CONTROLLING THE DATA NETWORK CONGESTION USING AN OPTIMAL CONTROLLER

This paper presents an error tolerance control technique based on the optimal control method of Linear Quadratic Regulator (LQR). Congestion occurs in a network when the traffic load exceeds the capacity. Congestion control is performed in computer networks to prevent the accumulation of excessive data in the waiting queue and the loss of packets. The method presented in this paper has used a Network State Space Model (NSSM). First, by adding a state variable, a tracking controller has been designed for the system, which is robust to changes in parameters and conditions such as output speed, input speed, delay, and other disturbances, and can track the reference queue length well. By designing the LQR controller and solving the Riccati Equation, we were able to eliminate the indeterminacy and change in the parameters and increase the system tracking speed