Group-Scheduling for Multi-Service Optical Burst Switching (OBS) Networks

We propose a new burst scheduling mechanism for Optical Burst-Switched (OBS) networks. The new approach is made possible by gathering data bursts into groups and performing the scheduling decision for each group collectively. In OBS group-scheduling, bursts will not be considered for scheduling until a pre-defined time period elapses, during which the group of burst header packets would be gathered. By transforming a set of data bursts into a set of corresponding time intervals, the problem of scheduling these bursts is transformed into a combinatorial optimization problem. Graph algorithms are applied to obtain the maximum number of non-overlapping bursts. The proposed OBS group-scheduling scheme is shown to improve the performance of OBS networks over existing scheduling schemes in terms of burst loss probability and channel utilization. With an extension through a sequential optimization, using a Branch-and-Bound technique, the proposed scheme can support multiple classes of service. It is shown that the new scheduling approach has several desired characteristics including fairness and service differentiability among classes in terms of burst loss probability and channel utilization.     

Framework for Operation and Maintenance (OAM) in Optical Burst Switched Networks

The problem of operation and maintenance (OAM) in optical burst switched (OBS) networks is not addressed by the optical-networking community even though OBS has been gaining research interest in recent years. In this paper, we introduce a functional model of OBS networks and an OAM architecture that is designed to meet the operational requirements based on this model. We present the first framework to realize OAM in OBS networks, including OAM activities, OAM-aware OBS nodes, OAM information and communication models and protocols. A number of practical examples of possible network failures and the corresponding reactions are presented.