Dynamic route selection and wavelength assignment in all-optical networks

We propose algorithms for joint route selection and wavelength assignment in circuit-switched WDM all-optical networks. Previous work on wavelength routing has been based on a priori assignment of routes (typically via shortest path routing) to source-destination pairs, and a subsequent search over the set of available wavelengths to accommodate these routes. This approach does not take into account the state of the network when making the routing decision. The algorithms proposed in this paper attempt to, jointly and dynamically, find a route and assign a wavelength to sessions using currently available network resources. In a static assignment of the routes to source-destination pairs, a session will be blocked if its assigned route is not available while there may be another route (perhaps slightly longer) that is available. Joint route and wavelength assignment efficiently searches for a route on which a wavelength is available, and thus minimizes the occurrence of session blocking