無線ボディエリアネットワークの人体運動に基づく送信電力制御: Transmission power control based on human body movement for wireless body area networks

This paper proposes the development of a transmit power control (TPC) protocol for wireless body area networks (WBANs). WBANs consist of wireless sensors attached to users. Each sensor had a transceiver and an inertial measurement unit (IMU) to measure the user's motion. The TPC protocol increased the lifetime of WBANs by reducing the power consumption of the transceiver. The protocol is based on a mathematical model of human motion by the user. The model was used to determine the minimum transmit power required to achieve a packet delivery ratio (PDR). The TPC protocol characterized the channel using received signal strength indicator (RSSI). IMU measurements were used to determine the parameters of the model, which in turn determined the transmit power level. Thus, the TPC protocol includes a method to reduce the complexity of the human motion model, which reduces the computations performed by the wireless sensors. The TPC protocol was implemented and tested in real time on a Shimmer2r wireless sensor. Experimental results on a biceps curl motion showed that the average power per packet was reduced from 31.3 mW to 19.0 mW, a reduction of 39%, while maintaining a PDR within 4% difference from the target PDR.