Cell Tower Functionality
Q: What is the maximum distance a pair of cell towers (cell sites) can be separated and still function? Obviously there is some overlap of coverage, but what is the maximum, and maybe minimum, too. Assuming flat terrain?
A. From Mark van der Hoek (internal link):
Too many variables! :D
At the limits? I know of analog calls being made several hundred miles away from the serving cell site. I've personally made analog calls 50 miles away from the site. Digital won't go that far because of timing issues. For CDMA, the practical limit seems to be around 30 miles or so and that only under ideal conditions. 20 is no problem, but rarely done. I've seen it in rural south Texas, west of McAllen in the Rio Grande Valley.
GSM has a hard stop by design at 35 km (22miles), but that can be doubled with some special equipment and software. The price you pay is that you cut in half the available time slots. Some years ago Nortel was trying to make GSM go 200km (124 miles) for an Australian operator, but that effort seems to have faded into obscurity.