Addressing claim construction issues in connection with “means-plus-function” limitations, the US Court of Appeals for the Federal Circuit affirmed the district court’s decision to uphold a non-infringement verdict based on a construction that introduced new functionality not explicitly recited in the means-plus-function claim. Core Wireless Licensing S.A.R.L. v. Apple Inc., Case No. 15-2037 (Fed Cir., Apr. 17, 2017) (O’Malley, J).

Core Wireless owns a patent directed to sending packet data in a cellular system. Core Wireless brought a patent infringement action against Apple, asserting that Apple infringed, among other things, a claim that requires “[a] mobile station connected with a cellular system, comprising means for sending uplink packet data to the system using a selected channel . . . characterized in that it also comprises: . . . means for comparing said threshold value of the channel selection parameter to a current value of the channel selection parameter for basis of said channel selection.” The district court construed this means-plus-function limitation to require that the mobile station have the capability to perform channel selection. Based on that construction, the jury found that Apple did not infringe any of the asserted claims.

According to 35 USC 112, ¶ 6, a means-plus-function limitation “shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.” The broadest reasonable interpretation of a means-plus-function limitation is determined by the structure in the specification that is described as performing the function recited in the means-plus-function limitation.

On appeal Core Wireless argued that the district court erred in construing the means-plus-function limitation. According to Core Wireless, because the claim did not explicitly recite the mobile station as performing channel selection, it was not proper for the district court to introduce this new functionality into the claim.

The Federal Circuit disagreed and found that each embodiment of the claimed invention disclosed in the specification, the prosecution history and the extrinsic evidence supported the district court’s claim construction, which required the mobile station to have the capability to perform channel selection. First, all of the embodiments of the claimed mobile station disclosed in the specification showed the mobile station both performing the comparison and subsequently using the result of the comparison for channel selection. The prosecution history indicated that the applicant’s position during prosecution was that the mobile station performed the channel selection. Similarly, the invention disclosure described the mobile station as having the capability to perform channel selection. 

Practice Note: A construction of means-plus-function limitations under 35 USC 112, ¶ 6 may introduce new functionality that is not explicitly required in the claim, if that functionality is required by the corresponding structure disclosed in the specification.