Impact of Power Control on Relay Load Balancing in Wireless Sensor Networks

When shortest path routing is employed in large scale multi-hop wireless networks, nodes located near the center of the network have to perform disproportional amount of relaying for others. In energy-constrained networks like sensor, such unfair forwarding results into early depletion of batteries of these congested nodes. To solve the problem, various divergent routing schemes are used which route the data on centeravoiding divergent routing paths. Though they achieve better load balancing, overall relaying is increased significantly due to their longer routing paths which in turn results into reduced energy efficiency. In this paper, we propose power control as a way of achieving better load balancing in multi-hop wireless networks. We show that when communication range of nodes are properly controlled using power control, better load balancing can be achieved using shortest paths only. Such a strategy also decreases overall relaying in the network when compared to divergent routing schemes. We use the concept of centrality to achieve appropriate balance between relay burden of nodes and their power levels. Numerical results confirm that centrality based load balancing significantly improves network lifetime of sensor networks.