RightQuestion v. T-Mobile: IMS Call Validation Patents Dismissed With Prejudice
RightQuestion, LLC filed suit against T-Mobile in the Eastern District of Texas, asserting three patents covering IMS network call validation, secure telephone identity verification, and scam-shield technology. The parties jointly stipulated to dismiss all claims with prejudice just 82 days after filing — each side bearing its own costs.
A fast exit: IMS call-validation suit ends by stipulation in under three months
RightQuestion, LLC — a patent assertion entity holding IP in call authentication and IMS network technology — filed suit against T-Mobile USA, Inc. and T-Mobile US, Inc. on September 24, 2025 in the Eastern District of Texas before Judge Rodney Gilstrap. The complaint alleged infringement of three U.S. patents: US11856132B2, US10674009B1, and US11005989B1, all directed at technologies underlying IMS (IP Multimedia Subsystem) networks, call validation treatment, and secure telephone identity verification services.
The case closed on December 15, 2025, when the parties filed a Stipulated Motion for Dismissal under Rule 41 of the Federal Rules of Civil Procedure. Judge Gilstrap accepted the stipulation and dismissed all claims with prejudice. A dismissal with prejudice is a final adjudication on the merits — RightQuestion is permanently barred from reasserting these specific claims against T-Mobile in any future proceeding. The order also specified that each party bears its own costs and fees, which is consistent with a negotiated resolution rather than a contested win for either side.
The 82-day duration from filing to closure is notably brief for an E.D. Texas patent case, which typically runs 18–24 months to trial. The speed of resolution suggests the parties reached a private agreement — potentially a license, covenant not to sue, or commercial settlement — shortly after filing. The public record is silent on the financial terms, if any, leaving the commercial outcome of the dispute undisclosed. The presence of experienced plaintiff-side counsel from Kramer Alberti Lim & Tonkovich LLP alongside defendant counsel Gillam & Smith LLP further suggests structured negotiation rather than early dismissal on legal grounds.
Filing to Dismissed with Prejudice in 82 days
82 days — significantly shorter than the median E.D. Texas patent case lifecycle.
Dismissed with prejudice: what the stipulated order means for both parties
Rule 41 stipulated dismissal with prejudice — a final, bilateral exit
A Rule 41 dismissal with prejudice, filed by stipulation, means both parties agreed to end the litigation and the court has no remaining jurisdiction over the claims. Unlike a without-prejudice dismissal, this order is res judicata — RightQuestion cannot refile these patent claims against T-Mobile in any court. The ‘each party bears own costs’ provision reinforces that neither side won a contested ruling.
Permanent bar on refilingRightQuestion: claims extinguished as against T-Mobile, patents survive elsewhere
A with-prejudice dismissal closes the door on these three patents against T-Mobile specifically, but does not invalidate the patents. RightQuestion retains the ability to assert US11856132B2, US10674009B1, and US11005989B1 against other parties in the IMS and call-validation ecosystem. The speed of resolution and mutual cost-bearing suggests RightQuestion may have secured a licensing arrangement or commercial consideration outside the court record.
Patents remain enforceable vs. othersT-Mobile: litigation risk cleared, but terms remain confidential
T-Mobile exits the litigation without any adverse court ruling on infringement or validity. The with-prejudice dismissal provides T-Mobile with certainty that RightQuestion cannot re-assert these specific claims. However, because the resolution is stipulated and terms are undisclosed, it is unclear whether T-Mobile paid any consideration. T-Mobile’s IMS network, CVT, STI-VS, and Scam Shield products carry no public judicial finding of infringement or non-infringement.
No infringement finding on recordIMS call-validation IP remains active threat to other carriers and vendors
The rapid settlement suggests these patents held sufficient claim scope to prompt T-Mobile to resolve quickly, which may signal risk for other IMS network operators — including AT&T, Verizon, and enterprise SBC/TAS vendors — who deploy similar STIR/SHAKEN and call validation infrastructure. Companies operating STI-VS compliant systems or similar scam-shield applications should assess their exposure to the RightQuestion portfolio as enforcement activity may continue.
Monitor for further assertionsFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | RightQuestion, LLC | Company | Patent assertion entity — holder of US11856132B2, US10674009B1, and US11005989B1 covering IMS call validation and STI-VS technology.Search in Eureka ↗ |
| Defendant | T-Mobile | Individual | T-Mobile USA, Inc. and T-Mobile US, Inc. — major U.S. wireless carrier operating IMS network infrastructure and Scam Shield services.Search in Eureka ↗ |
| Plaintiff counsel | Andrea Leigh Fair | Attorney | Counsel for RightQuestion, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Nicole E. Glauser | Attorney | Counsel for RightQuestion, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Robert C. Mattson | Attorney | Counsel for RightQuestion, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Robert F. Kramer | Attorney | Counsel for RightQuestion, LLCSearch in Eureka ↗ |
| Plaintiff law firm | Kramer Alberti Lim & Tonkovich LLP | Law Firm | Representing RightQuestion, LLCSearch in Eureka ↗ |
| Plaintiff law firm | Miller Fair Henry PLLC | Law Firm | Representing RightQuestion, LLCSearch in Eureka ↗ |
| Defendant counsel | Melissa Richards Smith | Attorney | Counsel for T-MobileSearch in Eureka ↗ |
| Defendant law firm | Gillam & Smith LLP | Law Firm | Representing T-MobileSearch in Eureka ↗ |
| Presiding judge | Judge Rodney Gilstrap | Judge | Texas Eastern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The court’s order accepts the parties’ stipulation verbatim and dismisses all claims with prejudice under Rule 41, with each party bearing its own costs. The phrase ‘each party shall bear its own costs and fees’ is a standard marker of a negotiated exit — had one side prevailed on a motion, cost-shifting would typically be contested. The denial of all pending relief ‘as moot’ confirms no substantive ruling was issued, leaving the patents’ validity and infringement questions unresolved on the public record.
US11856132B2, US10674009B1 & US11005989B1 — IMS Call Validation & STI-VS
The three asserted patents cover overlapping layers of IMS (IP Multimedia Subsystem) architecture as applied to call authentication and anti-spoofing. US11856132B2 (application filed April 2021) relates to call validation treatment within IMS networks. US10674009B1 (filed November 2018) covers methods for secure telephone identity verification. US11005989B1 (filed February 2020) addresses IMS telephony application server functionality. Together they map onto the STIR/SHAKEN regulatory framework mandated for U.S. carriers, making them commercially significant across the wireless industry.
The accused T-Mobile products — including its CVT (Call Validation Treatment) pipeline, STI-VS (Secure Telephone Identity Verification Service), CSCF, Session Border Controller, Telephony Application Server, and the T-Life/Scam Shield app — represent infrastructure that virtually every major U.S. carrier and many enterprise telecom vendors operate in functionally equivalent form. The breadth of accused components suggests RightQuestion’s claim charts likely targeted widely standardized IMS interfaces, raising the sector-wide risk profile of this patent cluster for any operator deploying STIR/SHAKEN-compliant systems.
Should you run an FTO against US11856132B2, US10674009B1 & US11005989B1?
Any organization deploying IMS network infrastructure with integrated call validation treatment, STIR/SHAKEN attestation, or secure telephone identity verification services should treat this patent cluster as a live commercial risk. The accused T-Mobile components — CVT, STI-VS, CSCF, SBC, TAS — are architectural standards across U.S. wireline and wireless carriers. If your product or platform touches call authentication, anti-spoofing, or scam-detection pipelines, an FTO assessment against these three patents is commercially advisable.
PatSnap Eureka’s FTO Search Agent can map the claim language of US11856132B2, US10674009B1, and US11005989B1 against your product architecture, identify prior art that may limit enforceability, and surface prosecution history disclaimers that could define design-around space. Eureka’s portfolio monitoring tools also allow you to track RightQuestion’s assertion activity across other jurisdictions in real time — giving R&D and legal teams early warning of follow-on enforcement.
Run a freedom-to-operate analysis on US11856132B2 to assess your product’s exposure
Run FTO in Eureka →Similar IMS and call-authentication patent cases in E.D. Texas
Explore patent infringement cases involving IMS network technology, STIR/SHAKEN call authentication, and secure telephone identity systems litigated in the Eastern District of Texas.
What this case signals for the IMS and call-authentication IP landscape
A sub-90-day resolution in E.D. Texas by a specialist plaintiff firm suggests these call-validation patents carry real commercial weight.
E.D. Texas speed signals a probable licensing deal, not a weak case
Cases that resolve this quickly in the Eastern District of Texas — especially with experienced plaintiff counsel from Kramer Alberti — rarely do so because the plaintiff’s case collapsed. The with-prejudice stipulation and mutual cost-bearing is the hallmark of a confidential settlement or license. Companies in the IMS and STIR/SHAKEN space should treat this as a signal that the RightQuestion portfolio has commercial traction.
Three patents asserted; all survive and remain enforceable against the market
None of the three asserted patents — US11856132B2, US10674009B1, US11005989B1 — were invalidated, narrowed, or subjected to IPR in this action. Competitors deploying IMS network elements, CVT/STI-VS pipelines, or call-authentication apps face an unreduced portfolio. Freedom-to-operate analysis against this cluster of patents is now commercially advisable for any telco or vendor in the STIR/SHAKEN ecosystem.
RightQuestion v T-Mobile — key questions answered
Dismissal with prejudice under Rule 41 means all of RightQuestion’s patent claims against T-Mobile are permanently extinguished. RightQuestion cannot refile suit against T-Mobile on the same claims under US11856132B2, US10674009B1, or US11005989B1. The dismissal operates as a final adjudication, but it does not invalidate the patents — RightQuestion may still assert them against other defendants.
RightQuestion asserted three U.S. patents: US11856132B2 (application no. US17/228566), US10674009B1 (US16/180373), and US11005989B1 (US16/785423). All three relate to IMS network call validation, secure telephone identity verification (STIR/SHAKEN), and related telephony application server technology deployed in T-Mobile’s network and consumer applications.
The complaint targeted T-Mobile’s IMS (IP Multimedia Subsystem) network infrastructure and associated software, specifically: CVT (Call Validation Treatment), STI-VS (Secure Telephone Identity Verification Service), CSCF (Call Session Control Function), Session Border Controllers, Telephony Application Servers, and the T-Life and Scam Shield consumer applications. These components are standard across major U.S. wireless carriers.
An 82-day resolution is well below the typical 18–24 month lifecycle of an E.D. Texas patent case. The stipulated nature of the dismissal and the mutual cost-bearing provision are consistent with a private licensing agreement or settlement reached shortly after filing. The public record does not disclose any financial terms. No substantive motions were decided, suggesting the parties negotiated directly rather than litigating on the merits.
No. The dismissal with prejudice only bars RightQuestion from reasserting these specific claims against T-Mobile. The patents US11856132B2, US10674009B1, and US11005989B1 remain valid, unexpired, and enforceable. RightQuestion is free to assert them against AT&T, Verizon, or any other IMS network operator or equipment vendor. The fast resolution may signal the portfolio has sufficient licensing value to warrant proactive FTO review by other market participants.
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