This paper proposes a model based controller design by exploiting μ-synthesis for a network based system with time varying delay and the plant model uncertainty. Much research has investigated network system with time delay and both frequency-domain based and time domain based approaches have been proposed. In this paper, we firstly review the study on conservativeness of existing approaches for time delay systems, then deduce that μ based controller is less conservative than other methods. To improve performance of the system, we proposes a model based control method with μ-synthesis. In the model based control, the modeling error between a plant model and a real plant can affect the performance and stability of the system. A μ-synthesis based robust control also works to avoid the instability due to uncertainty. To evaluate the performance of the proposed system, we carried out simulations and experiments on a motor control system. From the results, we verified the stability and satisfactory performance of the system with the proposed methods.