Optimum Parameters for VoIP in IEEE 802.11e Wireless LAN

摘要

IEEE 802.1 le is an enhanced standard in wireless LAN which has QoS mechanisms, EDCA and HCCA. This paper analyzes the performance of IEEE 802.11e EDCA functions through working testbeds and a large-scale simulation.EDCA has three parameters: AIFS, CW and TXOP to differentiate packets. This paper shows the effectiveness of EDCA by simple experiments. Then, we try to find the optimum values for EDCA parameters. It is interesting that default parameter values do not ensure good communication quality for VoIP communications.This paper also illustrates the results of a simulation which covering a large number of nodes. Again, it is shown that the default values are not ideal for VoIP communications on a larger scale.The results of this paper are meaningful when VoIP communications have priority over other traffic in a wireless LAN environment.