On The Enhanced LEACH Protocol For Wireless Sensor Networks

Recent advances in sensor technology, low-power electronics, and low-power radio frequency design have enabled the development of inexpensive and low-power wireless sensors that can be connected via a wireless network. Wireless sensor network can be applied to many areas such as military affairs, commerce, medical care, environmental monitoring, and becomes a new research focus in computer and communication fields.In this thesis, firstly the performance measures to estimate wireless sensor network communication protocol are discussed. Energy efficiency is an important performance measure of the network. In the present communication protocols, the network lifetime is usually used as a parameter to estimate the validity of power consumption. In this thesis, two existing lifetime definitions are analyzed. In order to overcome the disadvantage of inaccurate measurement, a new definition of network lifetime based on accurate measurement is proposed, together with the discussion on the applicability to three definitions.Next, routing protocols of wireless sensor network is discussed. Low Energy Adaptive Clustering Hierarchy (LEACH) and two existing improved protocols, LEACH_C and LEACH_D are analyzed. A new improved routing protocol based on the node importance is given, which improves cluster selection strategy while at the same time, reserves the advantage of adaptive clustering. In this protocol, the nodes with different importance would be treated differently. The nodes with lower importance and higher redundancy are charged with more communication relay work, in order to increase the network lifecycle as much as possible, as well as insuring the network overlaying percentage.The simulation of LEACH and its improved protocols has been carried out with VC++. By comparing the simulation results, it is shown that the improved protocols can increase the network lifecycle effectively, especially in the case of high network density.