diff --git a/gnss/aidl/default/Android.bp b/gnss/aidl/default/Android.bp
index 29bc5c4..b6df895 100644
--- a/gnss/aidl/default/Android.bp
+++ b/gnss/aidl/default/Android.bp
@@ -59,6 +59,7 @@
         "GnssBatching.cpp",
         "GnssGeofence.cpp",
         "GnssHidlHal.cpp",
+        "GnssNavigationMessageInterface.cpp",
         "GnssPowerIndication.cpp",
         "GnssPsds.cpp",
         "GnssConfiguration.cpp",
diff --git a/gnss/aidl/default/Gnss.cpp b/gnss/aidl/default/Gnss.cpp
index 03d9e31..8d58a20 100644
--- a/gnss/aidl/default/Gnss.cpp
+++ b/gnss/aidl/default/Gnss.cpp
@@ -22,6 +22,7 @@
 #include "GnssConfiguration.h"
 #include "GnssGeofence.h"
 #include "GnssMeasurementInterface.h"
+#include "GnssNavigationMessageInterface.h"
 #include "GnssPsds.h"
 
 namespace aidl::android::hardware::gnss {
@@ -104,4 +105,12 @@
     return ndk::ScopedAStatus::ok();
 }
 
+ndk::ScopedAStatus Gnss::getExtensionGnssNavigationMessage(
+        std::shared_ptr<IGnssNavigationMessageInterface>* iGnssNavigationMessage) {
+    ALOGD("Gnss::getExtensionGnssNavigationMessage");
+
+    *iGnssNavigationMessage = SharedRefBase::make<GnssNavigationMessageInterface>();
+    return ndk::ScopedAStatus::ok();
+}
+
 }  // namespace aidl::android::hardware::gnss
diff --git a/gnss/aidl/default/Gnss.h b/gnss/aidl/default/Gnss.h
index 8e573b5..128a6c1 100644
--- a/gnss/aidl/default/Gnss.h
+++ b/gnss/aidl/default/Gnss.h
@@ -42,6 +42,8 @@
             std::shared_ptr<IGnssBatching>* iGnssBatching) override;
     ndk::ScopedAStatus getExtensionGnssGeofence(
             std::shared_ptr<IGnssGeofence>* iGnssGeofence) override;
+    ndk::ScopedAStatus getExtensionGnssNavigationMessage(
+            std::shared_ptr<IGnssNavigationMessageInterface>* iGnssNavigationMessage) override;
 
     std::shared_ptr<GnssConfiguration> mGnssConfiguration;
     std::shared_ptr<GnssPowerIndication> mGnssPowerIndication;
diff --git a/gnss/aidl/default/GnssNavigationMessageInterface.cpp b/gnss/aidl/default/GnssNavigationMessageInterface.cpp
new file mode 100644
index 0000000..4bc859d
--- /dev/null
+++ b/gnss/aidl/default/GnssNavigationMessageInterface.cpp
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+#define LOG_TAG "GnssNavigationMessageAidl"
+
+#include "GnssNavigationMessageInterface.h"
+#include <aidl/android/hardware/gnss/BnGnss.h>
+#include <log/log.h>
+#include "Utils.h"
+
+namespace aidl::android::hardware::gnss {
+
+using namespace ::android::hardware::gnss;
+using GnssNavigationMessage = IGnssNavigationMessageCallback::GnssNavigationMessage;
+using GnssNavigationMessageType = GnssNavigationMessage::GnssNavigationMessageType;
+
+std::shared_ptr<IGnssNavigationMessageCallback> GnssNavigationMessageInterface::sCallback = nullptr;
+
+GnssNavigationMessageInterface::GnssNavigationMessageInterface() : mMinIntervalMillis(1000) {}
+
+GnssNavigationMessageInterface::~GnssNavigationMessageInterface() {
+    stop();
+}
+
+ndk::ScopedAStatus GnssNavigationMessageInterface::setCallback(
+        const std::shared_ptr<IGnssNavigationMessageCallback>& callback) {
+    ALOGD("setCallback");
+    std::unique_lock<std::mutex> lock(mMutex);
+    sCallback = callback;
+    start();
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus GnssNavigationMessageInterface::close() {
+    ALOGD("close");
+    stop();
+    std::unique_lock<std::mutex> lock(mMutex);
+    sCallback = nullptr;
+    return ndk::ScopedAStatus::ok();
+}
+
+void GnssNavigationMessageInterface::start() {
+    ALOGD("start");
+    mIsActive = true;
+    mThread = std::thread([this]() {
+        while (mIsActive == true) {
+            GnssNavigationMessage message = {
+                    .svid = 19,
+                    .type = GnssNavigationMessageType::GPS_L1CA,
+                    .status = GnssNavigationMessage::STATUS_PARITY_PASSED,
+                    .messageId = 2,
+                    .submessageId = 3,
+                    .data = std::vector<uint8_t>(40, 0xF9),
+            };
+            this->reportMessage(message);
+            std::this_thread::sleep_for(std::chrono::milliseconds(mMinIntervalMillis));
+        }
+    });
+    mThread.detach();
+}
+
+void GnssNavigationMessageInterface::stop() {
+    ALOGD("stop");
+    mIsActive = false;
+}
+
+void GnssNavigationMessageInterface::reportMessage(const GnssNavigationMessage& message) {
+    ALOGD("reportMessage()");
+    std::shared_ptr<IGnssNavigationMessageCallback> callbackCopy;
+    {
+        std::unique_lock<std::mutex> lock(mMutex);
+        if (sCallback == nullptr) {
+            ALOGE("%s: GnssNavigationMessageInterface::sCallback is null.", __func__);
+            return;
+        }
+        callbackCopy = sCallback;
+    }
+    callbackCopy->gnssNavigationMessageCb(message);
+}
+
+}  // namespace aidl::android::hardware::gnss
diff --git a/gnss/aidl/default/GnssNavigationMessageInterface.h b/gnss/aidl/default/GnssNavigationMessageInterface.h
new file mode 100644
index 0000000..600b23a
--- /dev/null
+++ b/gnss/aidl/default/GnssNavigationMessageInterface.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+#pragma once
+
+#include <aidl/android/hardware/gnss/BnGnssNavigationMessageInterface.h>
+#include <atomic>
+#include <thread>
+
+namespace aidl::android::hardware::gnss {
+
+struct GnssNavigationMessageInterface : public BnGnssNavigationMessageInterface {
+  public:
+    GnssNavigationMessageInterface();
+    ~GnssNavigationMessageInterface();
+    ndk::ScopedAStatus setCallback(
+            const std::shared_ptr<IGnssNavigationMessageCallback>& callback) override;
+    ndk::ScopedAStatus close() override;
+
+  private:
+    void start();
+    void stop();
+    void reportMessage(const IGnssNavigationMessageCallback::GnssNavigationMessage& message);
+
+    std::atomic<long> mMinIntervalMillis;
+    std::atomic<bool> mIsActive;
+    std::thread mThread;
+
+    // Guarded by mMutex
+    static std::shared_ptr<IGnssNavigationMessageCallback> sCallback;
+    // Synchronization lock for sCallback
+    mutable std::mutex mMutex;
+};
+
+}  // namespace aidl::android::hardware::gnss