The optimal positioning of switches in a mobile communication network is an important task, which can save costs and improve the performance of the network. In this paper we propose a model for establishing which are the best nodes of the network for allocating the available switches, and several hybrid genetic algorithms to solve the problem. The proposed model is based on the so-called capacitated p-median problem, which have been previously tackled in the literature. This problem can be split in two subproblems: the selection of the best set of switches, and a terminal assignment problem to evaluate each selection of switches. The hybrid genetic algorithms for solving the problem are formed by a conventional genetic algorithm, with a restricted search, and several local search heuristics. In this work we also develop novel heuristics for solving the terminal assignment problem in a fast and accurate way. Finally, we show that our novel approaches, hybridized with the genetic algorithm, outperform existing algorithms in the literature for the p-median problem. © 2007 Elsevier B.V. All rights reserved.
Bibliographical noteThe authors would like to thank anonymous reviewers for their interesting comments and suggestions to improve the paper. This work has been partially supported by a Universidad de Alcalá project number UAH-PI2005/078. X. Yao's work has been partially supported by a National Natural Science Foundation of China grant, number 60428202.
- Hybrid genetic algorithms
- Switch location problem
- Wireless communications networks