Where the claim language is particularly clear, “the specification plays a more limited role than in the common situation where claim terms are uncertain in meaning.” The Court of Appeals for the Federal Circuit explained that unless there is a disclaimer or redefinition, either explicit or implicit, the proper construction of any claim language must, among other things, “stay true to the claim language.”

Straight Path IP Group, Inc. owns U.S. Patent No. 6,108,704, entitled “Point-to-Point Internet Protocol,” which describes certain protocols for establishing communication links through a network. The specification described a system for allowing voice and video communications despite changing IP addresses in which the system would query a server as to whether a user “is connected to a computer network” by having the server search the database for “any stored information corresponding” to the user.

Previoulsy, on a petition for inter partes review filed by Sipnet EU S.R.O. (“petitioner”), the Patent Trial and Appeal Board (PTAB) cancelled claims 1–7 and 32–42 of the ’704 patent based on determinations of anticipation and obviousness. Sipnet EU S.R.O. v. Straight Path IP Group, Inc., IPR 2013-246, 2014 WL 5144564 (PTAB Oct. 9, 2014).

In cancelling the claims, PTAB, relied on a small portion of the specification, and greed with the petitioner, Sipnet, that the term “is connected to a computer network” included users that had previously been connected or registered with the server, even where those users were no longer connected at the time of the query. This broad interpretation invalidated many of the patent’s claim as anticipated or obvious in light of prior art. Straight path appealed.

The Court of Appeals for the Federal Circuit (conducting a de novo review) concluded that the Patent Trial and Appeal Board’s (PTAB or Board) construction of the term “is connected” was erroneous, even under the broadest reasonable interpretation (BRI) standard. Straight Path IP Group, Inc. v. Sipnet EU S.R.O., Case No. 15-1212 (Fed. Cir., Nov. 25, 2015) (Taranto, J.) (Dyk, J. dissenting).

The court explained that the specification does not provide a basis for reasonably adopting a construction that contradicts the plain meaning of the claim language. Rather, the portion of the specification cited by the Board—which says no more than that the unit is active and online at the time of registration—does not expressly or implicitly redefine the phrase “is connected.”