The static and semi-dynamic routing problems in the Wavelength Division Multiplexing (WDM) networks are generally very complicated. Finding the exact optima for most of these optimization problems is usually impossible with todays computation facility even for the medium size networks. Therefore, finding a sub-optimal solution within a reasonable computation time is the only choice, while knowing the proximity of the sub-optimal solution to the exact-optimum would be an additional advantage. Different from most of the existing heuristic approaches, this book provides strict formulations and...