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This paper studies the congestion control problem of multi-bottleneck TCP/AWM networks. Firstly, considering the interference of network UDP flow and the mutual influence between nodes, a multi-bottle-neck network node switching model is established. Then, in order to relax the requirement of the prescribed performance technique for the initial value, a new prescribed performance function is designed, and the designed function can be well adapted to the congestion control of the multi-bottleneck network. Finally, for the newly established multi-bottleneck network node switching model and adopting a new prescribed performance function, a novel prescribed performance event-triggered controller is developed. The designed congestion controller enables different nodes of a multi-bottleneck network to achieve consistency and good stability across nodes with time-varying number of sessions, and is validated by simulation. [ABSTRACT FROM AUTHOR]

A robust super-twisting sliding mode control (SMC) based on a disturbance observer is firstly investigated for transmission control protocol (TCP) network systems with unknown disturbance in this paper. To reject chattering from SMC, a super-twisting algorithm (STA) based on integral SMC is introduced to TCP/AQM systems. Meanwhile, to improve the estimation accuracy of the model, a disturbance observer is designed. By selecting the appropriate sliding surface coefficients, the stability of the closed-loop control system is achieved. At last, simulation comparison results are given to illustrate the feasibility and the superiority of the proposed approach. [ABSTRACT FROM AUTHOR]

The fixed-time congestion control problem of TCP/AQM networks with UDP flows and un-modeled uncertainties has been studied thoroughly in this paper. The fluid-flow based TCP/AQM network system model is analyzed, and a fixed-time adaptive congestion control algorithm is proposed for the nonlinear network system model with unknown UDP flows and un-modeled uncertainty. The new control algorithm was derived using combined requirements for the fixed-time control and the prescribed performance control by employing the back-stepping technique and the fuzzy approximation methodology. The universal approximation property of fuzzy-logic system models is used to deal with the external disturbance and the uncertainty that may appear in the network system. Using the prescribed performance technology, the transient and steady state performances of the tracking error are shown to have been enforced to meet the design requirements. Using the back-stepping methodology, a fixed-time AQM controller is designed so as to ensure that the fixed time of the closed-loop system response remains bounded. The obtained simulation results demonstrate the extent of effectiveness and superiority of the proposed design relative to known previous results. [ABSTRACT FROM AUTHOR]

For the nonlinear TCP/AWM network congestion control system with external disturbances, under the framework of backstepping control method, an adaptive network congestion control strategy based on event-triggered mechanism is proposed. This strategy reduces the waste of network resources by introducing an event-triggered mechanism and uses RBF neural network to deal with external disturbances. The Lyapunov theory is used to prove that all signals in the closed-loop system are bounded. Finally, the proposed method is verified by simulation and is compared with PID, which further verifies the effectiveness of the proposed control method. [ABSTRACT FROM AUTHOR]