Packet-based Polling Scheme for Video Transmission in IEEE 802.11e WLANs

IEEE 802.11e standard introduces HCF Controlled Channel Access (HCCA) to support quality of service (QoS) for multimedia traffics. In HCCA, the traffics scheduled according to their mean characteristics which favors the Constant Bit Rate (CBR) trans- mission approach. However, it does not efficiently cope with the fluctuation of the Variable Bit Rate (VBR) video streams where the traffic shows deviation from its mean during the traffic lifetime. In this paper, we propose a packet based polling mechanism to enhance the scheduling of pre-recorded VBR video streams in HCCA function. Our approach exploits feedback information about the arrival time of the subsequent video frame obtained through cross-layering approach to accurately schedule the uplink traffics. Simulation experiments reveal the efficiency of the proposed mechanism in providing less delay and high throughput while maintaining medium channel.