Design of Logical Topologies for Wavelength Routed Networks

A virtual topology over a wavelength routed WAN consists of clear optical channels between nodes called lightpaths. These carry traffic end-to-end without electronic switching, creating an optical layer of the topology. Virtual topology design aims at combining the best of optical switching and electronic routing abilities. Designing a virtual topology on a physical network consists of deciding the lightpaths to be set up in terms of their source and destination nodes and wavelength assignment. In this chapter we provide a complete formulation of the problem and survey the literature on the topic. We restrict ourselves to transport networks rather than local area networks, and static topology design as opposed to topologies in which individual lightpaths are set up and torn down in response to traffic demands.