Optimal design of asynchronous transfer mode local area network - Lagrangian relaxation approach

Abstract

In this thesis, we propose a combined optimization problem of determining optimal locations of switches and interconnections that can be applied to the area of designing Asynchronous Transfer Mode Local Area Network (ATM-LAN) with emphasis on connection-oriented data service. While pure location design problems have received much attention in the past, the combined location and interconnection problem has escaped the existing literature to our knowledge. The suggested optimization model is formulated as a binary integer programming problem and solved using Lagrangian relaxation technique. By solving the problem, overall network topology and capacities of chosen switches/links are determined. In the model, traffic demands between origin-destination node pairs are assumed known. Linear functions are used for modeling both switch and link costs. According to computational results maximum allowable error range was typically 5-9%. Execution time was around 2-3 minutes for the largest sample problem solved. For further research more accurate cost models should be used. Also, routing-based traffic must be taken into account. Meantime, the proposed formulation can be used in designing practical ATM-LANs.