Online Routing Algorithms for Maximum Lifetime in Wireless Sensor Networks

The importance of energy preservation in wireless sensor networks is long established, and a number of maximum lifetime routing schemes exist in the literature. Many of the existing online routing schemes are based on the use of some edge-weight functions, but those schemes exhibit diverse performances in terms of the obtained lifetime results. The major contribution of the present work is to critically analyze the existing edge-weight functions in order to identify their shortcomings. We obtain an insight into the desired behavior of weight functions, and design better functions that are employed in the proposed approaches. We present two online routing schemes, namely the fuzzy This work was supported by the Natural Sciences and Engineering Research Council of Canada under grant STPGP 322208-05. 1 maximum lifetime routing scheme (FML), and the fuzzy multiobjective routing scheme (FMO). The former tries to maximize the lifetime objective, whereas the latter strives to simultaneously optimize the lifetime as well as the energy consumption objective. Simulation results obtained under a variety of network scenarios indicate the superiority of the proposed schemes over a number of other online routing schemes in terms of the lifetime as well as the energy consumption metric. For better scalability, we also present a fully distributed implementation of the FML routing scheme. The overhead analysis shows that the distributed scheme is successful in considerably reducing the control overhead. keywords: Wireless sensor networks, lifetime maximization, energy-aware routing, online routing algorithms, distributed algorithms, multiobjective optimization, fuzzy functions and operators.