diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 9f63191..c69af06 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -80,6 +80,7 @@
 import static android.net.NetworkCapabilities.TRANSPORT_VPN;
 import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
 import static android.net.NetworkRequest.Type.LISTEN_FOR_BEST;
+import static android.net.NetworkScore.POLICY_TRANSPORT_PRIMARY;
 import static android.net.OemNetworkPreferences.OEM_NETWORK_PREFERENCE_TEST;
 import static android.net.OemNetworkPreferences.OEM_NETWORK_PREFERENCE_TEST_ONLY;
 import static android.net.shared.NetworkMonitorUtils.isPrivateDnsValidationRequired;
@@ -335,6 +336,9 @@
     protected int mLingerDelayMs;  // Can't be final, or test subclass constructors can't change it.
     @VisibleForTesting
     protected int mNascentDelayMs;
+    // True if the cell radio of the device is capable of time-sharing.
+    @VisibleForTesting
+    protected boolean mCellularRadioTimesharingCapable = true;
 
     // How long to delay to removal of a pending intent based request.
     // See ConnectivitySettingsManager.CONNECTIVITY_RELEASE_PENDING_INTENT_DELAY_MS
@@ -1375,6 +1379,12 @@
                 NetworkCapabilities.NET_CAPABILITY_VEHICLE_INTERNAL,
                 NetworkRequest.Type.BACKGROUND_REQUEST);
 
+        mLingerDelayMs = mSystemProperties.getInt(LINGER_DELAY_PROPERTY, DEFAULT_LINGER_DELAY_MS);
+        // TODO: Consider making the timer customizable.
+        mNascentDelayMs = DEFAULT_NASCENT_DELAY_MS;
+        mCellularRadioTimesharingCapable =
+                mResources.get().getBoolean(R.bool.config_cellular_radio_timesharing_capable);
+
         mHandlerThread = mDeps.makeHandlerThread();
         mHandlerThread.start();
         mHandler = new InternalHandler(mHandlerThread.getLooper());
@@ -1385,10 +1395,6 @@
         mReleasePendingIntentDelayMs = Settings.Secure.getInt(context.getContentResolver(),
                 ConnectivitySettingsManager.CONNECTIVITY_RELEASE_PENDING_INTENT_DELAY_MS, 5_000);
 
-        mLingerDelayMs = mSystemProperties.getInt(LINGER_DELAY_PROPERTY, DEFAULT_LINGER_DELAY_MS);
-        // TODO: Consider making the timer customizable.
-        mNascentDelayMs = DEFAULT_NASCENT_DELAY_MS;
-
         mStatsManager = mContext.getSystemService(NetworkStatsManager.class);
         mPolicyManager = mContext.getSystemService(NetworkPolicyManager.class);
         mDnsResolver = Objects.requireNonNull(dnsresolver, "missing IDnsResolver");
@@ -7824,6 +7830,30 @@
         bundle.putParcelable(t.getClass().getSimpleName(), t);
     }
 
+    /**
+     * Returns whether reassigning a request from an NAI to another can be done gracefully.
+     *
+     * When a request should be assigned to a new network, it is normally lingered to give
+     * time for apps to gracefully migrate their connections. When both networks are on the same
+     * radio, but that radio can't do time-sharing efficiently, this may end up being
+     * counter-productive because any traffic on the old network may drastically reduce the
+     * performance of the new network.
+     * The stack supports a configuration to let modem vendors state that their radio can't
+     * do time-sharing efficiently. If this configuration is set, the stack assumes moving
+     * from one cell network to another can't be done gracefully.
+     *
+     * @param oldNai the old network serving the request
+     * @param newNai the new network serving the request
+     * @return whether the switch can be graceful
+     */
+    private boolean canSupportGracefulNetworkSwitch(@NonNull final NetworkAgentInfo oldSatisfier,
+            @NonNull final NetworkAgentInfo newSatisfier) {
+        if (mCellularRadioTimesharingCapable) return true;
+        return !oldSatisfier.networkCapabilities.hasSingleTransport(TRANSPORT_CELLULAR)
+                || !newSatisfier.networkCapabilities.hasSingleTransport(TRANSPORT_CELLULAR)
+                || !newSatisfier.getScore().hasPolicy(POLICY_TRANSPORT_PRIMARY);
+    }
+
     private void teardownUnneededNetwork(NetworkAgentInfo nai) {
         if (nai.numRequestNetworkRequests() != 0) {
             for (int i = 0; i < nai.numNetworkRequests(); i++) {
@@ -8084,7 +8114,13 @@
                     log("   accepting network in place of " + previousSatisfier.toShortString());
                 }
                 previousSatisfier.removeRequest(previousRequest.requestId);
-                previousSatisfier.lingerRequest(previousRequest.requestId, now);
+                if (canSupportGracefulNetworkSwitch(previousSatisfier, newSatisfier)) {
+                    // If this network switch can't be supported gracefully, the request is not
+                    // lingered. This allows letting go of the network sooner to reclaim some
+                    // performance on the new network, since the radio can't do both at the same
+                    // time while preserving good performance.
+                    previousSatisfier.lingerRequest(previousRequest.requestId, now);
+                }
             } else {
                 if (VDBG || DDBG) log("   accepting network in place of null");
             }