Microsoft is finding itself on the spot yet again because of intellectual property infringement claims made by BackWeb Technologies. BackWeb has filed a lawsuit in the United States District Court in San Francisco, California, accusing the software giant that it is violating no less than four of its patents with the technology involved in Windows Update and Automatic Updates. Via WU and AU, Microsoft has set up a system to deliver updates to its software products including its main cash cows, the Windows platform and the Office system.

One of the patents awarded to BackWeb covers “unique and novel methods and processes for transmitting digital information in background mode over a communications link between a computer network and a local computer and throttling the transfer speed to create minimal interference with other processes communicating over the communications link. The digital information described in the patent could be in a variety of forms, including, but not limited to news, weather, stock quotes, sport scores, software updates or trip reservation information,” reads an excerpt from the complaint.

BackWeb indicates in the lawsuit that a range of Microsoft products infringe on its patents, but only specifically mentions the software giant's Background Intelligent Transfer Service (BITS) and Windows Update. The IP reference cited above comes from a patent that was awarded to BackWeb in 1999. The plaintiff indicated that Microsoft did not introduce BITS until 2001.

“BITS transfers files in the foreground or background, throttles the transfers to preserve the responsiveness of other network applications, and automatically resumes file transfers after network disconnects and machine restarts. In 2007, Microsoft began the commercial distribution of version 3.0 of BITS, that adds the capability of transferring files in a peer to peer networking fashion,” BackWeb added. Microsoft has yet to comment on the patent infringement lawsuit brought against it by BackWeb.