The networked control system typically introduces network delay that have not been considered at the design stage. As a consequence, the system performance is degraded with respect to the expected response. This thesis introduces a methodology to apply external gain assist networked control systems. The proposed methodology uses external gain to modify the controller output with respect to the current network traffic conditions in order to enable an existing controller for networked control systems and compensate the performance degradetion induced by network delay. This methodology can change existing traditional controller directly to network controller and not modify the original control algorithms.