Research On Key Technologies In Optical Burst Switching Network

Optical burst switching (OBS) is a new type of optical network, and it is one way to realize the all optical network. OBS separates data processing and channel controlling to realize the information transferring in an all optical manner. It combines the advantage of optical communication and electrical computer information processing technology, conquers the limit of electrical processing, and improves the efficiency of network.As a new type of network, there are many problems to be solved. One key problem is the high burst loss rate in OBS network due to its one-way reservation. This dissertation is centralized on decreasing of loss rate from many aspects of OBS network, and we find new methods in assembling of packet into burst, burst scheduling, and contention solution and congestion control to improve the network performance. In addition, for Synchronous Digital Hierarchy (SDH) is the optical network implemented in practice, we proposed integrated monitor for SDH, which has been used in business. The main contributions of the dissertation are as follows.By analyzing the assembly length of optical burst and considering the configuration time of optical switch matrix, we find that in the case of light network load, increasing the assembly length will decrease the loss rate of optical burst and reduce the electric processing cost. The research is conducted through theory performance analysis and experiment provement. With simulation result, the optimal assembling time is provided. Enhanced Smallest-Last Vertex Ordering (ESLV) is proposed for optical burst batch scheduling. In Smallest-Last Vertex Ordering (SLV), resource is allocated to the node with largest degree with high priority. When the network resource is limited, allocation for large degree node will cause more node be lost, that is because the largest degree node has higher collision. So ESLV is proposed. Making use of the advantage of SLV that it will occupy less wavelengths, and considering that wavelength processed in batch scheduling is limited, it allocates resources first, and then implements discarding to reduce the loss rate effectively.Joint Maximal Cliques First (JMCF) is proposed for batch scheduling in OBS network. When deleting the node, Maximal Cliques First (MCF) doesn't consider the length of burst. By modifying the rule of node deletion, JMCF is proposed to select the deleted node by considering the cliques jointly to reduce the number of deleted nodes and improve the efficiency of wavelength usage.Resource release scheme is proposed for contention solution of OBS network. When the traffic is heavy, loss rate of optical switching network will rise dramatically. The conventional method doesn't consider the waste caused by lost bursts. We analyze that no information exchange between controlling packet and data burst is the reason to resource waste, and propose the resource release contention solution to reduce the network congestion. The condition and rule for the setting of offset time are discussed.The integrated monitoring system of SDH devices is proposed. The SDH systems from different manufactories have different schemes, which will increase the difficulties for integrated real-time monitoring. A periphery based integrated monitoring system is proposed. Without modifying the SDH internal protocol of different manufactories, the method realized the real-time monitoring through serial port communication with low cost. The monitor can be easily merged with SDH system from different manufactories with simple installation and high compatibility.Optical burst switching is a new type of network, and there are many immature aspects. Many problems in electrical network will also appear, so the topics for future further study are discussed in the end of the dissertation.