Abstract. Ad hoc routing protocols that use broadcast for route discovery may be inefficient if the path between any source-destination pair is frequently broken. We propose and evaluate a simple mechanism that allows fast route repair in on demand ad hoc routing protocols. We apply our proposal to the Ad hoc On-demand Distance Vector (AODV) routing protocol. The proposed system is based on the Controlled Flooding (CF) framework, where alternative routes are established around the main original path between source-destination pairs. With alternative routing, data packets are forwarded through a secondary path without requiring the source to re-flood the whole network, as may be the case in AODV. We are interested in one-level alternative routing. We show that our proposal reduces the connection disruption probability as well as the frequency of broadcasts.

Ad hoc routing protocols that use broadcast for route discovery may be inefficient if the path between any pair sourcedestination is frequently broken. In order to efficiently use network resources, this paper proposes to use a controlled flooding (CF) mechanism to replace network-wide broadcast in route discovery procedures. CF is used to build alternative routes around the shortest-path between the source and the destination. With alternative routes, data packets are forwarded to a secondary path without requiring the source to re-broadcast the network. Furthermore, these alternative routes serve as guidelines indicating an approximative direction for future controlled floodings. CF is not orthogonal to the route discovery algorithm, but only complementary. Indeed, CF requires a pre-existing path to operate. The key idea is that the source only performs a new broadcast if all paths (shortest path and alternative paths) are lost. CF can be used for many purposes. We detail in this paper one of the applications of controlled flooding: connectivity maintenance. We show that our proposal reduces the connection disruption probability as well as the need for network-wide broadcasts.

Ad hoc routing protocols often use broadcast for route discovery. This can be inefficient if the path between any source-destination pair brokes frequently. We propose and evaluate a simple mechanism that allows fast route repair in on demand ad hoc routing protocols. We apply our proposal in the context of the Ad hoc On-demand Distance Vector (AODV) routing protocol. The proposed Controlled Flooding (CF) framework is used to build alternative routes around the main original path. With alternative routing, data packets are forwarded through a secondary path without requiring the source to re-flood the whole network, as often the case of AODV. We show that our proposal reduces the connection disruption probability as well as the frequency of broadcasts.