Collaborative broadcasting and compression in cluster-based wireless sensor networks

Achieving energy efficiency to prolong the network lifetime is an important design criterion for wireless sensor networks. In this paper, we propose a novel approach to conserve energy by allowing sensors to exploit the inherent broadcast nature of the wireless channel to carry out joint data compression. We illustrate this idea in a cluster-based wireless sensor network. The key idea is that when a particular sensor broadcasts its data to the cluster head, other sensors can receive and utilize that data to compress their own data. We formulate an optimization problem in which sensors in each cluster collaborate their transmitting, receiving, and compressing activities to maximize their lifetime, and solve for the optimal control scheme. By optimal, we mean that any other policy cannot increase the lifetime of the node which dies first. We also propose a heuristic scheme with lower complexity and near optimal performance. Numerical results show that by exploiting the broadcast nature of wireless media, our control schemes can achieve significant improvement in the sensors' lifetime.