Research On Burst Assembly Algorithm And Resource Reservation Strategy In Optical Burst Switched

With the quick development of Internet service, link voice, data and video, the data services will exceed the traditional telephone services. To build a high speed all optical WDM (Wavelength Division Multiplexing) network has been the trend of the development of communication network in this century. OBS (Optical Burst Switching) is one of the optional switching technologies proposed to implement all optical networks. Based on the current technologies and cost restriction, OBS take advantage of OPS (Optical Packet Switching) and OCS (Optical Circuit Switching) while avoiding the disadvantages of them. Thus, OBS offers a feasible and effective way for realizing all optical communication networks at present.Based on analyzation of the architecture and key technology in OBS, this paper researches a new burst assembly algorithm based on burst size and assembly time prediction, and a well-aware resource reservation strategy in OBS network, as well as develops Optical Burst Switched Networks Simulation Mainframe. The major research results are showed as follow.(1)In the chapter of A New Burst Assembly Algorithm Based on Burst Size and Assembly Time Prediction, by using a hybrid threshold to promptly detect the alternation of traffic load, the size threshold can be adjusted adaptively by the step size. Time Prediction Equation is investigated and demonstrated to be effective to control the prediction success probability, While the first IP packet is coming into the assembly queue, both data burst assembly size and time are immediately predicted respectively according to the size threshold and Time Prediction Equation, in order to reduce the latency and avoid unsuccessful data burst prediction. An aggressive algorithm is proposed to deliver better performance improvement with latency reduction and bandwidth utilization. The simulation results show that this assembly algorithm can reduce the End-To-End delay significantly without any additional time overhead, and any bandwidth wastage due to unsuccessful prediction.(2)In the chapter of A Resource Reservation Strategy Based on Intro-network Network State Model, A new reservation strategy for Optical Burst Switched networks is presented based on Intra-Domain Network Statue Model (INSM). By using control channel promptly to update the INSM, better decisions can be made in selecting light path and assigning wavelength at each edge node, which can make edge node avoid reserving those link resources are being used. Besides, a time slot has been introduced to detect the latent collision, which not only can achieve the goal in diminishing the forthcoming collision effectively, but also can better support multi-priority QoS. Furthermore, Virtual Configuration Table (VCT) at core node is further proposed to resolve collisions without bandwidth wastage. The analysis and simulation results verify the feasibility of the proposed scheme and show that enhancing the awareness capability of network state at edge node in the lack of full conversion capabilities and optical buffer, have profound effect on the burst drop probability and QoS support in an OBS network.(3)In the chapter of Optical Burst Switching Networks Simulation Mainframe, using Object Oriented Programming and JAVA language, an Optical Burst Switching Network Simulation Mainframe was developed in order to raise the accuracy of simulation, operate simply and keep the program architecture clear. The final object is to quicken the process of research in OBS.(4) The performances compose of two parts: one is for Burst Assembly Algorithm Based on Burst Size and Assembly Time Prediction, the result shows the Assembly better reduce the end to end delay and realize the adaptivity of Assembly Algorithm; another for Resource Reservation Strategy Based on Intro-network Network State Model, the result shows the strategy can low the burst drop rate dramatically and better offer the support of multi-QoS...