Energy aware routing protocol for heterogeneous wireless sensor networks

In this paper we present Energy Aware Random Asynchronous Wakeup (RAW-E), a novel crosslayer power management and routing protocol for heterogeneous wireless sensor and actor networks. RAW-E is an extension of our previously presented Random Asynchronous Wakeup (RAW), a power saving technique for sensor networks that has been shown to reduce energy consumption without significantly affecting the latency or connectivity of the network. RAW-E is a distributed, randomized algorithm where nodes make local decisions on whether to sleep, or to be active based on the energy level of its neighbors. The primary result of RAW-E is the reduction of energy disparity among sensor nodes. Therefore, while the energy reduction is spread uniformly among nodes, the life of network connectivity is prolonged. RAW-E is scalable to the change in network size, node type, node density and topology. RAW-E accommodates seamlessly such network changes, including the presence of actors in heterogeneous sensor networks. RAW-E takes advantage of actor nodes, and uses their resources when possible, thus reducing the energy consumption of sensor nodes. The performance of our protocol remains very good even in large networks, and it scales with density. Previously we have shown by analysis and simulations that RAW improves communication latency and system lifetime compared to current schemes. Through simulation evaluations, we show that RAW-E adds to those-features the improvement on energy consumption and extension of connectivity life for heterogeneous sensor and actor networks.