AT&T Corp. has filed a lawsuit against Microsoft Corp. accusing the software giant of selling products that include a patented digital speech technology developed by the telephone company.
The suit, filed in U.S. District Court for the Southern District of New York, charges that Microsoft's TrueSpeech software, which codes and decodes voice signals, violates a patent that was issued to AT&T in 1994. TrueSpeech is incorporated in certain Microsoft operating systems, including Windows 95, 2000 and Millennium Edition, the lawsuit says. AT&T 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 had no immediate comment on the suit.