Research On LEACH-based Clustering Routing Protocol In Sensor Networks

Wireless Sensor Network is an intelligent private network in which a large number of sensor nodes transmit information by means of self-organized wireless communication so as to accomplish a specific function collaberatively. Sensor node, with limited energy, usually runs in a hostile and hazardous remote environment where is inaccessible for human beings. Meanwhile, it is not practicable to supplement energy by replacing the battery. Therefore, the key issue for WSN involves in how to effectively use the energy of each node for routing forwarding, and design efficient routing protocols to extend the network lifetime.This paper first introduces the concept, systematic construction, characteristics and application of the wireless sensor network, then explicate the existing WSN routing protocols. Based on the merits-faults analysis of these routing protocols, we put emphasis on the Low Energy Adaptive Clustering Hierarchy (LEACH) routing protocol. The LEACH protocol circularly and randomly selects cluster head nodes and distributes the whole network energy load into each node evenly, thereby reduce energy consumption and prolong network lifetime. However, in this algorithm, each cluster head is selected randomly in equiprobability, without taking into account factors like the residual energy of nodes, which makes the generation of cluster heads with randomness and may result in the selection of non-optimal cluster heads thus further affect the entire WSN lifetime. For this reason, given the deficiency of LEACH protocol in cluster heads selection strategy, a novel selection mechanism (LEACH-TE) is proposed. The new algorithm makes improvement in determination of optimal number of network cluster heads and cluster heads selection algorithm.1. Improvement in determination of optimal number of network cluster heads:taking into account factors such as the monitering area size, sensor nodes quantity and location of base station, the algorithm for optimal number of cluster heads in LEACH routing protocol is recalculated.2. Improvement in cluster heads selection algorithm:First, compare residual energy of nodes with network average energy, screen out the nodes whose residual energy≥network average energy. Second, introduce residual energy of nodes, total network energy and expected number of cluster heads each round, adjust cluster head threshold T(n) in LEACH protocol. Nodes with greater residual energy shall get higher cluster heads threshold and their probability of becoming cluster heads is increased. These measures effectively balance network energy consumption and extend network lifetime significantly.At last, NS2 simulation platform is adopted for simulation and performance evaluation to the proposed routing algorithm. Simulation results analyzed and show that the LEACH-TE protocol has desirable performance in prolonging network lifetime, reducing energy consumption and improving data reception of the base station.