Research On Survivability And Routing Technologies In Automatic Switched Optical Network

With the increasing development of optical network and optical technology, next generation optical network which is represented by Automatic Switched Optical Network (ASON) appeared. It can allocate network resource dynamically through the introduction of intelligent network control technology, which can meet the needs of users and operators better. Protection and routing are two vital technologies which greatly impact the performance of optical networks. Meanwhile they are distinct and relative.In this dissertation, our research work focuses on protection and routing technologies in next generation optical network. The protection and routing technologies are presented and we focus on the research of two protection technologies: Shared Risk Link Group (SRLG) path protection algorithm and differentiated protection.SRLG has become a common sense in network failure management, and SRLG-based protection technology can largely reduce the possibility of working path and protection path failing contemporarily to improve the survivability of whole network. By explaining the concept of SRLG and the basic theory of SRLG protection and analyzing the key issues in SRLG protection, A constraint-shortest path first (CSPF) algorithm based on SRLG is presented, into which K backup routes are introduced to dig out potential routing information in the topology as much as possible, so as to obtain the optimal protection resource allocation in the whole network. Meanwhile, dynamical link weight is set for each link to take SRLG constraint and dynamical load balance into account synthetically, and SRLG trap is avoided through eliminating SRLG conflict link and iterative computing. The simulation results show that compared with previously proposed algorithms, the presented algorithm can achieve better performance.Differentiated service is another important concern of intelligent optical network, which can provide an appropriate survivability scheme for the traffic according to their recovery degree. A differentiated protection/restoration scheme in ASON is proposed in terms of recovery time and network capacity efficiency. Some different traffic degrees are defined and the implementation modules of control plane are designed and analyzed. At last, the feasibility of this scheme is tested in testing backbone ASON network of Heilongjiang Province. The testing results show that the network capacity efficiency and income have been improved obviously by using this scheme.