diff --git a/api/current.txt b/api/current.txt
index f4cdb5bbae1cd..2462f380e2882 100755
--- a/api/current.txt
+++ b/api/current.txt
@@ -27190,12 +27190,12 @@ package android.net {
 
   public static class ConnectivityManager.NetworkCallback {
     ctor public ConnectivityManager.NetworkCallback();
-    method public void onAvailable(android.net.Network);
+    method public void onAvailable(@NonNull android.net.Network);
     method public void onBlockedStatusChanged(@NonNull android.net.Network, boolean);
-    method public void onCapabilitiesChanged(android.net.Network, android.net.NetworkCapabilities);
-    method public void onLinkPropertiesChanged(android.net.Network, android.net.LinkProperties);
-    method public void onLosing(android.net.Network, int);
-    method public void onLost(android.net.Network);
+    method public void onCapabilitiesChanged(@NonNull android.net.Network, @NonNull android.net.NetworkCapabilities);
+    method public void onLinkPropertiesChanged(@NonNull android.net.Network, @NonNull android.net.LinkProperties);
+    method public void onLosing(@NonNull android.net.Network, int);
+    method public void onLost(@NonNull android.net.Network);
     method public void onUnavailable();
   }
 
diff --git a/api/system-current.txt b/api/system-current.txt
index 81eb858d43b9e..1a783dae65e07 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -97,6 +97,7 @@ package android {
     field public static final String MOVE_PACKAGE = "android.permission.MOVE_PACKAGE";
     field public static final String NETWORK_SCAN = "android.permission.NETWORK_SCAN";
     field public static final String NETWORK_SETUP_WIZARD = "android.permission.NETWORK_SETUP_WIZARD";
+    field public static final String NETWORK_SIGNAL_STRENGTH_WAKEUP = "android.permission.NETWORK_SIGNAL_STRENGTH_WAKEUP";
     field public static final String NOTIFICATION_DURING_SETUP = "android.permission.NOTIFICATION_DURING_SETUP";
     field public static final String NOTIFY_TV_INPUTS = "android.permission.NOTIFY_TV_INPUTS";
     field public static final String OBSERVE_APP_USAGE = "android.permission.OBSERVE_APP_USAGE";
@@ -3202,7 +3203,7 @@ package android.net {
   }
 
   public static class NetworkRequest.Builder {
-    method @NonNull public android.net.NetworkRequest.Builder setSignalStrength(int);
+    method @NonNull @RequiresPermission(android.Manifest.permission.NETWORK_SIGNAL_STRENGTH_WAKEUP) public android.net.NetworkRequest.Builder setSignalStrength(int);
   }
 
   public class NetworkScoreManager {
diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 4a64128f146be..6ba4a30abe224 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -3234,7 +3234,7 @@ public class ConnectivityManager {
          *
          * @hide
          */
-        public void onPreCheck(Network network) {}
+        public void onPreCheck(@NonNull Network network) {}
 
         /**
          * Called when the framework connects and has declared a new network ready for use.
@@ -3247,8 +3247,9 @@ public class ConnectivityManager {
          * @param blocked Whether access to the {@link Network} is blocked due to system policy.
          * @hide
          */
-        public void onAvailable(Network network, NetworkCapabilities networkCapabilities,
-                LinkProperties linkProperties, boolean blocked) {
+        public void onAvailable(@NonNull Network network,
+                @NonNull NetworkCapabilities networkCapabilities,
+                @NonNull LinkProperties linkProperties, boolean blocked) {
             // Internally only this method is called when a new network is available, and
             // it calls the callback in the same way and order that older versions used
             // to call so as not to change the behavior.
@@ -3272,7 +3273,7 @@ public class ConnectivityManager {
          *
          * @param network The {@link Network} of the satisfying network.
          */
-        public void onAvailable(Network network) {}
+        public void onAvailable(@NonNull Network network) {}
 
         /**
          * Called when the network is about to be disconnected.  Often paired with an
@@ -3288,7 +3289,7 @@ public class ConnectivityManager {
          *                     network connected.  Note that the network may suffer a
          *                     hard loss at any time.
          */
-        public void onLosing(Network network, int maxMsToLive) {}
+        public void onLosing(@NonNull Network network, int maxMsToLive) {}
 
         /**
          * Called when the framework has a hard loss of the network or when the
@@ -3296,7 +3297,7 @@ public class ConnectivityManager {
          *
          * @param network The {@link Network} lost.
          */
-        public void onLost(Network network) {}
+        public void onLost(@NonNull Network network) {}
 
         /**
          * Called if no network is found in the timeout time specified in
@@ -3316,8 +3317,8 @@ public class ConnectivityManager {
          * @param networkCapabilities The new {@link android.net.NetworkCapabilities} for this
          *                            network.
          */
-        public void onCapabilitiesChanged(Network network,
-                NetworkCapabilities networkCapabilities) {}
+        public void onCapabilitiesChanged(@NonNull Network network,
+                @NonNull NetworkCapabilities networkCapabilities) {}
 
         /**
          * Called when the network the framework connected to for this request
@@ -3326,7 +3327,8 @@ public class ConnectivityManager {
          * @param network The {@link Network} whose link properties have changed.
          * @param linkProperties The new {@link LinkProperties} for this network.
          */
-        public void onLinkPropertiesChanged(Network network, LinkProperties linkProperties) {}
+        public void onLinkPropertiesChanged(@NonNull Network network,
+                @NonNull LinkProperties linkProperties) {}
 
         /**
          * Called when the network the framework connected to for this request
@@ -3337,7 +3339,7 @@ public class ConnectivityManager {
          * a tunnel, etc.
          * @hide
          */
-        public void onNetworkSuspended(Network network) {}
+        public void onNetworkSuspended(@NonNull Network network) {}
 
         /**
          * Called when the network the framework connected to for this request
@@ -3345,7 +3347,7 @@ public class ConnectivityManager {
          * preceded by a matching {@link NetworkCallback#onNetworkSuspended} call.
          * @hide
          */
-        public void onNetworkResumed(Network network) {}
+        public void onNetworkResumed(@NonNull Network network) {}
 
         /**
          * Called when access to the specified network is blocked or unblocked.
diff --git a/core/java/android/net/LinkProperties.java b/core/java/android/net/LinkProperties.java
index 03d6d48bc8f6b..ad67763ac3fb0 100644
--- a/core/java/android/net/LinkProperties.java
+++ b/core/java/android/net/LinkProperties.java
@@ -316,9 +316,6 @@ public final class LinkProperties implements Parcelable {
     @SystemApi
     @TestApi
     public boolean removeLinkAddress(@NonNull LinkAddress toRemove) {
-        if (toRemove == null) {
-            return false;
-        }
         int i = findLinkAddressIndex(toRemove);
         if (i >= 0) {
             mLinkAddresses.remove(i);
@@ -391,10 +388,7 @@ public final class LinkProperties implements Parcelable {
     @TestApi
     @SystemApi
     public boolean removeDnsServer(@NonNull InetAddress dnsServer) {
-        if (dnsServer != null) {
-            return mDnses.remove(dnsServer);
-        }
-        return false;
+        return mDnses.remove(dnsServer);
     }
 
     /**
diff --git a/core/java/android/net/NetworkRequest.java b/core/java/android/net/NetworkRequest.java
index 3a41a079dad04..acafa1354a7fd 100644
--- a/core/java/android/net/NetworkRequest.java
+++ b/core/java/android/net/NetworkRequest.java
@@ -17,6 +17,7 @@
 package android.net;
 
 import android.annotation.NonNull;
+import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
 import android.annotation.UnsupportedAppUsage;
 import android.net.NetworkCapabilities.NetCapability;
@@ -343,10 +344,14 @@ public class NetworkRequest implements Parcelable {
          * current value. A value of {@code SIGNAL_STRENGTH_UNSPECIFIED} means no value when
          * received and has no effect when requesting a callback.
          *
+         * <p>This method requires the caller to hold the
+         * {@link android.Manifest.permission#NETWORK_SIGNAL_STRENGTH_WAKEUP} permission
+         *
          * @param signalStrength the bearer-specific signal strength.
          * @hide
          */
         @SystemApi
+        @RequiresPermission(android.Manifest.permission.NETWORK_SIGNAL_STRENGTH_WAKEUP)
         public @NonNull Builder setSignalStrength(int signalStrength) {
             mNetworkCapabilities.setSignalStrength(signalStrength);
             return this;
diff --git a/core/java/android/net/captiveportal/CaptivePortalProbeSpec.java b/core/java/android/net/captiveportal/CaptivePortalProbeSpec.java
index 6c6a16c4534ea..b354607b88566 100644
--- a/core/java/android/net/captiveportal/CaptivePortalProbeSpec.java
+++ b/core/java/android/net/captiveportal/CaptivePortalProbeSpec.java
@@ -50,8 +50,7 @@ public abstract class CaptivePortalProbeSpec {
     private final String mEncodedSpec;
     private final URL mUrl;
 
-    CaptivePortalProbeSpec(@NonNull String encodedSpec, @NonNull URL url)
-            throws NullPointerException {
+    CaptivePortalProbeSpec(@NonNull String encodedSpec, @NonNull URL url) {
         mEncodedSpec = checkNotNull(encodedSpec);
         mUrl = checkNotNull(url);
     }
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index f562dca57e15a..ccf5199d3d2bd 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1580,6 +1580,12 @@
     <permission android:name="android.permission.CONNECTIVITY_USE_RESTRICTED_NETWORKS"
         android:protectionLevel="signature|privileged" />
 
+    <!-- @SystemApi Allows an internal user to set signal strength in NetworkRequest. This kind of
+         request will wake up device when signal strength meets the given value.
+         @hide -->
+    <permission android:name="android.permission.NETWORK_SIGNAL_STRENGTH_WAKEUP"
+                android:protectionLevel="signature|privileged" />
+
     <!-- @SystemApi Allows a system application to access hardware packet offload capabilities.
          @hide -->
     <permission android:name="android.permission.PACKET_KEEPALIVE_OFFLOAD"
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 317eb93d7c1be..31d8113bbb543 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -1892,6 +1892,15 @@ public class ConnectivityService extends IConnectivityManager.Stub
         return false;
     }
 
+    private boolean checkAnyPermissionOf(int pid, int uid, String... permissions) {
+        for (String permission : permissions) {
+            if (mContext.checkPermission(permission, pid, uid) == PERMISSION_GRANTED) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     private void enforceAnyPermissionOf(String... permissions) {
         if (!checkAnyPermissionOf(permissions)) {
             throw new SecurityException("Requires one of the following permissions: "
@@ -1966,6 +1975,12 @@ public class ConnectivityService extends IConnectivityManager.Stub
                 NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
     }
 
+    private boolean checkNetworkSignalStrengthWakeupPermission(int pid, int uid) {
+        return checkAnyPermissionOf(pid, uid,
+                android.Manifest.permission.NETWORK_SIGNAL_STRENGTH_WAKEUP,
+                NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
+    }
+
     private void enforceConnectivityRestrictedNetworksPermission() {
         try {
             mContext.enforceCallingOrSelfPermission(
@@ -4959,13 +4974,19 @@ public class ConnectivityService extends IConnectivityManager.Stub
         }
     }
 
-    // This checks that the passed capabilities either do not request a specific SSID, or the
-    // calling app has permission to do so.
+    // This checks that the passed capabilities either do not request a specific SSID/SignalStrength
+    // , or the calling app has permission to do so.
     private void ensureSufficientPermissionsForRequest(NetworkCapabilities nc,
             int callerPid, int callerUid) {
         if (null != nc.getSSID() && !checkSettingsPermission(callerPid, callerUid)) {
             throw new SecurityException("Insufficient permissions to request a specific SSID");
         }
+
+        if (nc.hasSignalStrength()
+                && !checkNetworkSignalStrengthWakeupPermission(callerPid, callerUid)) {
+            throw new SecurityException(
+                    "Insufficient permissions to request a specific signal strength");
+        }
     }
 
     private ArrayList<Integer> getSignalStrengthThresholds(NetworkAgentInfo nai) {
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 46a8955dad933..c2fc0b311757e 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -3046,6 +3046,47 @@ public class ConnectivityServiceTest {
         }
     }
 
+    @Test
+    public void testInvalidSignalStrength() {
+        NetworkRequest r = new NetworkRequest.Builder()
+                .addCapability(NET_CAPABILITY_INTERNET)
+                .addTransportType(TRANSPORT_WIFI)
+                .setSignalStrength(-75)
+                .build();
+        // Registering a NetworkCallback with signal strength but w/o NETWORK_SIGNAL_STRENGTH_WAKEUP
+        // permission should get SecurityException.
+        try {
+            mCm.registerNetworkCallback(r, new NetworkCallback());
+            fail("Expected SecurityException filing a callback with signal strength");
+        } catch (SecurityException expected) {
+            // expected
+        }
+
+        try {
+            mCm.registerNetworkCallback(r, PendingIntent.getService(
+                    mServiceContext, 0, new Intent(), 0));
+            fail("Expected SecurityException filing a callback with signal strength");
+        } catch (SecurityException expected) {
+            // expected
+        }
+
+        // Requesting a Network with signal strength should get IllegalArgumentException.
+        try {
+            mCm.requestNetwork(r, new NetworkCallback());
+            fail("Expected IllegalArgumentException filing a request with signal strength");
+        } catch (IllegalArgumentException expected) {
+            // expected
+        }
+
+        try {
+            mCm.requestNetwork(r, PendingIntent.getService(
+                    mServiceContext, 0, new Intent(), 0));
+            fail("Expected IllegalArgumentException filing a request with signal strength");
+        } catch (IllegalArgumentException expected) {
+            // expected
+        }
+    }
+
     @Test
     public void testRegisterDefaultNetworkCallback() throws Exception {
         final TestNetworkCallback defaultNetworkCallback = new TestNetworkCallback();