Relay node placement based on balancing power consumption in wireless sensor networks

To alleviate the traffic burden of sensor nodes and extend the network lifetime in wireless sensor networks, one approach is to deploy a large number of low-cost micro-relay nodes for routing data. The question is how to deploy a minimum number of relay nodes in the sensing field with network lifetime constraint. If relay nodes are uniformly placed, the issue of uneven power consumption arises as relay nodes closer to the sink are required to relay more data and thus will deplete their energy more quickly. Here, the authors study the relay node deployment problem under the assumption that the relay node has the same energy supply as the sensor node. Based on balancing power consumption among all sensor nodes and relay nodes, the authors deduce a relay node density function according to which relay nodes are placed in the sensing field. Simulation results show that the approach can achieve high energy utilisation and the network lifetime is significantly extended compared with uniformly placing relay nodes.