Feng Li, Jae Chung, Mingzhe Li, Huahui Wu, Mark Claypool, and Robert Kinicki
The growth of wireless LANs has brought the expectation for high-bitrate streaming video to wireless PCs. However, it remains unknown how to best adapt video to wireless channel characteristics as they degrade. This paper presents results from experiments that stream commercial video over a wireless campus network and analyze performance across application, network and wireless link layers. Some of the key findings include: 1) Wireless LANs make it difficult for streaming video to gracefully degrade as network performance decreases; 2) Video streams with multiple encoding levels can more readily adapt to degraded wireless network conditions than can clips with a single encoding level; 3) Under degraded wireless network conditions, TCP streaming can provide higher video frame rates than can UDP streaming, but TCP streaming will often result in significantly longer playout durations than will UDP streaming; 4) Current techniques used by streaming media systems to determine effective capacity over wireless LAN are inadequate, resulting in streaming target bitrates significantly higher than can be effectively supported by the wireless network.
Mingzhe Li, Choong-Soo Lee, Emmanuel Agu, Mark Claypool, and Robert Kinicki. Performance Enhancement of TFRC in Wireless Ad Hoc Networks, In Proceedings of the 10th International Conference on Distributed Multimedia Systems (DMS), San Francisco, California, September 2004. Online at: http://www.cs.wpi.edu/~claypool/papers/re-tfrc/
James Nichols, Mark Claypool, Robert Kinicki and Mingzhe Li. Measurements of the Congestion Responsiveness of Windows Streaming Media, In Proceedings of the 14th ACM International Workshop on Network and Operating Systems Support for Digital Audio and Video (NOSSDAV), Kinsale, County Cork, Ireland, June 16-18, 2004. Online at: http://www.cs.wpi.edu/~claypool/papers/wsm/
This material is based upon work supported by the National Science Foundation under Grant Number CNS-0423362. Any opinions, findings and conclusions or recomendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).