An IPR petition that results in a final written decision finding all challenged claims unpatentable is unquestionably a success. But that’s not the only measure of success for IPR proceedings. In IPR2017-00588 (Nokia v. Huawei), T-Mobile, a real-party-in-interest to the IPR, appears to have found success long before the final written decision.

On September 9, 2017, just a month and a half after the IPR was instituted, Judge Payne (E.D. Tex.) issued a report and recommendation that T-Mobile’s motion for partial summary judgment of noninfringement be granted based on “clear and unmistakable” disclaimers made by Huawei in its Preliminary Response.

The patent at issue, U.S. 8,867,339, is directed to a method of error recovery in a communications network. Claim 1, reproduced below with the relevant feature shown in bold, is representative:

1. A method for processing an invalidation of a downlink data tunnel between networks, comprising:

receiving, by a core network user plane anchor, an error indication of a data tunnel from an access network device;

notifying, by the core network user plane anchor, a core network control plane to recover a downlink data tunnel if a user plane corresponding to the error indication uses a One Tunnel technology; receiving b the core network user plane anchor, an update packet data protocol (PDP) context request from the core network control plane; and updating, by the core network user plane anchor, a corresponding PDP context according to the update PDP context request.

In its Preliminary Response, Huawei argued that “each challenged independent claim” requires that the core network user plane anchor “not mark the PDP context as invalid” and the prior art required the opposite. However, Huawei’s theory of infringement was based on T-Mobile’s use of a standard that requires marking the PDP context as invalid. Judge Payne found this to be fatal to Huawei’s allegations based on the 339 patent.

As in routine patent prosecution, anything you say about the prior art in an IPR can—and, likely, will—be held against you in subsequent or concurrent district court litigation. If your “best” defense in the IPR runs counter to your infringement theory, you may want to try out your second-best defense.