diff --git a/gnss/2.1/default/GnssAntennaInfo.h b/gnss/2.1/default/GnssAntennaInfo.h
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+++ b/gnss/2.1/default/GnssAntennaInfo.h
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+/*
+ * 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.
+ */
+
+#ifndef ANDROID_HARDWARE_GNSS_V2_1_GNSSANTENNAINFO_H
+#define ANDROID_HARDWARE_GNSS_V2_1_GNSSANTENNAINFO_H
+
+#include <android/hardware/gnss/2.1/IGnssAntennaInfo.h>
+
+#include <mutex>
+#include <thread>
+
+namespace android {
+namespace hardware {
+namespace gnss {
+namespace V2_1 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+
+struct GnssAntennaInfo : public IGnssAntennaInfo {
+    GnssAntennaInfo();
+    ~GnssAntennaInfo();
+
+    // Methods from ::android::hardware::gnss::V2_1::IGnssAntennaInfo follow.
+    Return<GnssAntennaInfoStatus> setCallback(
+            const sp<IGnssAntennaInfoCallback>& callback) override;
+    Return<void> close() override;
+
+  private:
+    void start();
+    void stop();
+    void reportAntennaInfo(
+            const hidl_vec<IGnssAntennaInfoCallback::GnssAntennaInfo>& antennaInfo) const;
+
+    static sp<IGnssAntennaInfoCallback> sCallback;
+    std::atomic<long> mMinIntervalMillis;
+    std::atomic<bool> mIsActive;
+    std::thread mThread;
+    mutable std::mutex mMutex;
+};
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace gnss
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_GNSS_V2_1_GNSSCONFIGURATION_H
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