When I was an explorer, the private security did the inside stuff. Like getting rid of drunks, mosh pits and so on. And LE did the outside, traffic direction and close off the streets. The only time LE went in was if the inside security got over whelmed. As for monitoring the security air, most of the streets are blocked off, I guess you could always walk as close as you could and use the close call or signal stalker. It's in the middle of the DTC so you might get a lot of other stuff, but it's worth a try right?