Design And Implementation Of The Hybrid Optical Burst/Circuit Switching Network

Optical communication technology is advancing with such a speed that is far beyond our imagination. It has become the major solution of communications, especially for the backbone networks. Meanwhile, the fast growing IP traffic promotes increasing demands on the capacity and bit rate of the network. How to satisfy the bandwidth demand turns to be the main technology concern. In the switching nodes of the network, it is necessary to realize"all optical switching"in order to avoid bit rate bottleneck resulting from E/O/E transponders.Up to date, three switching schemes have are proposed on WDM networks, i.e., optical circuit switching (OCS), optical packet switching (OPS) and optical burst switching (OBS). The biggest challenge for OPS is that the required optical technologies such as optical logic and buffer devices are far from mature. Comparatively, OCS and OBS are easier to be implemented. They have their own advantages and adapt to different networks. If the two switching schemes can be merged into the switching nodes, obviously the network bandwidth utilization and adaptation can be improved greatly.In the dissertation, Introduction to the OCS,OPS and OBS is given and their characteristics are described together with the necessity and benefit of the hybrid OBS and OCS switching. Theoretical and experimental research was carried out on the key issues of the hybrid switching. The dissertation is divided into five chapters. The main contents include:Basic technologies for OBS are described in details, including burst assembly, channel scheduling, signaling protocol, and solution for burst conflicts. They serve as important fundamentals to implementation hybrid switching networks.The design scheme of optical hybrid switching networks is presented. The edge/core nodes structures and functions are given. The feasible signaling protocol and control/data packet formats for the edge nodes are proposed as well. The main units constructing a core node are described and node structure is designed.The implementation of hybrid switching based on Linux platform is presented in details. On the bottom IP layer of Linux, we added an extra layer, named hybrid-switching layer, to implement the mechanism of hybrid switching. By using the fast switching fabric developed by our group, an experimental hybrid switching system was configured. It includes three edge nodes and one core node. On this system, FTP data transmission and VOD services are successfully demonstrated.The conclusion for the dissertation is given with prospect for the future research.