diff --git a/framework/api/module-lib-current.txt b/framework/api/module-lib-current.txt
index 6df57c1..5b64d52 100644
--- a/framework/api/module-lib-current.txt
+++ b/framework/api/module-lib-current.txt
@@ -8,7 +8,7 @@
   public class ConnectivityManager {
     method @NonNull @RequiresPermission(anyOf={android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_STACK, android.Manifest.permission.NETWORK_SETTINGS}) public java.util.List<android.net.NetworkStateSnapshot> getAllNetworkStateSnapshot();
     method @RequiresPermission(anyOf={android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_SETTINGS}) public void registerSystemDefaultNetworkCallback(@NonNull android.net.ConnectivityManager.NetworkCallback, @NonNull android.os.Handler);
-    method @RequiresPermission(anyOf={android.Manifest.permission.NETWORK_SETTINGS, android.Manifest.permission.NETWORK_STACK, android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK}) public void requestBackgroundNetwork(@NonNull android.net.NetworkRequest, @Nullable android.os.Handler, @NonNull android.net.ConnectivityManager.NetworkCallback);
+    method @RequiresPermission(anyOf={android.Manifest.permission.NETWORK_SETTINGS, android.Manifest.permission.NETWORK_STACK, android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK}) public void requestBackgroundNetwork(@NonNull android.net.NetworkRequest, @NonNull android.os.Handler, @NonNull android.net.ConnectivityManager.NetworkCallback);
     method @RequiresPermission(anyOf={android.Manifest.permission.MANAGE_TEST_NETWORKS, android.Manifest.permission.NETWORK_STACK}) public void simulateDataStall(int, long, @NonNull android.net.Network, @NonNull android.os.PersistableBundle);
   }
 
diff --git a/framework/src/android/net/ConnectivityManager.java b/framework/src/android/net/ConnectivityManager.java
index 45ed317..adf22da 100644
--- a/framework/src/android/net/ConnectivityManager.java
+++ b/framework/src/android/net/ConnectivityManager.java
@@ -20,6 +20,7 @@
 import static android.net.NetworkRequest.Type.BACKGROUND_REQUEST;
 import static android.net.NetworkRequest.Type.LISTEN;
 import static android.net.NetworkRequest.Type.REQUEST;
+import static android.net.NetworkRequest.Type.TRACK_BEST;
 import static android.net.NetworkRequest.Type.TRACK_DEFAULT;
 import static android.net.NetworkRequest.Type.TRACK_SYSTEM_DEFAULT;
 import static android.net.QosCallback.QosCallbackRegistrationException;
@@ -4190,6 +4191,18 @@
     }
 
     /**
+     * @hide
+     */
+    // TODO: Make it public api.
+    @SuppressLint("ExecutorRegistration")
+    public void registerBestMatchingNetworkCallback(@NonNull NetworkRequest request,
+            @NonNull NetworkCallback networkCallback, @NonNull Handler handler) {
+        final NetworkCapabilities nc = request.networkCapabilities;
+        final CallbackHandler cbHandler = new CallbackHandler(handler);
+        sendRequestForNetwork(nc, networkCallback, 0, TRACK_BEST, TYPE_NONE, cbHandler);
+    }
+
+    /**
      * Requests bandwidth update for a given {@link Network} and returns whether the update request
      * is accepted by ConnectivityService. Once accepted, ConnectivityService will poll underlying
      * network connection for updated bandwidth information. The caller will be notified via
@@ -4979,10 +4992,10 @@
             NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK
     })
     public void requestBackgroundNetwork(@NonNull NetworkRequest request,
-            @Nullable Handler handler, @NonNull NetworkCallback networkCallback) {
+            @NonNull Handler handler, @NonNull NetworkCallback networkCallback) {
         final NetworkCapabilities nc = request.networkCapabilities;
         sendRequestForNetwork(nc, networkCallback, 0, BACKGROUND_REQUEST,
-                TYPE_NONE, handler == null ? getDefaultHandler() : new CallbackHandler(handler));
+                TYPE_NONE, new CallbackHandler(handler));
     }
 
     /**
diff --git a/framework/src/android/net/NetworkRequest.java b/framework/src/android/net/NetworkRequest.java
index 17a8ee1..aa69756 100644
--- a/framework/src/android/net/NetworkRequest.java
+++ b/framework/src/android/net/NetworkRequest.java
@@ -114,6 +114,10 @@
      *       for the network (if any) that satisfies the default Internet
      *       request.
      *
+     *     - TRACK_BEST, which causes the framework to send callbacks about
+     *       the single, highest scoring current network (if any) that matches
+     *       the specified NetworkCapabilities.
+     *
      *     - BACKGROUND_REQUEST, like REQUEST but does not cause any networks
      *       to retain the NET_CAPABILITY_FOREGROUND capability. A network with
      *       no foreground requests is in the background. A network that has
@@ -136,6 +140,7 @@
         REQUEST,
         BACKGROUND_REQUEST,
         TRACK_SYSTEM_DEFAULT,
+        TRACK_BEST,
     };
 
     /**
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 78853c7..3d55c16 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -5547,6 +5547,8 @@
                 //  request if the app changes network state. http://b/29964605
                 enforceMeteredApnPolicy(networkCapabilities);
                 break;
+            case TRACK_BEST:
+                throw new UnsupportedOperationException("Not implemented yet");
             default:
                 throw new IllegalArgumentException("Unsupported request type " + reqType);
         }
diff --git a/tests/net/java/android/net/ConnectivityManagerTest.java b/tests/net/java/android/net/ConnectivityManagerTest.java
index 6a09b02..098b029 100644
--- a/tests/net/java/android/net/ConnectivityManagerTest.java
+++ b/tests/net/java/android/net/ConnectivityManagerTest.java
@@ -376,13 +376,13 @@
                 eq(testPkgName), eq(testAttributionTag));
         reset(mService);
 
-        manager.requestBackgroundNetwork(request, null, callback);
+        Handler handler = new Handler(ConnectivityThread.getInstanceLooper());
+        manager.requestBackgroundNetwork(request, handler, callback);
         verify(mService).requestNetwork(eq(request.networkCapabilities),
                 eq(BACKGROUND_REQUEST.ordinal()), any(), anyInt(), any(), eq(TYPE_NONE),
                 eq(testPkgName), eq(testAttributionTag));
         reset(mService);
 
-        Handler handler = new Handler(ConnectivityThread.getInstanceLooper());
         manager.registerSystemDefaultNetworkCallback(callback, handler);
         verify(mService).requestNetwork(eq(null),
                 eq(TRACK_SYSTEM_DEFAULT.ordinal()), any(), anyInt(), any(), eq(TYPE_NONE),
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 15a7b91..a6b20fb 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -4027,7 +4027,8 @@
         grantUsingBackgroundNetworksPermissionForUid(Binder.getCallingUid());
         final TestNetworkCallback cellBgCallback = new TestNetworkCallback();
         mCm.requestBackgroundNetwork(new NetworkRequest.Builder()
-                .addTransportType(TRANSPORT_CELLULAR).build(), null, cellBgCallback);
+                .addTransportType(TRANSPORT_CELLULAR).build(),
+                mCsHandlerThread.getThreadHandler(), cellBgCallback);
 
         // Make callbacks for monitoring.
         final NetworkRequest request = new NetworkRequest.Builder().build();
@@ -11026,4 +11027,12 @@
         verifyNoNetwork();
         mCm.unregisterNetworkCallback(cellCb);
     }
-}
\ No newline at end of file
+
+    @Test
+    public void testRegisterBestMatchingNetworkCallback() throws Exception {
+        final NetworkRequest request = new NetworkRequest.Builder().build();
+        assertThrows(UnsupportedOperationException.class,
+                () -> mCm.registerBestMatchingNetworkCallback(request, new NetworkCallback(),
+                        mCsHandlerThread.getThreadHandler()));
+    }
+}