Performance Evaluation of QoS-Aware Optical Packet Switches

In this paper we evaluate the performance of Bufferless Optical Packet Switches equipped with shared Tunable Optical Wavelength Converters (TOWC) and supporting Quality of Service. The TOWCs sharing is partial, that is each Output Fiber shares one pool of TOWCs shared by all of the packets directed to that Output Fiber. The QoS, expressed in terms of Packet Loss Probability, is differentiated by giving the packets different priorities in accessing both the output wavelengths and the TOWCs. A scheduling algorithm is proposed and its complexity is evaluated. The QoS technique effectiveness is studied by means of a sophisticated analytical model validated by simulation results. The results show that the proposed technique to support QoS allows a good differentiation of the QoS offered to the packets.