Beacon-less mobility assisted energy efficient georouting in energy harvesting actuator and sensor networks

Abstract

In the next years, wireless sensor networks are expected to be more and more widely deployed. In order to increase their performance without increasing nodes' density, a solution is to add some actuators that have the ability to move. However, even actuators rely on batteries that are not expected to be replaced. In this paper, we introduce MEGAN (Mobility assisted Energy efficient Georouting in energy harvesting Actuator and sensor Networks), a beacon-less protocol that uses controlled mobility, and takes account of the energy consumption and the energy harvesting to select next hop. MEGAN aims at prolonging the overall network lifetime rather than reducing the energy consumption over a single path. When node s needs to send a message to the sink d, it first computes the "ideal" position of the forwarder node based on available and needed energy, and then broadcasts this data. Every node within the transmission range of s in the forward direction toward d will start a backoff timer. The backoff time is based on its available energy and on its distance from the ideal position. The first node whose backoff timer goes off is the forwarder node. This node informs its neighborhood and then moves toward the ideal position. If, on its route, it finds a good spot for energy harvesting, it will actually stop its movement and forward the original message by using MEGAN, which will run on all the intermediate nodes until the destination is reached. Simulations show that MEGAN reduces energy consumption up to 50% compared to algorithms where mobility and harvesting capabilities are not exploited. © 2013 Springer-Verlag.