Traffic statistics and optical burst overlap reduction in core router of OBS networks

Abstract

We describe here a burst scheduling algorithm to reduce burst overlapping with fiber delay lines (FDLs) in optical burst switching (OBS) network, and hence to improve the quality of service (QoS). We consider TAG (tell-and-go) protocol where many lightpaths pass in a given link and burst overlap may occur. In an intermediate node having two incoming links and one outgoing link at lower traffic loads, we found a relation for the burst loss and the throughput depending on burst size, inter-arrival time, and sizes of FDLs. It is shown that in low traffic loads, burst loss can be made zero using different sets of FDLs and with minimum usage of wavelengths. We used time-based assembly algorithm in an assembly node to build the burst at low and high traffic loads. Symmetric and asymmetric burst trends are considered and improvement of throughput is shown.