A Scheduling Algorithm in a Core Optical Router with Heterogeneous Traffic

Recent advances in optical networking reveal that large-scale optical networks supporting heterogeneous traffic may soon become economical as the underlying backbone in wide area networks, in which optical routers play a key role. One big challenge in designing future large-scale optical systems is packet scheduling for the core optical routers. The optical router is a delay system with packets waiting at its ingress queues. A scheduler is necessary to allocate resources so that delay and jitter sensitive real-time traffic can be served with higher priority than the non-delay sensitive traffic. The system capacity should also be efficiently utilized. This is achieved by a prioritised non-blocking scalable scheduling algorithm developed in this paper. The proposed algorithm is based on a heuristic approximation of a Linear Integer Programming model. The performance evaluations in a multi-service high capacity core optical router show that the heuristic solution is close to the optimal solution most of the time, yet it is much easier to implement.