A cooperative routing method with shared nodes for overlapping wireless sensor networks

In a wireless sensor network (WSN), one of the most important challenges is extending network lifetime because it is difficult to replace sensor nodes and recharge their batteries. In a WSN, nodes around a sink tend to die earlier than other nodes because these nodes have to transmit and relay more packets. To overcome this problem, many load-balancing methods were proposed. By the way, in recent years, two or more overlapping WSNs have been constructed in the same geographic area. In this situation, the overlapping WSNs are expected to extend their lifetime by cooperative packet forwarding. In this paper, we introduce shared nodes with multichannel communication capability as interchange points among respective WSN planes. With these shared nodes, we propose a novel cooperative routing method for WSNs to balance each other´s load. Finally, we show the effectiveness of the proposed method by simulation experiments.