Design of proportional-derivative-type state feedback controllers for congestion control of transmission control protocol networks

Abstract

A new proportional-derivative-type state feedback controller is proposed for congestion control of transmission control protocol (TCP) networks. An analytical TCP model is adopted. In the proposed control scheme, it is possible to efficiently control the TCP traffic using only the queue length at the router without the need to know the TCP window size which is not available locally. The results are presented in terms of delay-dependent linear matrix inequality. The proposed method is verified by simulation examples using NS software, and the effectiveness and superiority of our method over other control schemes, such as the proportional-integral, random early detection and generalised minimum variancemethods, are also shown.

PID-type congestion controller design for TCP networks

“…Delay Dependent Stability Analysis A theorem established by [20] which gives the delaydependent stability condition for the system (9) is presented in the following. …”

“…Due to the difficulty of the measurement of the window size at the routers side, we choose the method proposed by [20]. To achieve the best performance of the network, the integral of the queue length have been applied at the control signal.…”

“…In the next section a criterion about the stability of the systems in form of (9) established by [20] will be presented.…”

“…In this paper, the method proposed by [20] has been improved by applying the integral of the queue length in the control signal to improve the steady-state performance. This leads us to the PID-type state feedback controller design in terms of the queue length.…”

“…The window size has been approximated in a robust controller designed in [19]. Derivative of the queue length has been replaced with window size in design of the state feedback controller [20].This leads to a PD-type state feedback controller design in terms of the queue length.…”