Link cache extensions for predictive routing and repair in ad hoc wireless networks

In ad hoc networks that employ source-based on-demand routing protocols, network nodes can use information contained in packet headers to populate a link cache. Given sufficient route requests and network traffic, a link cache can provide a good view of the past spatial network topology. This view can be successfully applied to making future routing decisions, provided that links are allowed to expire through a timeout mechanism, so that the cache stays fresh. We further assume that each node has the ability to determine its location, velocity, and bearing. We propose a link timeout mechanism that is based on mobility prediction, and introduce link cache extensions that incorporate temporal information regarding the future state of the network topology. By utilizing spatial and temporal information, better and more efficient routing decisions can be made. Furthermore, local repairs can be initiated preemptively in anticipation of a link break.