Using IEEE 802.11e MAC for QoS over wireless

We study the behavior of the new MAC protocols for QoS in the proposed IEEE 802.11e draft standard and analyze them for their ability to fulfill their goals of better QoS and higher channel efficiency. We study the response of these mechanisms to various choices in available protocol parameters. We show that HCF reduces channel contention and allows better channel utilization. However, both the proposed MAC coordination functions, EDCF and HCF, are highly sensitive to protocol parameters. We believe that the effectiveness of these functions also depends on the scheduling algorithms. The effects of the various policy choices need to be understood and validated before the draft becomes a standard.