Optical Burst Switching (OBS) has been proposed as a most possible switching technology for optical networks. To achieve better performance in the edge node and the whole network, many burst assembly algorithms have been investigated. In this paper, a novel parallel burst assembly mechanism is proposed based on Internet traffic estimation in distributed control wavelength-routed OBS (DWR-OBS), which has a two-way reservation mechanism and can achieve better burst blocking probability while worse end-to-end delay compared with conventional one-way JET OBS. A simulation model is developed to evaluate the performance of the network. Simulation results indicate that with the proposed algorithm network performance improves a lot in DWR-OBS networks.
This paper investigates some key issues in designing an OBS edge node, such as burst assembler and burst scheduler, and then demonstrates a prototype of the OBS edge node based on current technology level. Experimental results verify various modules in the proposed OBS edge node.
Optical burst switching (OBS) provides a feasible paradigm for IP over DWDM. And one of key issues in OBS is the fast and efficient scheduling of bursts with different QoS demands. In this paper, we propose a novel window-based scheduling (WS) algorithm, in which all bursts arriving in the window are scheduled together based on priority BORA. Therefore batching scheduling can achieve an optimized BORA efficiency and then the number of contention in OBS can be reduced largely, and simultaneously priority scheduling in the window can efficiently enhance QoS. Simulation results show that the proposed WS algorithm with the optimal parameters such as window and max-delay, compared with BORA, can achieve more than one order blocking probability reduction for high priority bursts and approximately 3.5% improvement in bandwidth utilization at 0.8 load.
Wavelength Routed Optical Burst Switching (WR-OBS) is considered an efficient switching technique in optical networks, especially in the situation of no wavelength converters. A QoS scheme based on centralized scheduler has been proposed in this architecture. Unfortunately, this scheme has some drawbacks. To overcome these drawbacks, a distributed redundant reservation protocol and corresponding QoS scheme has been proposed in this paper. Simulation and analytical model are conducted to evaluate the performance of the newly proposed protocol in terms of burst lost probability.
Optical Burst Switching (OBS) has been proposed to be a competitive switching technology for DWDM networks. However, the abrupt burst for large traffic loads will result in unbearable performance degradation in the traditional JET network. To combat with the load sensitivity, a wavelength-routed OBS (WR-OBS) network architecture was confirmed effective. In this paper, we have proposed a distributed control WR-OBS network architecture combining JET protocol with a two-way reservation method. Based on this architecture, two new resource reservation protocols are compared by evaluating their performance. Then based on the Reduced Load Approximation, which is often used in the analysis of the circuit switch network, a novel analysis method was derived to evaluate the blocking performance of the network. And then we have developed a simulation model to evaluate the performance of the network and validate the proposed analysis method. Analytical and simulation results have indicated that the proposed architecture outperforms the traditional JET OBS network in burst blocking probability with a good trade-off between efficiency and complexity.