Summary: Plain language claim construction will not be narrowed based on the prosecution history unless the patentee clearly and explicitly disclaims claim scope.

The patent in suit describes an “application-aware resource allocator” that allocates bandwidth resources to transmit information from software applications over a packet-switched network.  The patent describes the application-aware resource allocator with reference to the seven-layer Open Systems Interface networking protocol stack standard, which includes a “physical layer” at layer 1, a “data link layer” at layer 2, a “network layer” at layer 3, a “transport layer” at layer 4, and an “application layer” at layer 7.  The parties disputed the constriction of “application-aware resource allocator.” Intellectual Ventures offered a construction requiring that the resource allocator “allocate[] resources based on application type.”  Under Intellectual Ventures’ construction, the application type could be discerned by the resource allocator using information obtained from any of network layer 3, transport layer 4, and application layer 7.  T-Mobile offered a construction requiring that the resource allocator “ha[ve] knowledge of the type of data application,” and allocate resources using information obtained from the application layer 7.  The district court adopted T-Mobile’s construction of “application-aware resource allocator,” noting that the construction was supported by the prosecution history, during which the patentee distinguished its invention from the prior art based on the fact that the invention is “aware of layer 7 application information” and that the resource allocator must “be able to take into account, when allocating bandwidth, information at . . .  layer 7.”  Following claim construction, T-Mobile moved for summary judgment of non-infringement, and the district court granted summary judgment, explaining that Intellectual Ventures’ opposition depended entirely on a claim construction position that the district court had rejected. Intellectual Ventures appealed.

On appeal, the Federal Circuit held that the district court’s grant of summary judgment resulted from an erroneous claim construction.  The Federal Circuit construed “application-aware resource allocator” to have its plain meaning, which permits the resource allocator to allocate resources based on application type, which can be discerned using information from any of network layer 3, transport layer 4, and application layer 7. The Federal Circuit found that the plain language of the claims, the specification, and the prosecution history all supported this construction. For example, the plain language of the claims did not require that the resource allocator use information obtained from application layer 7. Also, some embodiments described in the specification did not describe the resource allocator using information from application layer 7. The Federal Circuit found that the statements in the prosecution history referring to application layer 7 required the invention be aware of applications running at application layer 7, but did not require the resource allocator to use data obtained from application layer 7 when allocating resources. Because the district court’s grant of summary judgment of non-infringement resulted from a contrary construction, the Federal Circuit vacated-in-part and remanded.