diff --git a/Tethering/tests/unit/AndroidManifest.xml b/Tethering/tests/unit/AndroidManifest.xml
index 530bc07..4ff1d37 100644
--- a/Tethering/tests/unit/AndroidManifest.xml
+++ b/Tethering/tests/unit/AndroidManifest.xml
@@ -20,7 +20,16 @@
 
     <application android:debuggable="true">
         <uses-library android:name="android.test.runner" />
+        <service
+            android:name="com.android.server.connectivity.tethering.MockTetheringService"
+            android:permission="android.permission.TETHER_PRIVILEGED"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="com.android.server.connectivity.tethering.TetheringService"/>
+            </intent-filter>
+        </service>
     </application>
+
     <instrumentation android:name="androidx.test.runner.AndroidJUnitRunner"
         android:targetPackage="com.android.networkstack.tethering.tests.unit"
         android:label="Tethering service tests">
diff --git a/Tethering/tests/unit/src/com/android/server/connectivity/tethering/MockTetheringService.java b/Tethering/tests/unit/src/com/android/server/connectivity/tethering/MockTetheringService.java
new file mode 100644
index 0000000..355ece9
--- /dev/null
+++ b/Tethering/tests/unit/src/com/android/server/connectivity/tethering/MockTetheringService.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+package com.android.server.connectivity.tethering;
+
+import static org.mockito.Mockito.mock;
+
+import android.content.Intent;
+import android.net.ITetheringConnector;
+import android.os.Binder;
+import android.os.IBinder;
+
+public class MockTetheringService extends TetheringService {
+    private final Tethering mTethering = mock(Tethering.class);
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        return new MockTetheringConnector(super.onBind(intent));
+    }
+
+    @Override
+    public Tethering makeTethering(TetheringDependencies deps) {
+        return mTethering;
+    }
+
+    public Tethering getTethering() {
+        return mTethering;
+    }
+
+    public class MockTetheringConnector extends Binder {
+        final IBinder mBase;
+        MockTetheringConnector(IBinder base) {
+            mBase = base;
+        }
+
+        public ITetheringConnector getTetheringConnector() {
+            return ITetheringConnector.Stub.asInterface(mBase);
+        }
+
+        public MockTetheringService getService() {
+            return MockTetheringService.this;
+        }
+    }
+}
diff --git a/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringServiceTest.java b/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringServiceTest.java
new file mode 100644
index 0000000..d9d3e73
--- /dev/null
+++ b/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringServiceTest.java
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+package com.android.server.connectivity.tethering;
+
+import static android.net.TetheringManager.TETHERING_WIFI;
+import static android.net.TetheringManager.TETHER_ERROR_NO_ERROR;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.mockito.Mockito.when;
+
+import android.content.Intent;
+import android.net.IIntResultListener;
+import android.net.ITetheringConnector;
+import android.net.ITetheringEventCallback;
+import android.net.TetheringRequestParcel;
+import android.os.ResultReceiver;
+
+import androidx.test.InstrumentationRegistry;
+import androidx.test.filters.SmallTest;
+import androidx.test.rule.ServiceTestRule;
+import androidx.test.runner.AndroidJUnit4;
+
+import com.android.server.connectivity.tethering.MockTetheringService.MockTetheringConnector;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public final class TetheringServiceTest {
+    private static final String TEST_IFACE_NAME = "test_wlan0";
+    private static final String TEST_CALLER_PKG = "test_pkg";
+    @Mock private ITetheringEventCallback mITetheringEventCallback;
+    @Rule public ServiceTestRule mServiceTestRule;
+    private Tethering mTethering;
+    private Intent mMockServiceIntent;
+    private ITetheringConnector mTetheringConnector;
+
+    private class TestTetheringResult extends IIntResultListener.Stub {
+        private int mResult = -1; // Default value that does not match any result code.
+        @Override
+        public void onResult(final int resultCode) {
+            mResult = resultCode;
+        }
+
+        public void assertResult(final int expected) {
+            assertEquals(expected, mResult);
+        }
+    }
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+        mServiceTestRule = new ServiceTestRule();
+        mMockServiceIntent = new Intent(
+                InstrumentationRegistry.getTargetContext(),
+                MockTetheringService.class);
+        final MockTetheringConnector mockConnector =
+                (MockTetheringConnector) mServiceTestRule.bindService(mMockServiceIntent);
+        mTetheringConnector = mockConnector.getTetheringConnector();
+        final MockTetheringService service = mockConnector.getService();
+        mTethering = service.getTethering();
+        verify(mTethering).startStateMachineUpdaters();
+        when(mTethering.hasTetherableConfiguration()).thenReturn(true);
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        mServiceTestRule.unbindService();
+    }
+
+    @Test
+    public void testTether() throws Exception {
+        when(mTethering.tether(TEST_IFACE_NAME)).thenReturn(TETHER_ERROR_NO_ERROR);
+        final TestTetheringResult result = new TestTetheringResult();
+        mTetheringConnector.tether(TEST_IFACE_NAME, TEST_CALLER_PKG, result);
+        verify(mTethering).hasTetherableConfiguration();
+        verify(mTethering).tether(TEST_IFACE_NAME);
+        verifyNoMoreInteractions(mTethering);
+        result.assertResult(TETHER_ERROR_NO_ERROR);
+    }
+
+    @Test
+    public void testUntether() throws Exception {
+        when(mTethering.untether(TEST_IFACE_NAME)).thenReturn(TETHER_ERROR_NO_ERROR);
+        final TestTetheringResult result = new TestTetheringResult();
+        mTetheringConnector.untether(TEST_IFACE_NAME, TEST_CALLER_PKG, result);
+        verify(mTethering).hasTetherableConfiguration();
+        verify(mTethering).untether(TEST_IFACE_NAME);
+        verifyNoMoreInteractions(mTethering);
+        result.assertResult(TETHER_ERROR_NO_ERROR);
+    }
+
+    @Test
+    public void testSetUsbTethering() throws Exception {
+        when(mTethering.setUsbTethering(true /* enable */)).thenReturn(TETHER_ERROR_NO_ERROR);
+        final TestTetheringResult result = new TestTetheringResult();
+        mTetheringConnector.setUsbTethering(true /* enable */, TEST_CALLER_PKG, result);
+        verify(mTethering).hasTetherableConfiguration();
+        verify(mTethering).setUsbTethering(true /* enable */);
+        verifyNoMoreInteractions(mTethering);
+        result.assertResult(TETHER_ERROR_NO_ERROR);
+    }
+
+    @Test
+    public void testStartTethering() throws Exception {
+        final TestTetheringResult result = new TestTetheringResult();
+        final TetheringRequestParcel request = new TetheringRequestParcel();
+        request.tetheringType = TETHERING_WIFI;
+        mTetheringConnector.startTethering(request, TEST_CALLER_PKG, result);
+        verify(mTethering).hasTetherableConfiguration();
+        verify(mTethering).startTethering(eq(request), eq(result));
+        verifyNoMoreInteractions(mTethering);
+    }
+
+    @Test
+    public void testStopTethering() throws Exception {
+        final TestTetheringResult result = new TestTetheringResult();
+        mTetheringConnector.stopTethering(TETHERING_WIFI, TEST_CALLER_PKG, result);
+        verify(mTethering).hasTetherableConfiguration();
+        verify(mTethering).stopTethering(TETHERING_WIFI);
+        verifyNoMoreInteractions(mTethering);
+        result.assertResult(TETHER_ERROR_NO_ERROR);
+    }
+
+    @Test
+    public void testRequestLatestTetheringEntitlementResult() throws Exception {
+        final ResultReceiver result = new ResultReceiver(null);
+        mTetheringConnector.requestLatestTetheringEntitlementResult(TETHERING_WIFI, result,
+                true /* showEntitlementUi */, TEST_CALLER_PKG);
+        verify(mTethering).hasTetherableConfiguration();
+        verify(mTethering).requestLatestTetheringEntitlementResult(eq(TETHERING_WIFI),
+                eq(result), eq(true) /* showEntitlementUi */);
+        verifyNoMoreInteractions(mTethering);
+    }
+
+    @Test
+    public void testRegisterTetheringEventCallback() throws Exception {
+        mTetheringConnector.registerTetheringEventCallback(mITetheringEventCallback,
+                TEST_CALLER_PKG);
+        verify(mTethering).registerTetheringEventCallback(eq(mITetheringEventCallback));
+        verifyNoMoreInteractions(mTethering);
+    }
+
+    @Test
+    public void testUnregisterTetheringEventCallback() throws Exception {
+        mTetheringConnector.unregisterTetheringEventCallback(mITetheringEventCallback,
+                TEST_CALLER_PKG);
+        verify(mTethering).unregisterTetheringEventCallback(
+                eq(mITetheringEventCallback));
+        verifyNoMoreInteractions(mTethering);
+    }
+
+    @Test
+    public void testStopAllTethering() throws Exception {
+        final TestTetheringResult result = new TestTetheringResult();
+        mTetheringConnector.stopAllTethering(TEST_CALLER_PKG, result);
+        verify(mTethering).hasTetherableConfiguration();
+        verify(mTethering).untetherAll();
+        verifyNoMoreInteractions(mTethering);
+        result.assertResult(TETHER_ERROR_NO_ERROR);
+    }
+
+    @Test
+    public void testIsTetheringSupported() throws Exception {
+        final TestTetheringResult result = new TestTetheringResult();
+        mTetheringConnector.isTetheringSupported(TEST_CALLER_PKG, result);
+        verify(mTethering).hasTetherableConfiguration();
+        verifyNoMoreInteractions(mTethering);
+        result.assertResult(TETHER_ERROR_NO_ERROR);
+    }
+}
diff --git a/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java b/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
index 7532cdd..2955903 100644
--- a/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
+++ b/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
@@ -141,7 +141,9 @@
 import com.android.testutils.MiscAssertsKt;
 
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
+import org.junit.BeforeClass;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
@@ -440,6 +442,18 @@
         return buildMobileUpstreamState(false, true, true);
     }
 
+    // See FakeSettingsProvider#clearSettingsProvider() that this needs to be called before and
+    // after use.
+    @BeforeClass
+    public static void setupOnce() {
+        FakeSettingsProvider.clearSettingsProvider();
+    }
+
+    @AfterClass
+    public static void tearDownOnce() {
+        FakeSettingsProvider.clearSettingsProvider();
+    }
+
     @Before
     public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);