A measurement study and implication for architecture design in wireless body area networks

Reliability and energy efficiency are two key performance metrics in wireless body area network (WBAN) to meet the requirement of healthcare applications. The network architecture of WBAN has significant impact on transmission performance. In this paper, we investigate the network architecture through the measurement study of WBANs. In particular, we measure the performance achieved for star and multihop IEEE 802.15.4 WBANs in terms of packet reception ratio (PRR), collection delay, energy consumption, and energy balancing. The experimental results show that in the star architecture network, only 40% of on-body nodes are able to achieve required PRR performance (0.95) when transmitting at the maximum power. This indicates the demand of multihop transmissions. In the multihop experiment, we use a customized collection tree protocol (CTP) to formulate multihop networks. Our multihop measurement results show that the link quality based routing achieves good performance in terms of PRR (>0.96) and collection delay (<150 ms for 95% of nodes). We further suggest the choice of the optimal transmission power level by inspecting the average number of transmissions per packet, network energy consumption and average cost per hop.