Hierarchical time-sliced optical burst switching

To overcome the need for large buffers to store contending bursts in optical burst switched (OBS) networks, a recent variant called time-sliced OBS (TSOBS) suggested that bursts be sliced and spread across multiple frames of fixed-length time-slots. Since TSOBS is rigid in its frame structure, this paper generalises TSOBS to allow a hierarchy of frames. Termed hierarchical TSOBS (HiTSOBS), this scheme supports several granularities of rates, and permits multiple traffic classes with different loss-delay requirements to efficiently share the network. Our contributions are as follows: first, we present an architecture for HiTSOBS and offer it as a viable option for the realisation of flexible and cost-effective OBS networks. Second, we develop mathematical analysis to study the loss and delay performance of the proposed HiTSOBS system. Finally, we present simulation results that captures these loss-delay tradeoff values. Our HiTSOBS architecture gives network operators the freedom to choose the right mix of traffic with desired loss-delay requirements to coexist in the network.