Maintenance Activities, Operations and Environment Conditions Impact on the Availability of Highly Reliable Optical Transport Networks

The primary objective of this paper is to apply a new framework for integrated reliability based network design to actual highly reliable network architectures (4-fiber BLSR/DWDM architecture and (1+1) DWDM mesh architecture) using a hybrid technique that combines both analytical and simulation methods. This approach provides a comprehensive means to model and quantify the impacts of various network elements, operating conditions and protection schemes on the optical network availability and reliability. The network elements are modeled based to their actual configurations. Multiple ring and mesh network designs solutions are generated and their end-to-end reliability calculated. We then concern ourselves with the environmental effects by varying the rate of possible fiber cuts on the fiber links. In addition, we increase the frequency of fiber cuts when there is lack of route diversity. Network maintenance and operations practices effects on the networks availabilities are introduced via the variation of the frequency and duration of the span/link switching outages. We increase span/link switching outages when maintenance activities on the network links and nodes are intensified and more frequently required. We analyze, evaluate, and compare the impact of the environment (fiber cuts), the networks operation conditions (span/link switching) and the maintenance (duration of span/link switching) on the availabilities of these highly reliable networks and their economics