If this was 7 years ago, I'm guessing it was analog service; it
> certainly was not GSM. I'd be interested to see what happens on some
> of those calls today using GSM service.
Quite the contrary. GSM service was functional as early as January of
1996 for VoiceStream which is now T-Mobile. The first GSM network in the USA was turned on in 1995. That's at least 10 years ago.