Network awareness and dynamic routing: The ad hoc network case

For extremely dynamic networks, such as ad-hoc, the topology change awareness has a crucial impact on the routing performance and consequently many routing protocols adapt their processes to the state of the network, from some network awareness. While several works have already been done on routing adaptations, this paper is more focused on the network awareness topic and the choice of the best metrics for a given adaptation. More precisely, the paper considers the way to represent by means of metrics the node mobility, the link degradation or the graph topology. The notion of metrics is illustrated through two adaptations of two well known ad hoc routing protocols (DSR, OLSR). We evaluate the effect of different metric choices by considering several adaptation strategies to the topology change which are based on the awareness of both the node movement and the number of nodes. We analyze the adaptation strategies and evaluate the performance of the adaptation depending on the chosen metrics. It is shown that the performance of adaptation is strongly correlated to the metrics that are themselves correlated to the network size. A metric combination based on link duration and number of nodes is found to be a good way to represent the topology change.