Many prefer retro gaming on actual hardware via RGB on a quality CRT screen. Unfortunately each system adds at least one AV wire, usually SCART, and necessitates one more input on your display, which usually can only accommodate one or two RGB inputs, so you often have to switch cables manually. So I got to thinking, since we live in the future we may have the technology to get rid of the rat's nest, and solve the problem of switching between so many input sources.
Pretty much every retro system is driven by 5V internally. So perhaps a small board could be built that could be soldered on the inside of a console. This would take as input 5V, and the analogue R,G,B and sync signals that are present inside each console, somehow digitise the signal so it consumes less bandwidth, and transmit it via some existing off the shelf over the air communication protocol.
Then another board could be made that acts as a receiver of this signal to reproduce the RGB+sync signal in its original analogue form, ready to be output into a display. One could have many transmitters, one to solder inside each of your consoles, and just one receiver that you place near your TV, so you can route the signals into your display of choice.
The receiver/transmitter do not need to be able to transmit over a very long distance. The idea is you can place your consoles in relative proximity of your TV, but avoid one extra cable for each system, and not have to worry about unplugging and plugging RGB cables whenever you change systems.
Since the system is geared towards retro gamers it would only need to handle 15khz video signals. Things to look out for, the video signal should not lose much if any fidelity during the process, and the process should not add much lag as that would be unacceptable for retro gamers who often play games that require frame perfect controller input.
If possible it would certainly be useful if this system could be made to handle audio as well as that also needs to be routed from console to display.