Wireless Sensor Network Routing Technology

Wireless sensor network is composed of many densely deployedlow-cost sensor nodes with wireless communication capability. Itsperformance is mainly limited by nodes' low battery power, low capacityof computing and storage, as well as smaller transmission range.Therefore, the routing protocol of sensor network must be carefullydesigned to gain more efficient communication capacity of the sensornodes. In recent years, grate achievements have been made in wirelesssensor network protocol technology. Many protocols suitable to wirelesssensor network have been proposed, such as Directed Diffusion, LEACH,SPIN, TEEN, APTEEN and PEGASIS etc.This thesis will mainly make researches on wireless sensor network'sDirected Diffusion and LEACH cluster-head selection algorithm. It willpropose a multi-layer improvement scheme on the monolayer of DirectedDiffusion and improve the LEACH cluster-head selection algorithm. It isexpected to contribute a little to the development of this field.The content of this thesis mainly includes the following aspects:1. It introduces the basic concept of wireless sensor network,including wireless sensor network structure, characteristics andapplication field. Then it analyzes a few key technologies of wirelesssensor networks in accordance with the proposed network system andframework.2. It analyzes and classifies the current route protocols of wirelesssensor networks. Then it introduces some typical route protocols,analyzes and compares the two classical route protocols based on relatedperformance index.3. It puts forward a multi-layer improvement scheme base onDirected Diffusion. It adopts a multiple structure, builds up nodes'attribute in the process of data transmitting and conducts father-selectionas well as data-distribution. The simulation experiments demonstrate thatour improved scheme can save transmission energy up to about 50% overDirected Diffusion, without any reliability or delivery efficiency being endangered.4. It analyzes the classic LEACH routing algorithm in wirelesssensor network, and proposes improvement for its limitation of clusterhead selection. Based on awareness of the residual energy of each node,the improved LEACH algorithm distributes cluster heads equally in thewhole network. The simulation results demonstrate that the improvedalgorithm is capable of distributing energy dissipation more effectivelyamong the sensors and enhances network lifetime comparing withLEACH algorithm.