Study On The Survivability Of Mesh Optical Network

Recent years, with the increase of wavelength channels multiplexed in the optical network, as well as the growth of the transmission rate in a single-wavelength channel, the transmission capacity of optical network is expanding dramatically. In such kind of super high-rate and large-capacity optical network, once the service damaged by network failures can not be recovered immediately, the huge economic loss and severe social consequence will be caused. Hence, the survivability of optical networks now has become an important issue which is focused on by more and more people.The technique of survivability in mesh optical network is studied in this thesis and the path design algorithms adopted in the recovery technique are emphasized. The diverse fiber physical routing algorithm for multiple fibers optical network is used for reference. Based on the idea of the algorithm, two types of routing strategies are used to realize the algorithm. Moreover, the NSFNET is taken as the simulation network. Simulation results show that this algorithm can calculate two or more route which is diverse in the fiber physical topology. One route can be used for the work path, while the other routes can be used for the protection path.However, the simulation results also show that the diverse fiber physical routing algorithm for multiple fibers optical network will calculate the protection paths for the entire work path which is diverse in the fiber physical topology. In the actually application case, it is always not necessary to do that, especially when the protection paths are shared by some ring optical networks. It may waste some network resource. Therefore, the Share Risk Link Groups (SRLG) is adopted in this thesis and those links which are shared by the ring network is defined as the SRLG. The improved algorithm will separate the work paths and protection paths which belong to the SRLG while other paths could share some links. Simulation results show that the improved algorithm can reduce the possession of the ring optical network and improve the choice flexibly of work path and protection path.