diff --git a/gnss/1.1/IGnssMeasurement.hal b/gnss/1.1/IGnssMeasurement.hal
new file mode 100644
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+++ b/gnss/1.1/IGnssMeasurement.hal
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2017 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 android.hardware.gnss@1.1;
+
+import @1.0::IGnssMeasurement;
+import @1.0::IGnssMeasurementCallback;
+
+/**
+ * Extended interface for GNSS Measurements support.
+ */
+interface IGnssMeasurement extends @1.0::IGnssMeasurement {
+
+    /**
+     * Initializes the interface and registers the callback routines with the HAL. After a
+     * successful call to 'setCallback_1_1' the HAL must begin to provide updates at an average
+     * output rate of 1Hz (occasional intra-measurement time offsets in the range from 0-2000msec
+     * can be tolerated.)
+     *
+     * @param callback Handle to GnssMeasurement callback interface.
+     * @param enableFullTracking If true, GNSS chipset must switch off duty cycling. In such mode
+     *     no clock discontinuities are expected and, when supported, carrier phase should be
+     *     continuous in good signal conditions. All constellations and frequency bands that the
+     *     chipset supports must be reported in this mode. The GNSS chipset is allowed to consume
+     *     more power in this mode. If false, API must behave as in HAL V1_0, optimizing power via
+     *     duty cycling, constellations and frequency limits, etc.
+     *
+     * @return initRet Returns SUCCESS if successful. Returns ERROR_ALREADY_INIT if a callback has
+     *     already been registered without a corresponding call to 'close'. Returns ERROR_GENERIC
+     *     for any other error. The HAL must not generate any other updates upon returning this
+     *     error code.
+     */
+    setCallback_1_1(IGnssMeasurementCallback callback, bool enableFullTracking)
+         generates (GnssMeasurementStatus initRet);
+
+};