Heuristic for reducing congestion during logical topology design in de Bruijn WDM networks using survivable routing

This paper addresses the problem of reducing congestion during logical topology design in de Bruijn WDM networks that can withstand the failure of a single physical link. Survivable routing of a logical topology ensures that the lightpaths are routed in a way that a single link failure does not disconnect the network. Survivable routing of the logical topology demands setting up of additional lightpaths for the restoration of the disrupted lightpaths in case of failure of a physical link. Thus the conservation of network resources (typically channels in each link) is of prime importance in this context. The paper proposes heuristic to increase the availability of free channels by addressing the problem of reducing congestion. The results of the algorithm are shown for de Bruijn networks with various sizes of lightpath requests. Finally the performance of the algorithm is evaluated by comparing the results with those of a greedy survivable routing strategy. Comparisons show that the proposed heuristic is definitely a better option for reducing congestion.