Prosecution History Prevents Patent Owner from “Intercepting” Win on Appeal

By on May 20, 2021
Posted In Patents

In reviewing whether the Patent Trial & Appeal Board (Board) correctly interpreted the meaning of “intercepting” in the context of Voice over Internet Protocol (VoIP) technology, the US Court of Appeals for the Federal Circuit found that the claim language and prosecution history supported the Board’s decision. The Court thus affirmed the Board’s construction and subsequent finding of obviousness. Uniloc 2017 LLC v. Apple Inc., Case Nos. 20-1403, -1404 (Fed. Cir. May 12, 2021) (Prost, C.J.)

Uniloc owns a patent directed to a system and method for using various VoIP features, such as caller-ID, call waiting, multi-line service, and different levels of service quality known as the “codec specification.” The patent explains that in order to generate revenue for these features, service providers must maintain control over which subscribers have paid for these additional features. To achieve that control, the system employs an enforcement mechanism that sits between the sender of the communication and the intended recipient. The enforcement mechanism ensures that both parties are authorized to use the particular features by intercepting the signaling message, determining whether the client is authorized, and filtering the signaling message based on the authorization. The majority of the claims require authorization related to only one service type. However, one of the claims (claim 18) requires authorization related to at least two service types.

Apple filed a petition for inter partes review (IPR), alleging that all claims of the patent were invalid as obvious over a prior art patent referred to as Kalmanek. Kalmanek discloses signaling messages that are routed through at least one “gate controller,” which can authenticate the identity of the calling party and authorize the services sought. The services include at least caller-ID and enhanced levels of call quality. Kalmanek’s process is accomplished by sending a SETUP message, which the calling party sends to the gate controllers and then to the intended recipient. After receipt, the called party sends a SETUPACK message along a return path to the gate controllers and then to the caller.

During the IPR, Apple asserted that the term “intercepting” a signaling message associated with the call, as recited in all independent claims, should be interpreted to mean “the signaling [message] is received by a network entity located between the endpoints of the call.” Uniloc disagreed and argued that the term should be interpreted as excluding the receipt of a signaling message by the intended recipient of the message. The Board agreed with Apple’s construction and subsequently found that all terms were invalid as obvious with the exception of claim 18. With respect to claim 18, the Board concluded that Apple failed to meet its burden to show that Kalmanek disclosed authorization related to a codec service. Furthermore, the Board opined that even assuming Apple had properly advanced such an argument, it would have lost on the merits.

On appeal, Uniloc challenged the Board’s construction of the “intercepting” term, and Apple cross-appealed the Board’s finding with respect to the non-obviousness of claim 18. The Federal Circuit affirmed both of the Board’s findings. Regarding the claim construction issue, the Court reasoned that just because the receiving client device is the ultimate “intended recipient” does not mean that the sending client device cannot intentionally direct a message to the intercepting party. The claim language encompasses the situation in which a sending client device intentionally sends a signaling message to the intermediate network entity that performs the interception, after which it is sent to the “intended recipient.” The Court noted that this interpretation aligns with the prosecution history of the patent, during which the “intercepting” limitation was added to overcome prior art rejections. The applicant clarified that “the independent claims involve a network entity intercepting messages that are associated with a call between two end users.” Having affirmed the Board’s construction, the Court agreed that all claims with the exception of claim 18 (and the claims depending therefrom) were invalid as obvious over Kalmanek.

Regarding claim 18, the Federal Circuit stated that “it [is] unnecessary to reach the procedural issue of whether Apple raised a viable invalidity theory . . . because even assuming there was no defect in Apple’s petition . . . Apple would still lose on the merits of whether it showed that claim 18 would have been obvious in view of Kalmanek.” Claim 18, as admitted by Apple, prohibits two separate messages from satisfying the authorization of the two separate services (i.e., the caller-ID and codec services). Despite this admission, Apple’s argument required both of Kalmanek’s SETUP and SETUPACK messages in order to disclose this claim element. Accordingly, the Court affirmed the finding of non-obviousness of claim 18 over the Kalmanek reference.

Practice Note: In support of its claim construction position, Uniloc advanced numerous dictionary definitions and expert testimony. The Federal Circuit readily dismissed this evidence, however, as being outweighed by the intrinsic evidence supplied by the claim language and the prosecution history. This dismissal serves as a reminder of the imbalance in weighing the intrinsic evidence provided in the claims, specification and prosecution history against all other extrinsic evidence.

Thomas DaMario
Thomas DaMario focuses his practice on intellectual property litigation and transactions. Thomas has experience in all phases of litigation—from pre-filing investigations and discovery through trial and appeal. He has been involved in patent infringement cases in various United States district courts, the International Trade Commission and the Patent Trial and Appeal Board. Thomas is experienced in various technical areas, including Internet technologies, wireless and cellular communications, semiconductor chip design and fabrication, power tools, computer and networking systems and mechanical devices. Read Thomas DaMario's full bio.