A Comprehensive End-to-End Reliability Design of Optical Networks

The traditional approach of evaluating the availability of a few selected reference connections no longer provides a satisfactory outage representation of modern optical networks because of the large number of node and transport network elements used from end-to-end. The Network Planning and Solutions Center at Bell Labs has established an end-to-end reliability framework and developed a comprehensive assessment methodology and tool to provide a reliability-based optical network design. This methodology provides a comprehensive approach to assess the end-to-end network reliability for networks with any mix of protection schemes, including no protection, 1+1, and shared mesh protection within the same network. This methodology also assesses the reliability of networks with any mixture of node equipment and transport equipment within the same network. The general concept is not restricted to optical network only, but can be applied to all types of telecommunication networks. This paper deals with reliability from a network element and facility perspective. Other reliability issues such as procedural errors, and network operation support can be integrated into the framework, but are topics for separate papers.