If only you knew my background...Anyway I do know the difference and we're just having fun.
My analyst background is saying that it either has been shut off or broken. If it was a Spy communication network it could be easily replaced by the Internet. If it was used for Military Communications, a closed fiber optics network would be the logical alternative which are more secure and EMP proof...
The buzz is most likely a beacon used to home in ground based Satcom antennas. It would make sense to use short wave (HF) frequencies since they are pretty much immune to background radiation from a nuclear exchange.
I have Degrees in Electronics, and Communication Technology as well spending 10 years as an intelligence analyst.
