Optimal Scheduling Algorithms in WDM Optical Interconnects with Limited Range Wavelength Conversion Capability

Abstract

In this paper we study optimal scheduling algorithms to resolve output contentions in time slotted WDM optical interconnects with wavelength conversion ability. We consider the general case of limited range wavelength conversion with arbitrary conversion capability, as it is easier to implement and more cost effective than full range wavelength conversion, and also includes full range wavelength conversion as a special case. We consider the conversion scheme in which each wavelength can be converted to multiple wavelengths belongs to an interval and the intervals for different wavelengths are “ordered”. To be specific, the conversion range of λ i can be written as [begin(i), end(i)], where begin(i) and end(i) are positive integers and if i < j then begin(i) ≤ begin(j) and end(i) ≤ end(j). We will present linear time optimal scheduling algorithms for both buffered and unbuffered WDM switches. We will also give performance studies of these switches when scheduled by these algorithms.