Possible idea. Green mountain is NOT an actual military base but an experimentation ground for the zombies. As heard in the ORIGINAL Green Mountain transmission you hear the zombie roar, what some presume to be Patient Zero. I know this theory has been proposed but, its always good to refresh some minds. The UVB76 signal, which still occurs in Russia from an unknown location, follows this very same format. The buzzing continues for a very long time until suddenly, the buzzing stops. At this point, co-ordinates are read and the theory for UVB76 is that back in the USSR military bases would wait until the buzzing stopped, the tower broadcasting this sent out the co-ordinates, and as the co-ordinates were read the military bases at those co-ordinates would send back a series of numbers and letters themselves. Now this kind of sounds like what is going on in the game, buzzing, co-ordinates, and then the buzzing continuing. The DeerStands at those locations could be the "military bases or outposts" that need to radio back at the specific time. This is alpha and they probably only have part of this mystery in, (which sucks), so we will be left dangling. However, I have a strange feeling that with the addition of Svetlojarsk there is another radio signal up there. If there are signals in cities, as seen in elektro, maybe there are signals in every other large city? Maybe a distress call for all units to head to Green Mountain? Now what might be helpful is if someone were to find all of the "radio masts" in Chernarus and station people outside of them to see if a signal can be picked up from there, along with all MAJOR cities and minor outlying military bases. I know its creepy but if you could get you and a friend or a group of friends to investigate, things might be found faster.