On the wavelength assignment problem of multi-channel photonic dual bus networks

Abstract

In a multi-channel photonic bus network, each unidirectionnalbus contains a control channel and several data channels (wavelengths),and each station has n tunable transmitters and m tunable receivers.Given a set of serving traffic and a set of new traffic requests, thewavelength assignment problem ((n,m)-WAP) is to assign the transmissionwavelengths and receiving wavelengths of each station so that all thetraffic requests can be served simultaneously and the number of assignedwavelengths is minimized. In this paper, we prove that the (n,m)-WAP isNP-complete by showing that the simplified version of the (n,m)-WAP(SWAP, or (1,1)-WAP), in which each station has only one tunabletransmitter and one tunable receiver, is N P-complete. An efficientdistributed wavelength assignment algorithm (DWAA) is proposed for the(1,m)-WAP. The throughput and delay characteristics of the DWAA isevaluated by simulation. Simulation results show that for a limitednumber of available wavelengths, the solutions obtained by the DWAA isattractive in terms of throughput, access delay, as well as fairness,under general traffic demands.