Multimedia Communication in Wide-Area Networks

小行星9508274 广域网对多媒体应用提出了新的通信相关的挑战，因为分组丢失、更长的延迟和更大的用户群成为重要因素。虽然新兴的ATM网络提供支持这样的多媒体应用的通信服务，今天的互联网络的环境和遗产使端到端的ATM连接在两个终端主机之间在可预见的未来是不可能的。 在这个项目中的研究是一个及时的和重要的一步，在开发网络基础设施，需要支持实时多媒体应用。 该建议包括一个混合的理论和实验研究，旨在设计和评估可扩展的服务，以支持在广域网或互联网中的实时多媒体应用。具体来说，研究人员将：1）开发和评估面向接收方的方法，提供可扩展的可靠组播服务。基本问题是理解如何在发送者和接收者之间分配协议功能，如何使用多播来提供可靠的多播，以及如何在错误恢复协议中使用特定于应用的语义信息;以及2）开发和评估端主机机制，例如播出调整 算法和特殊用途的错误恢复协议，用于提高几种不同的实时应用程序所获得的服务质量。 研究人员将利用组件应用程序的特定于应用程序的信息-在这种情况下，它们的不同的时间约束。 *** ******* Darleen Fisher项目经理网络和通信研究项目4201 Wilson Blvd.地址：弗吉尼亚州阿灵顿1175室，邮编：22230 (703)306-1949（703）306-0621（传真）

9508274 Towsley Wide-area networks pose new communication-related challenges for multimedia applications as packet loss, longer delays, and larger user populations become important factors. While emerging ATM networks provide communication services for supporting such multimedia applications today's internetworked environment and legacy make end-to-end ATM connectivity between two end hosts unlikely in the foreseeable future. Research in this project represents a timely and important step in developing the network infrastructure needed to support real-time multimedia applications. This proposal includes a mix of theoretical and experimental research aimed at the design and evaluation of scalable services for supporting real-time multimedia applications in a wide-area network or internetwork. Specifically, the researchers will: 1) develop and evaluate receiver-oriented approaches for providing scalable reliable multicast services. The fundamental concerns are to understand how to allocate protocol functionality among the sender and receivers, how to use multicast to provide reliable multicast, and how to use application-specific semantic information in error recovery protocols; and 2) develop and evaluate end host mechanisms, such as playout adjustment algorithms and special-purpose error-recovery protocols, for enhancing the quality of service attained by several different real-time applications. The researchers will exploit application-specific information about the component applications - in this case their different timing constraints. *** ******* Darleen Fisher Program Manager Networking and Communications Research Program 4201 Wilson Blvd. Room 1175 Arlington Va 22230 (703) 306-1949 (703) 306-0621 (FAX)