Study On Hierarchical Routing Protocols For Wireless Sensor Networks

Rapid advances in sensor technology, micro-electro-mechanism systems, networks and wireless communications have enabled the development of wireless sensor networks. Wireless sensor networks usually consist of hundreds or thousands of nodes. Due to the limitation of power, calculation ability and communication bandwidth, the traditional wireless routing protocols are not suitable for wireless sensor networks. It is the key point for the research to save power and prolong the total network lifetime.This dissertation starts with the basic concept of wireless sensor networks, and then analyzes and compares several representative routing protocols, especially puts an emphasis on the typical hierarchical routing protocol-LEACH. By assimilating excellent ideas home and abroad, integrative improvements are made on the cluster head selection, cluster formation and inter-cluster communication according to some shortages of LEACH, and the improved routing protocol is named as CBEEHRP.(1) In the selection of cluster head, two methods are combined together: the random cluster head selection algorithm used in LEACH and the selection strategy based on nodes weight. The weight of each node is set considering its remaining energy, number of neighbors and the times to be cluster head before.(2) In the clustering process, each ordinary node selects a cluster to join according to the signal strength and residual energy of each cluster head. Select the close node which has more remaining energy to act as its cluster head as far as possible. Further more, the number of survival nodes is collected in this process, and then the cluster head selection strategy is decided accordingly.(3) In the inter-cluster communication method, each cluster head selects single-hop or multi-hop route to transmit integrated data to the base station according to the distance between them.(4) In CBEEHRP, A novel data correlation model is adopted tentatively, which is based on the distance between nodes. Combined with this model, the optimal number of cluster heads is analyzed and deduced theoretically .Simulation results on NS2 platform demonstrate that CBEEHRP has better performance than LEACH in terms of network lifetime, energy dissipation and amounts of data received at the base station.