The Implement And Improvement Of Directed Diffusion

Wireless sensor network is a new kind of network system that is proposed for some specific applications. It is very useful in some region. But wireless sensor network is limited by his resource such as energy, computation ability and communication distance. Moreover, its topology is dynamic and it is used for some specific application.Wireless sensor network is a data-centric system, data can't be transmitted without routing protocols in network. The design of routing protocol for wireless sensor network need to consider that nodes have no unique global Id and limited energy. So the existing Ad Hoc network routing protocols and algorithm are not suitable for wireless sensor network. By the analyse of several routing protocols, we find there are some shortcomings. A specific routing protocol is needed.Directed diffusion is designed for wireless sensor network. The data in the network should be named. Then the named data can be processed in-network by the sensor node and transmitted on reinforced path. So the articl design a method for data naming ("attribute-value-operation") and provide a rule for data matching and a method of gradient for deciding which path is selected. There are two parts of works in research: The first, by using Network Simulator 2(Ns2), the algorithm is implemented and simulated to prove that the result of saving energy and routing. The second, in order to save more energy, the algorithm is improved by changing the way of gathering data. By using Ns2, the articl implement directed diffusion and some examinations are tried to test the result that less energy and tolerable time is used. The result shows that directed diffusion is fit to wireless sensor network and have a good view in the future reseach.