Scheduling MPEG-4 video streams through the 802.11e enhanced distributed channel access

Abstract

The upcoming IEEE 802.11e standard improves the Medium Access Control (MAC) of the legacy 802.11 with regard to Quality of Service (QoS) by introducing the Enhanced Distributed Channel Access (EDCA) and the HCF Controlled Channel Access (HCCA). EDCA achieves QoS by providing independent transmit queues and MAC parameters for each traffic class, and hence higher prioritized traffic has a higher probability for transmission. Crucial to the success of such a strategy is a scheduler that assigns the data traffic to the respective transmit queues. This paper develops and accommodates a new dynamic scheduler for EDCA into the MPEG-4 Delivery Framework. Experiments prove that the new scheduling policy timely delivers up to 50% more frames than statical scheduling solutions. To the best of our knowledge this is one of very few scheduling approaches that considers MPEG-4 related traffic priorization in EDCA. © Springer-Verlag Berlin Heidelberg 2005.