Logical network design in WDM networks

Abstract

We consider several routing and wavelength assignment problems for the design of WDM(Wavelength Division Multiplexing) network. We present integer programming formulations of the problems and algorithms for them. First, We consider routing and wavelength assignment problem(RWA) in WDM ring network employing wavelength routing. We are given a physical ring network, a set of selected pairs of nodes, the number of required connections for each selected pair of nodes. Required connection between a pair of nodes is realized on the given network by establishing a path between that pair of nodes and assigning a specific wavelength to the path. RWA is to realize all the given required connections on the given network under the constraint that the paths which share a link should be assigned to different wavelengths. The objective is to minimize the number of required wavelengths. We present an integer programming formulation for the problem which is decomposed into a master problem and a column generation problem. We proposed a branchand-price algorithm to solve the problem. We develop a polynomial time algorithm for the column generation problem by decomposing it into several subproblems. We also develop a pseudo polynomial time algorithm to find kth optimal solution to the column generation problem. Using the algorithm, we can generate columns in branch-and-bound tree. Computational results show that the algorithm find an optimal solution in reasonable time. We also consider the RWA in survivable WDM mesh network. We assume an optical layer path protection scheme under the single-link failure. When a physical network and a set of working paths are given, we must select a link-disjoint protection path for each working path. We also assign a wavelength for each working and protection path. We will call this problem survivable routing and wavelength assignment(SRWA) problem. In wavelength assignment for protection paths, there are two possible methods. One method assigns...