Abstract

In the past, networks are traditionally designed with ring protection and (1+1) dedicated protection as they provide the best reliability for the networks. However, with the need to reduce capital expenditure and the demand for more efficient usage of resources for protection while keeping the availability similar to the ring networks, network designers need to have the capability to assess the end-to-end reliability of various design options in order to make intelligent and economical decision on network selection. One way to achieve this is to implement shared protection instead of using dedicated (1+1) or ring protection. However, designers understand that there will be sacrifices in the reliability levels in doing so, but there has not been a systematic methodology of quantifying the reliability of networks with shared protections.

This paper introduces a new framework for a reliability-based optical network design. This framework integrates the end-to-end reliability assessment of the network, which used to be conducted at the end stage of network design, into the network design process. A new hybrid analytical and simulation methodology has been developed to quantify the reliability of various network elements and protection schemes and generate a network reliability profile. This network reliability profile provides valuable information for network designers, planners and service providers to implement their design more economically, via the use of various protection, while maintaining an acceptable level of reliability. This paper illustrates two of the many benefits provided by this approach: (1) the use of the reliability profile to compare an actual provider optical backbone network with different protection schemes; (2) the use of the network reliability profile to identify and redesign the vulnerable and failing demand pairs.

© 2005 Optical Society of America