It was asked in the previous thread "what is the maximum distance a tower can be pinged from", in part to analyze the hypothesis that the ping from KB's phone was sent from an extended range via some sort of
booster. I replied in that thread but want to repeat here.
I am an engineer although not a cell phone engineer. After digging deeply into the technical documentation of various cell phone protocols I've come up with the following absolute distance limits:
GSM: 35 km (21 miles)
"Extended Range" GSM: 70 km (42 miles)
LTE: 100 km (62 miles)
These limits are due to
timing and not signal strength.
Without geeking out into the details, here is how a ping works:
Tower: Have any new phones wandered into my range?
Phone: I'm a phone!
Tower: Who are you?
Phone: I'm KB's phone!
Until the last message completes the phone has not identified itself. However, the cell phone standards requires that these messages happen with very strict timing. And that timing dictates that even for radio signals traveling at the speed of light, the sending phone isn't going to be further away than the standard allows.
Bottom line: The theory of a cowboy in his truck on a mountain in Colorado sticking up an antenna and pinging a tower in Idaho is impossible.
Source: I looked at about two dozen documents to figure this out. A very concise, although technical, description of the distance limit can be found in
this document.
