I. Introduction
Large-scale wireless sensor networks can be used in many ubiquitous applications such as environmental monitoring and battle-field surveillance. Nodes of these networks are generally battery operated resulting in energy-constrained sensor networks. Thus energy-aware sensor processing plays an important role in improving the life-time of the sensor network and preventing the loss of critical information due to node failures. Many approaches that facilitate energy consumption reduction in sensor networks have previously been proposed. Some of these can be found in [1]–[3] and [4].