A Scheme of wavelength assignment for PCE/GMPLS-based wavelength-switched Optical Networks

Proposed in this paper is a PCE-Assistant Collision-Avoiding Wavelength Assignment Scheme (PACAWAS) for transparent Wavelength Switched Optical Networks (WSONs) to solve the resource contention problem in distributed wavelength assignment scenario. In this scheme, several extensions are made to the GMPLS (Generalized Multi Protocol Label Switching) signaling, and a wavelength selection assistant unit (WSAU) is added to the Path Communication Element (PCE) to which the destination node would resort when making a wavelength selection decision. Simulation results show that the proposed scheme is able to avoid efficiently the collisions of wavelength resource reservation and thus performs better in decreasing total blocking probability than the traditional ones do under different traffic scenarios.