A Linkcache Invalidation Mechanism for Dynamic Source Routing (DSR) in AD HOC Networks

Dynamic source routing (DSR) is an efficient on-demand routing protocol for ad hoc networks, in which only needed routes are found and maintained. Route caching is necessary to avoid the need for discovering a route before each data packet is sent. The best cache structure is the link cache, which, in contrast to path cache, effectively utilizes all of the information that nodes have the potential to learn. Because of mobility, cached links might become stale. A mechanism to delete invalid links from the cache is necessary. The goal of this work is to develop a caching strategy that permits nodes to update their cache, when the topology of the network changes. To achieve it, all reachable nodes that have cached a broken link are notified when it fails. The designed caching strategy and the normal operation of DSR are compared showing that our approach outperforms the DSR protocol.