It is worth noting, that in additon to what Bernard stated, there is a third "standard" in digital cellular phones.
This standard is also based on TDMA, though not compatible with GSM. It's major proponent in the US is Cellular One/AT&T, as well as most of their "affiliates" (such as LA Cellular in California). This standard is actually the oldest digital standard used in the US, and the most widespread, as AT&T have been pushing it in virtually all their major markets.
An additional advantage to this technology is that it is "dual mode", which means that if the phone CAN'T find a local digital connection, it will revert to standard analog mode and connect that way. This means that AT&T/CellOne can provide nationwide coverage by depending on existing analog systems in sparsely-populated areas which do not yet have the traffic to justify digital. To the customer this is seamless. None of the other digital systems have true nationwide roaming, as far as I know.
Incidentally, it's worth noting that the "success" of CDMA in some Asian countries (most notably, Korea) has been due to political influence peddling, not because the technology is demonstrably better. (ie: Governments deciding on the standard, and outlawing anything else.)
We will probably have competing technologies in the US for some time. I'd expect that eventually GSM will win out as the closest thing to a global standard, but it'll take a while.
mg |
