Comcast sold Comcast Cellular to SBC Communications in 1999 for $400 million, releasing them from $1.27 billion in debt. Comcast acquired Greater Philadelphia Cablevision in 1999. In March 1999, Comcast offered to buy MediaOne for $60 billion. However, MediaOne decided to accept AT&T Corporation's offer of $62 billion instead. Comcast University started in 1999 as well as Comcast Interactive Capital Group to make technology and Internet related investments taking its first investment in VeriSign.

What was Comcast's telecommunication business prior to 1999?