AT&T filed a lawsuit in US district court on Monday against Microsoft in which it accused the software maker of selling products that include a patented digital speech technology developed by AT&T.
The suit, filed in US District Court for the Southern District of New York, charges that Microsoft's TrueSpeech software, used to code and decode voice signals, violates a patent that was originally issued to AT&T in 1984. TrueSpeech is incorporated in several Microsoft operating systems including Windows 95, Windows 2000 and Windows Me, according to the lawsuit.
The suit also charges that Microsoft's NetMeeting product, which lets users hold video and voice conference calls over the Internet, makes use of the same patented technology.
Microsoft spokesman Rick Miller declined to comment Monday afternoon saying the company had not had enough time to study the lawsuit.
The US phone giant is seeking unspecified damages from Microsoft, along with attorney fees and court costs. It also asked the court to permanently bar the software maker from distributing its patented technology, and has requested a jury trial.
AT&T said it informed Microsoft in April 1999 that it believed Microsoft was infringing on its patent. It has offered to license Microsoft the technology, but the software maker has so far refused, AT&T said in the lawsuit.
The carrier said it has licensed the technology, which it calls a "digital speech coder," to many companies, although it didn't name any in the suit. Such coding applications can reduce the size of sound files that contain voice recordings, which makes it faster to send those files over networks and also means they take up less space on a computer's hard drive, AT&T said in the lawsuit.
The technology was developed by AT&T engineers Bishnu S. Atal and Joel R. Remde, and is protected by US Patent Number Reissue 32,580, issued in January 1988, AT&T said. The patent is a reissue of US Patent Number 4,472,832, originally awarded in September 1984, AT&T said.