New approach to improve the robustness of AOMDV protocol

In Mobile Ad hoc Network (MANET) [1], packet loss rate is high because of frequent changes in the network topology and the lossy nature of radio links. In this context, it is very delicate, for reactive routing protocols, to support multimedia communication. Route request process, as well as route breakage notification, is frequently repeated. This contributes to congestion and degradation of communication quality. To cope with this problem, in difficult transmission contexts, we propose solutions to improve the robustness of on-demand routing approach. The basic idea of our first proposal is to record a reasonable number of paths at intermediate nodes for each route request process. These will be able to locally solve the problems of route breakages. Thus, the source node is rarely solicited to reinitiate route request process. As a second improvement, we propose taking into account links reliability in the route choice. We modify route request process so that reliable paths in terms of Bit Error Rate (BER) are preferred. The effectiveness of the new protocol taking into account these improvements has been tested under realistic conditions and compared to standard Ad hoc On-demand Multipath Distance Vector (AOMDV) [2] and Ad hoc On-demand Distance Vector (AODV) [3] protocols. The results show that we succeeded in improving the performance of standard AOMDV even in difficult conditions such as mobility or Multi-communication.