A concept for ant-routing with colored pheromones in wireless mesh networks

Different classes of traffic pose different requirements on the underlying network. For example, VoIP traffic has stricter requirements on delay and jitter than background traffic such as file downloads. Ant-routing algorithms store an amount of pheromone proportional to the measured ldquogoodnessrdquo of a link in the network. This approach assumes that a) links have only one dimension of ldquogoodnessrdquo and b) that ldquogoodnessrdquo is equal for all types of traffic. In reality, though, links can have several orthogonal dimensions of ldquogoodnessrdquo. In addition to bandwidth, delay, and jitter wireless links also experience changes of bandwidth over time and varying amounts of packet loss. Therefore, a route in a wireless mesh network may be suitable for one class of traffic but unsuitable for another. The proposed algorithm addresses this problem by introducing ldquocolored pheromonesrdquo which are matched to the traffic classes. Depending on the measurement of the different dimensions of ldquogoodnessrdquo and their match to the traffic classes an ant will deposit an apropriate amount of pheromones in the adequate ldquocolorrdquo in the routing tables. Traffic will then follow the appropriately colored paths.