Dynamic OBS offset allocation in WDM networks

An investigation is carried out into the traffic characteristics of an OC-192 link (9953 Mbps), based on the IP packet size distribution, traffic burstiness and self-similarity. The Generalised Exponential (GE) distribution is employed as a suitable model of interarrival times of bursty traffic flows of IP packets whilst self-similar traffic is generated for each wavelength of each source node in the optical network. In this context, a novel optical burst switching (OBS) allocation protocol is proposed, based on the offset values of adapting sourcedestination pairs, using preferred wavelengths specific to each destination node. Different traffic demands amongst the nodes of the optical network are taken into account and a dynamic updating of the offset is adopted based on the occurrence of blocked bursts and successful transmissions. Numerical evaluation results based on simulation are devised and favourable comparisons are carried out between the proposed OBS protocol and the Just Enough Time (JET) protocol, based on the performance metrics of mean queue length, blocking and throughput.