A deadline-aware virtual contention free EDCA scheme for H.264 video over IEEE 802.11e wireless networks
Contention-based access has been the key component for 802.11 wireless networks. As the video service is becoming more popular, contention-based access has been the key limiting factor in providing satisfactory quality-of-service (QoS) for video over wireless networks, especially when the data traffic includes both real-time video and other types of traffics. A contention free burst (CFB) scheme has been developed recently [1], would result in improved video QoS, but at the expenses of best effort and background traffics. In this paper, we proposed a deadline-aware virtual contention free (DVCF) scheme for H.264 video over 802.11e wireless networks. The main contribution of this paper is to jointly consider the characteristic of video source, 802.11e protocol, and network specifications by adjusting the parameters of 802.11e protocol. As a result, the proposed scheme (DVCF EDCA) maintains the transmission of all types of traffics provided that the deadline of transported video packets can be strictly observed. In this framework, the deadline of each video packet is estimated first as in [2]. The estimated deadline serves dual purpose: one is to guarantee the transmission of any given video packet before it expires and another one is to allow other types of data traffic to transmit when there is no pressing needs to transmit any video packet. Simulation results show that the proposed framework achieves virtually no loss for video packets and noticeable improvement in combined throughput of video and non-video traffics.