silpol » from archive
absorptions: Decoding radio-controlled bus stop displays - http://www.windytan.com/2013/11/decoding-radio-controlled-bus...
"In the previous post I told about the 16 kbps data stream on FM broadcast frequencies, and my suspicion that it's being used by the bus and tram stop display system here in Helsinki. Now it's time to find out the truth. I had the opportunity to observe a display stuck in the middle of its bootup sequence, displaying a version string. This revealed that the system is called IBus and it's made by the Swedish company Axentia. Sure enough, their website talks about DARC and how it requires no return channel, making it possible to use battery-powered displays in remote areas." ‎- silpol