Headwater Research LLC v. T-Mobile USA, Inc. et al.

Headwater Research LLC, a non-practicing entity (NPE) with a patent portfolio focused on mobile device intelligence, background data management, and network optimization technologies, initiated this patent infringement litigation. Headwater has demonstrated an active litigation strategy against major consumer electronics and telecommunications companies, having previously secured substantial jury verdicts against Verizon Communications and Samsung. The defendants, T-Mobile USA, Inc. and Sprint LLC (now largely integrated with T-Mobile), are major operating companies in the wireless telecommunications industry.

The lawsuit asserted U.S. Patent No. 8,667,571. While specific details of the accused products or services by T-Mobile and Sprint in this particular case are not extensively detailed in public records, Headwater's assertion patterns and related cases suggest the patent generally relates to securely delivering data to end-user devices, including methods for securely sending messages and credentials from application servers to mobile phones and tablets. In similar litigation against Apple involving this patent, the accused products included mobile devices, tablets, wearables, and servers utilizing push notification services.

The case was filed in the U.S. District Court for the Eastern District of Texas, Marshall Division, and was presided over by District Judge Rodney Gilstrap. This venue is historically significant and remains one of the top districts for patent litigation, often regarded as plaintiff-friendly due to its patent-specialized judges and reputation for moving cases efficiently to trial. The case was consolidated with another related action against T-Mobile (Case No. 2:23-cv-00379-JRG-RSP). This litigation is notable due to Headwater Research LLC's status as a prolific NPE with a track record of significant patent assertion successes, including nine-figure verdicts, making their suits closely watched within the mobile technology and patent litigation sectors. The case concluded with a confidential settlement and dismissal with prejudice, indicating a negotiated resolution between the parties.

The patent infringement case of Headwater Research LLC v. T-Mobile USA, Inc. et al. (Case No. 2:23-cv-00377) in the U.S. District Court for the Eastern District of Texas concluded with a confidential settlement and dismissal with prejudice.

Here is a chronological summary of the key legal developments and outcome:

• Filing & Initial Pleadings:

  • The case was filed on August 23, 2023, by Headwater Research LLC against T-Mobile USA, Inc. and Sprint LLC.
  • On November 2, 2023, the case 2:23-cv-00377 was consolidated for all pretrial issues with a lead case, Headwater Research LLC v. T-Mobile US, Inc. et al. (Case No. 2:23-cv-00379).
  • The defendants, Sprint Corp., T-Mobile USA, Inc., and T-Mobile US, Inc., filed their Answer to the Complaint, including a Jury Demand and Counterclaim against Headwater Research LLC, on November 2, 2023.

• Pre-trial Motions of Substance:

  • There is no public record of substantive pre-trial motions such as motions to dismiss, transfer, or for summary judgment being fully adjudicated or resulting in reported opinions in this specific case prior to settlement.
  • Similarly, there is no public record of motions to stay pending IPR specifically for this patent (US8667571) in this case. Courts generally consider factors like simplification of issues, discovery status, and potential prejudice when deciding on stays.

• Claim Construction (Markman) Outcomes:

  • Given the case's settlement and dismissal, it is unlikely that a Markman hearing was held or a claim construction order issued. The process of claim construction typically occurs later in the litigation lifecycle.

• Discovery Milestones:

  • The case progressed into the discovery phase. Expert reports were prepared by Dr. Coleman Bazelon, with a primary report on January 29, 2025, a supplemental report on February 13, 2025, and a second supplemental report on March 19, 2025. His deposition also occurred on March 21, 2025. These activities indicate substantial expert discovery was undertaken by the parties.

• Trial Events, Verdict, and Post-Trial Motions:

  • The case did not proceed to trial, verdict, or post-trial motions due to the settlement.

• Settlement, Dismissal, Judgment, or Appeal:

  • The case was dismissed with prejudice on May 17, 2025, after 816 days of litigation, indicating that a confidential settlement was reached between the parties.

• Parallel PTAB IPR/PGR Proceedings:

  • While Headwater Research LLC is known to be involved as a patent owner in several PTAB proceedings concerning other patents (e.g., IPR2024-01051 for US8639811, IPR2026-00138 for US9609544), and T-Mobile USA, Inc. has been a petitioner in various IPRs against other patent owners for different patents (e.g., IPR2023-00638 against VoIP-Pal.com, Inc., IPR2025-00692 against Smart RF Inc.), there is no public record of a parallel PTAB IPR or PGR proceeding specifically challenging U.S. Patent No. 8,667,571 involving either Headwater Research LLC as patent owner or T-Mobile/Sprint as a petitioner.
  • U.S. Patent No. 8,667,571 has, however, been asserted by Headwater Research LLC in other litigation, notably against Apple Inc. in the Western District of Texas, as of July 2025.

Here is the counsel of record representing Headwater Research LLC in Headwater Research LLC v. T-Mobile USA, Inc. et al., Case No. 2:23-cv-00377, in the U.S. District Court for the Eastern District of Texas:

Russ August & Kabat (Los Angeles, CA)

• Marc A. Fenster - Lead Counsel.
  • Mr. Fenster is a highly experienced patent litigator, consistently recognized for his work in high-stakes intellectual property disputes, particularly for patent owners.
• Adam S. Hoffman - Attorney to be Noticed.
  • Mr. Hoffman's practice focuses on patent, copyright, and trade secret litigation.
• Benjamin T. Wang - Attorney to be Noticed.
  • Mr. Wang's experience includes representing clients in patent infringement lawsuits across various technologies.
• Brian D. Ledahl - Attorney to be Noticed.
  • Mr. Ledahl has significant experience in patent litigation, including cases involving mobile technology and network optimization.
• Dale Chang - Attorney to be Noticed.
  • Mr. Chang is involved in intellectual property litigation, including patent infringement cases.
• Kristopher Ryan Davis - Attorney to be Noticed.
  • Mr. Davis's practice includes representing patent owners in infringement actions.
• Reza Mirzaie - Attorney to be Noticed.
  • Mr. Mirzaie has experience representing patent owners in various intellectual property disputes, including IPR proceedings.
• Neil Alan Rubin - Attorney to be Noticed.
  • Mr. Rubin is an attorney involved in patent litigation for Headwater Research LLC in related cases.
• James Shrin Tsuei - Attorney to be Noticed.
  • Mr. Tsuei is listed as an attorney for Headwater Research LLC in patent infringement actions.
• Jason Wietholter - Attorney to be Noticed.
  • Mr. Wietholter is an attorney appearing for Headwater Research LLC in patent infringement cases.
• Philip J. Wang - Attorney to be Noticed (also referred to as Philip X. Wang).
  • Mr. Wang's practice includes patent litigation for Headwater Research LLC.

Miller Fair Henry PLLC (Longview, TX)

• Andrea Leigh Fair - Local Counsel.
  • Ms. Fair is a Texas-based attorney, often serving as local counsel in patent infringement cases in the Eastern District of Texas.

BC Law Group, P.C. (Portland, OR)

• Amy Elizabeth Hayden - Attorney to be Noticed (terminated as of February 24, 2025).
  • Ms. Hayden was listed as an attorney for Headwater Research LLC in this and related patent infringement cases.

Attorney At Law

• James N. Pickens - Attorney to be Noticed.
  • Mr. Pickens has appeared as an attorney for Headwater Research LLC in other patent infringement suits.

This information is derived from PACER docket entries for this case and consolidated cases, as well as related IPR proceedings and other publicly available legal information. The case was dismissed with prejudice, signaling a confidential settlement.

The following individuals and firms represented defendants T-Mobile USA, Inc. and Sprint LLC in Headwater Research LLC v. T-Mobile USA, Inc. et al., Case No. 2:23-cv-00377, in the Eastern District of Texas:

Counsel for T-Mobile USA, Inc. and Sprint LLC:

• Josh A. Krevitt - Lead Attorney

  • Firm: Gibson, Dunn & Crutcher LLP
  • Office Location: New York, NY (Primary office for patent litigation)
  • Note: Krevitt is a well-known patent litigator with extensive experience representing major technology and telecommunications companies. He was noted as a lead attorney in this case.

• Melissa Richards Smith - Attorney to be Noticed

  • Firm: Gillam & Smith LLP
  • Office Location: Tyler, TX
  • Note: Smith is a prominent local counsel in the Eastern District of Texas, frequently involved in significant patent cases in the venue. She filed an amended answer and jury demand for the defendants.

• Katherine Dominguez - Attorney to be Noticed

  • Firm: Gibson, Dunn & Crutcher LLP
  • Office Location: Dallas, TX
  • Note: Dominguez made an appearance on behalf of Sprint Corp., T-Mobile US, Inc., and T-Mobile USA, Inc.

• Robert Vincent - Attorney to be Noticed

  • Firm: Gibson, Dunn & Crutcher LLP
  • Office Location: Dallas, TX
  • Note: Vincent also appeared on behalf of the defendants.

• Brian Ashley Rosenthal - Attorney to be Noticed

  • Firm: Gibson, Dunn & Crutcher LLP
  • Office Location: Dallas, TX
  • Note: Rosenthal entered an appearance for the defendants.

• Andrew William Robb - Attorney to be Noticed

  • Firm: Gibson, Dunn & Crutcher LLP
  • Office Location: Dallas, TX
  • Note: Robb also appeared for the defendants.

The case also involved economic experts who submitted reports. Dr. Coleman Bazelon and Dr. Paroma Sanyal of The Brattle Group submitted expert reports on behalf of T-Mobile US, Inc. and Sprint Corp.. While not counsel of record, their involvement indicates the economic and valuation aspects of the patent dispute. Dr. Bazelon has extensive experience in telecommunications and spectrum management, having worked at the Congressional Budget Office. Dr. Sanyal is also a telecommunications industry expert, specializing in asset valuation, spectrum policy, and intellectual property matters.