Gravel Rating Systems v. T-Mobile: Knowledge Filter Patent Dispute Ends in Settlement
Gravel Rating Systems LLC asserted US7590636B1 — a knowledge filter patent — against T-Mobile in the Eastern District of Texas. After 1,202 days of litigation, the parties jointly moved to dismiss with prejudice under a confidential settlement agreement, each side bearing its own costs.
Three-Year Texas Patent Battle Ends in Confidential Settlement
On 22 February 2021, Gravel Rating Systems LLC filed suit against T-Mobile USA, Inc. and T-Mobile US, Inc. in the Eastern District of Texas before Judge Amos L. Mazzant, asserting infringement of US7590636B1, a patent covering knowledge filter technology. The case was assigned Case No. 4:21-cv-00152 and presented as a classic NPE-versus-carrier dispute in one of the country’s most active patent litigation venues.
After 1,202 days, the parties filed a Joint Motion to Dismiss with Prejudice on 8 June 2024, citing a Settlement Agreement. Judge Mazzant granted the motion, ordering all claims, counterclaims, and causes of action dismissed with prejudice under Fed. R. Civ. P. 41. Each party was directed to bear its own costs, expenses, and attorneys’ fees — a cost-neutral resolution that offers no indication of which side held the stronger negotiating position at settlement.
The 1,202-day duration suggests the case survived at least initial motion practice and proceeded through substantive phases before resolution. The confidential settlement prevents public scrutiny of financial terms, and the with-prejudice dismissal forecloses Gravel from reasserting the same claims against T-Mobile. What drove the ultimate settlement — claim construction rulings, IPR activity, or commercial calculus — remains unknown from the public record.
Filing to Dismissed with Prejudice in 1202 days
1,202 days — over 3 years of litigation before settlement resolution
Dismissed with prejudice: what the joint settlement means for both parties
Rule 41 dismissal with prejudice operates as a final judgment on the merits
A dismissal with prejudice under Fed. R. Civ. P. 41 carries the force of a final adjudication. Gravel Rating Systems is permanently barred from reasserting the same claims under US7590636B1 against T-Mobile in any future action. Unlike a without-prejudice dismissal, this closure is absolute — the Eastern District of Texas retains no residual jurisdiction over the underlying patent claims between these parties.
Res judicata effectGravel permanently barred from re-filing against T-Mobile on this patent
Gravel Rating Systems secured whatever consideration the confidential Settlement Agreement provided, but paid the price of permanent claim extinction against T-Mobile. With prejudice dismissal means Gravel cannot revive this action if settlement terms are later disputed. The patent itself — US7590636B1 — remains valid and potentially enforceable against other parties; only T-Mobile is shielded by the settlement-linked dismissal.
Claims extinguished vs. T-MobileT-Mobile obtains permanent closure on US7590636B1 infringement claims
T-Mobile emerged with a with-prejudice dismissal that provides durable protection against Gravel on the asserted patent. The cost-neutral fee arrangement — each party bearing its own — is typical of negotiated settlements and does not signal either party’s litigation leverage. T-Mobile’s deployment of five law firms across the defence suggests robust resources committed to resisting the claims prior to settlement agreement.
Full dismissal, no fee awardKnowledge filter IP remains a live risk for other telecoms and tech platforms
The settlement resolves only the T-Mobile exposure. US7590636B1 survives as an active patent asset in Gravel’s portfolio and could be asserted against other carriers, platform operators, or content filtering services. Companies deploying knowledge filtering, recommendation, or content rating technologies should assess their exposure independently — this dismissal provides no safe harbour for non-parties.
Third-party risk remainsFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Gravel Rating Systems, LLC | Company | Patent assertion entity — holder of US7590636B1, knowledge filter technologySearch in Eureka ↗ |
| Defendant | T-Mobile | Individual | T-Mobile USA/T-Mobile US, Inc. — major U.S. wireless telecommunications carrierSearch in Eureka ↗ |
| Co-Defendant | T-Mobile US, Inc. | Company | Search in Eureka ↗ |
| Plaintiff counsel | Paul Max Richter | Attorney | Counsel for Gravel Rating Systems, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Timothy Devlin | Attorney | Counsel for Gravel Rating Systems, LLCSearch in Eureka ↗ |
| Plaintiff law firm | Devlin Law Firm LLC (Wilmington) | Law Firm | Representing Gravel Rating Systems, LLCSearch in Eureka ↗ |
| Defendant counsel | Austin Michael Schnell | Attorney | Counsel for T-MobileSearch in Eureka ↗ |
| Defendant counsel | Brian Christopher Nash | Attorney | Counsel for T-MobileSearch in Eureka ↗ |
| Defendant counsel | Edward Andrew Cavazos | Attorney | Counsel for T-MobileSearch in Eureka ↗ |
| Defendant counsel | Michael Eric Zeliger | Attorney | Counsel for T-MobileSearch in Eureka ↗ |
| Defendant counsel | Michael Hines Borofsky | Attorney | Counsel for T-MobileSearch in Eureka ↗ |
| Defendant counsel | Ranjini Acharya | Attorney | Counsel for T-MobileSearch in Eureka ↗ |
| Defendant counsel | Steven Tepera | Attorney | Counsel for T-MobileSearch in Eureka ↗ |
| Defendant counsel | Timothy Franklin Dewberry | Attorney | Counsel for T-MobileSearch in Eureka ↗ |
| Defendant law firm | Folio Law Group PLLC (Austin) | Law Firm | Representing T-MobileSearch in Eureka ↗ |
| Defendant law firm | Morrison & Foerster LLP | Law Firm | Representing T-MobileSearch in Eureka ↗ |
| Defendant law firm | Pillsbury Winthrop Shaw Pittman LLP | Law Firm | Representing T-MobileSearch in Eureka ↗ |
| Defendant law firm | Pillsbury Winthrop Shaw Pittman LLP (Palo Alto) | Law Firm | Representing T-MobileSearch in Eureka ↗ |
| Defendant law firm | Reed & Scardino LLP | Law Firm | Representing T-MobileSearch in Eureka ↗ |
| Presiding judge | Judge Amos L. Mazzant | Judge | Texas Eastern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The verdict text confirms a fully negotiated exit: both T-Mobile entities and Gravel jointly moved under Rule 41, with the dismissal expressly tied to a confidential Settlement Agreement. The with-prejudice designation is significant — it extinguishes all claims and counterclaims with finality, functioning as a merits-equivalent bar to re-litigation between these specific parties. The cost-neutrality clause is consistent with arm’s-length settlement practice and reveals nothing about the financial consideration exchanged under the referenced Settlement Agreement.
US7590636B1 — Knowledge Filter Technology Patent
US7590636B1, filed under application number US11/348037, is a granted US utility patent covering knowledge filter technology — broadly encompassing systems and methods for filtering, rating, or categorising information delivered across a network. The patent’s technical domain sits at the intersection of information retrieval, content classification, and network services, areas that underpin recommendation engines, parental controls, spam filtering, and carrier-level content management platforms.
For a major wireless carrier like T-Mobile, knowledge filtering functionality may appear across multiple product lines — from device-level content filtering to network-layer classification services. The strategic significance of US7590636B1 lies in its potential breadth: if claim language captures standard filtering or rating architectures, it could apply to a wide range of commercial implementations. Other carriers, platform operators, and enterprise software vendors with content rating or knowledge management features should treat this patent as an active monitoring priority.
Should your product team run an FTO against US7590636B1?
Any company building or deploying knowledge filtering, content rating, recommendation, or information classification technology on a network should assess exposure to US7590636B1. The patent’s asserted use against a tier-1 carrier confirms the patent holder views its claims as commercially viable and broadly applicable. The T-Mobile settlement provides no safe harbour for non-parties — the patent remains active and enforceable.
PatSnap Eureka’s FTO Search Agent enables R&D and product teams to map their specific implementation against the claim language of US7590636B1 in minutes. Run a claim-chart analysis, identify prior art candidates, and benchmark your exposure before product launch or when entering new markets where knowledge filtering functionality is a core feature. Proactive FTO analysis is significantly less costly than E.D. Texas litigation.
Run a freedom-to-operate analysis on US7590636B1 to assess your product’s exposure
Run FTO in Eureka →Similar Knowledge Filter & Telecom Patent Cases in E.D. Texas
Explore related patent infringement actions involving knowledge filter, content rating, and information classification technology filed in the Eastern District of Texas.
What this case signals for the knowledge filter and telecom IP landscape
A 3-year Eastern District case ending in confidential settlement carries practical signals for carriers and tech platforms facing similar NPE assertions.
Eastern District of Texas remains a preferred venue for NPE patent assertions
Gravel’s choice of E.D. Texas is consistent with the venue’s historical plaintiff-friendly reputation. Carriers and tech companies should anticipate filings in this district and ensure local counsel and defensive playbooks are current. The 1,202-day duration suggests the case was not resolved cheaply or quickly, even for a single-patent assertion.
Cost-neutral dismissals obscure negotiation leverage — read them carefully
The ‘each party bears own costs’ language in the dismissal order is standard settlement boilerplate and provides no reliable signal about financial settlement terms. IP professionals should not interpret cost-neutrality as evidence of defendant strength or plaintiff weakness — confidential settlement economics can run in either direction.
Gravel v T-Mobile — key questions answered
The case was dismissed with prejudice on 8 June 2024 pursuant to a joint motion filed by both parties under Fed. R. Civ. P. 41, tied to a confidential settlement agreement. Each party was ordered to bear its own costs, expenses, and attorneys’ fees. The dismissal permanently bars Gravel from reasserting the same claims against T-Mobile.
Gravel asserted US7590636B1 (application no. US11/348037), a US utility patent covering knowledge filter technology — broadly encompassing systems and methods for filtering, rating, or classifying network-delivered information. The product identified in the complaint was described as a ‘knowledge filter.’
A with-prejudice dismissal extinguishes Gravel’s claims against T-Mobile specifically — it does not invalidate US7590636B1. The patent remains granted and potentially enforceable against other defendants. T-Mobile alone is protected by the settlement-linked dismissal. Third parties cannot rely on this outcome as a shield against assertion.
The case ran for 1,202 days — approximately 3.3 years — from filing in February 2021 to closure in June 2024. This duration is consistent with a case that survived initial motions and proceeded through substantive litigation phases, including potentially claim construction, before the parties reached a settlement. It suggests neither party achieved an early dispositive victory.
The case was presided over by Judge Amos L. Mazzant in the Eastern District of Texas (Sherman Division), a court widely recognised as a frequent venue for patent infringement actions, particularly by non-practising entities asserting patents against major technology and telecommunications companies.
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