Southwestern Bell Mobile Systems, Inc. was a wireless telephone company. It was created in 1984 as a split-off of

Advanced Mobile Phone Service Advanced Mobile Phone Service, Inc. was a subsidiary of AT&T prior to the Bell System Divestiture. Abbreviated AMPS, the company was created in 1978 to build and operate the new Advanced Mobile Phone System, also abbreviated AMPS. AMPS was develop ...

, the original wireless subsidiary of the Bell System. It was a division of

Southwestern Bell Corporation AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile te ...

. It continued to operate as Southwestern Bell Mobile Systems until 2000, when SBC Communications and

BellSouth BellSouth, LLC (stylized as ''BELLSOUTH'' and formerly known as BellSouth Corporation) was an American telecommunications holding company based in Atlanta, Georgia. BellSouth was one of the seven original Regional Bell Operating Companies after ...

combined their wireless operations into a single company,

Cingular Wireless AT&T Mobility LLC, also known as AT&T Wireless and marketed as simply AT&T, is an American telecommunications company. It is a wholly owned subsidiary of AT&T Inc. and provides wireless services in the United States. AT&T Mobility is the t ...

. Southwestern Bell Mobile Systems' assets were then transferred to a Cingular as a

limited liability company A limited liability company (LLC for short) is the US-specific form of a private limited company. It is a business structure that can combine the pass-through taxation of a partnership or sole proprietorship with the limited liability of ...

named Cingular Southwestern Bell Mobile Systems, LLC. The company existed until 2006 when it was dissolved.Missouri Secretary of State, Filed Documents for Cingular Southwestern Bell Mobile Systems, LLC
/ref> Southwestern Bell Mobile Systems' physical assets survive in what is now AT&T Mobility.

References

{{AT&T AT&T subsidiaries Defunct mobile phone companies of the United States Defunct telecommunications companies of the United States American companies established in 1983 Telecommunications companies established in 1983 Telecommunications companies disestablished in 2006 American companies disestablished in 2006