Multicasting, Multiplexing, and Resource Allocation for Real-Time Communication in High-Speed Networks

摘要

This grant was awarded under the AASERT program (Augmentation Awards for Science and Engineering Research Training). The funding supported students conducting research in dynamic control of quality of service, and multicast routing for delay-constrained applications. In general, our investigation is on how to provide Quality of Service in the Internet, using either ATM or IP technology. Quality of service means low packet delays, low delay jitter, and low packet losses. Examples of applications which require QoS include voice and video transmission, real-time data acquisition, distributed control, distributed interactive simulation, and others. We believe our ideas offers significant advantages in ease of use, and efficiency. The issues of efficiency and flexibility are especially important for wireless networks, where bandwidth is in limited supply, and the network conditions change frequently and rapidly. We have worked on a number of protocol issues: multicasting, unicast routing, admission control, packet multiplexing, and resource allocation. The specific goals of the research supported by this grant included: (1) Demonstrate that dynamic resource allocation results in excellent quality of service (QoS) and dramatically higher bandwidth utilization for real-time traffic. Solve the practical implementation issues, and provide a firmer theoretical basis for its usage. Issues to be addressed include the feedback-delay problem that all dynamic control systems must overcome, system stability, and QoS apportionment to individual hops in a path (e.g., how to divide an end-to-end delay bound into smaller per-hop delay bounds). (2) Develop improved methods for routing of real- time data. This includes unicast, multicast, and broadcast routing algorithms that incorporate delay bounds. Investigate the potential for hierarchical multicast routing, and dynamic tree construction.