Payload and power consumption analysis of IEEE802.15.6 based WBAN with CSMA/CA

According to emergency of wireless body area network (WBAN), the IEEE802.15.6 standard was established in Feb. 2012. A physical (PHY) layer, medium access control (MAC) layer and network layer were almost decided, however a payload in every packet is varied within [0,250] bytes. Since the low influence on human body and the low transmit power are required, the received signal to noise ratio (SNR) of coordinator depends on distances between sensors and the coordinator and varies in a larger region. Therefore, the assumption of noise free is no longer available. The discrete time Markov chain method (DTMC) is proposed to calculate the access probability of every sensor and analyze the performance of system with regard to packet error rate. The calculation method of power consumption is also proposed to correctly estimate the power consumption of WBANs that adopt the carrier sense multiple access with collision avoidance (CSMA/CA) as a transmission protocol. The payload is optimized for every Eb/N0 in order to obtain the best energy efficiency. The calculation result indicates that the optimal payload decreases when the Eb/N0 decreases while the total data which a sensor should transmit to the coordinator is being fixed, whereas the optimal payload increases slightly in low Eb/N0 region when the total data increases.