Model Based On Improved Particle Swarm Optimization For Ad Hoc Networks Mobile

Ad Hoc network is a type of wireless mobile network of self-organization and no center. Its construction does not need the fixed communication infrastructure. Additionally it possesses the character of strong robustness and destroy-resistance. So it is widely used in various environments requesting temporary communication. Routing protocols are important guarantee of the successful transmission of data packets and the mobility model is basic for the researches of routing protocols in ad hoc network. Since the design of the mobility model directly affects the performance and the stabilitiy of the protocol, it is neccassary to design a realitic mobility model.Swarm intelligence optimization is a kind of bionic optimization algorithm, which has been being swiftly developed in these years. The proposed model here belongs to traces and can be applied to imitate these scenes, such as wild animals in forest and airplanes in an air battle. It is helpful to the evaluation of the routing protocol. To mimic the movement of the nodes, we improved the basic PSO algorithm using accelartioin and environmental varibles and then established a new mobility model based on the improved PSO alogrithm. The main tasks of the thesis are shown as follows:(1) According to the actual mobility model in ad hoc, we improved the PSO algorithm. In the improved PSO alogrithm we solved the abrupt change of speed and make it suitable to be used in mobility model of ad hoc network, this paper introduced the conception of acceleration and environmental variable into the updating formulas of the velocity and displacement of the PSO algorithm, and proposed to decompose its velocity and the displacement under rectangular coordinate system(2) We established a new mobility model based on the improved PSO algorithm, which included the obstacle model, the velocity initialization function and the boundless area. When the nodes come to an obstacle, it will round the obstacle according to some rules. We also initialize the distribution for the nodes. (3) We have proved the validity of the imoroved PSO algorithm in Matlab. To testify the actual application of the new mobility model, we made experiments in OPNET, which shows the performance parameters of the ad hoc network, such as the packet delivery rate,average end-to-end delay,throughput and network load, under the new mobility model were significantly better than the random waypoint mobility model (RWM).