Research Of Generalized Predictive Control In ATM

ATM is a connection-oriented , packet switching , and statistically multiplexing technology . However, With many burst traffic simultaneously arriving at a node , or high-speed link is emerged into slower one ,there will be in congestion. . In a word ,it is the first task to control congestion efficiently to increase resource utilization And improve the quality of services.ATM Forum selects rate-based feedback control as the standard algorithm . It merely provides some constructive sketch without detailed plan. The disadvantage of the experimental algorithms is that they all don't guarantee the fairness and cause the oscillation in queue of node or allowed cell rate of users . Linear control theory based design doesn't completely consider the uncertainties caused by time-varying transfer delay saturated non-linearity and dynamical variety of users. All these factors result it hard to control the system .The thesis first builds up the network fluid model of single bottleneck node. It only takes the link delay into account, and thinks others (queuing and switching delay )and uncertainties as disturbance. And generalized predictive congestion control algorithm is presented ,which ensures global stability of closed-loop system, and then adaptive generalized predictive congestion control algorithm is proposed, which improves the robustness to dynamical variety of users. Last ,with OPENT ware-operate to similate , The simulation results show that the algorithms enhance the transient performance, and increase robustness against uncertainly, and improve networks utilization, and realize fairness of bandwidth allocation in steady state.