Distributed self-healing network and its optimum spare-capacity assignment algorithm

Abstract

Rapid self-healing under link failure in high-capacity optical fiber is a basic issue in broadband networks. Failure restoration schemes are being studied which reroute failed paths using the control of path reconfiguration function of the Digital Cross Connect System (DCS). Distributed control schemes based on a flooding algorithm have been proposed to meet real-time requirements for large-scale transmission networks, but problems arise, such as message congestion at nodes and internode synchronization. The performance of the self-healing algorithm depends not only on the algorithm itself but also on physical network topology and spare capacity. In this paper, we propose a distributed restoration algorithm using a flooding technique and a centralized spare-capacity assignment algorithm minimizing total spare capacity in a network while meeting a given survivability objective. The failure restoration time, restoration ratio, and spare capacity cost of these algorithms will be evaluated by computer simulation.