The Research On Ad Hoc Mobility Model In Search And Rescue Scenario

In recent years, wireless networking technology has made rapid development and wide spread. In some scenarios that people cannot set up for some fixed infrastructure, or fixed infrastructure has been damaged, such as battlefields, disaster relief, etc., the traditional wireless networks with a centre cannot be competent. However, Ad Hoc networking technology can meet the needs of these special occasions.In Ad Hoc Networks, the performance of a network protocol can be reliably evaluated by actual measurements, but it is very difficult and costly to build a large number of nodes in Ad Hoc networks. Therefore, simulation tools have became the main means for evaluating the performance of Ad Hoc network protocols, and the performance of most of the existing varieties of network protocols are studied through simulation tools.Mobility model, which is to simulate the mobility patterns of mobile nodes in the real environment, is the core of Ad Hoc network performance evaluation. However, most of the current models cannot reflect the real patterns. Because in such models the simulation results do not accurately reflect the true performance of the network, or even its basic research may be misleading.The personnel moving features in search and rescue scenario are analyzed in detail in this paper. Thereafter, aiming to different moving features of search, rescue and transport people in rescue scene, three different mobility models based on the random way point model for search are proposed: random waypoint with area and direction limitation mobility model (RWPADL), random way point with attraction direction mobility model (RWPAD) and random way point with fixed access points mobility model (RWPFAP).Through NS2 simulation tests and analysis, the characteristics of the RWPADL, RWPAD and RWPFAP model are proved to be very different comparing with the classic RWP, RW and RD model, including the average neighbor rate, the average link time, the average link change rate and the average route change rate. The three models we proposed can describe the personnel groups and formations action properly and effectively in search and rescue scenario.After the model in its own characteristics being analyzed and compared, the impact of the model on the performance evaluation of routing protocols using two classic Ad Hoc network routing protocols DSR and AODV is considered and tested in this paper. The experiment results indicate that the performance of DSR and AODV protocol is better on the aspect of average delivery rate, average delay and average hop number under the RWPADL, RWPAD and RWPFAP model.At last, a relatively more realistic environment basis is provided for Ad Hoc networks research in the search and rescue scenarios by the models we proposed in this paper.