Research On Cluster Based Routing Protocols Of Wireless Sensor Networks

Wireless sensor network is a distributed intelligent network composed of a large amount of micro-sensors, which are deployed in the area to be monitored, and organized by themselves. It is generally used in unattended situations to monitor the environmental parameters or events of interest, transmits data collected by sensors to the remote observers, by which the data is analyzed to get a view of the environment or the events. WSN has a lot of characteristics which distinguish it from traditional network and ad-hoc network, thus the classical protocols which can well be applied to the latter networks can not be applied to WSN. From the view of routing, its architecture , addressing methods and communicating protocols are different from traditional network and ad-hoc network. It aims to perform the function of data collection from sensor nodes to the processing center, and its routing protocols are many to one oriented data streams and one to many oriented control streams, not any direct source to destination transmission; during transmission it usually adopts data fusion, and the whole network is data-centric. Because of the limit of energy, the aim of the design of routing protocols is to save energy and balance load of nodes, thus to prolong the lifetime of the network.Based on the analysis of some existing classical routing protocols, this paper proposed two new protocols, one is cluster based multi-hop routing protocol, short for CBMRP, the other is cluster based path strengthen protocol, short for CBPSP.CBMRP is based on clustering, it also introduces the conception of gateway and cluster id creatively. During data transmission, the cluster heads query its routing table and selects gateways according to the cluster id and the residual energy of gateways, by which the data can be forwarded among cluster heads, and finally to the base station. This protocol uses gateways and cluster heads to forward data, which can balance node energy cost efficiently, thus it is good for the extension of network and prolonging of network lifetime, it also supports dynamic clustering and data fusion between cluster heads, so it is a energy efficient protocol.CBPSP selects a critical node in a fixed part under monitoring to fuse the data collected by the nodes in this part, which reduces the redundancy of data. During every task, it only needs to build one path between the critical node and bs, so it eliminates the need to build multiple paths when there are many original nodes. This protocol combines the virtues of both cluster based protocol and directed diffusion, and can be applied to the application of uncertain monitoring of fixed parts.This paper introduces the idea and the implementation of the two new protocols in detail, and analyses the virtues of them theoretically. It also uses 0MNet++ to compare CBMRP and general cluster based routing protocol, validating the efficiency of balancing node energy cost and prolonging network lifetime.