Integrating power control with routing to satisfy energy and delay constraints in sensor networks

Wireless sensor networks (WSNs) demand the implementation of energy-aware techniques and low-complexity protocols in all layers. In this paper we propose, implement and evaluate a new protocol that combines energy-efficient routing with end-to-end delay minimisation, and embodies a basic power control scheme. We call this scheme energy-delay minimisation (EDEM). We focus on two parameters that mainly affect energy efficiency, the initial transmission power and the power step used through network operation. Therefore, we investigate the optimum values for these parameters and provide an analytical solution that optimises EDEM's performance. Finally, we evaluate the proposed scheme in terms of energy efficiency and time delays using several different metrics. such as total energy consumption. dying nodes rate. network lifetime, packet delivery ratio and total time delays. The results are promising since remarkable gains are provided with respect to existing protocols. Copyright (C) 2007 John Wiley & Sons, Ltd.