Adaptive polling MAC schemes for IEEE 802.11 wireless LANs

The IEEE 802.11 standard specifies the point coordination function (PCF) in the MAC sublayer for the transfer of real-time traffic, such as voice. The transfer of real-time traffic over wireless LANs is rapidly gaining acceptance, but little work has been done concerning the efficient use of IEEE 802.11 PCF mode to support voice services. In this paper, we propose adaptive polling MAC schemes for IEEE 802.11 PCF. Our proposed schemes reduce the polling overhead significantly, and provide efficient QoS guarantees as other polling protocols do. Our schemes use statistical behaviors of voice traffic sources to increase the performance of PCF mode. We analyze the applicability of our schemes to IEEE 802.11 WLANs and compare them with other related works.