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   <p>
     To improve device battery life, Android can affect the device state by
     monitoring device use and wakefulness. The platform can enter a state of
     sleep to pause activities from running while the device is unused.
   </p>

   <h2 id="doze">Doze</h2>

 <p>Doze extends battery life by deferring application background CPU and
 network activity when a device is unused for long periods.</p>

 <p>Idle devices in Doze periodically enter a maintenance window, during which
 apps can complete pending work (syncs, jobs, etc.). Doze then resumes
 sleep for a longer period of time, followed by another maintenance window. The
 platform continues the Doze sleep/maintenance sequence, increasing the length of
 idle each time, until a maximum of a few hours of sleep time is reached. At all
 times, a device in Doze remains aware of motion and immediately leaves Doze
 if motion is detected.</p>

 <p>Android 7.0 and higher extends Doze to trigger a lighter set of optimizations
 every time a user turns off the device screen, even when the user continues to
 move around, enabling longer lasting battery life.</p>

 <p>Critical system services are genereally set up by device manufacturers to be
   exempt from Doze. Users can also exempt specific apps from Doze via the
 Settings menu. However, exempting apps may cause battery drain on the device.
   By default, Doze is <strong>disabled</strong> in AOSP; for
 details on enabling Doze, see <a href="#integrate-doze">Integrating Doze</a>.
 </p>

 <h3 id="doze-reqs">Doze requirements</h3>
 <p>Doze support requires the device has a cloud messaging service, such as
 <a href="https://firebase.google.com/docs/cloud-messaging/" class="external">Firebase
 Cloud Messaging (FCM)</a>. External triggers events, such as cloud messages,
   can temporarily wake apps to do work while the device remains in Doze mode.</p>

 <p>Full Doze support also requires a
 <a href="/devices/sensors/sensor-types.html#significant_motion">Significant
 Motion Detector (SMD)</a> on the device; however, the lightweight Doze mode in
 Android 7.0 and higher does not require an SMD. If Doze is enabled on a device
 that:</p>
 <ul>
 <li>Has an SMD, full Doze optimizations occur (includes lightweight
 optimizations).</li>
 <li>Does not have an SMD, only the lightweight Doze optimizations occur.</li>
 </ul>

 <h3 id="doze-life">Doze lifecycle</h3>

 <p>Doze begins when the platform detects the device is idle and
 ends when one or more exit criteria activities occur.</p>

 <table>
 <tbody>
 <tr>
 <th width=20%>Detection</th>
 <th width=60%>During Doze</th>
 <th width=20%>Exit</th>
 </tr>
 <tr>
 <td><p>The platform detects a device is idle when:</p>
 <ul>
 <li>Device is stationary (using significant motion detector).</li>
 <li>Device screen is off for some amount of time.</li>
 </ul>
 <p>Doze mode does not engage when the device is plugged into a power charger.
 </p>
 </td>
 <td><p>The platform attempts to keep the system in a sleep state, periodically
 resuming normal operations during a maintenance window then returning the device
 to sleep for longer repeating periods. During sleep, the following
 restrictions are active:</p>
 <ul>
 <li>Apps not allowed network access.</li>
 <li>App wakelocks ignored.</li>
 <li>Alarms deferred. Excludes alarm clock alarms and alarms set using
 <code>setAndAllowWhileIdle()</code> (limited to 1 per 15 minutes per app while
 in Doze). This exemption is intended for apps (such as Calendar) that must show
 event reminder notifications.</li>
 <li>Wi-Fi scans not performed.</li>
 <li><code>SyncAdapter</code> syncs and <code>JobScheduler</code> jobs deferred
 until the next maintenance window.</li>
 <li>Apps receiving SMS and MMS messages are put on a temporary whitelist so
 they can complete their processing.</li>
 </ul>
 </td>
 <td><p>The platform exits the device from Doze when it detects:</p>
 <ul>
 <li>User interaction with device.</li>
 <li>Device movement.</li>
 <li>Device screen turns on.</li>
 <li>Imminent AlarmClock alarm.</li>
 </ul>
 <p>Notifications do not cause the device to exit from Doze.</p>
 </td>
 </tr>
 </tbody>
 </table>

 <p>Android 7.0 and higher extends Doze by enabling a lightweight sleep mode
 during screen off, before the device is idle.</p>

 <p><img src="/devices/tech/images/doze_lightweight.png"></p>
 <figcaption><strong>Figure 1.</strong> Doze modes for non-stationary and
 stationary devices.</figcaption>

 <table>
 <tbody>
 <tr>
 <th>Action</th>
 <th>Doze</th>
 <th>Lightweight Doze</th>
 </tr>
 <tr>
 <td>Trigger</td>
 <td>Screen off, on battery, stationary</td>
 <td>Screen off, on battery (unplugged)</td>
 </tr>
 <tr>
 <td>Timing</td>
 <td>Successively increasing periods with maintenance</td>
 <td>Repeated N-minute periods with maintenance windows</td>
 </tr>
 <tr>
 <td>Restrictions</td>
 <td>No network access, wake lock, or GPS/Wi-Fi scan. Alarms and jobs/syncs
 deferred.</td>
 <td>No network access. Jobs/syncs deferred except during maintenance windows.
 </td>
 </tr>
 <tr>
 <td>Behavior</td>
 <td>Only high-priority push notification messages received.</td>
 <td>All real-time messages (instant messages, calls, etc.) received.
 High-priority push notification message enables temporary network access.</td>
 </tr>
 <tr>
 <td>Exit</td>
 <td>Motion, screen on, or alarm clock alarm.</td>
 <td>Screen on.</td>
 </tr>
 </tbody>
 </table>

 <h3 id="doze-interactions">Interaction with App Standby</h3>
 <ul>
 <li>Time spent in Doze does not count towards App Standby.</li>
 <li>While the device is in Doze, idle applications are allowed to perform normal
 operations at least once a day.</li>
 </ul>

 <h3 id="integrate-doze">Integrating Doze</h3>

 <p>When Doze is enabled, devices that support
 <a href="/devices/sensors/sensor-types.html#significant_motion"><code>SENSOR_TYPE_SIGNIFICANT_MOTION</code>code></a>
 perform full Doze optimizations (including lightweight optimizations);
 devices without an SMD perform only lightweight Doze optimizations. Android
 automatically selects the appropriate Doze optimizations and no vendor
 configuration is necessary.</p>

 <p>To enable Doze for a device:</p>

 <ol>
 <li>Confirm the device has a cloud messaging service installed.</li>
 <li>In the device overlay config file
 <code>overlay/frameworks/base/core/res/res/values/config.xml</code>, set
 <code>config_enableAutoPowerModes</code> to <strong>true</strong>:
 <pre class="devsite-click-to-copy">
 &lt;bool name="config_enableAutoPowerModes"&gt;true&lt;/bool&gt;
 </pre>
 In AOSP, this parameter is set to false (Doze disabled) by default.<br>
 </li>
 <li>Confirm that preloaded apps and services:
 <ul>
 <li>Use the
 <a href="https://developer.android.com/training/monitoring-device-state/doze-standby.html" class="external">power-saving
 optimization guidelines</a>. For details, see <a href="#test-apps">Testing and
 optimizing applications</a>.
 <p><strong>OR</strong></p>
 <li>Are exempted from Doze and App Standby. For details, see
 <a href="/devices/tech/power/mgmt#exempt-apps">Exempting applications</a>.</li>
 </ul>
 </li>
 <li>Confirm the necessary services are exempted from Doze.</li>
 </ol>

 <h4 id="doze-tips">Tips</h4>
 <ul>
 <li>If possible, use FCM for
 <a href="https://firebase.google.com/docs/cloud-messaging/http-server-ref#send-downstream" class="external">downstream
 messaging</a>.</li>
 <li>If your users must see a notification right away, use a
 <a href="https://firebase.google.com/docs/cloud-messaging/concept-options#setting-the-priority-of-a-message" class="external">FCM
 high priority message</a>.</li>
 <li>Provide sufficient information within the initial
 <a href="https://firebase.google.com/docs/cloud-messaging/concept-options#notifications_and_data_messages" class="external">message
 payload</a> (to avoid unnecessary subsequent network access).</li>
 <li>Set critical alarms with
 <a href="http://developer.android.com/reference/android/app/AlarmManager.html#setAndAllowWhileIdle(int,%20long,%20android.app.PendingIntent)" class="external"><code>setAndAllowWhileIdle()</code></a>
 and
 <a href="http://developer.android.com/reference/android/app/AlarmManager.html#setExactAndAllowWhileIdle(int,%20long,%20android.app.PendingIntent)" class="external"><code>setExactAndAllowWhileIdle()</code></a>.
 </li>
 </ul>

 <h4 id="test-apps">Testing and optimizing applications</h4>
 <p>Test all applications (especially preloaded applications) in Doze mode. For
 details, refer to
 <a href="https://developer.android.com/training/monitoring-device-state/doze-standby.html#testing_doze_and_app_standby">Testing
 Doze and App Standby</a>.</p>

 <aside class="note"><strong>Note:</strong> MMS/SMS/Telephony services function
 independently of Doze and will always wake client apps even while the device
 remains in Doze mode.</aside>

   </body>
 </html>
	<html devsite>
	<head>
	<title>Platform Power Management</title>
	<meta name="project_path" value="/_project.yaml" />
	<meta name="book_path" value="/_book.yaml" />
	</head>
	<body>
	<!--
	Copyright 2018 The Android Open Source Project

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
	-->

	<p>
	To improve device battery life, Android can affect the device state by
	monitoring device use and wakefulness. The platform can enter a state of
	sleep to pause activities from running while the device is unused.
	</p>

	<h2 id="doze">Doze</h2>

	<p>Doze extends battery life by deferring application background CPU and
	network activity when a device is unused for long periods.</p>

	<p>Idle devices in Doze periodically enter a maintenance window, during which
	apps can complete pending work (syncs, jobs, etc.). Doze then resumes
	sleep for a longer period of time, followed by another maintenance window. The
	platform continues the Doze sleep/maintenance sequence, increasing the length of
	idle each time, until a maximum of a few hours of sleep time is reached. At all
	times, a device in Doze remains aware of motion and immediately leaves Doze
	if motion is detected.</p>

	<p>Android 7.0 and higher extends Doze to trigger a lighter set of optimizations
	every time a user turns off the device screen, even when the user continues to
	move around, enabling longer lasting battery life.</p>

	<p>Critical system services are genereally set up by device manufacturers to be
	exempt from Doze. Users can also exempt specific apps from Doze via the
	Settings menu. However, exempting apps may cause battery drain on the device.
	By default, Doze is <strong>disabled</strong> in AOSP; for
	details on enabling Doze, see <a href="#integrate-doze">Integrating Doze</a>.
	</p>

	<h3 id="doze-reqs">Doze requirements</h3>
	<p>Doze support requires the device has a cloud messaging service, such as
	<a href="https://firebase.google.com/docs/cloud-messaging/" class="external">Firebase
	Cloud Messaging (FCM)</a>. External triggers events, such as cloud messages,
	can temporarily wake apps to do work while the device remains in Doze mode.</p>

	<p>Full Doze support also requires a
	<a href="/devices/sensors/sensor-types.html#significant_motion">Significant
	Motion Detector (SMD)</a> on the device; however, the lightweight Doze mode in
	Android 7.0 and higher does not require an SMD. If Doze is enabled on a device
	that:</p>
	<ul>
	<li>Has an SMD, full Doze optimizations occur (includes lightweight
	optimizations).</li>
	<li>Does not have an SMD, only the lightweight Doze optimizations occur.</li>
	</ul>

	<h3 id="doze-life">Doze lifecycle</h3>

	<p>Doze begins when the platform detects the device is idle and
	ends when one or more exit criteria activities occur.</p>

	<table>
	<tbody>
	<tr>
	<th width=20%>Detection</th>
	<th width=60%>During Doze</th>
	<th width=20%>Exit</th>
	</tr>
	<tr>
	<td><p>The platform detects a device is idle when:</p>
	<ul>
	<li>Device is stationary (using significant motion detector).</li>
	<li>Device screen is off for some amount of time.</li>
	</ul>
	<p>Doze mode does not engage when the device is plugged into a power charger.
	</p>
	</td>
	<td><p>The platform attempts to keep the system in a sleep state, periodically
	resuming normal operations during a maintenance window then returning the device
	to sleep for longer repeating periods. During sleep, the following
	restrictions are active:</p>
	<ul>
	<li>Apps not allowed network access.</li>
	<li>App wakelocks ignored.</li>
	<li>Alarms deferred. Excludes alarm clock alarms and alarms set using
	<code>setAndAllowWhileIdle()</code> (limited to 1 per 15 minutes per app while
	in Doze). This exemption is intended for apps (such as Calendar) that must show
	event reminder notifications.</li>
	<li>Wi-Fi scans not performed.</li>
	<li><code>SyncAdapter</code> syncs and <code>JobScheduler</code> jobs deferred
	until the next maintenance window.</li>
	<li>Apps receiving SMS and MMS messages are put on a temporary whitelist so
	they can complete their processing.</li>
	</ul>
	</td>
	<td><p>The platform exits the device from Doze when it detects:</p>
	<ul>
	<li>User interaction with device.</li>
	<li>Device movement.</li>
	<li>Device screen turns on.</li>
	<li>Imminent AlarmClock alarm.</li>
	</ul>
	<p>Notifications do not cause the device to exit from Doze.</p>
	</td>
	</tr>
	</tbody>
	</table>

	<p>Android 7.0 and higher extends Doze by enabling a lightweight sleep mode
	during screen off, before the device is idle.</p>

	<p><img src="/devices/tech/images/doze_lightweight.png"></p>
	<figcaption><strong>Figure 1.</strong> Doze modes for non-stationary and
	stationary devices.</figcaption>

	<table>
	<tbody>
	<tr>
	<th>Action</th>
	<th>Doze</th>
	<th>Lightweight Doze</th>
	</tr>
	<tr>
	<td>Trigger</td>
	<td>Screen off, on battery, stationary</td>
	<td>Screen off, on battery (unplugged)</td>
	</tr>
	<tr>
	<td>Timing</td>
	<td>Successively increasing periods with maintenance</td>
	<td>Repeated N-minute periods with maintenance windows</td>
	</tr>
	<tr>
	<td>Restrictions</td>
	<td>No network access, wake lock, or GPS/Wi-Fi scan. Alarms and jobs/syncs
	deferred.</td>
	<td>No network access. Jobs/syncs deferred except during maintenance windows.
	</td>
	</tr>
	<tr>
	<td>Behavior</td>
	<td>Only high-priority push notification messages received.</td>
	<td>All real-time messages (instant messages, calls, etc.) received.
	High-priority push notification message enables temporary network access.</td>
	</tr>
	<tr>
	<td>Exit</td>
	<td>Motion, screen on, or alarm clock alarm.</td>
	<td>Screen on.</td>
	</tr>
	</tbody>
	</table>

	<h3 id="doze-interactions">Interaction with App Standby</h3>
	<ul>
	<li>Time spent in Doze does not count towards App Standby.</li>
	<li>While the device is in Doze, idle applications are allowed to perform normal
	operations at least once a day.</li>
	</ul>

	<h3 id="integrate-doze">Integrating Doze</h3>

	<p>When Doze is enabled, devices that support
	<a href="/devices/sensors/sensor-types.html#significant_motion"><code>SENSOR_TYPE_SIGNIFICANT_MOTION</code>code></a>
	perform full Doze optimizations (including lightweight optimizations);
	devices without an SMD perform only lightweight Doze optimizations. Android
	automatically selects the appropriate Doze optimizations and no vendor
	configuration is necessary.</p>

	<p>To enable Doze for a device:</p>

	<ol>
	<li>Confirm the device has a cloud messaging service installed.</li>
	<li>In the device overlay config file
	<code>overlay/frameworks/base/core/res/res/values/config.xml</code>, set
	<code>config_enableAutoPowerModes</code> to <strong>true</strong>:
	<pre class="devsite-click-to-copy">
	<bool name="config_enableAutoPowerModes">true</bool>
	</pre>
	In AOSP, this parameter is set to false (Doze disabled) by default.<br>
	</li>
	<li>Confirm that preloaded apps and services:
	<ul>
	<li>Use the
	<a href="https://developer.android.com/training/monitoring-device-state/doze-standby.html" class="external">power-saving
	optimization guidelines</a>. For details, see <a href="#test-apps">Testing and
	optimizing applications</a>.
	<p><strong>OR</strong></p>
	<li>Are exempted from Doze and App Standby. For details, see
	<a href="/devices/tech/power/mgmt#exempt-apps">Exempting applications</a>.</li>
	</ul>
	</li>
	<li>Confirm the necessary services are exempted from Doze.</li>
	</ol>

	<h4 id="doze-tips">Tips</h4>
	<ul>
	<li>If possible, use FCM for
	<a href="https://firebase.google.com/docs/cloud-messaging/http-server-ref#send-downstream" class="external">downstream
	messaging</a>.</li>
	<li>If your users must see a notification right away, use a
	<a href="https://firebase.google.com/docs/cloud-messaging/concept-options#setting-the-priority-of-a-message" class="external">FCM
	high priority message</a>.</li>
	<li>Provide sufficient information within the initial
	<a href="https://firebase.google.com/docs/cloud-messaging/concept-options#notifications_and_data_messages" class="external">message
	payload</a> (to avoid unnecessary subsequent network access).</li>
	<li>Set critical alarms with
	<a href="http://developer.android.com/reference/android/app/AlarmManager.html#setAndAllowWhileIdle(int,%20long,%20android.app.PendingIntent)" class="external"><code>setAndAllowWhileIdle()</code></a>
	and
	<a href="http://developer.android.com/reference/android/app/AlarmManager.html#setExactAndAllowWhileIdle(int,%20long,%20android.app.PendingIntent)" class="external"><code>setExactAndAllowWhileIdle()</code></a>.
	</li>
	</ul>

	<h4 id="test-apps">Testing and optimizing applications</h4>
	<p>Test all applications (especially preloaded applications) in Doze mode. For
	details, refer to
	<a href="https://developer.android.com/training/monitoring-device-state/doze-standby.html#testing_doze_and_app_standby">Testing
	Doze and App Standby</a>.</p>

	<aside class="note"><strong>Note:</strong> MMS/SMS/Telephony services function
	independently of Doze and will always wake client apps even while the device
	remains in Doze mode.</aside>

	</body>
	</html>