Key Technologies And Experimental Management System In Automatically Switched Optical Network

Automatically switched optical network (ASON) is the key technology in next generation optical transport network. The most important characteristic of ASON is the development of separated intelligent control plane. With the control plane, functions including automatical discovery, automatical routing, call/connection management, protection and recovery can be performed. Thus, the dynamic call/connection management can be realized.Many key theories and technologies are being researched now, such as the routing and survivability technology which can ensure the reliable data transmission, the survivability and planning of signaling communication network (SCN), the ASON management technology. These technologies are very important to the further development and application of ASON. This thesis will focus on these issues and give an in-deep research. Firstly a systematic analysis is given on the characteristics of ASON routing. Then many new algorithms and mechanisms are proposed including dynamic weight based traffic balance algorithm, partial risk-disjoint routing algorithm, path protection mechanism in SCN and reliable SCN planning under singnal risk failure etc. During those researches, we developed a distributed experimental system of ASON.This thesis is divided into three parts: (1) the systematic research on ASON routing technologies, including traffic balance and risk-disjoint routing, (2) the research on the performance, survivability and reliable planning of SCN, (3) the research and experimental system of ASON management technology, including the definition of management object and management messages.The main innovations can be summarized as follows:1) Based on current load balance and minimum interference routing technology, a novel dynamic weight based traffic balance algorithm (DW-TB) is proposed. In this algorithm, the link weight is adjusted according to its residual capacity and the connections it carried during path calculating, and the traffic is distributed to several different paths when loading the connections. Simulation results showed that, compared with current dynamic-weight algorithm, routing connections with DW-TB, the block ratio of dynamic traffic can be greatly reduced for more than 30%; while as a penalty, the operation cost will be raised for about 10%.2) A partial risk-disjoint routing algorithm (PRDRA) is proposed based on the current compelte risk-disjoint routing algorithm (CRDRA). In this algorithm, when calculating the protection path, the links which share certain risks with those in the working path are not removed from the available resources directly, but filterd with their availability, and then had their weight adjusted according to both availability and the dimension of their SRLG vector. Simulations results showed that, compared with CRDRA, routing connections with PRDRA can achieve an improvement of 10%-15% in network throughput; while as a penalty, the average reliability declines for about 2%-6%.3) The performance of SCN is analyzed with both theorically calculations and experimental simulations. The path protection technology is suggested to be applied in SCN. Simulations results showed that during the process of setting, maintaining and tearing a connection, SCN with dynamic recovery policy can achieve faster signaling transport and smaller demand on bandwidth; while when certain network elements in SCN go wrong, SCN with path protection policy is superior in the recovery of signaling transport. An SCN planning method is proposed which can ensure all connections to be reovered successfully when one single risk in the network fails.4) Three management objects and corresponding operations are defined, including nodes, links and connections. On this basis, the ASON management messages are defined. The ASON simulation system is designed and developed.