Optimal offset-time decision for QoS in optical burst switching networks

Abstract

In this paper, we propose the optimal offset-time decision (OOD) algorithm which can effectively reduce the pre-transmission delay compared to the perfect isolation model, and can also be extended to general n priority classes while the target loss probability of each class is guaranteed for the variable offered load. In order to drive the OOD algorithm, we first analyze the loss probability of each priority class through class aggregation and iteration method; the analytic results obtained through the proposed algorithm are then validated with results garnered from extensive simulation tests.

A model of QoS differentiation burst assembly with padding for improving the performance of OBS networks

“…With OTD, an extra offset time is assigned to high-priority (HP) bursts, which results in an earlier resource reservation for them ( Figure 1a). Based on the extra offset time, OTD allows isolating HP bursts from low-priority (LP) bursts, but with the condition that the extra offset time has to be as long as at least a few average LP burst lengths to achieve perfect isolation [13]. In BLD, due to short bursts being more likely to fit in the voids generated between scheduled bursts, HP packets are aggregated into short bursts for enhancing the performance of HP packets relative to LP packets in terms of the loss probability (Figure 1b).…”