An Adaptive Polling Scheme to Improve Voice Transmission over Wireless LANs

Motivated by the promising voice over IP technology, and the wide availability of WLANs, the application of Voice over WLAN (VoWLAN) is expected to encounter dramatic growth in the near future. IEEE 802.11e standard was established to achieve a high level QoS, it introduced a new medium access mechanism HCF in order to solve the QoS provisioning problem in the legacy IEEE 802.11. In this work we propose an adaptive polling scheme, which works on the HC side in HCCA mode, in which HC maintains two dynamic polling lists to reduce both access delay and polling overhead. Both VBR and CBR traffic are taken into consideration. Simulation results showed that the polling overhead is reduced significantly, in addition to high throughout and low access delay comparing to the classical Round-Robin polling scheme and the reference scheme in the standard.