Performance Enhancement of WLAN IEEE 802.11 for Asymmetric Traffic

Conference: PIMRC 2005 - 16th Annual IEEE International Symposium on Personal Indoor and Mobile Radio Communications
09/11/2005 - 09/14/2005 at Berlin, Germany

Proceedings: PIMRC 2005

Pages: 5Language: englishTyp: PDF

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Lopez-Aguilera, Elena; Casademont, Jordi; Cotrina, Josep; Rojas,Alfonso (Wireless Networks Group - Telematics Department, Technical University of Catalonia, Mod. C3 Campus Nord, c/ Jordi Girona 1-3, 08034 Barcelona, Spain)

Most studies about the performance of IEEE 802.11 consider scenarios of ad-hoc topology and networks where all stations have the same traffic load (symmetric traffic conditions). This paper presents a study of performance parameters of more realistic networks. We focus the attention on WLAN with infrastructure networks, where the traffic distribution is asymmetric. In this case, the traffic load at the Access Point is much heavier than that at user stations. These studies are more realistic because most nowadays installed WLAN are infrastructure topology type, due to the fact that they are used as access networks. In this case, the Access Point has to retransmit all incoming traffic to the Basic Service Set and therefore its traffic load is higher. Finally, the paper presents the tuning of the Contention Window, taken from IEEE 802.11e, used to increase the system performance under asymmetric traffic conditions, and the proposal of an adaptive algorithm to adapt the MAC layer settings to the system traffic load.