Since they expect most of your long distance charges to be initiated from within their covered area, they can easily forward them over their own extensive long haul backbone network to the city you are calling. Contrary to their main purpose of being a long distance carrier, cellular is considered local carrier and they weren't interested in it or couldn't break into the early market. Apparently, they had to acquire their later bandwidth frequencies from the FCC in the range of 1900 Mega hertz. Normally cellular is in the 800 Mega hertz range. Evidently they contracted with Ericsson and Nokia for cellular phones that could handle it.
All cellular data is handled over analog.
For many RVers, including us, it would be well worth it. I could cancel my 800 number voice answering service, discontinue using my long distance calling cards, talk simultaneously to friends and relatives at two telephone numbers, have regular telephone service in the RV at many of the places we go to and not often need to use pay phones. Tom Gonser, publisher of RversOnline, says people are having trouble acquiring the modem to cell phone cable. He's absolutely right. However, they did not volunteer any information about else how to acquire them.