An improved lightpath allocation for grade of services in survivable WDM mesh networks

A large optical network may carry multiple traffic with different grade of services. Several previous papers suggest a preemptive multi-class routing scheme: (1) low grade of services’ primary path can share resources with high grade of services’ backup path; (2) low grade of services can be preempted by high grade of services in case of a failure. However, they just optimize the network resources without considering the high grade of services’ failure state. In this paper, we propose an improved lightpath allocation for grade of services to implement in single-link failure WDM mesh networks. The main advantages are to consider Grade 3 (the highest level) lightpath’s failure state when a link fault happens and to make the best of Grade 1(the lowest level) lightpaths working resources as the backup resources of Grade 3 lightpaths. Compared to the previous work, it can obtain better performances in resource utilization ratio, lightpath establishment and the number of average interrupted lightpaths.