US 10737709

I'll search for authoritative information on this patent, including any 2026 CAFC docket activity.

Let me retrieve the actual claim text and confirm whether any 2026 CAFC docket specifically involves 10737709.

US Patent 10,737,709 B2 — Analyst Summary

1. Search scope and negative results (stated explicitly)

• USPTO full-text / PatentCenter: the patent is confirmed present and active in USPTO records; the granted front page was retrieved via the PTAB/PTACTS document repository (EX1001 in IPR2023-00460 and the uspto.report grant record).
• CAFC 2026 dockets: I found no 2026 CAFC docket, appeal, or opinion that names U.S. Patent 10,737,709. The only 2026 Metrom Rail Federal Circuit matter I located is *Appeal No. 24-2223, Metrom Rail, LLC v. Siemens Mobility, Inc., nonprecedential opinion issued May 11, 2026* — and that appeal concerns U.S. Patent Nos. 9,043,131 and 8,812,227, not 10,737,709. I did not auto-substitute those numbers; I am reporting the mismatch rather than conflating the cases.
  • Source: https://www.cafc.uscourts.gov/05-11-2026-24-2223-metrom-rail-llc-v-siemens-mobility-inc-opinion-24-2223-opinion-5-11-2026_2691571/
• PTAB: the '709 patent was the subject of IPR2023-00460 (Siemens Mobility, Inc. et al. v. Metrom Rail, LLC, filed Jan. 9, 2023). Institution was DENIED (decision dated Jul. 6, 2023), so there is no final written decision and, correspondingly, no appealable PTAB outcome on the '709 patent.
  • Source: https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2023-00460
• District court: the '709 patent was asserted in D. Del. 1:22-cv-00049 and appears in later-filed matters D. Del. 1:23-cv-00314, S.D.N.Y. 1:23-cv-02920, and S.D.N.Y. 1:23-cv-03057 (per the Google Patents family/litigation panel).

If a brand-new 2026 CAFC filing on the '709 patent exists, it is not surfaced in the sources I could reach, and I will not fabricate one. I do not have authoritative evidence of a 2026 CAFC docket specifically for 10737709.

2. Bibliographic data (as printed on the granted patent)

Priority chain as literally printed in the patent (Col. 1): "This patent application is a continuation of U.S. Provisional Patent application Ser. No. 15/078,427, filed on Mar. 23, 2016, which makes reference to, claims priority to and claims benefit from U.S. Provisional Patent Application Ser. No. 62/177,683, filed on Mar. 23, 2015."

Literal-reading flag (no auto-correction): the patent text styles Ser. No. 15/078,427 as a "Provisional" application, yet a 15/ series number is the non-provisional series. I am preserving the identifier and the "Provisional" label exactly as printed and flagging the internal inconsistency rather than correcting it.

3. Abstract (verbatim)

"A worker protection system may include a train-mounted unit for use on a train, and one or more wayside units, configured for placement on or near a track traversed by the train. Each of the train-mounted unit and the one or more wayside units may include a corresponding communication component, with one or more antennas, configured to transmit and/or receive wireless signals, with the signals comprise ultra-wideband (UWB) signals, and one or more circuits configured for processing signals and data, and for performing applications or functions relating to operations of the corresponding unit. The train-mounted unit may operate cooperatively with the one or more wayside units, to provide alerts to one or more workers operating on or near the track, based on communication of the UWB signals with at least one of the one or more wayside units."

4. Independent claims — plain-language overview

The patent has 20 claims, of which three are independent: claims 1, 12, and 20. (Claim breakdowns below are reconstructed from the granted-claim text as mapped in the IPR2023-00460 petition exhibit and the co-pending district-court infringement chart; I flag where I am inferring phrasing.)

Independent Claim 1 — "A system for worker protection, the system comprises:" (train-side unit)

• Covers a train-mounted unit for use on a train.
• That unit has a communication component with one or more antennas that transmit and/or receive wireless signals.
• The signals comprise ultra-wideband (UWB) signals (the core distinguishing feature of the family).
• The unit has one or more circuits to process signals/data and run applications/functions relating to the unit's operation.
• Dependent claims add features such as: the train-mounted unit configured to broadcast alert-triggering signals; the unit being made of a plurality of separate physical units, including an operator unit with I/O components placed for use by the train operator.

Independent Claim 12 — wayside-unit-centric claim

• "one or more wayside units configured for placement on or near a track;"
• Each wayside unit has a communication component with antenna(s) for wireless transmit/receive.
• "wherein the signals comprise ultra-wideband (UWB) signals;"
• Each wayside unit has circuitry to process signals/data and perform wayside-unit functions.
• The wayside unit(s) must operate cooperatively with any train-mounted unit deployed on a train traversing the track, to provide alerts to workers on or near the track, based on UWB communication between the wayside unit(s) and the train-mounted unit.
• Dependents add: a power supply, a housing, a support structure (e.g., tripod), and broadcasting of alert-related signals when a train approaches.

Independent Claim 20 — "A system for protecting workers near railroad tracks, comprising:" (ranging/time-of-flight architecture)

• One or more UWB radios at pre-determined locations along the railroad tracks (wayside anchors).
• One or more worker UWB radios associated with workers on/near the tracks.
• A vehicle UWB radio associated with a vehicle on the track.
• A processor determines the vehicle's position based on time-of-flight (TOF) measurements from communication between the vehicle UWB radio and at least one pre-positioned UWB radio.
• The processor determines the workers' location based on TOF information from communication with at least one worker UWB radio.
• The processor generates an alert to the vehicle operator based on the determined worker location, and generates alerts to a worker based on defined conditions.
• This is the claim most closely tied to UWB ranging / TOF positioning rather than mere UWB signaling.

Uncertainty note: the granted claim set was not reproduced in the fetched full text, and the patent owner filed a "Disclaimer in Patent" exhibit on Apr. 19, 2023 during IPR2023-00460 (per the IPR docket). I cannot confirm from my sources which, if any, claims were statutorily disclaimed, so the live claim scope may be narrower than the as-granted 20 claims. Treat the claim list as the as-granted set.

5. Technical/embodiment highlights (from the specification)

• Three-device architecture: wearable Portable Alert Devices (PADs) 110, vehicle-mounted Vehicle Alert Devices (VADs) 120, and stand-alone Wayside Detection Units (WDUs) 130; three deployment scenarios (PAD+VAD; PAD+WDU; all three for redundancy).
• Speed-based, not just distance-based, alert triggering; three threshold types — time-to-arrival (TTA), distance-from-train (DFT), and low-speed close-proximity distance alert (CPD).
• GNSS (GPS/GLONASS/Galileo) integration; location-specific rule customization via NFC at entry points; per-track unique VAD identification to avoid false alerts; PAD-to-PAD/WDU alert relaying; diversity antennas; accelerometer-based power saving; inductive (wireless) charging and NFC data exchange on PADs; log files including GPS coordinates, RSS, and antenna used.

6. Discrepancies and data-integrity flags

1. Third-party database conflicts (Unified Patents portal, US-20190283787-A1 record): it lists Priority Date 2015-03-22, Application Date 2019-01-13, and "Grant Date" 2019-09-18. These conflict with the authoritative granted front page and Google Patents (2015-03-23, 2019-01-14, issue 2020-08-11). Per the operating rule to prefer authoritative/USPTO-derived data, I treat the front page and Google Patents values as correct and note the portal values as likely off-by-one/indexing artifacts. The "2019-09-18" figure actually matches the publication date of US 2019/0283787 A1, not the grant.
2. Inventor spelling: USPTO front page prints "Peter Strezve"; Google Patents lists "Peter Strezev." Both are reproduced literally; I am not normalizing either.
3. CAFC relevance mismatch: the 2026 Metrom Rail appellate outcome (No. 24-2223, May 11, 2026) involves the '131 and '227 patents. Any inference that 10,737,709 was invalidated or affirmed in 2026 would be incorrect.
4. Related family members for context (not this patent): US 10,778,363; US 11,492,027 ("Methods and systems for worker protection system with ultra-wideband (UWB) based anchors"); US 8,812,227; US 9,043,131; US 10,179,595; US 11,952,028 — all Metrom Rail.

I'll research litigation involving US patent 10737709 using multiple sources.

Let me get more specifics on each case and confirm which assert the '709 patent.

Litigation Involving U.S. Patent No. 10,737,709

Bottom line: I found four U.S. district court actions in which Metrom Rail LLC asserted U.S. Patent No. 10,737,709 (the "'709 patent") against Siemens‑/Thales‑/Humatics‑/Piper‑related defendants, plus one PTAB inter partes review directed at the '709 patent itself (institution denied). All four suits arose from Metrom's UWB train‑control/worker‑protection dispute over New York MTA (NYCT) contracts. I found no final judgment, settlement, or dismissal specifically resolving the '709 claims, and no Federal Circuit appeal in which the '709 patent was at issue (the 2026 Federal Circuit decision in Metrom Rail v. Siemens Mobility concerned the '131 and '227 patents, not the '709).

1. Patent identification (as verified against the source text)

⚠️ Flag on current status: the Google Patents record lists the '709 patent as "Expired – Fee Related," which typically indicates lapse for non‑payment of a maintenance fee, notwithstanding the 2036 nominal expiration date. I could not independently confirm the fee lapse or any revival/petition from a primary USPTO record in the sources retrieved, so treat this as a third‑party listing rather than a legal conclusion.

Google Patents' own "Family has litigation" list for this patent names exactly: S.D.N.Y. 1:23‑cv‑02920; S.D.N.Y. 1:23‑cv‑03057; D. Del. 1:23‑cv‑00314; D. Del. 1:22‑cv‑00049; and PTAB IPR2023‑00460 — i.e., the four suits and one IPR below.

2. District court litigation asserting the '709 patent

A. Metrom Rail, LLC v. Siemens Mobility, Inc.; Thales Transport & Security, Inc.; Thales USA, Inc.; Humatics Corp.; Piper Networks, Inc.

• Court / No.: U.S. District Court for the District of Delaware, 1:22‑cv‑00049
• Filed: January 12–13, 2022 (press release dated January 18–19, 2022)
• Asserted patents: 10,778,363; 8,812,227; 9,043,131; 10,737,709; 10,179,595 — plus state‑law counts for tortious interference with prospective economic advantage and conspiracy.
• Subject matter: Siemens/Thales/Humatics/Piper bids and MTA New York City Transit UWB deployments.
• Status: Records I retrieved show this docket as superseded/closed, with the action carried forward into the 2023 Delaware filing (see B). Unified Patents' record for the related '595 patent lists a Delaware case captioned Metrom Rail LLC v. Siemens Mobility GMBH, Piper Networks Inc., Ground Transportation Systems USA Inc., Humatics Corp., Thales SA with case number 1:22‑cv‑00049, filed 2022‑01‑12, status "closed," and also references a 1:23‑cv‑00581 (D. Del.) docket. I could not confirm a written dismissal order.

Sources: https://goldencompass.patentpia.com/en/report/reportResult.hs?INPUTITEM_VARSET=TECHCATE&LANG=EN&LOCALE=US&MENUID_3DEPTH=M3_TechCate_2_17_X&TECHCATE=83002&UI_LANG=EN ; https://www.einpresswire.com/article_print/560943289/metrom-rail-files-patent-infringement-suit-to-protect-ultrawide-band-technology-ip ; https://metrom-rail.com/filebin/Lawsuit/Metrom_Rail_Press_Release_1.18.22.pdf ; https://portal.unifiedpatents.com/patents/patent/US-9595-A

B. Metrom Rail, LLC v. Ground Transportation Systems USA Inc. et al. (later Hitachi Rail GTS USA Inc.)

• Court / No.: U.S. District Court for the District of Delaware, 1:23‑cv‑00314
• Filed: March 22, 2023 (amended complaint, exhibits A–L)
• Judge: Richard G. Andrews; jury trial demanded
• Defendants: Ground Transportation Systems USA Inc. (renamed Hitachi Rail GTS USA Inc.) and Piper Networks, Inc.
• Asserted patents (per the Rule 3 "Report to the Commissioner"): US 10,778,363 B2; US 8,812,227 B2; US 9,043,131 B2; US 10,737,709 B2; US 10,179,595 B2
• Status: Superseded by / related to the S.D.N.Y. action below; the Delaware docket and the S.D.N.Y. docket (C) share the identical case caption, and the sources list both, so it is possible that 1:23‑cv‑00314 (D. Del.) is the same action as 1:23‑cv‑02920 (S.D.N.Y.) before and after transfer. I could not definitively resolve this from the retrieved records.

Sources: https://services.patexia.com/lawsuits/Metrom-Rail-LLC-v-Ground-Transportation-Systems-USA-Inc-et-al-id-[188184](/patent/188184)/documents ; https://search.patentpia.com/event/US/EN/[127451](/patent/127451)/SUIT

C. Metrom Rail, LLC v. Ground Transportation Systems USA Inc. et al. (Hitachi Rail GTS USA Inc. line)

• Court / No.: U.S. District Court for the Southern District of New York, 1:23‑cv‑02920
• Filed: April 6, 2023
• Judge: Analisa Torres; jury trial
• Asserted patents: 10,179,595; 10,737,709; 10,778,363; 8,812,227; 9,043,131
• Status: This is the S.D.N.Y. case referenced in the MBTA/Piper opinion as "Metrom Rail v. Hitachi Rail GTS USA Inc., et al., 23cv2920." I found no disposition of the '709 claims in this docket.

Sources: https://search.patentpia.com/event/US/EN/127451/SUIT ; https://www.courtlistener.com/docket/72043751/113/metrom-rail-llc-v-massachusetts-bay-transportation-authority/

D. Metrom Rail, LLC v. Siemens Mobility, Inc.

• Court / No.: U.S. District Court for the Southern District of New York, 1:23‑cv‑03057
• Filed: April 12, 2023
• Cause: Patent infringement (35 U.S.C. §271) — three patent counts (Counts I–III) plus a tortious interference count (Count IV)
• '709 patent asserted: Likely yes — the Patentpia litigation record associates the '709 patent with four suits, the most recent dated 2023‑04‑12, which matches this filing date. Moderate confidence; I could not independently read the '709 claim chart from the Second Amended Complaint (Docket 69‑1), which is 356 pages.
• Status: The court granted a complete stay of the action pending the IPR proceedings, reasoning that the patent claims were "the main thrust of this litigation" and that the PTAB's validity determinations would simplify the intertwined tortious interference claim. A written Order in this litigation references "Siemens," "Humatics," Counts I–IV, and the IPRs.

Sources: https://ai-lab.exparte.com/case/dct/nysd/1:23-cv-03057/metrom-rail-llc-v-siemens-mobility-inc ; https://www.docketalarm.com/cases/PTAB/IPR2024-00947/Siemens_Mobility_Inc/05-22-2024-Petitioner/Exhibit-1019-... ; https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1556106](/patent/1556106)/download-documents?artifactId=Ssj3y9hQ1-1mC94kqMr9gEweZ1Pv33CQclzX11MncbI-5qjyj6PVF-k

3. PTAB proceeding directed at the '709 patent

Siemens Mobility, Inc. et al. v. Metrom Rail, LLC — IPR2023‑00460

• Filed: January 9, 2023 (Petitioners: Siemens Mobility, Inc. et al.)
• Patent challenged: US 10,737,709 (Application 16/246,940; Tech Center 3600)
• Outcome: Institution DENIED — on the merits, Institution Decision dated July 6, 2023 (Unified Patents/Google Patents label: "Not Instituted – Merits")
• Notable docket events: Patent Owner Preliminary Response and an exhibit captioned "Disclaimer in Patent" filed April 19, 2023 (suggesting a statutory disclaimer of one or more claims in the IPR, scope not confirmed); Petitioner's Request for Refund of Post‑Institution Fees, July 28, 2023; Notice: Refund Approved, August 4, 2023
• Counsel: Petitioner — Rahmeier, Thatcher et al.; Patent Owner — Schodde, Gregory et al.
• Representative cited art in the petition: Grisham (US 7,148,791), Fullerton (US 6,133,876), Blevins (US 5,283,589), Harrison (US 6,597,293), Meyer (DE 10 2008 020 700 A1), WO 2013/056244 A1 (Cross), and others.

Sources: https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2023-00460 ; https://patents.google.com/patent/US10737709/en

4. Related litigation / appellate activity (NOT the '709 patent — for context only)

• IPR2023‑00468 and IPR2023‑00470 (US 9,043,131 and US 8,812,227), petitioners Siemens Mobility, Hitachi Rail GTS USA, Humatics, Piper Networks → Federal Circuit Nos. 2024‑2223, 2024‑2236, 2024‑2264, decided May 11, 2026 (nonprecedential; Dyk, J.). Affirmed unpatentability of all '227 claims and '131 claims 1–16; reversed the Board's holding that '131 claims 17–20 survived. (https://cafc.uscourts.gov//opinions-orders/24-2223.OPINION.5-11-2026_2691571.pdf)
• IPR2024‑00947 (Siemens Mobility) — procedural activity citing the Second Amended Complaint in Metrom v. Siemens, S.D.N.Y. 1:23‑cv‑03057.
• IPR challenging U.S. 9,731,738 — USPTO declined institution on Nov. 20, 2024 (requested by Siemens Mobility, Ground Transportation Systems USA, and Piper Networks). (https://www.mcandrews-ip.com/mcandrews-secures-victory-for-client-metrom-rail-llc/)
• Metrom Rail, LLC v. Massachusetts Bay Transportation Authority / Piper Networks — originally D. Mass. (25‑cv‑10417 / 25‑cv‑11446), transferred to S.D.N.Y. (1:25‑cv‑10417, Judge Denise Cote) on Dec. 8, 2025. This action asserts the '738 and '131 patents — not the '709. Piper's motion to dismiss was denied in part on May 20, 2026 ('738 claim survives); case stayed June 4, 2026 pending the '131 Federal Circuit mandate. (https://www.courtlistener.com/docket/72043751/113/metrom-rail-llc-v-massachusetts-bay-transportation-authority/)

Note: I also encountered IPR2024‑00582 (US 11,175,738) and IPR2024‑00714 (US 10,627,907) in a securities‑filing excerpt referencing "Valve litigation" — those are unrelated to Metrom Rail and to the '709 patent, and I exclude them.

5. Summary table — '709‑specific matters

6. Caveats on completeness and confidence

• No auto‑correction applied. All numbers above are reproduced as they appear in the sources; note two source‑level oddities I did not "fix": the press release's "US 10,179,5959" appears in one docket entry as "10,179,595" elsewhere, and Unified Patents spells a defendant "Siemens Mobility GMBH" / "Thales SA" (foreign parents) whereas the complaints name "Siemens Mobility, Inc." / "Thales USA, Inc."
• Defendant‑lineage changes: Ground Transportation Systems USA Inc. is now Hitachi Rail GTS USA Inc. (the Federal Circuit caption uses "FKA Ground Transportation Systems USA Inc.").
• Duplicate‑docket risk: Delaware 1:23‑cv‑00314 and S.D.N.Y. 1:23‑cv‑02920 carry the same caption and may be one action (filed in Delaware, then transferred). If so, the true count of distinct '709 suits is three, not four — but two commercial databases count four, and I have not resolved it.
• Which patents were in the S.D.N.Y. 1:23‑cv‑03057 Second Amended Complaint was not directly verifiable from the retrieved excerpt; inclusion of the '709 in that case is inferred from Patentpia's "most recent suit date = 2023‑04‑12" record for the '709 patent.
• Current enforceability: the "Expired – Fee Related" listing plus the April 19, 2023 statutory "Disclaimer in Patent" exhibit in IPR2023‑00460 mean the '709 patent may be narrowed and/or lapsed. I could not confirm this from a USPTO Patent Center/assignment record, and I expressly note that uncertainty rather than assume a status.
• Sources searched: Google Patents (patent page + "Family has litigation" links), Unified Patents litigation/PTAB portal, CourtListener/RECAP, PTAB dockets via ptacts.uspto.gov, CAFC opinion PDF, IPVerse/GreyB, Patentpia/Golden Compass, Patexia, Finnegan D. Mass. update, and party press releases.

I'll start by researching the PTAB proceedings referenced in the patent record and checking for any others.

Let me dig into the institution decision details and check for any other PTAB proceedings.

Let me find the actual institution decision and the related IPR family details.

PTAB Proceedings — U.S. Patent No. 10,737,709 ("Worker protection system," Metrom Rail, LLC)

Note on the structured data: The USPTO ODP block says no AIA trial proceedings are on file. That ingest is incomplete. A real IPR exists on the public PTAB record and is reflected on the patent's Google Patents page. Flagging it below, with source links and explicit uncertainty markers where I could not retrieve the underlying decision text.

Proceedings overview

Independent research surfaces exactly one AIA trial proceeding against the '709 patent — IPR2023-00460 — and it was denied institution (active: 0; claims invalidated: 0; claims sustained: 0; settled: 0; institution denied: 1). The bottom line for a defendant: no claim of the '709 patent has ever been canceled or sustained by the PTAB, and because institution was denied, no § 315(e)(2) estoppel exists — but the record also shows Metrom filed a "Disclaimer in Patent" alongside its Preliminary Response, the same statutory-disclaimer tactic it used in a sibling IPR, so you must check the disclaimer record before assuming every claim is live.

(Sourcing caveat: the denial reason, judge panel, and claim mapping for IPR2023-00460 are not in the sources I could retrieve. I flag those gaps rather than fill them.)

IPR2023-00460 — Siemens Mobility, Inc. et al. v. Metrom Rail, LLC

• Type: Inter Partes Review
• Filed: 2023-01-09 (Board accorded the filing date 2023-01-19)
• Patent: U.S. 10,737,709 B2 (application 16/246,940, Tech Center 3600)
• Status: "Institution Denied" (verbatim). Google Patents classifies it as "Not Instituted – Merits," which suggests a merits-based refusal, but I could not confirm the Board's reasoning.
• Judge panel: Not confirmed in the sources I retrieved (the ipverse case page does not list the APJ panel; the PTAB E2E / PTABIS docket would).
• Petitioner: Siemens Mobility, Inc. et al. — per the parallel PTAB decision (IPR2023-00439), the petitioner group is Siemens Mobility, Inc., Ground Transportation Systems USA, Inc., Humatics Corp., and Piper Networks, Inc. — i.e., the Delaware defendants, not a defensive aggregator. (The "Unified Patents" name on the Google Patents page is the data-source attribution for its PTAB dataset, not the petitioner.)
• Petition grounds: Exact statutory grounds and claim mapping not confirmed. The petition's exhibit list indicates an obviousness/anticipation attack built on railway-vehicle UWB and collision-avoidance art, including:
  • EX1006/EX1007 — DE 10 2008 020 700 A1 (Meyer) + translation
  • EX1009 — U.S. 7,148,791 (Grisham)
  • EX1010 — WO 2013/056244 A1 (Cross)
  • EX1011 — U.S. 6,133,876 (Fullerton)
  • EX1012–EX1018 — Sheardown, Rangan, King, Blevins, Harrison, Qu, Johnson
  • EX1019 — Bennett 1978; EX1003 — Declaration of Dr. Braasch ("709 Patent")
  • I could not verify which § 102 / § 103 combinations were asserted or which claims were challenged. Treat the claim-level ground map as unverified.
• Institution decision: Denied, 2023-07-06. Patent Owner's Preliminary Response was filed 2023-04-19, and on the same date Metrom filed a "Disclaimer in Patent" exhibit (EX2001). In the parallel IPR2023-00439 on U.S. 10,179,595, Metrom statutorily disclaimed all challenged claims (1–30) and the Board denied institution under 37 C.F.R. § 42.107(e) ("No inter partes review will be instituted based on disclaimed claims"). I could not retrieve the text of the '709 institution decision, so I cannot state whether the '709 denial rested on a statutory disclaimer of the challenged claims or on the merits — this is an open item to verify. Sources: ipverse case page (https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2023-00460) and the sibling '595 decision (https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1550883](/patent/1550883)/download-documents).
• Final Written Decision: None. No institution means no FWD, so the Board never reached a claim-level patentability verdict on the '709 patent.
• Settlement / termination: No settlement. Petitioners requested a refund of post-institution fees on 2023-07-28, and the Board approved the refund on 2023-08-04 — confirming the trial never started.
• Appeal: None for this proceeding. There is nothing to appeal from a non-institution decision (and non-institution decisions are non-appealable).
• Defensive value: This is close to a "free bite." Because institution was denied, there is no § 315(e)(2) estoppel against Siemens/Thales/Humatics/Piper or their privies — they (and you) can still raise the same art in district court, and a properly framed follow-on petition remains theoretically available. But before relying on that, pull the '709 file history to see exactly which claims (if any) Metrom statutorily disclaimed in April 2023 — a disclaimer under 35 U.S.C. § 253(a) permanently removes those claims regardless of the IPR.

Strategic summary

Canceled vs. sustained vs. untested. At the PTAB, the '709 patent is entirely untested: one petition, denied at the institution stage, no FWD. No claim has been held unpatentable by the Board and no claim has been held patentable by the Board. The only live narrowing risk lives in the statutory disclaimer Metrom filed on 2023-04-19 — and whether it covers all challenged claims or only some is unresolved in the sources I could retrieve. Getting the'709 Application/Patent Center record and the disclaimer (Reel/Frame) is the single highest-value next step, because it tells you the true surviving claim set. Separately, Google Patents lists the '709 as "Expired – Fee Related" with an anticipated expiration of 2036-03-23 — if that reflects a maintenance-fee lapse, it materially changes the assertion picture, but Google explicitly labels its legal-status data as an unverified assumption, so confirm it at the USPTO before relying on it.

Estoppel landscape. There is no estoppel on this patent. Section 315(e)(2) estoppel attaches only after a final written decision; IPR2023-00460 was never instituted, so neither the Siemens-led petitioners nor any privy is barred from raising the Meyer/Grisham/Cross/Fullerton art in the Delaware litigation. That said, a fresh petition on the same art by the same or a privy party would face § 314(a) / General Plastic discretionary-denial headwinds, and — more importantly — § 325(d) would let the Board deny if the same art/arguments were already presented to the Office. Practically, unless the disclaimer wiped out the asserted claims, the strongest validity path for a defendant today is the district-court invalidity case plus a well-differentiated new petition (new primary reference or new claim/limitation mapping not in the '709 petition).

Pattern signals — and the family you can't ignore. This was not an aggregator hit; it was defendant-funded litigation defense by the accused infringers (Siemens Mobility, Ground Transportation Systems USA, Humatics, Piper) who are the defendants in Metrom's Delaware and SDNY suits (e.g., D. Del. 1:22-cv-00049; 1:23-cv-00314; S.D.N.Y. 1:23-cv-02920 and 1:23-cv-03057). The same petitioner group filed a cluster of IPRs against the Metrom family — IPR2023-00439 (the '595 patent, denied on PO's disclaimer of claims 1–30), IPR2023-00460 (the '709 patent, denied), and IPR2023-00452, -00468, and -00470 (patent mapping not confirmed in the sources retrieved). At least one sibling IPR was instituted and litigated to a Final Written Decision dated 2024-06-18, after which Metrom noticed an appeal on 2024-08-15, and a related Metrom v. Siemens Mobility oral argument is on the Federal Circuit (CourtListener: https://www.courtlistener.com/audio/[104244](/patent/104244)/metrom-rail-llc-v-siemens-mobility-inc/) — evidence that Metrom litigates PTAB outcomes aggressively and appeals adverse FWDs. The takeaway: the family has produced real invalidity traction at the Board, but not against the '709 patent, which slipped the net on a non-merits (or merits-tagged) denial.

Recommended next steps

1. Do not assume the '709 is "hardened." It isn't — it simply never got instituted on. Neither the "survived the PTAB" nor the "claims are dead" narrative fits this patent.
2. Pull the disclaimer. Obtain the "Disclaimer in Patent" (filed 2023-04-19, EX2001 in IPR2023-00460) and the corresponding USPTO Reel/Frame to determine which '709 claims were statutorily disclaimed. If the challenged claims were disclaimed, they are treated as never having existed (§ 253(a)) and any infringement theory resting on them is gone — that is your strongest defense and worth quoting directly.
3. Retrieve the 2023-07-06 institution decision from PTAB E2E / PTABIS (https://ptab.uspto.gov/) to confirm whether the denial was on disclaimer or on the merits, and to capture the APJ panel. The merits-vs-procedural distinction changes both your estoppel analysis and whether the petition art remains fully available.
4. Confirm the legal status. Verify the maintenance-fee status at Patent Center — Google's "Expired – Fee Related" flag, if accurate, may end the dispute outright.
5. No estoppel trap. Since no FWD issued on this patent, defendants are not barred by § 315(e)(2) from re-using the '709 petition's art in district court. Map your invalidity contentions to Meyer, Grisham, Cross, Fullerton, and the secondary references, keeping in mind § 325(d) if you later file a new petition.
6. Watch the family. Because a sibling IPR reached an FWD (2024-06-18) with a pending Federal Circuit appeal from Metrom, the appellate outcome on the related claims may inform (but will not collaterally estop) the '709 analysis — track the CAFC docket for Metrom Rail, LLC v. Siemens Mobility, Inc. for the docket number and disposition.

Accuracy notes / unverified items. The IPR2023-00460 petitioner group, filing and denial dates, POPR date, and refund events are sourced from the ipverse PTAB case page and the parallel '595 decision; the exhibit list is from the same ipverse page. The institution-decision reasoning, APJ panel, exact challenged claims, and exact statutory grounds for the '709 petition are unverified and should be confirmed on PTAB E2E. The presence of a "Disclaimer in Patent" exhibit is confirmed; which claims it covers is not. The sibling-IPR FWD/appeal dates come from a Patexia docket aggregation and are attributed to the Siemens v. Metrom family but the specific proceeding number-to-patent mapping for IPR2023-00452/-00468/-00470 is not confirmed. No claim-level invalidation or sustention of any '709 claim is asserted, because none occurred.

I'll research the assignment chain, litigation, and ownership details for US 10737709.

Let me dig deeper into the assignment records and litigation specifics.

Ownership & Assignment Analysis — US 10,737,709 B2 ("Worker protection system")

Scope note (read first): Direct query of USPTO Assignment Center was not completed in this session (tool-step limit). The findings below are grounded in (a) the Google Patents "Legal Events / Reassignment" record for this patent and (b) the litigation/PTAB record cross-references. I do not have the reel/frame numbers or the recording correspondent for the one post-filing assignment below, and I will not invent them. Treat reel/frame as "not captured."

Inventors

Pattern assessment: No unusual pattern. All six appear to be Metrom Rail personnel and several recur across the Metrom portfolio from 2013 through 2023 — i.e., they stayed, rather than departing within 12 months of filing. There is no evidence of a pre-fire-sale inventor exodus. (Note: the Google Patents header renders one name as "Strezec Peter"/"Strezev"; the patent text and family records read Peter Strezev — interpreted literally, not auto-corrected.)

Original assignee

Metrom Rail, LLC (an Illinois LLC; headquarters Lakemoor / Crystal Lake, Illinois). Also the current assignee per Google Patents.

• Ships a product embodying the claims: YES. Metrom publicly describes itself as "the first company to provide UWB technology to the rail industry," with deployments "on thousands of railway maintenance-of-way vehicles." Its commercial product line is branded AURA (including the AURA CAS collision-avoidance system), with AURA trademarks registered 2019–2020 and a SenTrack mark dating to 2012. The Federal Circuit opinion in Metrom Rail v. Siemens Mobility (No. 24-2223, Fed. Cir. May 11, 2026) discusses Metrom's AURA CAS product and secondary-considerations evidence tied to it.
• Primary line of business: Ultra-wideband (UWB)-based railway signaling, train control, collision avoidance, and worker protection.
• Current status: Operating (privately held; CEO Jim Marchi as of the Jan. 2022 releases). No bankruptcy, dissolution, or acquisition found. Portfolio of ~18–25 granted US patents per PatentView/onscope/plainpatent aggregations.
• Caveat specific to this patent: Google Patents lists the legal status of US 10,737,709 as "Expired – Fee Related" (anticipated expiration 2036-03-23), i.e., it appears to have lapsed for non-payment of maintenance fees. Separately, the PTAB docket for IPR2023-00460 shows the Patent Owner filed a "Disclaimer in Patent" exhibit on 2023-04-19 alongside its Preliminary Response — consistent with a statutory disclaimer of claims.

Assignment timeline

Only one assignment is documented for this specific patent in the legal-events record:

• 2019-01-14 (executed) / recorded 2019-01-14 — Reel/Frame: not captured (Assignment Center not directly queried)
  • Conveyance: Assignment — "ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)"
  • Assignor: Richard Carlson; Kurt Gunther; Sara Jo Woitel; Marc Wayne Cygnus; Peter Strezev; John Albert Plutt, Jr.
  • Assignee: METROM RAIL, LLC (Illinois)
  • Correspondent: not captured / not available in the sources retrieved
  • Context: Original inventor-to-employer assignment, recorded concurrently with the 16/246,940 continuation filing. No licensing, security, merger, or change-of-name component.

Family-level data point (not this patent): An earlier Metrom record — Reel 036186/0589, effective 2014-09-03, assignors Carlson/Gunther/Cygnus et al. → METROM RAIL, LLC, ILLINOIS — appears in the Google Patents legal events of Metrom's Rail Vehicle Signal Enforcement family (priority 2013-09-03). I am not attributing that reel/frame to the '709; it is cited only to show that the inventor→Metrom assignment pattern for this team predates the '709 by years.

Key negative finding: There is no post-issuance assignment of the '709 to any third party. No LLC-to-LLC cascade, no NPE or aggregator appears anywhere in the chain. The chain terminates at the original operating assignee.

Timeline diagram

timeline
    title Ownership of US 10737709
    2015 : Priority provisional filed
    2016 : Parent application filed
    2019 : Continuation filed and assigned
         : Inventors to Metrom Rail LLC
    2020 : Patent granted
    2022 : Metrom Rail sues Siemens group
    2023 : Siemens group files IPR
         : IPR institution denied
    2026 : Federal Circuit ruling on siblings

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. No assignee bears "IP / Patents / Licensing / Holdings / Ventures" branding; no single-purpose LLC appears. The sole assignee, Metrom Rail, LLC, is an operating manufacturer headquartered in Illinois (Lakemoor/Crystal Lake) with commercial products (AURA CAS, SenTrack) — evidence of actual commerce, per the Fed. Cir. 2026 opinion and Metrom's own product literature.

2. Known asserter in the chain — NOT PRESENT. Neither Metrom Rail, LLC nor any entity in the chain matches the supplied NPE list (Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation, Spangenberg entities), and Metrom is not surfaced as a high-frequency plaintiff by Unified Patents or RPX. Note the role inversion: the PTAB and IPR activity here is defensive — Siemens Mobility, Inc. et al. petitioned against Metrom (IPR2023-00460, filed 2023-01-09; institution denied 2023-07-06; sibling IPR2023-00468 against US 9,043,131 filed 2023-01-13). Metrom is the patent owner being challenged, not the challenger.

3. Repeat correspondent across the chain — NOT PRESENT / UNVERIFIABLE. With only one recorded assignment in the '709 chain and no correspondent captured, recurrence cannot be shown. Flagging for completeness: the litigation counsel of record (Schodde/R. Spuhler of McAndrews, Held & Malloy as Metrom's IP counsel; Farnan LLP as Delaware local counsel) is litigation, not assignment-recording, correspondent — do not conflate the two.

4. Cascading transfers — NOT PRESENT. A single assignment over the patent's 11-year life, not multiple transfers within 24 months.

5. Pre-litigation transfer — NOT PRESENT. The only assignment (2019-01-14) precedes the first infringement suit (1:22-cv-00049, filed 2022-01-13) by ~36 months — far outside the 6-month window. No venue-manufacturing transfer.

6. Bankruptcy fire-sale — NOT PRESENT. No Chapter 7/11, no trustee sale, no SEC-driven asset sale found for Metrom Rail. The "Expired – Fee Related" status reflects maintenance-fee lapse (and a possible statutory disclaimer), which is a fee/lifecycle event, not an insolvency sale. Do not over-read it.

7. Privateering — NOT PRESENT. This is the inverse fact pattern: the operating company (Metrom) asserts its own patents directly against competitors (Siemens Mobility, Thales / Ground Transportation Systems USA, Humatics, Piper Networks) over the MTA NYC Transit UWB contract. No operating company transferred to a proxy asserter.

8. Defensive aggregator — NOT PRESENT. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. Unified Patents appears in the Google Patents page only as the data-source attribution for the PTAB field, not as an assignee or licensee. The patent has not been neutralized by aggregation.

Verdict

Operating-company assertion.

Metrom Rail, LLC is the original and current assignee with no intervening transfers (single assignment recorded 2019-01-14, inventors → Metrom Rail, LLC; no NPE, LLC, or aggregator anywhere in the chain). Metrom is an active Illinois manufacturer that sells UWB rail-safety hardware claimed to embody the patents (AURA CAS line) and sued genuine competitors — Siemens Mobility, Thales/Ground Transportation Systems, Humatics, and Piper Networks — in D. Del. 1:22-cv-00049 (filed 2022-01-13) and the 2023 successor/severed cases (1:23-cv-00314, 1:23-cv-03057, 1:23-cv-02920) asserting the '709. That is the textbook operating-company fact pattern, not an NPE one — even though the patent itself now shows as fee-lapsed and the PTAB docket reflects a possible claim disclaimer (2023-04-19).

Caveats / contrary signals worth noting: (i) a third-party classifier (Ex Parte) tagged the 1:23-cv-03057 patent owner as "NPE (L)," which conflicts with RPX/Ex Parte's own "Operating Company" tag on 1:22-cv-00049 — I do not credit the NPE label absent evidence; (ii) the fee lapse and disclaimer mean the '709 may no longer be enforceable, undercutting its practical value; (iii) the sibling patents '227 and '131 were held unpatentable, affirmed by the Federal Circuit on 2026-05-11 (Metrom Rail, LLC v. Siemens Mobility, Inc., No. 24-2223).

Verify at: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (patent-number search) and https://assignment.uspto.gov/patent/index.html. Google Patents legal events: https://patents.google.com/patent/US10737709/en. To confirm, request the reel/frame and recording correspondent for the 2019-01-14 METROM RAIL, LLC entry directly from Assignment Center — that field is the one gap in this reconstruction.

I'll research US patent 10737709 and its prior art citations. Let me run several searches.

Let me get the complete citation list and cited-by data from the patent page.

Let me retrieve the full Google Patents citation table and the IPR petition details.

Prior-Art Analysis — US 10,737,709 B2 ("Worker Protection System")

0. Scope, sources, and honesty caveats (read first)

• I located the target patent and two independent bodies of prior art: (a) references cited on the face of / during prosecution of US 10,737,709 ("the '709 patent"), and (b) references actually relied upon by a challenger in IPR2023-00460. I did not retrieve the full, character-by-character claim set of the '709 patent or full claim charts for every reference, so the § 102 mapping below is my reasoned best‑effort based on the abstract, description, and the cited prior art identified — it is not a substitute for a claim‑by‑claim chart.
• I could not fully verify that every item in the "Citations (17)" table belongs to the '709 record (one retrieved page was titled "Distance estimation system and method for a railway vehicle" while surfacing the '709 entry nearby). Items I regard as lower confidence are flagged ⚠.
• No reference number has been "corrected." Identifiers are reproduced exactly as retrieved (including the internal inconsistency noted in § 1).
• Where I state a legal conclusion (anticipation), treat it as a preliminary technical observation, not a legal opinion.

1. The patent under review (literal identifiers as retrieved)

Priority statement (quoted literally from the description): "This patent application is a continuation of U.S. Provisional patent application Ser. No. 15/078,427, filed on Mar. 23, 2016, which makes reference to, claims priority to and claims benefit from U.S. Provisional Patent Application Ser. No. 62/177,683, filed on Mar. 23, 2015." (Note the internal oddity: Ser. No. 15/078,427 is called a "provisional." Reproduced as‑is.)

Subject matter of the claims (from abstract/description): a worker protection system comprising a train‑mounted unit and one or more wayside units placed on/near a track; each unit has a communication component with antenna(s) transmitting/receiving ultra‑wideband (UWB) signals and circuit(s) for processing; the train‑mounted unit operates cooperatively with the wayside unit(s) to provide alerts to workers. Dependent subject matter described includes alerting thresholds (TTA, DFT, CPD), GNSS positioning, NFC rule reconfiguration, VAD distributed units, logging, diversity antennas, and power‑saving.

Litigation/administrative context: Delaware cases 1:22‑cv‑00049 and 1:23‑cv‑00314; New York S.D.N.Y. 1:23‑cv‑02920 and 1:23‑cv‑03057; PTAB IPR2023‑00460 (Petitioner Siemens Mobility, Inc. et al.; instituted? No — Institution Denied, decision 2023‑07‑06).

2. Group A — References cited (prosecution / face‑of‑patent citations)

These are the references surfaced in the "Citations (17)" table associated with the '709 record. ⚠ = confidence that the item belongs to the '709 prosecution record is moderate rather than high. Each is a railway positioning/communication or UWB reference, consistent with the '709 field.

Non‑patent citations (3):

• Gresham, Ian, et al., "Ultra‑Wideband Radar Sensors for Short‑Range Vehicular Applications," IEEE Transactions on Microwave Theory and Techniques, vol. 52, No. 9, Sep. 2004. This is the most probative NPL item because it teaches UWB radar for short‑range vehicular applications — directly relevant to the claimed "UWB signals." Potential § 102 relevance to claims reciting UWB transmit/receive and range detection; likely a § 103 combination reference.
• Mirabadi, et al., "Application of Sensor Fusion to Railway Systems," Proc. 1996 IEEE/SICE/RS… — sensor‑fusion for railways; background on wayside/train sensing.
• A third NPL citation was truncated in the retrieved data and could not be verified.

3. Group B — Prior art actually asserted in IPR2023‑00460 (the most probative prior art)

These exhibits were assembled by Petitioner Siemens Mobility et al. to challenge US 10,737,709. They are the references a skilled analyst should treat as the most relevant prior art, because they were selected (with expert declarations by Braasch and Gigas) as an anticipation/obviousness attack on this specific patent. Confidence in these identifiers is high (exhibit list retrieved in full).

Outcome note: the PTAB denied institution on 2023‑07‑06, meaning the Board was not persuaded the petition established a reasonable likelihood that at least one claim is unpatentable. That is evidence the asserted art did not, on the record presented, squarely anticipate the '709 claims — an important qualification on any "anticipation" statement below.

4. Group C — Family / citing patents (context, not § 102 art)

These appeared as "family/cited‑by" neighbors and are not § 102 prior art to the '709 patent, but they are useful context for claim scope:

• US 20258058B2 / US 12,258,058 B2 — Metrom Rail LLC — "Rail Vehicle Signal Enforcement and Separation Control" (priority 2013‑09‑03).
• US 11,492,027 B2 — Metrom Rail LLC — "Track worker safety system / Methods and systems for worker protection system with ultra‑wideband" (priority 2015‑03‑23) — same priority family.
• US 8,344,877 B2 — "Track worker safety system" (priority 2015‑03‑23) — same family.
• US RE47,835 E1 — Railware, Inc. — "Railroad maintenance‑of‑way personnel warning system apparatus and method therefor" (2020‑02‑04) — third‑party railroad MOW worker‑warning art; potentially relevant § 102/§ 103 art to worker‑alerting claims, though its exact priority date vs. 2015‑03‑23 needs verification.
• US 6,208,260 B1 — "Personal warning method and apparatus for traveling loads" (2001‑03‑27) — personal‑warning art.
• US 6,113,037 — cited in the same citation cluster.

5. Bottom line — where the § 102 risk actually concentrates

1. Closest art to the independent claim(s) (UWB train‑mounted unit + wayside unit(s) cooperating to alert workers): DE 10 2008 020 700 A1 (Meyer) with US 7,148,791 (Grisham) and US 2010/0039978 A1 (Rangan), plus the Gresham 2004 UWB‑radar NPL — these are the references that target the "UWB signals" limitation and train↔wayside ranging.
2. Closest art to the "cooperative units / alerting" limitation: US 2012/0182191 (King), US 6,597,293 (Harrison), and US RE47,835 E1 (Railware).
3. Any reference that alone could anticipate the full independent claim would have to disclose all of: (i) a train‑mounted unit, (ii) one or more wayside units, (iii) UWB transmit/receive at both, and (iv) cooperative worker‑alert generation. On the retrieved record I did not find a single reference that clearly shows all four; the strongest challenger (IPR2023‑00460) was denied institution, which supports that conclusion. Accordingly, my preliminary assessment is that the cited art is stronger as a § 103 obviousness combination than as § 102 anticipation of the independent claim(s), with the dependent claims (TTA/DFT/CPD thresholds, NFC re‑configuration, distributed VAD sub‑units, GNSS, power‑saving via accelerometer, diversity antennas) facing progressively weaker art.

6. What I could not confirm (so you don't over‑rely on this)

• The exact issued claim set (claim 1 independent claim language, exact claim numbers) of US 10,737,709 — so I cannot assign anticipation to specific claim numbers; the mapping above is by claim feature, not by claim number. Retrieving the granted claims would be required for a defensible § 102 chart.
• Whether the Group A "(17)" citation items all belong to the '709 prosecution record or to an adjacent record (one retrieved page carried a different title).
• The third non‑patent citation (truncated).
• Full bibliographic dates for US RE47,835 E1 relative to the 2015‑03‑23 priority date.

If you can supply the granted claims of US 10,737,709 (or grant me another retrieval pass), I can convert this into a claim‑by‑claim § 102/§ 103 table with specific claim numbers and element‑by‑element mapping.

I'll start by gathering the authoritative claim text and the prior-art references cited on the patent's face, since the provided full text was truncated before the claims.

Let me pull the full claim set and the IPR2023-00460 petition materials (which typically identify the closest prior art and grounds).

The IPR petition materials are the key. Let me identify the specific grounds and references used against the '709 patent.

Bottom line up front

On the record I retrieved, claims 1, 12 and 20 of US 10,737,709 ("the '709 patent") — and the dependent claims — are strongly vulnerable under § 103 as a combination of (i) a conventional radio-based railway worker/collision warning system and (ii) Grisham's ultra-wideband (UWB) "impulse radio" platform. This is not a hypothetical: it is exactly the theory petitioners advanced in IPR2023-00460, which Google Patents' litigation data lists against the '709 patent (https://portal.unifiedpatents.com/[ptab](/ptab)/case/IPR2023-00460). The parent/sibling patents in the same family ('131 and '227) were held unpatentable as obvious over the same class of art, and the Federal Circuit affirmed on May 11, 2026 (Metrom Rail, LLC v. Siemens Mobility, Inc., No. 24-2223) — https://www.vitallaw.com/news/patent-fed-cir-ptab-s-invalidation-of-railroad-collision-avoidance-patent-claims-affirmed-surviving-claims-also-obvious/ipm0139724f39c7384235bd25d80517150a21.

1. Caveats on the record actually used (please read before relying on this)

1. The claim text was not in the fetched page. The Google Patents text supplied to me is truncated inside the FIG. 4 description; the claims, and the "References Cited / Prior Art" listing, were not included. I therefore reconstructed the claim set from the PTAB petition papers for the '709 patent (claims 1–20 are mapped element-by-element at https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1550904](/patent/1550904)/download-documents?artifactId=OAAGbWHll57RD2_GoaTF_PwGKKKr8WA7hNq2qAORDgNemXLL3smDe8g) and from the infringement contentions in Metrom Rail v. Siemens (https://insight.rpxcorp.com/litigation_documents/14728170). I could not retrieve the literal text of dependent claims 2, 3 and 4, and I do not guess at them below.
2. Reference identities. "Grisham" = U.S. Patent No. 6,759,948 (railroad collision-avoidance using UWB/impulse radio) — confirmed by the Federal Circuit reporting. "Douglas" = U.S. Patent No. 8,874,359; "Nixon" = WO 03/009254 A1 — both confirmed in the same source. "Meyer," "Cross," "McDaniel," "Richardson" and "Suzuki" appear in the petition materials only by name/host paragraph cites; I could not confirm their patent or publication numbers, so I cite them by name rather than invent an identifier.
3. Procedural posture. Google Patents labels IPR2023-00460 "Not Instituted – Merits," yet the PTAB file for the '709 petition contains a patent-owner response and a reply — an internal tension I cannot resolve from the retrieved material. Either way, no final written decision on the '709 claims exists, so the following is my independent § 103 analysis, not a restatement of a PTAB holding.

2. The claimed subject matter (as mapped in the petition)

Claim 1 (independent, system): a worker protection system comprising a train-mounted unit having (a) a communication component with one or more antennas for wireless signals, (b) the signals comprise UWB signals, (c) one or more circuits to process signals/data and perform functions of the train-mounted unit, and (d) the train-mounted unit operates cooperatively with one or more wayside units placed on or near the track to provide alerts to workers on or near the track, based on communication of the UWB signals with at least one wayside unit.

Claim 12 (independent): the mirror-image, wayside-unit-centric claim (wayside unit with UWB antenna component + circuits, cooperating with "any train-mounted unit deployed on a train traversing the track").

Claim 20 (independent): the most specific claim — UWB radios at predetermined locations along the track, worker UWB radios, a vehicle UWB radio; a processor (i) determines vehicle position from time-of-flight (TOF) measurements against a wayside UWB radio, (ii) determines worker location from TOF with a worker UWB radio, (iii) alerts the vehicle operator based on worker location, and (iv) alerts the worker based on determined distance to the vehicle, estimated time of closest approach, or approach speed.

Dependents add: broadcast of alert-triggering signals (cl. 5), alert logging (cl. 6), operator I/O (cl. 7), housing (cl. 8), portability/detachability (cl. 9), split train-mounted unit with externally deployed "broadcast unit" (cl. 10), separate operator unit (cl. 11), wayside power supply/housing/support structure (cl. 13–15), wayside broadcast of alert-related signals (cl. 16), forwarding of alerts (cl. 17), wayside logging (cl. 18), and wayside sensors for detecting/tracking a train (cl. 19).

Level of ordinary skill: a POSITA here is a degreed electrical/railway-systems engineer (or equivalent experience) with familiarity with RF/wireless communication, ranging/localization, and railroad operating-safety equipment — consistent with the Federal Circuit record, where the parties stipulated to a POSITA having "no railroad safety experience" at the margin (CourtListener opinion, https://www.courtlistener.com/opinion/[10856969](/patent/10856969)/metrom-rail-llc-v-siemens-mobility-inc/).

3. The prior art and what each reference teaches

4. The § 103 combination — primary grounds

Ground 1: Meyer + Grisham (renders claims 1, 12, and most dependents obvious)

• Missing element in Meyer: the signals are generic "radio signals," not UWB.
• Grisham fills it: UWB impulse radio units mounted on the train and at wayside poles, plus a person-carried device, delivering precision ranging and alerting.
• Motivation (KSR, Graham v. John Deere):
  1. Same field and same problem — both are railway collision/proximity warning systems; the petition's own words: "Meyer and Grisham's systems are remarkably similar in configuration and operation," both using a train-mounted device exchanging signals with wayside devices to determine that a train is approaching, and both triggering alerts to the person at risk and/or the operator.
  2. Express technical teaching in Grisham that UWB is "highly resistant to interference" (12:1-8), resolves multipath, uses low power, and yields "relatively fine resolution" (15:27-35) — precisely the attributes a worker-protection system needs to distinguish a worker standing on the track from one standing beside it.
  3. Predictable result / simple substitution — replacing Meyer's conventional RF link with a known wireless-and-ranging technology (UWB) that Grisham already deploys in the identical railroad context is "a simple substitution of one known element for another" yielding no more than expected results (KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 416–17 (2007)).
  4. Reasonable expectation of success — Grisham already puts UWB on locomotives and along track; Meyer's units already "transmit radio signals" containing travel information, so no redesign of the system architecture is required.
  5. Motivation need not be the best combination — In re Fulton, 391 F.3d 1195, 1200 (Fed. Cir. 2004), which the petitioners invoked: an alternative benefit (e.g., eliminating even some nuisance alarms) suffices.

Ground 2: Cross + Grisham (renders claims 1, 12, 16–19 obvious; strongest for claim 1)

Cross is the closer art because it discloses the complete three-node worker-protection topology: train-mounted VCUs, worker-worn PNUs, and wayside priority detectors that forward real-time vehicle/worker activity and alert notifications between them (Cross ¶¶ 49, 55, 62, 67), with the PNU entering an alert mode based on the received AVL packets and emitting audio/vibration/LED alerts (¶¶ 43–44, 56, 61). The petition maps this directly onto claim 1's "operate cooperatively with one or more wayside units … to provide alerts to one or more workers … based on communication of the wireless signals between the train-mounted unit and the wayside unit."

• Missing element: Cross's links are conventional wireless; Grisham supplies UWB for those links (petition: "the AVL packets sent by VCUs would be sent using UWB signals").
• Motivation: same field (worker/vehicle track-safety); Cross already contemplates a wireless network of exactly the same three node types, so implementing those links with Grisham's UWB radios is a known-technique-for-known-device improvement with predictable benefits; KSR permits precisely this.

Ground 3: Grisham + Cross + Douglas/Nixon (+ McDaniel) — claim 20

• 20[A]–[C] (UWB radios at predetermined locations, on workers, and on the vehicle): Grisham's impulse radio units at railroad poles, carried by persons, and on locomotives.
• 20[E] (vehicle position from TOF against a wayside radio): Grisham's propagation-delay/"time position measurement" ranging; Douglas/Nixon optionally supply GPS-based absolute position (Douglas = location tracking; Nixon = GPS functionality), both as alternatives and as complements.
• 20[F]–[G] (worker location determined via TOF; operator alerted based on worker location): Cross's VCU/PNU/wayside network already derives and communicates vehicle and worker activity/location; combining with Grisham's TOF provides the location precision.
• 20[H] (worker alerted based on distance, estimated time of closest approach, or approach speed): Grisham's distance-based warnings plus McDaniel's velocity-based threshold warning distance and Cross's AVL velocity data provide the final element. Motivation: the whole point of the art is to time warnings appropriately — McDaniel expressly teaches varying the warning threshold with velocity, which is the same design rationale recited in the '709 specification's TTA/DFT/CPD discussion.

Ground 4: + Richardson for claims 10–11

Richardson's vehicle with four offset UWB transceivers supports splitting the train-mounted unit into separate physical units (broadcast unit external to the train, separate operator unit) while retaining UWB capability — a conventional packaging choice motivated by antenna placement/coverage and operator ergonomics, both concerns the '709 specification itself raises.

Dependent-claim notes

Claims 5 (broadcast alert-triggering signals), 6 (alert logging), 7/11 (operator I/O), 8 (housing), 9 (portable/detachable), 10 (split units), 13–15 (wayside power supply, housing, support structure), 16 (wayside broadcast), 17 (wayside forwarding), 18 (wayside logging) and 19 (wayside sensors) recite off-the-shelf hardware and routine data-handling features. Cross supplies forwarding/relaying, alert-mode signaling, and vehicle/worker alert notifications; Grisham supplies train-mounted and wayside broadcast of alerting signals; the housing/power/support-structure/logging features were indisputably conventional in portable railroad wayside equipment as of March 2015. Under KSR, such "known technique[s] … to improve similar devices in the same way" do not rescue the claims absent a showing of unexpected results. I could not retrieve the text of claims 2–4, so I express no view on them.

5. Secondary considerations — why they are unlikely to save the claims

The Federal Circuit has already addressed this family's objective evidence and rejected it:

• Nexus (Fox Factory, Inc. v. SRAM, LLC, 944 F.3d 1366 (Fed. Cir. 2019)): the Board found Metrom's AURA CAS product included important unclaimed features (machine-function monitoring, remote data reporting), so no presumption of nexus; and Metrom's expert "did not identify any inventive characteristics that distinguish the system from prior art."
• Long-felt need: foreclosed because the prior art already resolved the need (Grisham's system protects "work vehicle[s]" and discloses UWB-based rail control). Nike, Inc. v. Adidas AG, 955 F.3d 45, 55 (Fed. Cir. 2020).
• Skepticism: rejected; UWB was in fact being used in railroad systems, and the very reference invoked for "UWB is dead" said UWB radar "was not dead after all."

Those holdings concerned the '131/'227 patents, but they rest on evidence about the same UWB/rail field and the same commercial product, so a '709 challenger would reuse them.

6. Where the '709 claims may retain some footing (residual nonobviousness arguments)

1. Claim 20's TOF-to-fixed-wayside-beacon architecture. Grisham's TOF is largely train-to-train/train-to-object; a claim tying vehicle position to TOF against wayside radios at predetermined locations and worker location to TOF against worker radios is a more specific architecture. Petitioners must show the combination, not just the references side-by-side. Note the Federal Circuit's claim-construction-driven ruling that "data representing the separation distance" can be satisfied by any over-the-air signals whose timing is used for a TOF calculation (CourtListener opinion) — an expansive reading that actually helps a challenger, and that Metrom has asked the full court to reconsider (petition for rehearing, https://fedcircuitblog.com/wp-content/uploads/2026/06/COMBINED-PETITION-FOR-PANEL-REHEARING-AND-REHEARING-EN-BANC-FOR-APPELLANT-METROM-RAIL-LLC.pdf).
2. "Cooperatively with any train-mounted unit deployed on a train traversing the track" (claim 12) reads on interoperability — a challenger should show the art contemplates a wayside unit agnostic to which train/unit is approaching.
3. Claim 19's on-board sensing (visual/infrared/laser ranging train detection) is narrower than the rest of the family and requires its own mapping.
4. Procedural fact to weigh: IPR2023-00460 was not instituted on the merits per Google Patents. That does not establish patentability — non-institution is discretionary and frequently reflects petition defects rather than claim strength — but a litigator should not assume the PTAB has already blessed the invalidity case.

7. Evidence of real-world exposure (context, not proof)

The '709 patent has been asserted in N.Y.S.D. cases 1:23-cv-02920 and 1:23-cv-03057 and D. Del. cases 1:22-cv-00049 and 1:23-cv-00314, alongside U.S. Patents 10,778,363, 8,812,227, 9,043,131 and 10,179,595, over UWB deployments in the MTA New York City Transit system. The infringement contentions assert claims 1, 3–4, 7, 12–16 and 20 — i.e., the very independent claims analyzed above, which confirms their commercial significance and their centrality to any invalidity challenge.

8. Confidence and verification checklist

To finalize this opinion I still need: (a) the verbatim text of claims 2–4; (b) the References Cited list and "Prior Art" listing from the Google Patents page (the section the prompt directs me to but which was absent from the fetched text); and (c) the cover-page identifiers and dates for the "Meyer," "Cross," "McDaniel," "Richardson" and "Suzuki" references, to confirm each qualifies as prior art against the 2015-03-23 priority date (and, if the priority chain to provisional 62/177,683 is not fully supported — note the patent's own priority paragraph mislabels the 2016-filed 15/078,427 as a "provisional" — against the 2016-03-23 fallback date).