Study on the Performance of Slotted and non-slotted Optical Burst Switched Networks

Current progress in optical communication is driven by the continuous growth of the number of Internet users and the explosion of bandwidth greedy applications. Three main optical switching paradigms are being investigated to cope with this evolution: Optical Circuit Switching (OCS), Optical Packet Switching (OPS) and Optical Burst Switching (OBS). Among these paradigms, OBS is seen as the most appropriate solution. However, OBS still suffers from high burst loss as a result of contention at the buffer-less core node. There exist two categories of OBS, slotted and non-slotted. In this paper, the performance of these two categories is evaluated. The evaluation is done through simulation and it consists of comparing Hierarchical Time Sliced OBS (HiTSOBS) a slotted OBS to the conventional non-slotted OBS. Simulation results show that, HiTSOBS architecture outperforms conventional OBS in terms of Burst Loss Ratio (BLR) and throughput. The high performance of HiTSOBS is attributed to the flexibility of its hierarchy and support of QoS.