Context-aware quality of service provisioning for real-time multimedia communications

对连续媒体（音频/视频）服务（即IP上的媒体流和多媒体会议）的日益增长的兴趣，加上无线和移动的联网中的技术进步，为服务质量（QoS）提供提出了新的挑战和机遇。例如，数以百万计的在线用户以各种方式连接到互联网，包括高速连接（电缆或ADSL）、调制解调器或无线连接，观看一些体育赛事。对如此大量的连续媒体用户、网络连接异构性以及多媒体应用的不同QoS要求进行分级是重大的挑战。 这些挑战要求新一代的QoS供应，考虑到网络和应用程序的上下文，以提供可接受的QoS。通过在QoS控制过程中结合上下文信息，可以确定质量差的原因并采取最适当的控制措施。在该提议中考虑的上下文信息包括多个方面，包括移动终端的位置、会话用户的数量、应用的QoS要求以及将用户链接到因特网的连接的性质。 实时传输协议（RTP）通常用于在Internet上传输实时多媒体。相关的真实的时间控制协议（RTCP）提供RTP会话中的QoS监控所需的控制和反馈信息。所提出的研究旨在分析RTCP的进一步增强功能，以可扩展和有效的方式将其集成到上下文感知框架中。 这项工作的影响是提供一个全面的定量了解的基本问题，提供上下文感知的QoS。另一个重要的成果是发展的一个可扩展的上下文感知的QoS控制架构的原型实现的全球互联网的21世纪世纪。

The growing interest in continuous media (audio/video) services, namely media streaming and multimedia conferencing over IP, coupled with technological advances in wireless and mobile networking, present new challenges and opportunities for Quality of Service (QoS) provisioning. For example, some sports events are watched by millions of online users connected to the Internet in a variety of ways including high speed connections (Cable or ADSL), modems, or wireless connections. Accommodating such large number of continuous media users, network connection heterogeneity, and the different QoS requirements for multimedia applications represents significant challenges.       These challenges call for a new generation of QoS provisioning that takes into account the network and the application context to provide acceptable QoS. By incorporating contextual information in the QoS control process, it is possible to determine the reason for poor quality and take the most appropriate control action. Context information considered in this proposal include a variety of aspects including the location of a mobile device, the number of session users, the QoS requirements of the application, and the nature of the connection linking the user to the Internet.       The Real-time Transport Protocol (RTP) is commonly used to deliver real-time multimedia over the Internet. The associated Real Time Control Protocol (RTCP) provides control and feedback information necessary for QoS monitoring in RTP sessions. The proposed research aims at analyzing further enhancements to RTCP to integrate it in a context-aware framework in a scalable and effective way.       The impact of this work is to provide a comprehensive quantitative understanding of the fundamental issues involved in providing context-aware QoS. Another important outcome is the development of a prototype implementation of a scalable context-aware QoS control architecture for the global Internet of the 21st century.