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 the design of future large-scale optical systems is packet scheduling for the core optical routers. The optical router essentially is a delay system with packets waiting at its ingress queues. A scheduler is necessary to allocate resources so that satisfactory delay and jitter performance of different types of traffic can be achieved and system capacity is efficiently utilized. This paper develops a nonblocking scalable scheduling algorithm and presents related performance evaluations in a multi-service high capacity core optical router. The proposed algorithm is based on a heuristic approximation of a Linear Integer Programming model. It is shown that the heuristic solution is ‘close’ to the optimal solution ‘most of the time’, yet it is much easier to implement.