| Optical Burst Switching (OBS) is a hybrid technique between coarse grain optical circuit switching and fine grain optical packet switching. In OBS networks, user data is switched entirely in the optical domain, while control and management functions are performed in the electrical domain. This separation of the data plane and the control plane allows OBS networks to provide reasonably high levels of utilization while circumventing the need for optical buffering. In spite of OBS favorable features, several issues need to be addressed before OBS can be deployed in the Internet backbone.;QoS provisioning is a major research problem in OBS networks. This is mainly because of the absence of the concept of "packet queues" in OBS networks. This thesis proposes two approaches for QoS provisioning in OBS networks. The first approach is a simple, yet effective scheme, called preemptive prioritized just enough time (PPJET). PPJET provides better service for high priority traffic by dropping reservations belonging to lower priority traffic using a new channel scheduling algorithm called preemptive latest available unused channel with void filling (PLAUC-VF). Simulation results show that PPJFT outperforms offset-based QoS schemes both in terms of dropping probability and end-to-end delay.;As a second approach for solving the QoS problem in OBS networks, we present a detailed architecture for providing quantitative QoS guarantees with respect to end-to-end delay, throughput, and packet loss probability in labeled OBS networks. The architecture describes a novel approach for applying fair scheduling algorithms in both the data plane of labeled OBS edge nodes and the control plane of core nodes without the need for optical buffering. In addition, we present analytical results for delay, throughput, and blocking probability in the proposed architecture. Simulation results demonstrate that the proposed architecture provides accurate and controllable service differentiation in labeled OBS networks.;The absence of optical buffers in OBS nodes, coupled with the one way nature of OBS signaling protocols, drives the blocking probability to become the main performance measure in OBS networks. (Abstract shortened by UMI.).;The objectives of this thesis are twofold: devise new methods for quality-of-service (QoS) provisioning in OBS networks, and develop new wavelength scheduling algorithms for enhancing the blocking probability in OBS networks. |
