In reference to cell phone Pings.
The incoming call or data comes back from the backhaul and up through the switch to the antenna, where it then hits your phone wirelessly, presuming your phone is still communicating with the same site. If you are moving, then there's a handoffa new but more or less identical cell site transmits the data to your phone, once your phone checks in and says "I'm here."
A cellphone or modem radios the nearest towers, saying, basically, "I'm here!" When you make a call or logon, your phone then sends a message via radio that's picked up by the antenna array.
http://gizmodo.com/5177322/giz-explains-how-cell-towers-work
The girls walking around on trail being dropped off 1:00/1:30 from prior locations
(unknown) and last cell cummication being video image of suspect at 2:30 it makes perfect sense (to me) that the cell phone was Pinging around town(multipy celltowers). Jmo