Department of Computer Science , UTSA Technical Report : CS - TR - 2008 - 016 Multi - Path Planning for Mobile Element to Prolong the Lifetime of Wireless Sensor Networks ∗

Mobile elements, which can traverse the deployment area and convey the observed data from static sensor nodes to a base station, have been introduced for energy efficient data collection in wireless sensor networks (WSNs). However, most existing solutions only plan a single path for the mobile element, which may lead to quick energy depletion for the sensor nodes that are far away from the path. In this paper, for data collection in WSNs, we study the multi-path planning (MPP) problem for the mobile element to prolong the lifetime of WSNs. Observing the intractability of the problem, two MPP heuristic schemes, namely fixed-K and adaptive-K, are proposed. The central idea of these schemes is to plan multiple paths and have the mobile element follow them in turn to balance the energy consumption on individual sensor nodes, thus extending the lifetime of WSNs. The proposed schemes are evaluated through extensive simulations. The results show that, compared to that of the single path solution, the multi-path approaches can extend the lifetime of WSNs by up to 4 times. Moreover, the adaptive-K scheme treats the sensor nodes more fairly with less variation on their energy consumptions.