An Experimental Investigation of the Effects of Contention on Video Streaming Applications over IEEE 802.11b WLAN Networks (original) (raw)

The bursty nature of video streaming applications is due to the frame-based structure of video and this has an important impact on the resource requirements of the WLAN, affecting its ability to provide Quality of Service (QoS) particularly under heavily loaded conditions. For video streaming applications, packet loss and packets dropped due to excessive delay are the primary factors that affect the received video quality. In this paper, we analyse the effects of contention on the performance and behaviour of video streaming applications over IEEE 802.11b WLANs. We show that as contention levels increase, the packet delay increases significantly, despite the total offered load in the network remaining the same. The increased delay is shown to be related to the MAC mechanism used in the IEEE 802.11 standard. We also show that the characteristics of the video content significantly affect the degree to which the stream is affected by contention.