Fading-aware reliable and energy efficient routing in wireless sensor networks

In this paper, we introduce two fading-aware reliability based routing algorithms for wireless sensor networks (WSNs) with lossy radio links. The proposed algorithms are able to find optimal multi-hop paths in polynomial complexity, over lossy links, which are modeled by using standard fading models (e.g. Rayleigh and Rice fading). These algorithms minimize the energy consumption and ensure reliable packet transmission to the base station (BS) at the same time. A reliable path is defined in terms of successful packet transfer to the BS despite the lossy links. More precisely, the probability of correct reception of the packet at the BS must exceed a predefined threshold. The first algorithm minimizes the total energy consumption sending a packet over the selected path to the BS. On the other hand, the second algorithm selects a path which maximizes the minimum remaining energy on the node closest to exhaustion and, as a result, balances the energy consumption yielding high longevity. In both cases, reliable and energy efficient packet forwarding in WSN can be reduced to a constrained optimization problem. By using a specific link metrics, these problems can then be mapped into shortest path problems solved in polynomial time. Thus the obtained results ensure the selection of reliable paths which also guarantee minimum energy consumption in real time. (C) 2010 Elsevier B.V. All rights reserved.