Sub-Graph p-cycle formation for span failures in all-Optical Networks

TL;DR

This paper proposes a sub-graphing approach to optimize p-cycle formation for protecting all links in large optical networks, significantly improving computational efficiency with minimal spare capacity increase.

Contribution

It introduces a novel sub-graphing method to efficiently optimize p-cycle protection in large networks, addressing scalability issues of traditional ILP approaches.

Findings

Enhanced computational efficiency for large networks

Marginal increase in spare capacity required

Effective protection against multiple link failures

Abstract

p-Cycles offer ring-like switching speed and mesh-like spare capacity efficiency for protecting network against link failures. This makes them extremely efficient and effective protection technique. p-Cycles can also protect all the links in a network against simultaneous failures of multiple links. But it has been mostly studied for single link failure scenarios in the networks with the objective to minimize spare capacity under the condition of100% restorability. For large networks, use of p-cycles is difficult because their optimization requires an excessive amount of time as the number of variables in the corresponding Integer Linear Program (ILP) increase with the increase in the network size. In a real-time network situation,setting up a highly efficient protection in a short time is essential.Thus, we introduce a network sub-graphing approach, in which a network is segmented into smaller parts based on certain network attributes. Then, an optimal solution is found for each sub-graph. Finally, the solutions for all the sub-graphs is combined to get a sub-optimal solution for the whole network. We achieved better computational efficiency at the expense of marginal spare capacity increases with this approach.