A Routing Protocol For Asymmetric Ad Hoc Mobile Network

In recent years, with the development of wireless communication technology, the study of mobile ad hoc networks has been more and more popular. Mobile ad hoc networks is a kind of multi-hop and autonomous network system without central node and fixed base station, composed by a number of mobile nodes with wireless transceiver devices.In such a network, the communication between the nodes usually needs other nodes'assistance. The traditional routing protocols for mobile ad hoc networks are mainly designed on the base of the hypothesis that the links between nodes are symmetrical links. It means that all nodes have the same transmission range. However, the different power of nodes usally causes the existence of asymmetric links in real wireless network. Which will cause the existing routing protocols cannot better suit for this situation. Therefore, our research has the very practical demand and academic significance.In this text, we make several improvements for AODV and give the routing protocol adapting to the MANET with asymmetric links. In order to achieve the object, we carry out studies surrounding the mobile ad hoc routing strategy. Firstly, we introduce the three types of routing protocols for mobile ad hoc network: proactive routing protocols, reactive routing protocols,hybrid routing protocols.We introduc DSDV, AODV and ZRP of the classical routing protocols for the three types and analyze their merits and drawbacks.In chapter 3, we give the opinion that there are asymmetric links in real MANET.Then,we analyze the factors of its exists and its influences in networks.In chapter 4,we put forward an on-demand routing protocol for mobile ad hoc with asymmetric links. The routing protocol use RREQ (request message) and RREP (response message) to search the forward route and backward route.In the route discovery phase, RREQ and RREP will record the nodes which relay it and compute the weights of the links. If the route is a pure two-way path, the routing finding process will become an approximate AODV. If it is not a pure two-way path which includes some asymmetric links, the source needs to spread the RACK along the route and inform the route-related nodes to establish the corresponding route. For the route maintenance, we give a complete scheme of detecing link for MANET with asymmetric links. We propose route-related nodes table.It makes route maintenance better for the suitation with asymmetric links.Finally; we conduct simulation and analysis against performance of the routing algorithms and make the comparison with three protocols, including AODV, AODV-H and RODA. The experiment results show that the proposed routing protocol is fit on mobile Ad hoc networks with asymmetric links.