On Efficient Multipolling with Various Service Intervals for IEEE 802.11e WLANs

Abstract

Hybrid coordination function (HCF) is proposed in IEEE 802.11e standard to support quality of service (QoS). HCF defines two channel access mechanisms; one of them is HCF controlled channel access (HCCA) designed for contention free transmission. In HCCA, each QoS-enhanced station (QSTA) obtains polled transmission opportunity (TXOP) from the hybrid coordinator (HC), which is in charge of scheduling the channel access and responding the poll messages to each QSTA. However, forwarding polling messages causes a significant overhead and degrades the channel utilization of data transmission. The goal of this work is to develop an efficient multipolling scheme that can reduce the overhead of polling messages. The simulation results show that the proposed algorithm can reduce the control overhead and, thus, improve the channel utilization significantly.