<title>Optical protection ring architectures and applications</title>

Abstract

This paper surveys recent progress in optical protection rings with the focus on transparent optical protection rings. Generic requirements and attributes for optical protection rings, different optical protection ring architectures such as dedicated and shared protection rings in both the optical channel layer and the optical multiplex section layer are described. In particular, optical channel shared protection rings are discussed in detail including node architecture designs, ring protocols, triggers and messaging channels. Feasibility studies and experimental results from Corning Incorporated and other companies are reviewed. The paper also discusses how protection switching times scale with number of nodes and number of wavelengths, and shows examples of applications using the scaling rules for practical optical networks such as metro, regional and long haul ring network. Finally, the paper discusses remaining issues and future developments in the optical protection ring area.

Design and analysis of p-cycle-based fault-restorable optical networks with multicast capability

“…SONET and SDH networks are generally deployed as a ring topology [45] due to its high degree of network survivability [46]. There are three choices available for ring based protection [47][48][49][50][51][52][53][54] Because half of the capacity in each fiber is reserved for protection, the redundancy of ring protection approaches is at least 100%. Thus, the drawback of ring protection approaches is the inefficient usage of the expensive bandwidth resources of the network.…”