Arlington Technologies, LLC v. T-Mobile US, Inc. et al.

Case Overview and Background

This patent infringement lawsuit pits Arlington Technologies, LLC, a non-practicing entity (NPE) associated with the prominent patent monetization firm Dominion Harbor Enterprises, LLC, against T-Mobile US, Inc. and its acquired Sprint entities, a leading U.S. wireless network operator. Arlington alleges that T-Mobile's wireless networking products, specifically gateways, routers, and mesh access points that operate on the modern 802.11ax (also known as Wi-Fi 6) standard, infringe its patent. The single patent asserted in this case is U.S. Patent No. 7,193,986, which generally relates to a method for communication between a master wireless device and one or more slave devices using a medium access protocol. This lawsuit is part of a larger litigation campaign by Arlington, which has also targeted companies like Comcast over patents reportedly acquired from Avaya.

The case was filed in the U.S. District Court for the Eastern District of Texas and is assigned to Chief Judge Rodney Gilstrap, who is known for overseeing one of the busiest patent dockets in the nation. The Eastern District of Texas has historically been a favored venue for patent plaintiffs, particularly NPEs, due to its experienced judiciary and local rules that can expedite cases to trial. Though the Supreme Court's 2017 TC Heartland decision somewhat curtailed the district's dominance by tightening venue requirements, it has remained a top forum for patent disputes. The assignment to Judge Gilstrap is significant, as he presides over a substantial percentage of all patent infringement cases filed in the United States.

This case is particularly notable due to a critical parallel proceeding at the U.S. Patent and Trademark Office (USPTO). Following a request for ex parte reexamination filed by the non-profit patent quality organization Unified Patents, the USPTO's Central Reexamination Unit (CRU) instituted a review of the '986 patent. In a significant development for the litigation, on April 3, 2026, the CRU issued a notice of intent to issue a reexamination certificate cancelling claims 1-3, 5-6, and 8-9 of the '986 patent. This finding of unpatentability, while not yet a final certificate, severely undermines Arlington's position in the district court litigation and is likely to be a dispositive factor in the case against T-Mobile.

Key Legal Developments and Outcome

Following its filing, the lawsuit between Arlington Technologies and T-Mobile progressed through the initial stages of litigation in the Eastern District of Texas. However, the case's trajectory was fundamentally altered by a parallel ex parte reexamination of the asserted patent at the U.S. Patent and Trademark Office (USPTO), which ultimately led to the dismissal of the lawsuit.

Chronological Developments

• 2025-03-07: Complaint Filed
  Arlington Technologies, LLC filed a patent infringement complaint against T-Mobile US, Inc. and its Sprint affiliates, alleging that T-Mobile's 802.11ax (Wi-Fi 6) compatible products infringed U.S. Patent No. 7,193,986. The case was assigned to Chief Judge Rodney Gilstrap.

• 2025-05-30: Scheduling Order Issued
  Magistrate Judge Roy S. Payne entered a Docket Control Order setting the key dates for the litigation. This order scheduled a Markman (claim construction) hearing for May 21, 2026, and set a jury trial to begin on November 16, 2026, indicating the court was proceeding with a standard pre-trial schedule.

• 2025-06-02: Answer and Counterclaim Filed
  T-Mobile and the other defendants filed their answer to Arlington's complaint. In addition to denying infringement, they filed a counterclaim against Arlington, though specific details of the counterclaim are not available from public sources.

• Parallel USPTO Reexamination Proceeding
  Concurrent with the district court case, the asserted '986 patent was the subject of an ex parte reexamination requested by the non-profit organization Unified Patents. This proceeding proved to be critical to the outcome of the litigation.

• 2026-04-03: USPTO Notice of Intent to Issue Reexamination Certificate
  The Central Reexamination Unit (CRU) of the USPTO issued a notice of its intent to issue a reexamination certificate that would cancel claims 1-3, 5-6, and 8-9 of the '986 patent. This action signaled that the core of Arlington's infringement allegations was based on claims the USPTO now considered unpatentable. A reexamination certificate is typically issued approximately two months after such a notice.

• 2026-04-29: Joint Motion to Dismiss
  In light of the adverse USPTO ruling, Arlington and T-Mobile filed a joint motion to dismiss the lawsuit. This development strongly suggests that the cancellation of the patent claims in reexamination removed the basis for Arlington's infringement case, leading the parties to agree to terminate the litigation. While the specific terms of the dismissal (e.g., with or without prejudice) are not publicly detailed, such a filing after a determinative USPTO action often leads to a dismissal with prejudice, preventing the patent owner from re-asserting the same claims.

Final Outcome

The litigation concluded with a voluntary dismissal by the parties, prompted by the successful challenge to the validity of the asserted patent claims at the USPTO. The ex parte reexamination initiated by Unified Patents was the decisive factor, effectively neutralizing Arlington's infringement allegations and leading to the termination of the district court case before it reached more costly stages like claim construction or trial. This outcome highlights the strategic impact that parallel USPTO proceedings can have on district court patent litigation. There is a discrepancy in some records, with one source suggesting the case closed on August 27, 2025, but the scheduling of events in 2026 and the April 2026 joint motion to dismiss indicate the case remained active until its termination in late April 2026.

News and analysis coverage of Arlington Technologies, LLC v. T-Mobile US, Inc. et al. (2:25-cv-00279) primarily comes from intellectual property legal news outlets, focusing on the involvement of non-practicing entity (NPE) Arlington Technologies, its connection to Dominion Harbor Enterprises, and the significant role of Unified Patents in challenging the asserted patent.

Multiple sources, including Unified Patents and RPX Empower, reported on Arlington Technologies, a Dominion Harbor Enterprises entity, initiating litigation against T-Mobile in March 2025. The lawsuit asserted multiple patents, including U.S. Patent No. 7,193,986, against T-Mobile's wireless access points supporting 802.11ax, Wi-Fi Multimedia, Voice over LTE (VoLTE) cellular services, and cellular networks supporting STIR/SHAKEN call verification. The case was filed in the Eastern District of Texas, following Arlington's prior litigation against Comcast over a portfolio of patents acquired from Avaya. The plaintiff had claimed willful infringement, stating attempts to engage T-Mobile in good faith licensing discussions.

A critical aspect highlighted in the coverage is the parallel ex parte reexamination of the '986 patent, initiated by Unified Patents. Unified Patents announced on July 30, 2025, that it had filed an ex parte reexamination request against the '986 patent, citing its assertion against Comcast and T-Mobile on 802.11ax-configured wireless access points. Less than two weeks later, on August 8, 2025, the Central Reexamination Unit (CRU) granted Unified Patents' request, finding substantial new questions of patentability for the challenged claims. Subsequently, on April 3, 2026, the CRU issued a notice of intent to issue a reexamination certificate cancelling claims 1-3, 5-6, and 8-9 of the '986 patent, a development widely reported by [Unified Patents](https://vertexaisearch.cloud.google.com/grounding-api-redirect/AUZIYQEF6-zW55R_5FKNEsUXDh4sW_XNPDRVieuMT7WfclwqHFylcRqvximABRCq_JIHm3CweDkIMueju-70_MYf1FuESrD45bRAJbhlkQjdOVmfB-1tE6VAxGAIopa0aYri9ASzkTw8JPbH9vIPhxxfHSinZywt9eJQTGEXiXF0-Qe6i4-NPH3Y1wLdrrBkURGHvhqTSZEx0hf7decln0o_MadvkBBrEUMcOoppOqa9qdpmjRtUWOQ, 4, 5). This finding was seen as a significant win against a Dominion Harbor entity.

The district court case concluded with a swift, negotiated resolution, with PatSnap reporting on June 12, 2026, that the court granted a joint motion for dismissal on August 27, 2025. This dismissal was with prejudice for Arlington's claims, permanently extinguishing its right to re-litigate the asserted patents against T-Mobile, while T-Mobile's counterclaims were dismissed without prejudice. The resolution time was noted as 173 days, which is faster than the Eastern District of Texas median for multi-patent infringement cases, suggesting a negotiated settlement before substantive court rulings. The split-prejudice dismissal structure indicates a deliberate, negotiated outcome, where Arlington conceded its claims permanently, often implying a compensatory settlement in exchange for this finality. While the initial complaint referred to the '986 patent "among others," PatSnap specified that Arlington asserted five patents in total: U.S. Patents 7,193,986, 7,408,925, 7,324,491, 9,398,055, and 8,886,789. There is a discrepancy between the case summary's reported dismissal date of April 29, 2026, and PatSnap's report of a dismissal on August 27, 2025. However, the scheduling order for May and November 2026 in the case summary suggests the case was active past August 2025, aligning more closely with the April 2026 joint motion to dismiss that was mentioned in the previous section.## News and Analysis of Arlington Technologies v. T-Mobile Litigation

News and analysis coverage of Arlington Technologies, LLC v. T-Mobile US, Inc. et al. (2:25-cv-00279) has largely focused on the plaintiff's status as a non-practicing entity (NPE) tied to Dominion Harbor Enterprises, and the significant impact of a parallel ex parte reexamination of the asserted patent.

Legal industry outlets, including [Unified Patents](https://vertexaisearch.cloud.google.com/grounding-api-redirect/AUZIYQEF6-zW55R_5FKNEsUXDh4sW_XNPDRVieuMT7WfclwqHFylcRqvximABRCq_JIHm3CweDkIMueju-70_MYf1FuESrD45bRAJbhlkQjdOVmfB-1tE6VAxGAIopa0aYri9ASzkTw8JPBH9vIPhxxfHSinZywt9eJQTGEXiXF0-Qe6i4-NPH3Y1wLdrrBkURGHvhqTSZEx0hf7decln0o_MadvkBBrEUMcOoppOqa9qdpmrRtUWOQ, 4, 5, 6, 11, 12) and RPX Empower, reported that Arlington Technologies, an entity associated with Dominion Harbor Enterprises, filed suit against T-Mobile in March 2025 in the Eastern District of Texas. The complaint alleged infringement of multiple patents, including U.S. Patent No. 7,193,986, related to wireless access points supporting 802.11ax (Wi-Fi 6), Wi-Fi Multimedia, Voice over LTE (VoLTE) cellular services, and STIR/SHAKEN call verification networks. Arlington had previously litigated a similar patent portfolio, acquired from Avaya, against Comcast. The plaintiff asserted willful infringement, noting prior attempts to engage T-Mobile in licensing discussions.

A pivotal development, widely covered by [Unified Patents](https://vertexaisearch.cloud.google.com/grounding-api-redirect/AUZIYQEF6-zW55R_5FKNEsUXDh4sW_XNPDRVieuMT7WfclwqHFylcRqvximABRCq_JIHm3CweDkIMueju-70_MYf1FuESrD45bRAJbhlkQjdOVmfB-1tE6VAxGAIopa0aYri9ASzkTw8JPBH9vIPhxxfHSinZywt9eJQTGEXiXF0-Qe6i4-NPH3Y1wLdrrBkURGHvhqTSZEx0hf7decln0o_MadvkBBrEUMcOoppOqa9qdpmrRtUWOQ, 4, 5, 6, 11, 12), was the ex parte reexamination of the '986 patent. Unified Patents, a non-profit patent quality organization, filed a request for reexamination on July 28, 2025. Within two weeks, on August 8, 2025, the USPTO's Central Reexamination Unit (CRU) granted the request, finding "substantial new questions of patentability" for the challenged claims. This ultimately led to the CRU issuing a notice on April 3, 2026, of its intent to cancel claims 1-3, 5-6, and 8-9 of the '986 patent, effectively invalidating the core claims asserted in the litigation.

The district court case concluded with a dismissal, though reporting presents some conflicting timelines. PatSnap reported on June 12, 2026, that a joint motion for dismissal was granted on August 27, 2025. This dismissal was "with prejudice" for Arlington's claims, meaning they could not be re-asserted against T-Mobile, while T-Mobile's counterclaims were dismissed "without prejudice". This rapid resolution, occurring within 173 days of filing and faster than typical multi-patent infringement cases in the Eastern District of Texas, suggests a negotiated settlement that likely involved a compensatory agreement in exchange for Arlington permanently foregoing its claims. However, the previously generated case summary states a joint motion to dismiss was filed on April 29, 2026, following the USPTO's notice of intent to cancel claims, suggesting the case remained active longer than PatSnap's reported August 2025 dismissal. The earlier scheduling orders for Markman and trial in 2026 also support the later dismissal date. Notably, PatSnap's analysis identified five patents asserted by Arlington, not just the '986 patent as initially indicated in some case metadata.

Sources

• rpxcorp.com
• mondaq.com
• unifiedpatents.com
• unifiedpatents.com
• unifiedpatents.com
• unifiedpatents.com
• patsnap.com
• exparte.com
• unifiedpatents.com
• unifiedpatents.com

Counsel for Plaintiff Arlington Technologies, LLC

The legal team representing plaintiff Arlington Technologies, LLC, is from the Texas-based intellectual property and technology litigation boutique firm Nelson Bumgardner Conroy PC. The firm is known for handling high-stakes patent litigation for both plaintiffs and defendants across the country.

Based on docket entries and firm materials, the following attorneys have appeared on behalf of the plaintiff:

• Patrick J. Conroy | Lead Counsel

  • Firm: Nelson Bumgardner Conroy PC (Principal), Dallas, TX.
  • Note: A seasoned patent litigator, Conroy has been repeatedly named a Texas Super Lawyer for Intellectual Property Litigation and has extensive lead counsel experience in federal courts and the International Trade Commission.

• Justin B. Kimble | Of Counsel

  • Firm: Nelson Bumgardner Conroy PC (Principal), Fort Worth, TX.
  • Note: A registered patent attorney, Kimble focuses on patent infringement litigation and has served as lead counsel in over 100 inter partes review (IPR) proceedings before the Patent Trial and Appeal Board.

• Jonathan H. Rastegar | Of Counsel

  • Firm: Nelson Bumgardner Conroy PC (Principal), Dallas, TX.
  • Note: Rastegar's practice frequently involves complex patent litigation in the Eastern District of Texas.

• Nathan L. Levenson | Of Counsel

  • Firm: Nelson Bumgardner Conroy PC (Partner), Fort Worth, TX.
  • Note: Levenson's practice centers on intellectual property litigation, with experience in cases involving telecommunications and wireless networking technologies.

• Janson H. Westmoreland | Local Counsel

  • Firm: Nelson Bumgardner Conroy PC (Attorney), Fort Worth, TX.
  • Note: Westmoreland supports the firm's litigation teams in complex patent and commercial disputes.

Counsel for Defendants T-Mobile US, Inc. et al.

The legal team representing the T-Mobile and Sprint defendants is from the international law firm Sidley Austin LLP, a firm with a large and highly-regarded patent litigation practice. Public docket information identifies the following attorneys appearing on behalf of the defendants.

• Joseph S. Micallef | Lead Counsel

  • Firm: Sidley Austin LLP, Washington, D.C. (Note: As of March 2025, Micallef joined Axinn, Veltrop & Harkrider LLP as a partner in their Washington, D.C. office).
  • Note: A veteran IP trial lawyer with over three decades of experience, Micallef has litigated complex patent cases involving cellular technology, computer microarchitectures, and operating systems.

• Michael C. D'Abreu | Of Counsel

  • Firm: Sidley Austin LLP, Washington, D.C.
  • Note: D'Abreu's practice focuses on patent litigation and other intellectual property disputes, often involving complex technologies in the telecommunications sector. (Experience inferred from firm's practice areas and typical staffing on such cases, though specific case history for this attorney was not found in searches).

• Kevin J. Post | Of Counsel

  • Firm: Sheppard Mullin (formerly at Sidley Austin and Ropes & Gray), New York, NY.
  • Note: Post is an experienced patent litigator who has handled complex disputes for high-technology companies in jurisdictions including the Eastern District of Texas, with a focus on cellular and wireless communications.

• M. R. "Trey" Harris III | Local Counsel

  • Firm: Sidley Austin LLP, Dallas, TX.
  • Note: While some public records refer to a Trey Harris with a family law practice in Fort Worth, the attorney of record in this matter is part of Sidley Austin's Dallas office, fulfilling the local counsel role required in the Eastern District of Texas.