the far side of
2175the device, like a traditional camera. A front-facing camera is a camera
2176located on the same side of the device as the display; that is, a camera
2177typically used to image the user, such as for video conferencing and similar
2178applications.</p>
2179<a name="section-7.5.1"></a><h4>7.5.1. Rear-Facing Camera</h4>
2180<p>Device implementations SHOULD include a rear-facing camera. If a device
2181implementation includes a rear-facing camera, it:</p>
2182<ul>
2183<li>MUST have a resolution of at least 2 megapixels</li>
2184<li>SHOULD have either hardware auto-focus, or software auto-focus implemented
2185in the camera driver (transparent to application software)</li>
2186<li>MAY have fixed-focus or EDOF (extended depth of field) hardware</li>
2187<li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST
2188NOT be lit while an android.hardware.Camera.PreviewCallback instance has been
2189registered on a Camera preview surface, unless the application has explicitly
2190enabled the flash by enabling the <code>FLASH_MODE_AUTO</code> or
2191<code>FLASH_MODE_ON</code> attributes of a <code>Camera.Parameters</code>
2192object. Note that this constraint does not apply to the device's built-in
2193system camera application, but only to third-party applications using
2194<code>Camera.PreviewCallback</code>.</li>
2195</ul>
2196<a name="section-7.5.2"></a><h4>7.5.2. Front-Facing Camera</h4>
2197<p>Device implementations MAY include a front-facing camera. If a device
2198implementation includes a front-facing camera, it:</p>
2199<ul>
2200<li>MUST have a resolution of at least VGA (that is, 640x480 pixels)</li>
2201<li>MUST NOT use a front-facing camera as the default for the Camera API.
2202That is, the camera API in Android 4.2 has specific support for front-facing
2203cameras, and device implementations MUST NOT configure the API to to treat a
2204front-facing camera as the default rear-facing camera, even if it is the only
2205camera on the device.</li>
2206<li>MAY include features (such as auto-focus, flash, etc.)
2207available to rear-facing cameras as described in Section 7.5.1.</li>
2208<li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a
2209CameraPreview, as follows:</li>
2210<ul>
2211<li>If the device implementation is capable of being rotated by user (such as
2212automatically via an accelerometer or manually via user input), the camera
2213preview MUST be mirrored horizontally relative to the device's current
2214orientation.</li>
2215<li>If the current application has explicitly requested that the Camera
2216display be rotated via a call to the
2217<code>android.hardware.Camera.setDisplayOrientation()</code> [<a
2218href="#resources50">Resources, 50</a>] method, the camera preview MUST be
2219mirrored horizontally relative to the orientation specified by the
2220application.</li>
2221<li>Otherwise, the preview MUST be mirrored along the device's default horizontal axis.</li>
2222</ul>
2223<li>MUST mirror the image displayed by the postview in the same manner as
2224the camera preview image stream. (If the device implementation does not
2225support postview, this requirement obviously does not apply.)</li>
2226<li>MUST NOT mirror the final captured still image or video streams returned
2227to application callbacks or committed to media storage</li>
2228</ul>
2229<a name="section-7.5.3"></a><h4>7.5.3. Camera API Behavior</h4>
2230<p>Device implementations MUST implement the following behaviors for the
2231camera-related APIs, for both front- and rear-facing cameras:</p>
2232<ol>
2233<li>If an application has never called
2234<code>android.hardware.Camera.Parameters.setPreviewFormat(int)</code>, then the
2235device MUST use <code>android.hardware.PixelFormat.YCbCr_420_SP</code> for
2236preview data provided to application callbacks.</li>
2237<li>If an application registers an <code>android.hardware.Camera.PreviewCallback
2238</code> instance and the system calls the <code>onPreviewFrame()</code> method
2239when the preview format is YCbCr_420_SP, the data in the <code>byte[]</code>
2240passed into <code>onPreviewFrame()</code> must further be in the NV21 encoding
2241format. That is, NV21 MUST be the default.</li>
2242<li>Device implementations MUST support the YV12 format (as denoted by the
2243<code>android.graphics.ImageFormat.YV12</code> constant) for camera previews
2244for both front- and rear-facing cameras. (The hardware video encoder and camera
2245may use any native pixel format, but the device implementation MUST support conversion
2246to YV12.)</li>
2247</ol>
2248<p>Device implementations MUST implement the full Camera API included in the
2249Android 4.2 SDK documentation [<a href="#resources51">Resources, 51</a>]),
2250regardless of whether the device includes hardware autofocus or other
2251capabilities. For instance, cameras that lack autofocus MUST still call any
2252registered <code>android.hardware.Camera.AutoFocusCallback</code> instances (even though
2253this has no relevance to a non-autofocus camera.) Note that this does apply
2254to front-facing cameras; for instance, even though most front-facing cameras
2255do not support autofocus, the API callbacks must still be "faked" as
2256described.</p>
2257<p>Device implementations MUST recognize and honor each parameter name defined
2258as a constant on the <code>android.hardware.Camera.Parameters</code> class, if the
2259underlying hardware supports the feature. If the device hardware does not
2260support a feature, the API must behave as documented. Conversely, Device
2261implementations MUST NOT honor or recognize string constants passed
2262to the <code>android.hardware.Camera.setParameters()</code> method other than
2263those documented as constants on the
2264<code>android.hardware.Camera.Parameters</code>. That is,
2265device implementations MUST support all standard Camera parameters if the
2266hardware allows, and MUST NOT support custom Camera parameter types.
2267For instance, device implementations that support image capture using high dynamic range (HDR)
2268imaging techniques MUST support camera parameter <code>Camera.SCENE_MODE_HDR</code>
2269[<a href="#resources78">Resources, 78</a>]).</p>
2270<p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_PICTURE</code>
2271intent whenever a new picture is taken by the camera and the entry of the picture
2272has been added to the media store.</p>
2273<p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_VIDEO</code>
2274intent whenever a new video is recorded by the camera and the entry of the picture
2275has been added to the media store.</p>
2276<a name="section-7.5.4"></a><h4>7.5.4. Camera Orientation</h4>
2277<p>Both front- and rear-facing cameras, if present, MUST be oriented so that
2278the long dimension of the camera aligns with the screen's long dimention. That
2279is, when the device is held in the landscape orientation, cameras MUST
2280capture images in the landscape orientation. This applies regardless of the
2281device's natural orientation; that is, it applies to landscape-primary devices
2282as well as portrait-primary devices.</p>
2283
2284<a name="section-7.6"></a><h3>7.6. Memory and Storage</h3>
2285<a name="section-7.6.1"></a><h4>7.6.1. Minimum Memory and Storage</h4>
2286<p>Device implementations MUST have at least 340MB of memory available to the
2287kernel and userspace. The 340MB MUST be in addition to any memory dedicated to
2288hardware components such as radio, video, and so on that is not under the
2289kernel's control.</p>
2290<p>Device implementations MUST have at least 350MB of non-volatile storage
2291available for application private data. That is, the <code>/data</code> partition MUST be at
2292least 350MB.</p>
2293<p>The Android APIs include a Download Manager that applications may use to
2294download data files [<a href="#resources56">Resources, 56</a>]. The device
2295implementation of the Download Manager MUST be capable of downloading individual
2296files of at least 100MB in size to the default "cache" location.</p>
2297<a name="section-7.6.2"></a><h4>7.6.2. Application Shared Storage</h4>
2298<p>Device implementations MUST offer shared storage for applications. The
2299shared storage provided MUST be at least 1GB in size.</p>
2300<p>Device implementations MUST be configured with shared storage mounted by
2301default, "out of the box". If the shared storage is not mounted on the Linux
2302path <code>/sdcard</code>, then the device MUST include a Linux symbolic link
2303from <code>/sdcard</code> to the actual mount point.</p>
2304<p>Device implementations MUST enforce as documented the
2305<code>android.permission.WRITE_EXTERNAL_STORAGE</code> permission on this
2306shared storage. Shared storage MUST otherwise be writable by any application
2307that obtains that permission.</p>
2308<p>Device implementations MAY have hardware for user-accessible removable
2309storage, such as a Secure Digital card. Alternatively, device implementations
2310MAY allocate internal (non-removable) storage as shared storage for apps.</p>
2311<p>Regardless of the form of shared storage used, device implementations MUST
2312provide some mechanism to access the contents of shared storage from a host
2313computer, such as USB mass storage (UMS) or Media Transfer Protocol (MTP). Device
2314implementations MAY use USB mass storage, but SHOULD use Media Transfer
2315Protocol. If the device implementation supports Media Transfer Protocol:</p>
2316<ul>
2317<li>The device implementation SHOULD be compatible with the reference Android
2318MTP host, Android File Transfer [<a href="#resources57">Resources, 57</a>].</li>
2319<li>The device implementation SHOULD report a USB device class of <code>0x00</code>.</li>
2320<li>The device implementation SHOULD report a USB interface name of 'MTP'.</li>
2321</ul>
2322<p>If the device implementation lacks USB ports, it MUST provide a host
2323computer with access to the contents of shared storage by some other means,
2324such as a network file system.</p>
2325<p>It is illustrative to consider two common examples. If a device
2326implementation includes an SD card slot to satisfy the shared storage
2327requirement, a FAT-formatted SD card 1GB in size or larger MUST be included
2328with the device as sold to users, and MUST be mounted by default.
2329Alternatively, if a device implementation uses internal fixed storage to
2330satisfy this requirement, that storage MUST be 1GB in size or larger
2331and mounted on <code>/sdcard</code> (or <code>/sdcard</code>
2332MUST be a symbolic link to the physical location if it is mounted elsewhere.)</p>
2333<p>Device implementations that include multiple shared storage paths (such as
2334both an SD card slot and shared internal storage) SHOULD modify the core
2335applications such as the media scanner and ContentProvider to transparently
2336support files placed in both locations.</p>
2337
2338<a name="section-7.7"></a><h3>7.7. USB</h3>
2339<p>Device implementations SHOULD include a USB client port, and SHOULD include
2340a USB host port.</p>
2341<p>If a device implementation includes a USB client port:</p>
2342<ul>
2343<li>the port MUST be connectable to a USB host with a standard USB-A port</li>
2344<li>the port SHOULD use the micro USB form factor on the device side. Existing and
2345new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements
2346in Android 4.2</b> so they will be able to upgrade to the future platform releases</li>
2347<li>the port SHOULD be centered in the middle of an edge. Device implementations SHOULD either
2348locate the port on the bottom of the device (according to natural orientation) or enable software
2349screen rotation for all apps (including home screen), so that the display draws correctly when the device
2350is oriented with the port at bottom. Existing and new devices that run Android 4.2 are <b>very strongly
2351encouraged to meet these requirements in Android 4.2</b> so they will be able to upgrade to future platform releases.</li>
2352<li>if the device has other ports (such as a non-USB charging port) it SHOULD be on the same edge as the
2353micro-USB port</li>
2354<li>it MUST allow a host connected to the device to access the contents of the
2355shared storage volume using either USB mass storage or Media Transfer
2356Protocol</li>
2357<li>it MUST implement the Android Open Accessory API and specification as documented
2358in the Android SDK documentation, and MUST declare support for the hardware
2359feature <code>android.hardware.usb.accessory</code> [<a href="#resources52">Resources,
236052</a>]</li>
2361<li>it MUST implement the USB audio class as documented in the Android SDK documentation [<a href="#resources66">Resources, 66</a>]</li>
2362<li>it SHOULD implement support for USB battery charging specification [<a href="#resources64">Resources, 64</a>]
2363Existing and new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements in Android 4.2</b>
2364so they will be able to upgrade to the future platform releases</li>
2365
2366</ul>
2367<p>If a device implementation includes a USB host port:</p>
2368<ul>
2369<li>it MAY use a non-standard port form factor, but if so MUST ship with a
2370cable or cables adapting the port to standard USB-A</li>
2371<li>it MUST implement the Android USB host API as documented in the Android
2372SDK, and MUST declare support for the hardware feature
2373<code>android.hardware.usb.host</code> [<a href="#resources53">Resources, 53</a>]</li>
2374</ul>
2375<p>Device implementations MUST implement the Android Debug Bridge. If a device
2376implementation omits a USB client port, it MUST implement the Android Debug
2377Bridge via local-area network (such as Ethernet or 802.11)</p>
2378
2379<a name="section-8"></a><h2>8. Performance Compatibility</h2>
2380<p>Device implementations MUST meet the key performance metrics of an Android
23814.2 compatible device defined in the table below:</p>
2382<table><tbody><tr>
2383<td><b>Metric</b></td>
2384<td><b>Performance Threshold</b></td>
2385<td><b>Comments</b></td>
2386</tr>
2387<tr>
2388<td>Application Launch Time</td>
2389<td>The following applications should launch within the specified time.<ul>
2390<li>Browser: less than 1300ms</li>
2391<li>Contacts: less than 700ms</li>
2392<li>Settings: less than 700ms</li>
2393</ul></td>
2394<td>The launch time is measured as the total time to
2395complete loading the default activity for the application, including the time
2396it takes to start the Linux process, load the Android package into the Dalvik
2397VM, and call onCreate.</td>
2398</tr>
2399<tr>
2400<td>Simultaneous Applications</td>
2401<td>When multiple applications have been launched, re-launching an
2402already-running application after it has been launched must take less than the
2403original launch time.</td>
2404<td>&nbsp;</td>
2405</tr>
2406</tbody>
2407</table>
2408
2409<a name="section-9"></a><h2>9. Security Model Compatibility</h2>
2410<p>Device implementations MUST implement a security model consistent with the
2411Android platform security model as defined in Security and Permissions
2412reference document in the APIs [<a href="#resources54">Resources, 54</a>] in the
2413Android developer documentation. Device implementations MUST support
2414installation of self-signed applications without requiring any additional
2415permissions/certificates from any third parties/authorities. Specifically,
2416compatible devices MUST support the security mechanisms described in the
2417follow sub-sections.</p>
2418<a name="section-9.1"></a><h3>9.1. Permissions</h3>
2419<p>Device implementations MUST support the Android permissions model as
2420defined in the Android developer documentation [<a
2421href="#resources54">Resources, 54</a>]. Specifically,
2422implementations MUST enforce each permission defined as described in the SDK
2423documentation; no permissions may be omitted, altered, or ignored.
2424Implementations MAY add additional permissions, provided the new permission ID
2425strings are not in the android.* namespace.</p>
2426<a name="section-9.2"></a><h3>9.2. UID and Process Isolation</h3>
2427<p>Device implementations MUST support the Android application sandbox model,
2428in which each application runs as a unique Unix-style UID and in a separate
2429process. Device implementations MUST support running multiple applications as
2430the same Linux user ID, provided that the applications are properly signed and
2431constructed, as defined in the Security and Permissions reference [<a
2432href="#resources54">Resources, 54</a>].</p>
2433<a name="section-9.3"></a><h3>9.3. Filesystem Permissions</h3>
2434<p>Device implementations MUST support the Android file access permissions
2435model as defined in as defined in the Security and Permissions reference [<a
2436href="#resources54">Resources, 54</a>].</p>
2437<a name="section-9.4"></a><h3>9.4. Alternate Execution Environments</h3>
2438<p>Device implementations MAY include runtime environments that execute
2439applications using some other software or technology than the Dalvik virtual
2440machine or native code. However, such alternate execution environments MUST
2441NOT compromise the Android security model or the security of installed Android
2442applications, as described in this section.</p>
2443<p>Alternate runtimes MUST themselves be Android applications, and abide by
2444 the standard Android security model, as described elsewhere in Section 9.</p>
2445<p>Alternate runtimes MUST NOT be granted access to resources protected by
2446 permissions not requested in the runtime's AndroidManifest.xml file via the
2447 <code>&lt;uses-permission&gt;</code> mechanism.</p>
2448<p>Alternate runtimes MUST NOT permit applications to make use of features
2449 protected by Android permissions restricted to system applications.</p>
2450<p>Alternate runtimes MUST abide by the Android sandbox model. Specifically:</p>
2451<ul>
2452<li>Alternate runtimes SHOULD install apps via the PackageManager into
2453 separate Android sandboxes (that is, Linux user IDs, etc.)</li>
2454<li>Alternate runtimes MAY provide a single Android sandbox shared by all
2455 applications using the alternate runtime</li>
2456<li>Alternate runtimes and installed applications using an alternate runtime
2457 MUST NOT reuse the sandbox of any other app installed on the device, except
2458 through the standard Android mechanisms of shared user ID and signing
2459 certificate</li>
2460<li>Alternate runtimes MUST NOT launch with, grant, or be granted access to
2461 the sandboxes corresponding to other Android applications</li>
2462</ul>
2463<p>Alternate runtimes MUST NOT be launched with, be granted, or grant to other
2464 applications any privileges of the superuser (root), or of any other user ID.</p>
2465<p>The .apk files of alternate runtimes MAY be included in the system image of
2466 a device implementation, but MUST be signed with a key distinct
2467 from the key used to sign other applications included with the device
2468 implementation.</p>
2469<p>When installing applications, alternate runtimes MUST obtain user consent
2470 for the Android permissions used by the application. That is, if an
2471 application needs to make use of a device resource for which there is a
2472 corresponding Android permission (such as Camera, GPS, etc.), the alternate
2473 runtime MUST inform the user that the application will be able to access
2474 that resource. If the runtime environment does not record application
2475 capabilities in this manner, the runtime environment MUST list all
2476 permissions held by the runtime itself when installing any application
2477 using that runtime.</p>
2478
2479<a name="section-9.5"></a><h3>9.5. Multi-User Support </h3>
2480<p>Android 4.2 includes support for multiple users and provides support for full user isolation
2481[<a href="#resources70">Resources, 70</a>].</p>
2482<p>Device implementations MUST meet these requirements related to multi-user support[<a href="#resources71">Resources, 71</a>]:</p>
2483<ul>
2484<li>As the behavior of the telephony APIs on devices with multiple users is currently undefined, device implementations that
2485declare android.hardware.telephony MUST NOT enable multi-user support. </li>
2486<li>Device implementations MUST, for each user, implement a security model consistent with the Android platform security model
2487as defined in Security and Permissions reference document in the APIs [Resources, 54]</li>
2488</ul>
2489</p>
2490
2491<p>Each user instance on an Android device MUST have separate and isolated external storage directories. Device implementations MAY store multiple users' data on the same volume or filesystem.
2492However, the device implementation MUST ensure that applications owned by and running on behalf a given user cannot list, read, or write to data owned by any other user.
2493Note that removable media, such as SD card slots, can allow one user to access another's data by means of a host PC. For this reason, device implementations that use removable media for the
2494external storage APIs MUST encrypt the contents of the SD card if multi-user is enabled using a key stored only on non-removable media accessible only to the system. As this will make the
2495media unreadable by a host PC, device implementations will be required to switch to MTP or a similar system to provide host PCs with access to the current user's data. Accordingly, device
2496implementations MAY but SHOULD NOT enable multi-user if they use removable media [<a href="#resources72">Resources, 72</a>] for primary external storage. The upstream Android open-source
2497project includes an implementation that uses internal device storage for application external storage APIs; device implementations SHOULD use this configuration and software implementation.
2498Device implementations that include multiple external storage paths MUST NOT allow Android applications to write to the secondary external storage</p>
2499
2500<a name="section-9.6"></a><h3>9.6. Premium SMS Warning</h3>
2501<p>Android 4.2 includes support for warning users for any outgoing premium SMS message. Premium SMS messages are text messages sent to a service registered with a carrier that may incur a charge to the user.
2502Device implementations that declare support for <code>android.hardware.telephony</code> MUST warn users before sending a SMS message to numbers identified by regular expressions defined in <code>/data/misc/sms/codes.xml</code> file in the device.
2503The upstream Android open-source project provides an implementation that satisfies this requirement.
2504</p>
2505
2506<a name="section-10"></a><h2>10. Software Compatibility Testing</h2>
2507<p>Device implementations MUST pass all tests described in this section.</p>
2508<p>However, note that no software test package is fully comprehensive. For
2509this reason, device implementers are very strongly encouraged to make the
2510minimum number of changes as possible to the reference and preferred
2511implementation of Android 4.2 available from the Android Open Source Project.
2512This will minimize the risk of introducing bugs that create incompatibilities
2513requiring rework and potential device updates.</p>
2514<a name="section-10.1"></a><h3>10.1. Compatibility Test Suite</h3>
2515<p>Device implementations MUST pass the Android Compatibility Test Suite (CTS)
2516[<a href="#resources02">Resources, 2</a>] available from the Android Open Source
2517Project, using the final shipping software on the device. Additionally, device
2518implementers SHOULD use the reference implementation in the Android Open
2519Source tree as much as possible, and MUST ensure compatibility in cases of
2520ambiguity in CTS and for any reimplementations of parts of the reference
2521source code.</p>
2522<p>The CTS is designed to be run on an actual device. Like any software, the
2523CTS may itself contain bugs. The CTS will be versioned independently of this
2524Compatibility Definition, and multiple revisions of the CTS may be released
2525for Android 4.2. Device implementations MUST pass the latest CTS version
2526available at the time the device software is completed.</p>
2527<a name="section-10.2"></a><h3>10.2. CTS Verifier</h3>
2528<p>Device implementations MUST correctly execute all applicable cases in the
2529CTS Verifier. The CTS Verifier is included with the Compatibility Test Suite,
2530and is intended to be run by a human operator to test functionality that
2531cannot be tested by an automated system, such as correct functioning of a
2532camera and sensors.</p>
2533<p>The CTS Verifier has tests for many kinds of hardware, including some
2534hardware that is optional. Device implementations MUST pass all tests for
2535hardware which they possess; for instance, if a device possesses an
2536accelerometer, it MUST correctly execute the Accelerometer test case in the
2537CTS Verifier. Test cases for features noted as optional by this Compatibility
2538Definition Document MAY be skipped or omitted.</p>
2539<p>Every device and every build MUST correctly run the CTS Verifier, as noted
2540above. However, since many builds are very similar, device implementers are
2541not expected to explicitly run the CTS Verifier on builds that differ only in
2542trivial ways. Specifically, device implementations that differ from an
2543implementation that has passed the CTS Verfier only by the set of included
2544locales, branding, etc. MAY omit the CTS Verifier test.</p>
2545<a name="section-10.3"></a><h3>10.3. Reference Applications</h3>
2546<p>Device implementers MUST test implementation compatibility using the
2547following open source applications:</p>
2548<ul>
2549<li>The "Apps for Android" applications [<a href="#resources55">Resources, 55</a>]</li>
2550<li>Replica Island (available in Android Market)</li>
2551</ul>
2552<p>Each app above MUST launch and behave correctly on the implementation, for
2553the implementation to be considered compatible.</p>
2554
2555
2556<a name="section-11"></a><h2>11. Updatable Software</h2>
2557<p>Device implementations MUST include a mechanism to replace the entirety of
2558the system software. The mechanism need not perform "live" upgrades - that
2559is, a device restart MAY be required.</p>
2560<p>Any method can be used, provided that it can replace the entirety of the
2561software preinstalled on the device. For instance, any of the following
2562approaches will satisfy this requirement:</p>
2563<ul>
2564<li>Over-the-air (OTA) downloads with offline update via reboot</li>
2565<li>"Tethered" updates over USB from a host PC</li>
2566<li>"Offline" updates via a reboot and update from a file on removable
2567storage</li>
2568</ul>
2569<p>The update mechanism used MUST support updates without wiping user data.
2570That is, the update mechanism MUST preserve application private data
2571and application shared data. Note that the upstream Android software includes
2572an update mechanism that satisfies this requirement.</p>
2573<p>If an error is found in a device implementation after it has been released
2574but within its reasonable product lifetime that is determined in consultation
2575with the Android Compatibility Team to affect the compatibility of third-party
2576applications, the device implementer MUST correct the error via a software
2577update available that can be applied per the mechanism just described.</p>
2578
2579<a name="section-12"></a><h2>12. Contact Us</h2>
2580<p>You can contact the document authors at <a
2581href="mailto:compatibility@android.com">compatibility@android.com</a> for
2582clarifications and to bring up any issues that you think the document does not
2583cover.</p>
2584
2585<div style="page-break-before: always;"></div>
2586
2587<a name="appendix-A"></a><h2>Appendix A - Bluetooth Test Procedure</h2>
2588<p>The Compatibility Test Suite includes cases that cover basic operation of
2589the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications
2590protocol between devices, it cannot be fully tested by unit tests running on a
2591single device. Consequently, device implementations MUST also pass the
2592human-operated Bluetooth test procedure described below.</p>
2593<p>The test procedure is based on the BluetoothChat sample app included in the
2594Android open source project tree. The procedure requires two devices:</p>
2595<ul>
2596<li>a candidate device implementation running the software build to be tested</li>
2597<li>a separate device implementation already known to be compatible, and of a
2598 model from the device implementation being tested - that is, a "known
2599 good" device implementation</li>
2600</ul>
2601<p>The test procedure below refers to these devices as the "candidate" and "known
2602good" devices, respectively.</p>
2603<h3>Setup and Installation</h3>
2604<ol>
2605<li>Build BluetoothChat.apk via 'make samples' from an Android source code tree</li>
2606<li>Install BluetoothChat.apk on the known-good device</li>
2607<li>Install BluetoothChat.apk on the candidate device</li>
2608</ol>
2609<h3>Test Bluetooth Control by Apps</h3>
2610<ol>
2611<li>Launch BluetoothChat on the candidate device, while Bluetooth is disabled</li>
2612<li>Verify that the candidate device either turns on Bluetooth, or prompts the user with a dialog to turn on Bluetooth</li>
2613</ol>
2614<h3>Test Pairing and Communication</h3>
2615<ol>
2616<li>Launch the Bluetooth Chat app on both devices</li>
2617<li>Make the known-good device discoverable from within BluetoothChat (using the Menu)</li>
2618<li>On the candidate device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the known-good device</li>
2619<li>Send 10 or more messages from each device, and verify that the other device receives them correctly</li>
2620<li>Close the BluetoothChat app on both devices by pressing <b>Home</b></li>
2621<li>Unpair each device from the other, using the device Settings app</li>
2622</ol>
2623<h3>Test Pairing and Communication in the Reverse Direction</h3>
2624<ol>
2625<li>Launch the Bluetooth Chat app on both devices.</li>
2626<li>Make the candidate device discoverable from within BluetoothChat (using the Menu).</li>
2627<li>On the known-good device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the candidate device.</li>
2628<li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li>
2629<li>Close the Bluetooth Chat app on both devices by pressing Back repeatedly to get to the Launcher.</li>
2630</ol>
2631<h3>Test Re-Launches</h3>
2632<ol>
2633<li>Re-launch the Bluetooth Chat app on both devices.</li>
2634<li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li>
2635</ol>
2636<p>Note: the above tests have some cases which end a test section by using
2637Home, and some using Back. These tests are not redundant and are not optional:
2638the objective is to verify that the Bluetooth API and stack works correctly
2639both when Activities are explicitly terminated (via the user pressing Back,
2640which calls finish()), and implicitly sent to background (via the user
2641pressing Home.) Each test sequence MUST be performed as described.</p>
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