Combining Contention Resolution Schemes in WDM Optical Packet Switches with Multi-Fiber Interfaces

Optical Packet Switch (OPS) architectures with multi-fiber interfaces are considered here to combine space, wavelength and time domains contention resolution. The switch is equipped with Fiber Delay Lines (FDLs) as well as a pool of Tunable Wavelength Converters (TWCs) that can be shared within the node or the single interface. Contention resolution algorithms can exploit space, wavelength and time domains. In particular the proposed multi-fiber solution, consisting of a bundle of fibers for each interface, allows to isolate output wavelengths on each fiber and to repeat them on different fibers. As a consequence the wavelength converters employed result to be easier to implement due to the narrower bandwidth required for each of them. These architectures also allow to implement quality of service mechanisms to obtain application related performance. Packet loss evaluation is obtained via simulation and analysis in the special case of buffer-less design. The advantages of the proposed solution both in terms of performance and cost saving are shown.