diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 5b2a29e..3da00b1 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -175,6 +175,11 @@
      * {@hide}
      */
     public static final String EXTRA_IS_ACTIVE = "isActive";
+    /**
+     * The lookup key for a long that contains the timestamp (nanos) of the radio state change.
+     * {@hide}
+     */
+    public static final String EXTRA_REALTIME_NS = "tsNanos";
 
     /**
      * Broadcast Action: The setting for background data usage has changed
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index ffc748f..68b779c 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -1183,9 +1183,9 @@
 
     private INetworkManagementEventObserver mDataActivityObserver = new BaseNetworkObserver() {
         @Override
-        public void interfaceClassDataActivityChanged(String label, boolean active) {
+        public void interfaceClassDataActivityChanged(String label, boolean active, long tsNanos) {
             int deviceType = Integer.parseInt(label);
-            sendDataActivityBroadcast(deviceType, active);
+            sendDataActivityBroadcast(deviceType, active, tsNanos);
         }
     };
 
@@ -2169,10 +2169,11 @@
         sendStickyBroadcastDelayed(makeGeneralIntent(info, bcastType), delayMs);
     }
 
-    private void sendDataActivityBroadcast(int deviceType, boolean active) {
+    private void sendDataActivityBroadcast(int deviceType, boolean active, long tsNanos) {
         Intent intent = new Intent(ConnectivityManager.ACTION_DATA_ACTIVITY_CHANGE);
         intent.putExtra(ConnectivityManager.EXTRA_DEVICE_TYPE, deviceType);
         intent.putExtra(ConnectivityManager.EXTRA_IS_ACTIVE, active);
+        intent.putExtra(ConnectivityManager.EXTRA_REALTIME_NS, tsNanos);
         final long ident = Binder.clearCallingIdentity();
         try {
             mContext.sendOrderedBroadcastAsUser(intent, UserHandle.ALL,