In radio a digital signal always means a less robust signal than analog. Digital doesn't go as far, requiring many more multi-million dollar base stations to cover the same area as analog. It is cost efficient for a cellular carrier to switch to digital, since they can carry several calls on a single frequency, instead of just one for analog. But coverage and audio quality will suffer. H reports below from South Dakota:
Dear Tom,
You've discussed AMPS coverage in rural locations (internal link). Despite this being 2002, there's still very little in the way of digital coverage here in South Dakota. Cellular One (Western Wireless) has the only digital coverage, and their footprint is expanding at a rather impressive rate. They initially deployed TDMA, but have begun migrating sites to CDMA. Word, according to the trade magazines, is they are eying a transition to GSM.
In the interest of complete disclosure, Sioux Falls, the largest city with 125,000, has decent cellular coverage with a new Nextel installation, Sprint, Verizon, RCC Unicel (small GSM only carrier similar in marketing paradigm to Cricket) and perhaps T- Mobile, in addition to the Western Wireless digital coverage. Rapid City, number two in population with about 55,000 has a tiny Qwest digital footprint, Verizon, and WW. With Qwest being run into the ground by stupid execs; I'm waiting to see who that asset will be sold to. Verizon has put most of their effort into the cities where there is a student population -- Brookings with SD State, Vermillion with the U of SD, and Madison with Dakota State. Population densities are, as one might guess, significantly higher in the college towns.
For the bulk of the state, however, (in terms of area, not population), the coverage is AMPS, and not even very advanced AMPS.
The cellular sites were built in the early 90s by CommNet cellular, and are spaced from 20 to 40 miles distant. I travel regularly on US 14. With a handheld operating at the full .6w, calls were never able to be handed off as the call faded before reaching the edge of the cell. It wasn't until I purchased a rather nice external antenna that I was able to have a conversation spanning cells. Needless to say, this simple, aged feature of cellular communications was quite impressive to me. It never worked before.
For work, we use the old Motorola bag phones with the 3w transmitter and external antenna. They're harder and harder to find, and the models we have are at least 8 years old. They work, and where we travel in the state, coverage is still amazingly pathetic. I've been in areas in South Dakota where there was zero coverage, even with the bag phones and antennas. Nobody who travels anywhere out of the populated areas is impressed by digital or handheld phones. I suspect that this is one of the few states where people still clamor over a hulking black bag phone, and look with disdain at the shrinking size of cell phones. We did pick up what is probably one of the last and most feature laden bag phones about two years ago, new. It had a most amazing feature. Something which greatly impressed us: Caller ID.
Your prediction of a phase-out of AMPS in five years is a bit optimistic, I think. The phase out will happen when the present equipment breaks, and AMPS-compatible replacements can't be found. Only then will things go digital here. I do see it isn't easy to build a cellular network to cover counties with a population density of less than 3 people per square mile. Want more specifics?
I've endlessly nagged Verizon, my cellular provider, to transition the larger cities (Pierre, where I live has 13,000) to digital but they're not too interested in doing that it seems. AT&T has nothing here, T-Mobile, Cingular, nothing. In some succinct emails with a Verizon RF Engineer out of Minneapolis, he was rather forthcoming with an explanation. The gist of his comment was that the Verizon execs (much like most cellular execs) live in Sub/Urban markets, and have zero understanding of what terrain, demographics, and the reality of rural and frontier markets. Hence, they're not too interested in the sparse areas. I inquired as to the expansion of digital coverage, and the target was, as you might guess, on well-traveled corridors, and not much beyond that.
Western Wireless has astounded me as to their endless expansion of digital coverage. Granted, they're really hurting financially, but they got significant Federal grants to provide wireless coverage in areas like Pine Ridge -- a place which didn't even have landline service. That blows my mind. How they could be so overlooked as to have been ignored by Qwest.
I see the F.C.C. announcement not so much a phase-out of AMPS, but merely the elimination of the requirement to provide AMPS service. There may not be a future increase in AMPS coverage, but the status quo will be the same long into the future.
H.
