on the performance of ieee 802.11 qos mechanisms under spectrum competition
WLANs based on IEEE 802.11 are becoming more and more popular both in commercial and residential settings. However, the very success of 802.11 may become a threat to the technology itself. Since there are only a limited number of non-overlapping channels available in the IEEE 802.11 WLAN standards, this can lead to interference among WLANs in dense areas. In this paper, we investigate the effects of interference on WLANs when they operate in DCF, PCF, and EDCA modes in order to support QoS sensitive traffic, such as Voice over IP (VoIP). The results show that DCF, PCF, and EDCA will suffer considerably under these conditions and will not be able to provide good support for real-time applications. From our results, we can infer that the polling mechanism with centralized control on which the 802.11e standard is based will not be a suitable access control mechanism under spectrum competition. Thus, there is a need to change the current technical direction of QoS support in WLANs for future dense deployments.
wireless lan computer network performance