Design of layered networks for communication and supply chain networks

Abstract

This thesis considers layered network design problems for communication and supply chain networks, where the main decision problem is to determine the set of logical tunnels to be established and the logical paths, through which any given demands should be routed. The problems are described in mathematical expressions, for which solution algorithms are developed in the integer programming approaches. In Chapter 2 and Chapter 3, layered communication network design problems for ATM networks and virtual private networks (VPN’s) are considered. Chapter 4 considers a layered supply chain network design problem for cross-docking networks. Specifically, Chapter 2 considers a combined problem of establishing virtual paths (VP’s) and routing traffic (packet) demands through the virtual paths in ATM networks where each physical link is subject to its capacity constraints. The problem is modeled as a path-based formulation for which a branch-and-price solution algorithm is derived. The solution algorithm is composed of an efficient pricing algorithm and branching rules based on a variable dichotomy which does not destroy the structure of the associated pricing problems. Computational experiments are performed to test the efficiency of the algorithm, which show that the proposed solution algorithm works quite well in finding optimal solutions (for the test instances) within reasonable time. Its immediate application may be made to a centralized ATM network management on mid-term global reconfiguration and long-term VP planning. Chapter 3 considers a VPN tunnel design problem of establishing VPN tunnels between nodes subject to a VPN tunnel hop count restriction. The relationship between the VPN tunnel design problem and the minimum-cost directed Steiner tree problem is investigated in detail. The problem is modeled as a layered network flow model for which the exact solution is derived based on the path-based branch-and-price methodology with a preprocessing technique in...