Delay analysis of Admission Control mechanism for supporting QoS in 802.11e

IEEE 802.11e standard is developed for QoS provisioning in WLANs. Admission Control is a mechanism that controls stations to be served in WLANs. In practice, evaluation of admission control plays an important role for QoS support. The goal of this paper is to calculate the WLAN delays with ACs. The delay calculation can be used to guarantee the QoS of the VoIP and video streams, which is divided into three parts. One is the propagation delay. Another is that packets queue up in stations or APs. Lastly, the delay is taken due to collisions. For VoIP and video streams, the second delay is more important than other two delays. Consequently, we will focus on the calculation of the second delay. Some simulations and numerical results are provided and discussed in detail. Experimental results show that the proposed method is more accurate in calculating the delay of packets in WLANs.