Congestion Avoidance in Source Routed Ad Hoc Networks

As well as suffering from the same congestion causes as fixed networks wireless ad hoc-networks introduce several new congestion factors due to both the medium used and the mobility of the user. Unlike in fixed networks, which utilise predominately end-to-end transport layer solutions, congestion control in an ad-hoc network must be local, fast and adaptive. Congestion management attempts to predict when congestion is about to occur and reduces the transmission rate at this time. In an ad hoc network, congestion occurs locally and must be dealt with in a localised fashion. When a node becomes congested, it alerts its neighbouring nodes and these backoff according to the volume of data they are forwarding through the congest node. This paper demonstrates the effectiveness of such congestion control techniques in ad-hoc networks, showing improvement over data delivery rates provided by standard Ad Hoc techniques.