6th International ICST Symposium on Modeling and Optimization

Research Article

Access Point Assignment Algorithms in WLANs Based on Throughput Objectives

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  • @INPROCEEDINGS{10.4108/ICST.WIOPT2008.3054,
        author={Ioannis Koukoutsidis and Vasilios A. Siris},
        title={Access Point Assignment Algorithms in WLANs Based on Throughput Objectives},
        proceedings={6th International ICST Symposium on Modeling and Optimization},
        keywords={WLAN 802.11 access point assignment throughput optimization branch-and-bound algorithms},
  • Ioannis Koukoutsidis
    Vasilios A. Siris
    Year: 2008
    Access Point Assignment Algorithms in WLANs Based on Throughput Objectives
    DOI: 10.4108/ICST.WIOPT2008.3054
Ioannis Koukoutsidis1,*, Vasilios A. Siris2,*
  • 1: Dept. Informatics and Telecommunications, National & Kapodistrian University of Athens, Ilissia, 157 84 Athens, Greece.
  • 2: Foundation for Research and Technology - Hellas, Institute of Computer Science (FORTH-ICS), University of Crete P.O. Box 1385, 711 10 Heraklion Crete, Greece.
*Contact email: I.Koukoutsidis@di.uoa.grol, vsiris@ics.forth.gr


In this article we present branch-and-bound algorithms for the access point assignment problem in WLANs, when the objective function is based on the throughput of stations in the network. We consider: a) maximizing the aggregate throughput, b) achieving lexicographically max-min fair throughputs, c) achieving proportionally fair throughputs. The performance of all branch-and-bound algorithms is examined for various degrees of approximation. Thus we show trade-offs between the increased cost of exploration and improvement in the objective value. We further compare their performance to that of greedy algorithms, embedded as a depth-first-search in the branchand- bound methods. An omnipresent result is the near-optimal performance of the greedy algorithms, which is particularly important when considering their practical application. In all cases, the performance of the algorithms improves as the distribution of wireless stations becomes more concentrated in areas of the network, as in hotspot topologies.