Cocasting and power control for energy efficient information dissemination in WSNs

This paper considers energy efficient information dissemination in Wireless Sensor Networks (WSNs) deploying co-operating nodes which by adjusting their transmission ranges minimize the total transmitted power in the network. Specifically, the design of routing protocols with a single relay node along a data path is proposed for multiple unicast sessions in a network with randomly distributed nodes. The protocols take advantage of topological diversity created by adapting the transmission power and exploit the benefits of network coding in a system where nodes are periodically generating data packets. Energy efficiency of the conventional, store-and-forward, and network coding based relaying schemes is analyzed in different propagation conditions and for various node densities. The best-case improvement in the energy efficiency achievable with network coding over store-and-forward is 25% for two node exchange of data. In WSNs, it is demonstrated through simulations that network coding offers realistically between 11% to 19% energy savings over the store-and-forward strategy. The deployment of the relaying node contributes to the improvement in energy efficiency over direct transmissions in a range of 80%.