Efficient Scheduling for High-Throughput OBS Networks with Partial Wavelength Conversion

Cost-efficient contention resolution is an urgent topic in Optical Burst Switching. This paper examines the performance of a core OBS node equipped only with partial wavelength conversion, and investigates how the choice of burst scheduling algorithm can affect its blocking rate performance and converter usage. In particular, sensitivity of performance is examined with respect to burst length. A novel threshold-based scheduling scheme called Conversion Reduction Scheduling (CRS) is presented. We show that CRS can ensure that a node requires only 65-75% of the full number of wavelength converters under dynamic traffic loads. We show a further 35-40% converter savings through a proactive scheduling algorithm called Coordinated Wavelength Assignment (CWA) applied at the ingress nodes. By minimizing redundant use of wavelength conversion, the strategy reduces the required number of converters while preserving high burst throughput.