On Optical Burst Switching Paradigm And Key Parameters Optimizing Based On 2×2 Optical Switch

Because the current network bandwidth is exhausting, the network capacity must be expanded to meet the increasing bandwidth demand of IP services. Optical switching is the key to enlarge the network capacity. Presently, the practical optical switching protocol mainly includes optical packet switching (OPS) and optical burst switching (OBS). OBS becomes the focus of the international research of the optical switching protocols, for its slightly functional demand of the optical devices. This paper introduces the key optical devices, such as fiber, optical amplifier, laser and wavelength selective devices, and also several representative resource reservation protocols, including RFD, TAG and IBT. The principle and pivotal technologies of OBS are formulated, and the frame of the OBS is designed in detail. The burstification process of the edge node and the routing course of the core node based on the designed frame are studied, and a novel burst assembly algorithm, double-threshold burst assembly algorithm (DTBA) is put forward. This assembly algorithm can improve the variety of the burst length and smooth the data flow in theory. The function configuration of OBS networks is discussed, and the whole function configuration of node and two configurations of 2×2 optical switch are presented. These configurations can simplify the node configuration and lessen the block rate of the node; the JET protocol is investigated and a simple algorithm, supporting QoS to set offset-time based on JET protocol is brought forward. The algorithm and the core routing algorithm are simulated on the 2×2 optical switch matrix, the parameters are optimized. And key factors to set the offset time are pointed out also. The simulation results show that the block rate of 2×2 optical switch reaches about 3.7% as the single wavelength transmission rate, 400Gbit/s, and the shortest burst length, 2.6Mbit, q=5000, s=2.95. This work is significant to the construction of the future OBS network both in theory and in practical.