On-Line Burst Header Scheduling in Optical Burst Switching Networks

Optical burst switching (OBS) is a promising solution for allowing various-size data burst to be transported optically over dense wavelength division multiplexing (DWDM) without O/E/O (optical/electronic/optical) conversion. In OBS, networks, burst headers are sent ahead of the data bursts on a separate control channel to set up optical paths for the data bursts. While data bursts travel entirely in the optical domain, the burst headers have to be converted to electronic form and processed electronically. As the data channel bandwidth increases dramatically, the electronic control path for header processing is likely to become the performance bottleneck. It has been shown that control path overloading can severely degrade the performance of an OBS router. In this paper, we propose to formulate the burst header scheduling problem as an on-line time-constrained optimization problem for which we present a novel priority assignment method and a greedy on-line algorithm that consider both the urgency of the headers and the lengths of the bursts that the headers are representing. To the authors´ best knowledge, it is the first paper that targets on solving control channel´s overloading in OBS networks by improving the performance on throughput, as well as burst loss rate. Simulation results have shown that our technique is very effective.