The Federal Circuit reinstated part of Lucent Technology's patent infringement claim against Microsoft and Dell for allegedly infringing on two patents: one for digitizing speech and another for allowing computer hosts to exchange information with personal computers, phones and other devices.

A three-judge panel ruled that Microsoft and Dell did not infringe on Lucent's speech-compression technology, but reversed a finding of no infringement for the second patent.
The appellate court disagreed with the lower court's interpretation of the term "terminal device" in the patent description. A terminal device refers to PCs, phones and other devices that receive information from a host, such as a server.