Improved antnet routing algorithm with link evaporation and multiple ant colonies to overcome stagnation problem

Antnet is a software agent based routing algorithm that is influenced by the unsophisticated and individual ants emergent behaviour. Ants (nothing but software agents) in antnet are used to collect traffic information and to update the probabilistic distance vector routing table entries. One of the major problems with antnet is called stagnation and adaptability. This occurs, when the network freezes and consequently the routing algorithm gets trapped in the local optima and is therefore unable to find new improved paths. There are several methods to overcome stagnation problem such as noise, evaporation, multiple ant colonies and using other heuristics. In this paper, multiple ant colonies are applied to the packet switched networks and results compared with the antnet employing evaporation. Results showed that employing multiple ant colonies has no effect on the average delay experienced per packet but it has improved the throughput of the network slightly.