Improving transmission method of a cluster head node in a two-level wireless sensor network

WSN is a wirelessly configured network of nodes equipped with sensors that can collect data and monitor surroundings in the real world. In practical usage of sensor networks, sensor nodes have limited energy capacity because they are configured wirelessly. Minimising energy consumption of sensor nodes is important to maintain the network. Many researches to increase energy efficiency have been studied, and the LEACH protocol, which increases energy efficiency by equally granting transmission opportunities for nodes and by evenly selecting CHs, is one of the typical and representative one. This protocol gives all nodes the even opportunity to be a CH, but it does not take transmission distance to BS into account, which causes to increase energy consumption. To improve this issue, TL-LEACH protocol has been proposed. In this protocol, the second clusters are composed only for CHs, so that the transmission distance can be reduced. However, depending on a specific constellation of sensor nodes in sensor field, the transmission distance increases. In this paper, we apply the dual-hop method to improve this issue, which reduces transmitting distance of nodes, and show better network lifetime performances than the existing protocol.