A preventive conversion mechanism for conflict resolution in Optical Burst Switched Networks

In this paper we present an algorithm, called the Wavelength before Time with Preventive Conversion (WTPC) algorithm, that aims at reducing the loss rate in an optical burst switched network. The algorithm resolves contention in both the time and wavelength domain and uses a preventive conversion mechanism for some optical bursts that cause large voids. Without this mechanism our algorithm coincides with the Wavelength before Time (WT) algorithm of Muretto [7]. We explore two variants of WTPC that differ in the Wavelength and Delay Selection algorithm used: the minimum Gap and the minimum Length approach, both proposed by [2]. A detailed simulation study is included that shows the impact of the preventive conversion mechanism on the loss and the influence of a variety of parameters, e.g., the number of wavelengths, the number of FDLs and the load on the WTPC algorithm.