Solving SONET problems using a hybrid scatter search algorithm

Abstract

Nowadays the Synchronous Optical NETworking (SONET) standard is widely used in telecommunications. In this paper we consider three problems that arise in SONET networks: (1) Weighted Ring Edge-Loading Problem (WRELP), (2) SONET Ring Assignment Problem (SRAP) and, (3) Intraring Synchronous Optical Network Design Problem (IDP), known to be NP-hard. WRELP asks for a routing scheme such that the maximum load on the edges of a ring will be minimum. In SRAP the objective is to minimise the number of rings (i.e., DXCs). In IDP the objective is to minimise the number of ADMs. The last two problems are subject to a ring capacity constraint. We study these three problems without demand splitting and for solving them we propose a Hybrid Scatter Search (HSS) algorithm. Coupled with the Scatter Search algorithm, we use a Tabu Search algorithm to locate the global minimum. We show that HSS is able to achieve feasible solutions, improving the results obtained by previous approaches. © 2012 Springer-Verlag GmbH Berlin Heidelberg.