Integrating optical transport quality, availability, and cost through reliability-based optical network design

Abstract

The design of the optical transport network (OTN) must meet the challenges of providing a high capacity, highly dependable and reliable network and the flexibility in bandwidth management to support multi-services in a cost-effective manner. The core objective of the OTN design activity focuses on carefully balancing these design objectives. This paper presents a comprehensive design approach that integrates the OTN design with its end-to-end reliability assessment. Quantitative reliability assessment becomes an integral part of the OTN design process when considering network survivability using various protection and restoration schemes. This value-based reliability approach provides a complete set of network reliability profiles. These profiles provide a means to: 1) drive network architecture and infrastructure design by identifying both strong and vulnerable region(s); 2) provide reliability/availability cost and worth (benefit) tradeoff by quantifying the impact of various network elements and/or protection schemes; and 3) allow design of reliability-based revenue offers or service level agreements (SLAs). We will illustrate the application and benefits of using OTN reliability-based design processes in several service provider networks featuring synchronous optical network/synchronous digital hierarchy (SONET/SDH) ring and dense wavelength division multiplexing (DWDM) mesh architectures including dedicated and shared protection/restoration schemes in backbones and in metropolitan networks.