Evaluation of QoS differentiation mechanism in shared-per-wavelength Optical Packet Switches

The performance of a bufferless optical packet switch, which employs shared fixed input tunable output wavelength converters, namely shared-per-wavelength, supporting quality of service is presented. The aims of the paper are both to reduce switch costs, by using simpler optical components and low complexity space switching matrices, and to provide service differentiation among packets belonging to different class of services. The QoS, expressed in term of packet loss rate, is differentiated by giving the packets different priorities in accessing both the output wavelength channels and the wavelength converters. The related scheduling algorithm and his complexity evaluation is provided in the paper. The effectiveness of the differentiation scheme is evaluated by an analytical model validated through simulations. Results show how the proposed scheme offers a good differentiation in terms of QoS offered to the different class of services.