Rate-Based Flow Control Algorithms for High Speed Networks

In this project a new control-theoretic framework will be developed for rate-based robust ow controller design for high speed networks, and the algorithms derived from this framework will be adapted for implementation in ATM networks and in the Internet. For this purpose the PIs will collaborate to investigate speciic issues arising in their areas of expertise: ATM and Internet ow control, and robust control of innnite dimensional systems. The mathematical models to be considered in this project are systems with time-varying time-delays. For this class of systems, controller design methods will be developed by i n vestigating several diierent approaches from H 1 control,-synthesis, gain scheduling for linear parameter varying systems, and Lyapunov stability theory. In particular, existing gain scheduling techniques for nite dimensional linear parameter varying systems will be extended to time delay systems. Controllers derived in this framework will be validated by comparing them with the existing controllers designed for ATM traac management. New ow controllers will also be implemented and tested experimentally. First they will be translated into algorithms to be implemented at the network-layer switches and routers within the scope of existing standards. Both connection-oriented networks e.g. ATM networks and connectionless networks e.g. IP based Internet will be considered in the project. Towards this goal, new techniques will be developed to translate rate-based control solutions into window-based control solutions especially for applicability i n Internet traac management. The algorithm design will be followed by a performance evaluation using simulation and experimentation to assess the impact of these methods on best-eeort services ooered to networked multimedia applications. Speciically, experimental techniques will be used to determine network measures of application quality, to be used in simulation studies of these algorithms in representative network conngurations.