Cooperative and Low-Power Wireless Sensor Networks for Body-Centric Applications

Research on sensor network has been carried out using small, low-power digital radio based on an IEEE 802.15 standard, a high-level communication protocols suitable for wireless body area networks (WBANs). The most straightforward approach to deploy a WBAN is considering single-hop communications between the sensors and the sink. However, the body impact on the signal can result in path losses usually larger than 50 dB. Due to these high losses, direct communication between the sensors and the sink will not always be convenient (or even possible), especially when extended sensor lifetime is targeted for ultra-low range transceivers. Multi-hop communications exploit spatial diversity as an advantageous solution (and sometimes even as an absolute requirement) to ensure connectivity, improve link reliability, and possibly improve the energy efficiency of WBANs. This chapter will look into the application of cooperative networking schemes in WBAN and the cost of energy in deploying such multi-hop systems rather than the conventional star network topology.