Packet loss and delay performance of feedback and feed-forward arrayed-waveguide gratings-based optical packet switches with WDM inputs-outputs

This paper analyzes the packet loss and delay performance of an arrayed-wav eguide-grating-based (AWG) optical packet switch developed within the EPSRC -funded project WASPNET (wavelength switched packet network). Two node desi gns are proposed based on feedback and feed-forward strategies, using shari ng among multiple wavelengths to assist in contention resolution. The feedb ack configuration allows packet priority routing at the expense of using a larger AWG. An analytical framework has been established to compute the pac ket loss probability and delay under Bernoulli traffic, justified by simula tion. A packet loss probability of less than 10(-9) was obtained with a buf fer depth per wavelength of 10 for a switch size of 16 inputs-outputs, four wavelengths per input at a uniform Bernoulli traffic load of 0.8 per wavel ength. The mean delay is less than 0.5 timeslots at the same buffer depth p er wavelength.