Originally Posted by dtsm
I don't even recall Cingular being around back then. And don't forget, ATT Wireless (now part of Cingular) only made the decision to switch from tmda to gsm in the last couple of years.
Cingular was formed by merging AT&T Wireless with the former SBC/BellSouth mobile units. The wikipedia entry for Cingular has a pretty good history. Basically, the former SBC/BellSouth entities which eventually become part of Cingular were TDMA up until 2002, when they started converting to GSM. This was complete by 2004.
Then in 2004 the company bought AT&T Wireless and was renamed Cingular. AT&T pre-merger was a TDMA system.
My expectation is that over time all the former TDMA users from whichever system will be transitioned to GSM.