Virtual circuit allocation with QoS guarantees in the ECOFRAME optical ring

We present the ECOFRAME metro ring network and how we can provide virtual circuit emulation with QoS guarantee at a subwavelegth level. The architecture is based on a centralized HUB and reservations. The scheduler in the HUB reserves a set of rectangles, called a pattern to describe the slots allocated to a node. We study the tradeoff between the complexity of the reservation at the HUB level and the performance of the network: distribution of the end to end delay and utilization of the ring.