diff --git a/gnss/2.1/default/GnssAntennaInfo.cpp b/gnss/2.1/default/GnssAntennaInfo.cpp
new file mode 100644
index 0000000..d32a0af
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+++ b/gnss/2.1/default/GnssAntennaInfo.cpp
@@ -0,0 +1,109 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "GnssAntennaInfo"
+
+#include "GnssAntennaInfo.h"
+#include "Utils.h"
+
+#include <log/log.h>
+
+using ::android::hardware::gnss::common::Utils;
+
+namespace android {
+namespace hardware {
+namespace gnss {
+namespace V2_1 {
+namespace implementation {
+
+sp<IGnssAntennaInfoCallback> GnssAntennaInfo::sCallback = nullptr;
+
+GnssAntennaInfo::GnssAntennaInfo() : mMinIntervalMillis(1000) {}
+
+GnssAntennaInfo::~GnssAntennaInfo() {
+    stop();
+}
+
+// Methods from ::android::hardware::gnss::V2_1::IGnssAntennaInfo follow.
+Return<GnssAntennaInfo::GnssAntennaInfoStatus> GnssAntennaInfo::setCallback(
+        const sp<IGnssAntennaInfoCallback>& callback) {
+    ALOGD("setCallback");
+    std::unique_lock<std::mutex> lock(mMutex);
+    sCallback = callback;
+
+    if (mIsActive) {
+        ALOGW("GnssAntennaInfo callback already set. Resetting the callback...");
+        stop();
+    }
+    start();
+
+    return GnssAntennaInfoStatus::SUCCESS;
+}
+
+Return<void> GnssAntennaInfo::close() {
+    ALOGD("close");
+    std::unique_lock<std::mutex> lock(mMutex);
+    stop();
+    sCallback = nullptr;
+    return Void();
+}
+
+// Private methods
+void GnssAntennaInfo::start() {
+    ALOGD("start");
+    mIsActive = true;
+    mThread = std::thread([this]() {
+        while (mIsActive == true) {
+            if (sCallback != nullptr) {
+                auto antennaInfos = Utils::getMockAntennaInfos();
+                this->reportAntennaInfo(antennaInfos);
+            }
+
+            /** For mock implementation this is good. On real device, we should only report
+                antennaInfo at start and when there is a configuration change. **/
+            std::this_thread::sleep_for(std::chrono::milliseconds(mMinIntervalMillis));
+        }
+    });
+}
+
+void GnssAntennaInfo::stop() {
+    ALOGD("stop");
+    mIsActive = false;
+    if (mThread.joinable()) {
+        mThread.join();
+    }
+}
+
+void GnssAntennaInfo::reportAntennaInfo(
+        const hidl_vec<IGnssAntennaInfoCallback::GnssAntennaInfo>& antennaInfo) const {
+    std::unique_lock<std::mutex> lock(mMutex);
+
+    if (sCallback == nullptr) {
+        ALOGE("%s: No non-null callback", __func__);
+        return;
+    }
+
+    auto ret = sCallback->gnssAntennaInfoCb(antennaInfo);
+    if (!ret.isOk()) {
+        ALOGE("%s: Unable to invoke callback", __func__);
+    }
+}
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace gnss
+}  // namespace hardware
+}  // namespace android
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