Analysis of OBS Burst Assembly Queue with Analysis of OBS Burst Assembly Queue with Renewal Input

Ongoing research in Optical Burst Switching (OBS) requires more in-depth studies both in theory and in practice before the technology is realized. In OBS paradigm, traffic from access networks is groomed at edge OBS nodes in the forms of large chunks called bursts. This grooming called assembly is crucial in analyzing the overall performance of OBS networks as it affects the esign of almost all major functions of OBS nodes. The characteristics of assembled traffic and its effects on OBS performance have been already extensively studied in literature. In this work, the sembled traffic is studied using a transform-based approach, since it is a natural way of analyzing such processes where random variables are summed. The main contribution of this paper is formulation of distributions of burst length and burst inter-departure time in form of Laplace transforms, which are valid for general independent lengths and inter-arrival times of assembled ackets. The results can be subsequently inverted analytically or numerically to give full densities or serve as moment generating functions for partial characteristics. A simple method for the distribution of the number of packets in a burst based on discrete Markov chain is provided. Detailed analytical derivations with numerical results are presented for Erlangian traffic and verified by simulations to show good exactness of this approach.