The Improved Algorithm Of Energy Aware Routing Protocol For Wireless Sensor Network

The development of micro-electronics, computation and wireless communication technologies has enabled the rapid advancement of low-power wireless sensors which have the functions of information collecting, data processing and wireless communication in a small space. Because of the cosmically using of low-power and cheap wireless sensors, Wireless Sensor Network emerged. WSN has particular characteristics, so the traditional wireless routing protocols can not run on it. The application-oriented routing protocol becomes the hard core of the researching of network layer.In this paper, the issues of the routing protocols for wireless sensor network are discussed. Through researching of Energy Aware Routing Protocol and discussing the strongpoint and defect of it, Negotiation-based Energy Aware Routing Protocol with Threshold for Wireless Sensor Network is designed. In this protocol, an energy threshold is gained by the Sink Node which surveys the energy scales of neighbor nodes, and then broadcasts a message for route establishing. Using the energy threshold, it generates the route tree by least-hop-number method and maintains the route tree by periodically broadcasting the message which is used for route establishing. The route tree is composed of the nodes whose remainder energy is higher than the energy threshold. The other nodes which become the isolated nodes gain routing information by periodically surveying their neighbor nodes'information and calculate the probability of the the next-hop nodes based on the cost of transmitting. When the data needs to be transmitted, the nodes in the route tree transmit data through the route tree, and the isolated nodes choose the next-hop node by the probability to transmit data.Paper implements the NEAR protocol on ns2 platform, and compares it with the EAR protocol. Through the analyzing of the result of experiments, it shows that the NEAR protocol can effectively prolong the energy-exhausting time of the low-energy nodes. Thereby, the NEAR protocol achieves the aim of evenly distributing the energy load among all the nodes and prolonging network life time.