Route maintenance against route flapping in Ad hoc networks

Since route flapping weakens the quality of service in Ad hoc networks, this paper proposes two protocols of multiple route maintenance based on Ad hoc On Demand Distance Vector (AODV). In the first protocol, called AODV-CRM protocol, the complete routes from the origination are maintained. It gets all available routes between the origination and the destination, and any two of these routes share no common middle nodes. The second protocol, called AODV-SRM protocol, chooses a route maintenance method according to network topology. If there are multiple routes between the origination and the destination, the backup routes are maintained. Otherwise, a recursive method is applied from the origination to the destination until one node gets multiple sub-routes to the destination. We first analyze the performance of the two protocols against route flapping; then carry out simulations by NS-2. Results show that the two proposed protocols with backup routes perform better against route flapping than the existing protocols. The control message cost of AODV-SRM is less than that of AODV-CRM.