On September 9, 2017, an Eastern District of Texas magistrate judge issued a report and recommendation holding that a plaintiff was estopped from asserting its patent infringement claims because statements made in response to an inter partes review (IPR) petition constituted a disclaimer.

T-Mobile US, Inc. (“T-Mobile”) filed a lawsuit against Huawei Technologies Co. Ltd. (“Huawei”) alleging infringement of U.S. Patent No. 8,867,339 (the “’339 Patent”). The ’339 Patent generally relates to error recovery for a tunnel architecture between a radio control network and a gateway general packet radio service node (GGSN). The error recovery involves managing a “packet data protocol (PDP) context,” which is a data structure relating to a user’s cellular data connection.

In response to Huawei’s suit against T-Mobile, Nokia Solutions and Networks LLC (“Nokia”) filed an IPR petition against the ’339 Patent. Nokia alleged that the claims of the ’339 Patent were obvious in light of a combination of prior art references that involved the PDP context. In its response to Nokia’s petition, Huawei repeatedly argued that the combination of prior art references on which Nokia relied did not make the claims of the ’339 Patent obvious.   Specifically, Huawei took the position that the prior art combination did not preserve the PDP context as claimed in the ’339 Patent and instead marked the PDP context as invalid. The Patent Trial and Appeal Board (PTAB) instituted the IPR and rejected Huawei’s argument.

In its district court suit, Huawei generally accused T-Mobile’s 3G network of infringing the ’339 Patent by complying with a 3GPP standard. There was no dispute that the relevant 3GPP standard required the GGSN to mark the PDP context as invalid in response to an error. T-Mobile moved for partial summary judgment based on Huawei’s statements in response to Nokia’s IPR petition differentiating the prior art combination that marked the PDP context invalid in response to an error. In a report and recommendation, Magistrate Judge Roy S. Payne stated that Huawei’s statements to the PTAB constituted a clear disclaimer. The court therefore held that Huawei was precluded from alleging that the ’339 Patent covered a network, such as T-Mobile’s 3G network, in which a GGSN marks the PDP context invalid in response to an error. The court recommended granting T-Mobile’s motion because there was no evidence from which a reasonable jury could find that T-Mobile’s 3G network infringed the claims of the ’339 Patent.

Huawei Technologies Co. Ltd. v. T-Mobile US, Inc., No. 2-16-cv-00052 (E.D. Tex., September 9, 2017, Report and Recommendation) (Payne, R. S.)