Sandstrom v. Ericsson: Four Networking Patents, Voluntary Dismissal With Prejudice
Individual inventor Mark Sandstrom filed suit against Ericsson Inc. and Telefonaktiebolaget L.M. Ericsson in the Eastern District of Virginia, asserting four patents spanning data transport bus architecture, binary file transfer network management, and packet transport systems. The action was voluntarily dismissed with prejudice after 260 days — before Ericsson filed any answer or dispositive motion.
Solo inventor takes on Ericsson over legacy and modern networking IP
On 23 September 2024, individual inventor Mark Sandstrom filed Case No. 1:24-cv-01682 in the Eastern District of Virginia against Ericsson Inc. and its Swedish parent Telefonaktiebolaget L.M. Ericsson. The complaint asserted infringement of four United States patents: US10848546B2, US10567474B2, US7333511B2, and US7558260B2 — collectively covering byte-timeslot-synchronous data transport bus architectures, direct binary file transfer network management, and dynamically channelizable packet transport networks. These patents span application filings from the early 2000s through the mid-2010s, suggesting a portfolio assembled over a significant inventor career.
The case was closed on 10 June 2025 when Sandstrom filed a notice of voluntary dismissal with prejudice pursuant to Federal Rule of Civil Procedure 41(a)(1)(A)(i). That rule permits a plaintiff to dismiss an action without a court order where the defendant has neither answered nor moved for summary judgment — both conditions confirmed on the face of the dismissal notice. Critically, the dismissal was entered with prejudice, meaning Sandstrom is permanently barred from re-filing the same claims against these defendants on these patents.
The 260-day duration and the pre-answer timing suggest the parties likely reached a private resolution — whether a licensing arrangement, a covenant not to sue, or some other commercial agreement — though the public record is entirely silent on terms. It is also possible Sandstrom concluded that further prosecution was not commercially viable after pre-litigation assessment of Ericsson’s defensive position. The with-prejudice designation is the most strategically consequential fact in the public record: unlike a without-prejudice dismissal, it extinguishes any future assertion of these four patents against Ericsson entities.
Filing to Voluntary dismissal in 260 days
260 days from filing to closure — resolved before any responsive pleading from Ericsson
Dismissed with prejudice: what the Rule 41 filing means for both parties
Rule 41(a)(1)(A)(i): plaintiff’s right to dismiss without court order
Federal Rule of Civil Procedure 41(a)(1)(A)(i) allows a plaintiff to voluntarily dismiss a case without needing court approval, provided the defendant has not yet served an answer or a motion for summary judgment. Ericsson had done neither. The dismissal is self-executing upon filing and takes immediate effect. The plaintiff chose to attach a with-prejudice designation, which is not the default under Rule 41 — that election is legally significant and binding.
Pre-answer voluntary dismissalWith prejudice bars re-filing — a permanent relinquishment of these claims
A dismissal with prejudice operates as a final judgment on the merits. Sandstrom cannot refile infringement claims against Ericsson Inc. or Telefonaktiebolaget L.M. Ericsson based on US10848546B2, US10567474B2, US7333511B2, or US7558260B2. Without prejudice would have preserved the right to refile; the public record confirms with prejudice was expressly chosen. Whether this reflects a negotiated settlement term or a unilateral strategic decision is not disclosed.
Permanent claim bar against EricssonSandstrom exits litigation — future enforcement options narrowed
For Sandstrom, the with-prejudice dismissal forecloses any future infringement action on these four patents against the named Ericsson entities. If a licensing deal was reached, the dismissal serves as the clean exit mechanism. If no deal was reached, Sandstrom has surrendered enforcement rights against Ericsson permanently. His ability to assert the same patents against third parties, however, is unaffected by this dismissal — the bar applies only to these defendants.
Ericsson-specific enforcement endedEricsson secures permanent closure without contested litigation
Ericsson achieved closure without filing an answer, mounting invalidity challenges, or engaging in discovery — the strongest possible procedural outcome short of a successful motion to dismiss. Ericsson is permanently shielded from any future assertion of these four patents by Sandstrom. The pre-answer timing suggests Ericsson’s legal team may have applied early pressure through licensing negotiations or by signalling strong invalidity arguments, though the record does not confirm this.
Full immunity, no merits exposureFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Mark Sandstrom | Individual | Individual inventor and patent holder — asserting four networking and data transport patentsSearch in Eureka ↗ |
| Defendant | Ericsson, Inc. | Company | Ericsson Inc. and Telefonaktiebolaget L.M. Ericsson — global telecommunications equipment and networking infrastructure groupSearch in Eureka ↗ |
| Co-Defendant | Telefonaktiebolaget L.M. Ericsson | Individual | Search in Eureka ↗ |
| Plaintiff counsel | Charles Bennett Molster, III | Attorney | Counsel for Mark SandstromSearch in Eureka ↗ |
| Plaintiff law firm | The Law Offices of Charles B. Molster III PLLC | Law Firm | Representing Mark SandstromSearch in Eureka ↗ |
| Defendant counsel | Brent Ryan Gary | Attorney | Counsel for Ericsson, Inc.Search in Eureka ↗ |
| Defendant counsel | Christian Bennett Hecht | Attorney | Counsel for Ericsson, Inc.Search in Eureka ↗ |
| Defendant counsel | Jacob Baron | Attorney | Counsel for Ericsson, Inc.Search in Eureka ↗ |
| Defendant counsel | Mark Masutani | Attorney | Counsel for Ericsson, Inc.Search in Eureka ↗ |
| Defendant law firm | Holland & Knight LLP | Law Firm | Representing Ericsson, Inc.Search in Eureka ↗ |
| Defendant law firm | Holland & Knight LLP (MA-NA) | Law Firm | Representing Ericsson, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Virginia Eastern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The dismissal notice expressly states the action is dismissed with prejudice under Rule 41(a)(1)(A)(i), and confirms that Ericsson had neither answered nor moved for summary judgment at the time of filing. The with-prejudice designation is a plaintiff-elected modification to the Rule 41 default — it carries the legal weight of a final judgment on the merits as between these parties and these patents, permanently extinguishing Sandstrom’s right to reassert these four patents against the named Ericsson entities. No merits adjudication occurred.
US10848546B2 and three further patents — data transport and network management
The four asserted patents span two technology eras and three product concepts. US10848546B2 and US10567474B2 represent more recent patent grant dates and likely reflect continuation or continuation-in-part prosecution strategies building on earlier foundational disclosures. US7333511B2 and US7558260B2, with application numbers dating to 2002–2003, cover byte-timeslot-synchronous and dynamically channelizable transport architectures that were foundational concepts in early 2000s multi-service switching infrastructure. Together they form a layered assertion portfolio targeting data plane transport and network management coordination.
For Ericsson — a global leader in telecommunications switching, transport, and IP networking infrastructure — these patents are commercially proximate to core product lines. Byte-timeslot-synchronous transport and dynamically channelizable packet networks are concepts embedded in Ericsson’s legacy and modern transport portfolio. The assertion of a binary file transfer network management patent is also notable given Ericsson’s extensive OSS/BSS and element management product range. Third-party vendors supplying similar transport or network management technologies should treat this portfolio as a potential assertion risk.
Should your team run an FTO against the Sandstrom networking patent portfolio?
Any organisation developing, selling, or deploying byte-timeslot-synchronous transport systems, dynamically channelised packet switching infrastructure, or binary file transfer-based network management tools should assess freedom to operate against this four-patent portfolio. The patents span application filing dates from 2002 to the mid-2010s, meaning standard prior art searches must cover a wide temporal range. The dismissal against Ericsson does not affect Sandstrom’s ability to assert these patents against other defendants.
PatSnap Eureka’s FTO Search Agent enables R&D and IP teams to map all four asserted patents against your product architecture in a single workflow — identifying claim-level overlap, locating prior art that could support invalidity arguments, and flagging continuation family members that may pose future assertion risk. Given that this portfolio spans multiple continuation chains, family-level monitoring is as important as single-patent clearance.
Run a freedom-to-operate analysis on US10848546B2 to assess your product’s exposure
Run FTO in Eureka →Similar patent cases: networking and data transport IP in US district courts
Cases involving legacy networking, data transport bus, and packet switching patents asserted by individual inventors against major telecom defendants in US district courts.
What this case signals for the telecommunications IP enforcement landscape
Individual inventors asserting legacy networking patents against major telecoms carriers face significant structural headwinds — this case illustrates the pattern.
With-prejudice election signals likely private resolution, not capitulation
When a plaintiff voluntarily dismisses with prejudice before the defendant has even answered, it typically signals either a negotiated exit — such as a licence or covenant not to sue — or a calculated decision that continued litigation is not commercially viable. The permanent bar suggests Sandstrom received something in exchange, or made a deliberate strategic choice. IP teams monitoring similar inventor-driven assertion campaigns should track dismissal terms closely.
Legacy networking patents from the 2000s remain assertion vehicles in 2024
Three of the four asserted patents originate from application filings in the early-to-mid 2000s (US7333511B2 and US7558260B2), with more recent continuation-era patents also in the mix. The persistence of older data transport and network management patents as litigation assets highlights the importance of prior art searches extending back to pre-2005 architectures when clearing freedom to operate in modern telecom infrastructure products.
Sandstrom v Ericsson — key questions answered
Mark Sandstrom filed patent infringement claims against Ericsson Inc. and Telefonaktiebolaget L.M. Ericsson in the Eastern District of Virginia in September 2024, asserting four US patents covering data transport bus, binary file transfer network management, and packet transport technologies. The case was voluntarily dismissed with prejudice in June 2025 after 260 days, before Ericsson filed any answer or dispositive motion.
A with-prejudice dismissal operates as a final judgment on the merits. Sandstrom is permanently barred from reasserting US10848546B2, US10567474B2, US7333511B2, or US7558260B2 against Ericsson Inc. or Telefonaktiebolaget L.M. Ericsson. He retains full enforcement rights against any other potential infringer — the bar applies only to the named defendants.
Sandstrom asserted four US patents: US10848546B2 (byte-timeslot-synchronous dynamically switched data transport bus), US10567474B2 (direct binary file transfer network management), US7333511B2, and US7558260B2 (dynamically channelizable packet transport network architectures). Two patents originate from application filings in the early 2000s, indicating a portfolio spanning foundational and more recent networking inventions.
The public record does not specify why Ericsson had not yet answered at the time of dismissal. Under Rule 41(a)(1)(A)(i), the plaintiff may dismiss without court order only while no answer or summary judgment motion has been filed. The pre-answer timing — 260 days after filing — suggests the parties were likely engaged in pre-litigation dialogue, potentially including licensing discussions, during that period, though no terms are publicly disclosed.
No. The with-prejudice dismissal binds only the named defendants — Ericsson Inc. and Telefonaktiebolaget L.M. Ericsson. Sandstrom retains full rights to assert US10848546B2, US10567474B2, US7333511B2, and US7558260B2 against any other company. Telecom equipment manufacturers, network operators, and OSS/BSS vendors operating in overlapping technology spaces should conduct their own freedom-to-operate assessment against this portfolio.
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