Credit for the picture goes to these guys:

I am developing a wireless system for large scale model trains based on the Xbee Series 1 2.4 Ghz radio network devices. Phase 1 is complete and working, I’ve learned much from this and am currently working on Phase 2.

Basically, this system provides a point to multi-point industrial strength wireless network. Any node can talk to any other node. There is no concept of ‘channels’, so locomotives can talk to each other or to any other device connected to the network. The destination device can drive a battery powered or live steam locomotive. It can also operate as an accessory device for turnouts, signals, etc. It can drive servos, serial devices, motor controllers, LEDs and relays. It can also be used as an input device and can read digital, analog or serial enabled devices and return those to the controller or other network device such as a computer.

I also have a DCC output which can drive DCC decoders up to 3 amps. This design supports by-passing the motor driver in the DCC system so you can use the DCC for sound and lighting control while driving a much larger, higher amp motor with a low cost motor controller. This enables the use of lower cost HO scale sized DCC decoders in large scale locomotives for sound and lighting control if you wish.

Click Here to browse from my newest entry. I have several interests in the large scale train hobby including styrene buildings, 3D printed people figures and electronics.