Energy Saving Research On Routing Protocol In Wireless Sensor Network

Wireless Sensor Network(WSN) is one of important technologies in wireless communications. WSN is characterized by inexpensive nodes, low transmition rate, low energy consumption, short communication range and etc. WSN can be widely used for many applications, for example, military, industry, transportation, intelligent building, agriculture, environment monitoring and health care.Routing protocol is one of significant protocols in WSN protocol stack. The main task for a routing protocol is to transmit data from source node to destination node through the network. Routing design depended on the basic characteristics of WSN requires more consideration on the network’s limit energy supply, multi-hop, self-organizing, local topology based, and other details, which makes a big difference than routing in wire-based network and traditional wireless network. Therefore, a research on routing protocol becomes an interesting topic in the protocol stack of the WSN. Based on the features of WSN routing protocol design and their different classifications, several existing routing protocol which are classic in WSN are carefully researched in the thesis. Advantages as well as disadvantages of each protocol are also analyzed. By contrasting each protocol’s performance, it is found that hierarchical routing can save more energy per node and has a longer lifetime than flat routing.Low Energy Adaptive Clustering Hierarchy (LEACH) protocol is selected to further discuss its mechanism, network model, work flow, channel model and energy model. It is an important clustering routing protocol in WSN. It proposed a clustering structure when routing, which can avoid maintaining the route table, balance and efficiently utilize the energy comparing with the flat routing protocol. However, it assumes that every node can communicate directly with the Sink node, and each node has computing capacity to support different MAC protocols. Therefore, LEACH is not suitable to be applied in large-scale wireless sensor networks. At the same time, it is completely random when choosing cluster heads, and does not take into consideration the difference among nodes after the network works. Yet the effect caused by communication distance between cluster head and the base station is not thought about.Accordingly, this thesis proposes a new cluster head selection algorithm called i-LEACH. The new algorithm takes the residual energy and distance between node and the base station as parameters. At the Steady-state, a two-level communication structure is used intra-cluster to forestall long-range communication of far-away node in the cluster. At last, the NS-2network simulator employed to simulate the new protocol. The results show that i-ELACH has longer network lifetime and lower energy consumption than LEACH%LEACH-C and MTE.