The railway system contains many subsystems, including a Control and Dispatching System (Signaling System), Environment Monitoring System, Video Networking Surveillance System, and Electric Power Supply System. These subsystems, which handle key aspects of railway operation, are generally distributed at remote locations, such as the different railway stations making up the rail line.

A layered network is often use to integrate all of these systems into one complete railway system.

	The device-level control network is a fieldbus network that uses gateways to communicate with the Ethernet network. All of the information transmitted from the field is forwarded to the upper layer network via the Ethernet network.
	The station-wide control network connects the main subsystems of each railway station with the Ethernet network. The station-wide networks are then integrated via the backbone network to transmit the operation information between stations.
	The backbone network collects and transmits all of the operation information from each station to the Central Control Room. In this way, the Central Control Room will have sufficient information for further control and analysis.

The device level network collects all of the operation information from devices such as PLCs, DCS systems, field I/O devices, and also SCADA and CCTV systems. All of this information is communicated by the gateways and then sent to the Ethernet network. The backbone uses a Gigabit Ethernet network, which provides enough bandwidth to handle data and video communication from station to station easily. The three layers of networks connect all of the stations together, and integrate all of the information that is required to keep the system operating smoothly. The end result is a railway control system that is fast enough to respond in real-time, and that runs more efficiently.