Célio Albuquerque and Tatsuya Suda. University of California, Irvine. Brett J. Vickers. Rutgers University.

In an era of proliferating multimedia applications, support for video transmission is rapidly becoming a basic requirement of network architectures. Furthermore, since most video applications (e.g., teleconferencing, television broadcast, video surveillance) are inherently multicast in nature, support for point-to-point video communication is not sufficient. Unfortunately, multicast video transport is severely complicated by variation in the amount of bandwidth available throughout the network.

A scalable solution to the problem of available bandwidth variation is to use multi-layered video. A multi-layered video encoder encodes raw video data into one or more streams, or layers, of differing priority. The layer with the highest priority, called the base layer, contains the most important portions of the video stream. One or more enhancement layers with progressively lower priorities may then be encoded to further refine the quality of the base layer stream.

However, multi-layered video is not by itself sufficient to provide ideal network bandwidth utilization or video quality. To improve the bandwidth utilization of the network and optimize the quality of video received by each of the destinations, the source must respond to constantly changing network conditions by dynamically adjusting the number of video layers it generates as well as the rate at which each layer is transmitted. For the source to do this, it must have congestion feedback from the destinations and the network.

In our research, we have introduced and studied several novel feedback mechanisms for the transport of adaptively encoded, multi-layered video.

[To view or print some of the following papers, you will need to download Adobe Acrobat Reader.]

	"Source-Adaptive Multi-Layered Multicast Algorithms for Real-Time Video Distribution"
	By Brett J. Vickers, Célio Albuquerque and Tatsuya Suda, submitted to IEEE/ACM Transactions on Networking, 1999.
	"Credit-Based Source-Adaptive Multi-Layered Video Multicast"
	By Célio Albuquerque, Brett J. Vickers and Tatsuya Suda, to appear in a forthcoming issue of the Performance Evaluation Journal, 1999.
	"Adaptive Multicast of Multi-Layered Video: Rate-Based and Credit-Based Approaches"
	By Brett J. Vickers, Célio Albuquerque, and Tatsuya Suda. This paper studies the tradeoffs between two novel feedback-based congestion control mechanisms for the multicast of multi-layered video. Both mechanisms allow for an arbitrary number of video layers. In Proc. of IEEE Infocom '98, San Francisco, March 1988.
	"An End-to-End Source-Adaptive Multi-layered Multicast (SAMM) Algorithm"
	By Célio Albuquerque, Brett J. Vickers, and Tatsuya Suda. In Proc. 9th International Packet Video Workshop, New York, April 1999.
	"Multicast Flow Control with Explicit Rate Feedback for Adaptive Real-Time Video Services"
	By Célio Albuquerque, Brett J. Vickers and Tatsuya Suda, In Proc. of SPIE's 1998 Performance and Control of Network Systems II, November 1998.
	"Feedback Control Mechanisms for Real-Time Multipoint Video Services"
	By Brett J. Vickers, Meejeong Lee, and Tatsuya Suda. This paper presents two feedback mechanisms for the multicast of two-layer video to a large number of destinations. Appeared in the IEEE Journal on Selected Areas in Communications, vol. 15, no. 3, pp. 512-530, April 1997.
	"An ATM Service Architecture for the Transport of Adaptively Encoded Live Video"
	By Brett J. Vickers and Tatsuya Suda. (Postscript format.) This paper deals with feedback controlled point-to-point video in ATM networks and its interaction with feedback-controlled ABR data. Appeared at ICCCN '96, Oct. 1996. Computer Communications Journal.
	Back to Netgroup's Current Projects