Abstract: In some implementations, a mobile device can analyze motion sensor data and proximity sensor data during a voice call to determine whether the mobile device is on a stationary object or worn on a user's body (e.g., in the lap or pocket of a user of the mobile device). The mobile device can adjust the transmit power level of the telephony transceiver during the voice call based on the determination.

Abstract: In an example method, a mobile device connects a voice call for a user. The voice call causes one or more radio frequency transmitters of the mobile device to transmit radio waves at a first power level. Motion data describing movement of the mobile device is obtained, and the orientation of the mobile device is determined based on the motion data. A determination whether the mobile device is on the user's body or on an inanimate object is made based on the orientation of the mobile device over the period of time. The transmit power level is adjusted based on the determination.

Abstract: In one aspect, the present disclosure relates to a method including obtaining, by a heart rate sensor of a fitness tracking device, a heart rate measurement of a user of the fitness tracking device; obtaining, by at least one motion sensor, motion data of the user; analyzing, by the fitness tracking device, the motion data of the user to estimate a step rate of the user; estimating, by the fitness tracking device, a load associated with a physical activity of the user by comparing the heart rate measurement with the step rate of the user; and estimating, by the fitness tracking device, an energy expenditure rate of the user using the load and at least one of the heart rate measurement and the step rate.

Abstract: A calibration track to use for pedometer calibration can be automatically selected based on detecting sustained locomotion activity and an ability to obtain and maintain a reliable location fix over a calibration period. Calibration tracks can be generated, rated for quality, and used to compute calibration parameters to convert accelerometer data to stride length and/or distance traveled. Quality of a calibration can be assessed, and old and new calibration parameter sets can be combined based on quality weights assigned to each. Calibration parameters can be separately maintained for different locomotion activities and/or different on-body locations of the pedometers. Pedometer devices can also cooperatively calibrate each other.

Abstract: In some implementations, a mobile device can analyze motion sensor data and proximity sensor data during a voice call to determine whether the mobile device is on a stationary object or worn on a user's body (e.g., in the lap or pocket of a user of the mobile device). The mobile device can adjust the transmit power level of the telephony transceiver during the voice call based on the determination.