Jury Clears AT&T in Patent Fight Over 5G Network Tech

Case Background

Daingean Technologies Ltd. sued AT&T Corp., AT&T Mobility LLC, AT&T Mobility II LLC and AT&T Services Inc. in the United States District Court for the Eastern District of Texas, Marshall Division. The case carried docket number 2:23-cv-00123-JRG-RSP and went before District Judge Rodney Gilstrap. Daingean's complaint originally also named AT&T Inc. and AT&T Communications LLC, but the parties later filed a joint stipulation dismissing those two entities from the case.

Cause

Daingean accused AT&T of infringing six patents connected to wireless communication technology: U.S. Patent No. 8,576,803 ("Communication System"), U.S. Patent No. 10,484,976 ("Signaling, Procedures, User Equipment and Base Stations for Uplink Ultra Reliable Low Latency Communications"), U.S. Patent No. 10,841,958 ("Access Node, a Method for an Access Node, a Wireless Terminal, and a Method for a Wireless Terminal"), U.S. Patent No. 10,932,207 ("Terminal Apparatus, Base Station Apparatus, Communication Method, and Integrated Circuit"), U.S. Patent No. 11,134,400 ("User Equipment, Base Station, Related Methods") and U.S. Patent No. 11,196,509 ("Terminal, Apparatus, Base Station Apparatus, and Communication Method"). Daingean tied its allegations to AT&T's operation of a wireless telecommunications network under the AT&T and Cricket Wireless brand names, and to features of AT&T's 4G LTE and 5G service that Daingean said matched standards published by the Third Generation Partnership Project, known as 3GPP.

Injury

Daingean alleged that AT&T's wireless network infringed each of the six patents through its use of 3GPP-based 5G and LTE technology, including features tied to uplink communications, base station and terminal operations, and signaling procedures described in various 3GPP technical specifications.

Key Arguments and Proceedings

Legal Representation

Plaintiff: Daingean Technologies Ltd., a company organized under the laws of Ireland with its principal place of business in Dublin.

Defendant: AT&T Corp., AT&T Mobility LLC, AT&T Mobility II LLC and AT&T Services Inc.

· Experts Retained by parties: Van Der Weide | Stephen E. Dell | Martin J. Feuerstein

Key Arguments or Remarks by Counsel

AT&T answered the complaint by denying nearly every substantive allegation Daingean raised. Where Daingean's complaint quoted AT&T's own website or referenced third-party technical documents such as 3GPP specifications, AT&T repeatedly responded that the cited material "speaks for itself" and denied any characterization Daingean placed on it. AT&T admitted basic corporate facts about each named entity, admitted that it operated wireless networks under the AT&T and Cricket Wireless brands, and admitted that its network interoperated with certain aspects of 3GPP standards, but it denied that any of this amounted to patent infringement.

Claims

Daingean organized its complaint into six counts, one for each asserted patent. Each count alleged that AT&T's network infringed a specific claim drawn from the patent at issue. Daingean pointed to Claim 1 of the '803 Patent, claim 2 of the '976 Patent, Claim 1 of the '958 Patent, claim 4 of the '207 Patent, Claim 5 of the '400 Patent, and Claim 10 of the '509 Patent, and tied each claim to specific 3GPP technical specifications that it said described how AT&T's network operated.

Defense

AT&T raised fourteen separate defenses in its answer. It argued that the complaint failed to state a claim, that it had not infringed any valid and enforceable claim of the asserted patents, and that Daingean could not meet the legal standard for willful infringement. AT&T also argued that each patent claim was invalid under various sections of the Patent Act, including Sections 101, 102, 103 and 112. Beyond invalidity, AT&T argued that Daingean's claims were barred by license, patent exhaustion, or failure to mark products as required by law. AT&T further questioned Daingean's standing to sue, arguing that Daingean might not hold full ownership rights to the patents, and it raised equitable defenses including waiver, estoppel and prosecution laches. AT&T also invoked a statutory limitation tied to government-used equipment under 28 U.S.C. § 1498, denied that Daingean was entitled to injunctive relief, and argued that any damages award was limited by AT&T's rights under fair, reasonable and non-discriminatory licensing obligations tied to standard-setting organizations. AT&T closed with a defense of ensnarement, arguing that stretching the patent claims under the doctrine of equivalents would improperly capture technology already found in the prior art.

Alongside its defenses, AT&T filed six counterclaims, one for each asserted patent, asking the Court to declare that AT&T did not directly or indirectly infringe any of the six patents and that it owed no damages or injunctive relief on any of them. AT&T also demanded a jury trial and asked the Court to award it attorney's fees under 35 U.S.C. § 285 if the case qualified as an exceptional case.

Jury Verdict

The case went to a jury trial that began on September 5, 2025. The jury deliberated and returned a unanimous verdict on September 11, 2025. The jury found that AT&T Corp., AT&T Mobility LLC, AT&T Mobility II LLC and AT&T Services Inc. did not infringe Claim 12 of the '803 Patent, the sole claim submitted to the jury.

Based on that verdict, Judge Rodney Gilstrap entered final judgment on November 10, 2025. The Court ordered that AT&T had not infringed the asserted claim and that Daingean would take nothing from AT&T in the case. The Court also ruled that AT&T qualified as the prevailing party under Federal Rule of Civil Procedure 54(d), Local Rule CV-54 and 28 U.S.C. § 1920, and it directed AT&T to file a bill of costs to recover its litigation expenses from Daingean. The judgment denied all other pending requests for relief between Daingean and AT&T that the order did not specifically address.

Court documents are available upon request at [email protected]