Survivability in Hierarchical Telecommunications Networks Under Dual Homing

• Published in: INFORMS journal on computing Vol. 26; no. 1; pp. 1 - 15
• Main Authors: Karaan, Oya Ekin, Mahjoub, A. Ridha, Ozkok, Onur, Yarnan, Hande
• Format: Journal Article
• Language: English
• Published: Linthicum INFORMS 01.01.2014; Institute for Operations Research and the Management Sciences; Institute for Operations Research and the Management Sciences (INFORMS)
• Subjects: Algorithms; branch and cut; Communications networks; Computer Science; Digital multiplexing; dual-homing survivability; facets; hierarchical network design; Integer programming; Mathematical models; Methods; Multichannel communication; Multiplexing; Optical communications; Studies; Telecommunication systems; two-edge connectedness; variable fixing; two-edge connectedness; hierarchical network design; variable fixing; branch and cut; dual-homing survivability; facets
• ISSN: 1091-9856; 1526-5528; 1091-9856
• DOI: 10.1287/ijoc.1120.0541

The motivation behind this study is the essential need for survivability in the telecommunications networks. An optical signal should find its destination even if the network experiences an occasional fiber cut. We consider the design of a two-level survivable telecommunications network. Terminals compiling the access layer communicate through hubs forming the backbone layer. To hedge against single link failures in the network, we require the backbone subgraph to be two-edge connected and the terminal nodes to connect to the backbone layer in a dual-homed fashion, i.e., at two distinct hubs. The underlying design problem partitions a given set of nodes into hubs and terminals, chooses a set of connections between the hubs such that the resulting backbone network is two-edge connected, and for each terminal chooses two hubs to provide the dual-homing backbone access. All of these decisions are jointly made based on some cost considerations. We give alternative formulations using cut inequalities, compare these formulations, provide a polyhedral analysis of the small-sized formulation, describe valid inequalities, study the associated separation problems, and design variable fixing rules. All of these findings are then utilized in devising an efficient branch-and-cut algorithm to solve this network design problem.