Wireless Sensor Networks Research And Design Of Cluster-based Routing Protocol

Recent advances in sensor technology, microelectro-mechanical systems and wireless communications have motivated the development of wireless sensor networks. It can be defined as an autonomous, ad hoc system consisting of a collective of networked sensor nodes designed to intercommunicate via wireless radio. Typically, these nodes coordinate to perform a common task. They apperceive ,collecte and compute the informations of the objects, then transmit the aggregated data to the observer. Wireless sensor network is being used in a wide of variety of commercial and military applications and becomes a new research area of modern technology.In this dissertation, the conceptions and key technologies of WSN are introduced briefly, and some applications of WSN and structure of the networks are covered. Then we give the classification of the routing protocols for WSN and summarize the characteristic of routing protocols. We also list and make comparison of several kinds of existing protocols. Finally, we abstract the target of design for routing protocols.Researching cluster-based routing protocol of WSN is the main part of this work.. LEACH is selected to be the research target as the representative of the cluster-based routing protocols. We bring forward some improvements to LEACH protocol based on analyzing the shortages of it. The former LEACH algorithms for adapting clusters and rotating cluster head positions. In every round, the cluster heads are determined randomly. The improved LEACH periodically selects cluster heads according to their residual energy. Through simulation results, it is proved that the improved algorithms can achieve good performance in terms of system lifetime.In this dissertation, we proposal MHAC, a multi-hop adaptive clustering algorithm.MHAC clusters nodes into groups and builds routing tree among the cluster heads,among which only the root node communications the base station directly. MHAC prolongs network lifetime by distributing energy consumption.and achieves fairly uniform cluster heads distribution across the network. The limit on the number of hops allows the cluster heads to schedule their transmissions. The simulations show its effectiveness in prolonging the network lifetime and balanceing load among nodes in the WSN.Finally, we research the cluster-based routing protocol of WSN base on the ZigBee. The manner of formation for cluster-based network is presented at the base of describing three kinds of network topology...