Research On Routing Algorithms For MANET With Unidirectional Links Supported

Mobile Ad hoc Networks(MANET) are collections of wireless mobile hosts forming networks without the aid of any established infrastructure or centralized administration, and because of this, they are gaining increasing popularity in recent years. Generally in a MANET, routing protocols are challenged with establishing and maintaining multihop routes in the face of mobility, bandwidth limitation and power constraints. In this thesis we study the routing strategies for MANET. Table-driven routing protocols and source initialed on-demand routing algorithms are analyzed and compared against each other. Our study shows the on-demand protocols are better suited for MANET because they generate less control overhead and manage the mobility in a more efficient manner. Then we focus on the problems caused by the Unidirectional Links in the wireless environments. We discuss the formation of the unidirectional links and their influence on the MANET routing protocols such as DSR, DSDV, AODV. Solutions are given to overcome the problems, we analyze some of they and point out their limitations. In the third part, we show a new on-demand routing strategy supported unidirectional links, it use the two circuits route search algorithms to establish the route from the source node to the destination and backward with directions; it transfer the route error messages from the backward positions to the forward positions one by one; it apply the packet encapsulation technique to forward the packets through the unidirectional links and introduced the circuit path to transmitinformation from the forward node to the backward node. In the last part, we actulize the new strategy based on the AODV protocol, and then we test this model in the Network Simulation 2.1. Plenty of simulative data shows that our strategy really works.