Research On Energy-efficient Unequal Clustering Algorithm In Wireless Sensor Networks

Wireless sensor networks are integration of sensor techniques, nested computation techniques, distributed computation techniques and wireless communication techniques.Sensor networks are composed of a large number of sensor nodes that are densely deployed inside the phenomenon. Since the number of sensor nodes in WSN is numerous and single node is extraordinarily limited in resource, the important aim of designing routing protocol in WSNs is to reduce the overall energy dissipated in the network and to maximize the network lifetime.Hierarchical management is widely applied in the wireless sensor networks, since it can not only provide flexible, reliable communication but also promote the expansibility of the network. The network is divided into clusters, which are composed of the cluster head and some members. These cluster heads can further form the higher-level cluster according to the requirement of the application. The cluster head is responsible for the coordination, the data retransfer and the management of all the nodes in the cluster. Moreover, the cluster head can be pre-assigned or elected automatically.This dissertation compares some classic routing protocols that proposed by researchers, analyse the performance requirement of the WSN, and propose an energy-efficient routing protocol with the idea of unequal clustering in the circle area.Based on the structure of wireless sensor networks, all the normal nodes are distributed around the sink node. In this algorithm, the network is subdivided into multi-layers from inner to outer. Cluster heads not only sense, but also receive data and do data aggregation from nodes in its transmission range, in addition that transmit the data to the sink node using multi-hops. To prolong the lifetime, the networks must consume energy balanced from inner layers to outer layer. How to define the radius and transmission ranges of each layer and make sure the optimized solution are the main problems we focus. In addition, to reduce the energy consumption, the cluster head in the same ring use the aggregation strategy, then the aggregated date is sent to the inner layer. From the simulation, the multi-layer algorithm has better performance in prolonging the lifetime of networks, but it has long date latency as the layers increased. In addition, we compare our algorithm with HEED and LEACH and obtain longer rounds of the first node died and the last node died.