Abstract
This paper studies the light-trail routing problem in optical WDM networks. Light-trail has been an attractive architecture in optical WDM networks, and be considered as a backbone in the next generation network. We investigate how to find a light-trail set that contains minimum network resources to support the traffic requests in optical WDM networks. The algorithm of finding a light-trail set can adopt ILP(Integer Linear Programming) formulation to find an optimal solution. We also propose a heuristic for solving this problem, because the complexity of ILP formulation is too high. In proposed heuristic, we assign the traffic request to all candidate light-trails, next we according to the selection rule to choose a best candidate light-trail that efficiently use network resources, at last add this candidate light-trail to the light-trail set. Repeat the above action until satisfy all traffic requests. In this paper, a number of performance measures including total number of transceiver, total waste of bandwidth, total number of wavelength and total number of wavelength link are used to compare with other algorithms. Simulation results show proposed heuristic can use less number of transceiver, waste of bandwidth, number of wavelength and number of wavelength link.