Impact Zone Analysis of p-Cycle

TL;DR

This paper analyzes how the impact zone of a p-cycle in optical networks affects protection after failures, proposing methods to optimize p-cycle configurations for better fault tolerance with minimal spare capacity.

Contribution

It introduces impact zone analysis for p-cycles and proposes methods to optimize p-cycle configurations to enhance fault tolerance while minimizing spare capacity.

Findings

Impact zone analysis helps in understanding protection loss after failures.

Optimized p-cycle configurations can reduce the impact zone.

Proposed methods improve fault tolerance with minimal spare capacity.

Abstract

Pre-configured cycle (p-Cycle) method has been studied in literature extensively for optical network protection. A large p-cycle has high capacity efficiency and can protect a large number of nodes against the single link failure scenarios. All the links protected by such a p-cycle lose protection when the p-cycle is consumed to restore traffic after a failure. As the probability of multiple link failure is high for a large network, it also means that with higher probability, on the second failure, protection may not be there for the failed link. Thus, if the number of links protected by a p-cycle is large, it makes the network unprotected with high probability on the advent of the second failure. In this paper, we study the impact zone due to a first link failure in the various configurations of the p-cycles. The study gives insight into how to choose the p-cycle configuration to reduce the impact zone while using minimum spare capacity. We propose few methods and compare them to show how the impact zone analysis can be used to improve the fault tolerance in an optical network.