Cingular was Joint Venture between BellSouth and Southwestern Bell (SBC). SBC also bought, Pacific Bell, Ameritech and AT&T, when it did, it changes its name t

Cingular was Joint Venture between BellSouth and Southwestern Bell (SBC). SBC also bought, Pacific Bell, Ameritech and AT&T, when it did, it changes its name to AT&T. Later they bought out BellSouth, and changed its name as well. Cingular grew in phases as they acquired former RBOC's, but once SBC bought out BellSouth, Cingular became AT&T Wireless. The current corporate entity that calls itself AT&T is formerly SBC.