Abstract:
Energy efficient communication is a key requirement of energy-constrained wireless sensor networks. In this chapter we show that cooperative communication can be deployed in wireless sensor networks as an effective practical energy saving technique. In cooperative communication a partner node is recruited to help with communicating a source node’s message by overhearing and repeating it to the destination receiver. We present an energy analysis of cooperation to demonstrate that cooperative communication has the potential to significantly reduce the total energy cost of wireless communication, provided the transmission range is beyond a certain threshold. We examine the feasibility of practically exploiting this energy saving potential in a wireless sensor network by considering the energy savings achieved for a given source node cooperating with a range of potential partners, using optimal power allocation for the cooperative transmission. We demonstrate that the partner choice region for energy efficient cooperation is large relative to the source-destination separation, meaning that significant energy savings can be achieved in practice from cooperation with a wide range of partners. We present a simple distributed cooperation protocol for wireless sensor networks, whereby each source node autonomously makes cooperation decisions based on a simple yet near-optimally energy efficient cooperation strategy. We thus show that large network-wide energy savings can be attained via cooperative communication without the need for central coordination.