This research was supported in part by DARPA contracts/grants N66001-97-C-85222, N66001-97-C-8523, and F19628-95-C- 0193, and by Tektronix, Inc., and Intel Corporation.
Computer network architectures, Multimedia systems, Telecommunication -- Traffic -- Management, Adaptive computing systems, Computer networks -- Scalability
Applications with real-rate progress requirements, such as mediastreaming systems, are difficult to deploy in shared heterogenous environments such as the Internet. On the Internet, mediastreaming systems must be capable of trading off resource requirements against the quality of the media streams they deliver, in order to match wide-ranging dynamic variations in bandwidth between servers and clients. Since quality requirements tend to be user- and task-specific, mechanisms for capturing quality of service requirements and mapping them to appropriate resource-level adaptation policies are required. In this paper, we describe a general approach for automatically mapping user-level quality of service specifications onto resource consumption scaling policies. Quality of service specifications are given through utility functions, and priority packet dropping for layered media streams is the resource scaling technique. The approach emphasizes simple mechanisms, yet facilitates fine-grained policy-driven adaptation over a wide-range of bandwidth levels. We demonstrate the approach in a streamingvideo player that supports user-tailorable quality adaptation policies both for matching its resource consumption requirements to the capabilities of heterogeneous clients, and for responding to dynamic variations in system and network load.
"QoS Scalability for Streamed Media Delivery," Charles Krasic and Jonathan Walpole, Oregon Graduate Institute School of Science & Engineering Technical Report CSE-99-011, September, 1999.