This thesis focuses on the integration of wired and wireless nodes running on top of Gigabit Ethernet and WiFi respectively in Networked Control Systems. Such a networked control system investigated in this work consists of two wireless sensors, two wireless actuators, 14 wired sensors, two wired actuators and one wired supervisor. The architecture is based on Sensor-To-Actuator model. It is revealed through OMNeT++ simulations that the wired and wireless packet end-to-end delays in the developed model satisfy system requirements with no packet loss. Moreover, wired, wireless and mixed interferences are studied and quantified. The amount of interference that the model can withstand is determined. All results are subjected to a 95% confidence analysis. Additionally, the thesis focuses on reliability in the design of networked control systems that is becoming greatly important. Fault-tolerance is often used to increase system reliability. In this work, Triple Modular Redundancy (TMR) and Parallel Redundancy Protocol (PRP) are both applied to a Sensor-to-Actuator architecture with 16 sensors, four Actuators and one Supervisor. Two of the 16 sensors as well as two of the four actuators are wireless while the rest of the nodes are wired. It is first shown that this NCS succeeds in meeting all control system requirements (zero packet loss and bounded end-to-end delay). Reliability models are then developed to help designers choose the appropriate mix of fault-tolerant techniques in order to maximize lifetime while at the same time minimizing the extra cost due to the added redundancy
