US 6417801

I'll verify the patent details and check for any CAFC litigation activity before summarizing.

Let me check the litigation history and any current CAFC docket activity.

US Patent 6,417,801 B1 — Analyst Summary

Verification note: I can't query USPTO PatentCenter/CAFC CM-ECF directly; I searched Google Patents (authoritative full text provided), Unified Patents' litigation portal, the CAFC opinion PDF, FindLaw, and CourtListener. All sources corroborate the bibliographic data below. No active 2026 CAFC docket tied to this patent was found.

Bibliographic Data

Family/assignment chain: Global Locate (2001) → Broadcom Corp. (2015) → Avago Technologies General IP (Singapore) (2017) → Avago Technologies International Sales Pte. Ltd. (2018). The family includes a continuation-in-part, US 6,734,821 B2 ("Method and apparatus for processing of satellite signals without time of day information"), which shares the 2000-11-17 priority date.

Abstract (as published)

"A method and apparatus for computing GPS receiver position without using absolute time information transmitted by the satellite or by an alternative source of timing available at the GPS receiver. The GPS receiver is contained in an integrated receiver that also includes a wireless communication transceiver, but does not have access to an accurate source of absolute time information. The wireless transceiver communicates through a wireless network to a server. The GPS receiver measures satellite pseudoranges and uses the wireless communication transceiver to send the pseudoranges to the server. The server fits the pseudoranges to a mathematical model in which the GPS receiver position and the absolute time are unknown parameters. The server then computes a position and absolute time that best fit the model, thus yielding the correct position for the GPS receiver, and the absolute time at which the pseudorange measurements were made."

Independent Claims — Plain-Language Overview

Claim 1 — Position and time, without trusted absolute time (the core "five-state" claim).
A method for computing both the receiver's absolute position and the absolute time of reception. Steps: (i) obtain pseudoranges to multiple GPS satellites; (ii) obtain a rough estimate of absolute reception time (no accuracy requirement stated); (iii) obtain a rough estimate of receiver position; (iv) obtain satellite ephemeris; and (v) compute position and absolute time by updating those estimates. The teaching point is that a poor/unknown clock is not a bar — the time error and the "common mode" clock offset are solved for as unknowns alongside the 3-D position (the specification builds a 5-column H matrix: x, y, z, t_C, t_S).

Claim 17 — Absolute time alone, given a position estimate.
A method for computing just the absolute time of reception of satellite signals at a GPS receiver: provide pseudoranges to multiple satellites and an estimate of receiver position, then compute absolute time from the pseudoranges and that position estimate. This is the inverse framing of Claim 1 — time is the output, position is (assumed) known/estimated.

Claim 28 — Grid-search with a-posteriori residual rejection (resolving integer-ms ambiguity from a poor starting guess).
A method for computing GPS position from "partial" pseudoranges that are ambiguous by an integer number of milliseconds: (a) choose an a-priori position; (b) compute integer milliseconds consistent with it; (c) compute a navigation solution; (d) compute a-posteriori residuals; (e) use the relative size of those residuals to decide whether the integers were correct; and (f) repeat (c)–(e) with another a-priori position until residuals fall below a threshold. Dependent claims 29–32 stress that the starting guess need not be within 100 km — it may be >100 km away, more than one integer millisecond off, or a wholly arbitrary guess (the specification's Figures 5A/5B show the correct solution "snapping into place" after ~1,663 rejected candidates).

Claim 33 — System claim: mobile device + server split.
A system with (a) a mobile device containing a GPS receiver and a wireless transceiver, and (b) a server in wireless communication with it. The GPS receiver computes pseudoranges and the transceiver sends them to the server; the server computes the absolute position and absolute time using the pseudoranges plus an estimate of position and time. This is the client/server implementation of the Claim 1 method.

Litigation History (this is where the case law lives, not 2026)

• ITC Inv. No. 337-TA-602 — In re Certain GPS Devices and Products Containing Same. Global Locate/Broadcom v. SiRF Technology. Final Determination issued 2009-01-15: the '801 patent was among six patents found infringed, not invalid, and not unenforceable; limited exclusion and cease-and-desist orders issued (scope later narrowed per Kyocera Wireless Corp. v. ITC).
• CAFC No. 2009-1262 — SiRF Technology, Inc. v. International Trade Commission, 601 F.3d 1319 (Fed. Cir. Apr. 12, 2010) (Michel, Clevenger, Dyk, J.J.; Dyk authored). The Federal Circuit affirmed the ITC. Three holdings matter for this patent:
  1. Recorded PTO assignments carry a rebuttable presumption of validity (standing challenge rejected).
  2. The asserted method claims satisfy the then-governing Bilski machine-or-transformation test because "a GPS receiver is a machine and is integral to each of the claims," and the claims "could not be performed without the use of a GPS receiver." Claim 1 of the '801 patent was expressly analyzed here.
  3. Direct infringement (not merely joint) was found notwithstanding intermediary servers forwarding data.
• California Central District Court, No. 8:06-cv-01216 — parallel district-court action listed by Unified Patents.
• Google Patents flags "First worldwide family litigation filed" via Darts-IP (family ID 24875767).
• One search result (USITC Publication 4137) contains priority/conception testimony about the '801 patent — van Diggelen's April 2000 "alchemy engine" notes, an April 11, 2000 date, and a June 15, 2000 reduction to practice — discussed against an RX Networks '670-patent provisional (filed 2000-09-15) and Dr. Chansarkar. Uncertainty note: I could not confirm with high confidence which proceeding Publication 4137 belongs to; treat the priority-dispute detail as suggestive rather than confirmed.

Uncertainty / Caveats

• No 2026 CAFC docket was found. The only Federal Circuit appeal identified is No. 2009-1262, decided 2010-04-12. The patent's term expired 2020-11-17 (Google Patents legal status: "Expired – Lifetime"), so no live appellate activity is expected.
• Claim 18 as literally printed reads: "The method of claim 1 wherein said pseudoranges are sub-millisecond pseudoranges." Given its position after claim 17, this dependency on claim 1 (rather than claim 17) appears anomalous — I am reporting the text as published rather than correcting it, per instruction.
• The provided source text contains typos ("oc" in claim 2; "pluarlity" in claim 17; "pseudoreanges"), which I have not silently corrected.
• The "Current Assignee" field reflects Google Patents' listing and its own disclaimer that the assignment list may be inaccurate; the chain above (Broadcom → Avago entities) is corroborated by the assignment records shown.

Sources: https://patents.google.com/patent/US6417801/en · http://cafc.uscourts.gov/opinions-orders/09-1262.pdf · https://caselaw.findlaw.com/court/us-federal-circuit/[1521419](/patent/1521419).html · https://portal.unifiedpatents.com/patents/patent/US-6417801-B1 · https://www.courtlistener.com/opinion/1604/sirf-technology-v-itc/ · https://www.finnegan.com/files/Upload/FCN_May10_8.html

I'll research litigation involving US patent 6417801 across patent litigation databases and court records.

I have strong leads. Let me dig into the specific cases referenced: ITC 337-TA-602, the Central District of California case, and the CAFC appeal.

The ITC and CAFC proceedings are well documented. Let me pin down the district court actions and any other litigation asserting the '801 patent.

Litigation Involving U.S. Patent No. 6,417,801

Patent: U.S. 6,417,801 B1, "Method and apparatus for time-free processing of GPS signals"
Inventor: Frank van Diggelen | Original assignee: Global Locate, Inc. | Priority/filing: Nov. 17, 2000 | Granted: July 9, 2002 | Status: Expired – Lifetime (anticipated expiration Nov. 17, 2020)

The '801 patent was asserted in one major patent-enforcement campaign — the Global Locate / Broadcom v. SiRF dispute — which ran through the ITC, a parallel district court action, and a Federal Circuit appeal. Below are the known proceedings.

1. ITC Investigation No. 337-TA-602 — Certain GPS Devices and Products Containing Same

Sources: USITC Notice of Investigation (E7-8624, 72 FR 25777) · USITC Commission Final Determination notice (E9-1428, 74 FR 4807) · USITC Commission Opinion, Pub. 4137

Follow-on modification proceeding: On August 16/20, 2010, the ITC instituted a modification proceeding (19 C.F.R. § 210.76) on respondents' petition to modify the limited exclusion and cease-and-desist orders. (75 FR 51481) Separately, in May 2009 U.S. Customs determined that SiRF's redesigned chips fell outside the scope of the exclusion order.

2. SiRF Technology, Inc. v. International Trade Commission (Federal Circuit appeal)

Sources: CAFC opinion 09-1262 (PDF) · CourtListener combined opinion · FindLaw summary

3. SiRF Technology, Inc. v. Global Locate, Inc. (parallel district court action)

Source: Unified Patents litigation record, C.D. Cal. 8:06-cv-01216 (as also flagged on the Google Patents family page, which lists this district court case, the Fed. Cir. appeal 09-1262, and ITC 337-TA-602 as the family's litigation).

Note on scope / uncertainty: Global Locate's counterclaims in this district court action included the '801 patent (a defense expert engagement description lists the '801 among "patents-in-suit" for SiRF Technology, Inc. v. Global Locate, Inc.). However, the record I retrieved does not independently confirm the precise claim-by-claim assertion of the '801 in the district court case, so I flag that as less certain than the ITC/CAFC record.

Related proceedings that did NOT involve the '801 patent (for disambiguation)

• ITC Inv. No. 337-TA-596 — Certain GPS Chips, Associated Software and Systems, and Products Containing Same: SiRF as complainant against Global Locate (instituted Mar. 13, 2007), asserting U.S. 6,304,216; 7,043,363; 7,091,904; and 7,132,980. The '801 patent was not among these asserted patents.
• Broadcom Corp. v. SiRF Technology, Inc. (C.D. Cal., complaint filed May 14, 2008), asserting four Broadcom patents relating to SiRF's multimedia processors and GPS receivers. I could not confirm from the retrieved record whether the '801 was among the four patents in that particular May 2008 complaint (SiRF sought ex parte reexamination of those four patents), so I do not list '801 as asserted there.

Summary / Bottom Line

• Yes — litigation is known involving U.S. 6,417,801.
• The '801 patent's enforcement history consists of a single three-front campaign: (1) ITC Inv. No. 337-TA-602 (Global Locate/Broadcom v. SiRF, Pharos, MiTAC, Mio, E-TEN; complaint filed Apr. 2, 2007; violation found, exclusion + cease-and-desist orders, final Mar. 16, 2009); (2) the Fed. Cir. appeal SiRF v. ITC, No. 2009-1262, decided Apr. 12, 2010, 601 F.3d 1319 (affirmed — '801 valid, enforceable, infringed); and (3) the related, stayed-then-dismissed district court action SiRF v. Global Locate, 8:06-cv-01216 (C.D. Cal.), dismissed without prejudice Jan. 18, 2011.
• I found no other litigation (no later NPE/assertion suits, and no other district court or IPR/PGR proceedings) specifically asserting U.S. 6,417,801. The patent expired Nov. 17, 2020.

If you need the ITC's public record (EDIS) docket entries or the PACER/CAFC docket sheets for 337-TA-602 and 09-1262 pulled directly, note that EDIS is at usitc.gov and PACER access requires a paid account — I can help frame those retrieval requests.

I'll verify the canonical "no proceedings" default with targeted searches before reporting.

Proceedings overview

Zero AIA trial proceedings on file. The structured PTAB block (USPTO Open Data Portal ingest) returns no IPR, PGR, or CBM proceeding naming US 6,417,801, and my independent searches of PTAB E2E-indexed material, Unified Patents' patent portal, and the litigation press found no petition, institution decision, or Final Written Decision for this patent — so the bottom-line for a defendant is unusual: this patent was never PTAB-tested, but it is also dead on its own terms (term expired 2020-11-17), which means the relevant defensive posture is not "hardened by surviving IPRs" but rather "fully exposed to prior-art attack and no longer commercially assertable."

Before going further, one important calibration: the absence of PTAB activity here is not the usual signal ("well-asserted patents eventually attract IPRs"). This patent was heavily asserted (ITC § 337 action, parallel district court, CAFC appeal) — but the assertion window largely predated the AIA's 2012-09-16 IPR start date, the dispute resolved in 2009–2010, and the patent then expired in 2020. The IPR-eligible window (2012–2020) passed with the patent already adjudicated and nearing end-of-life.

AIA proceedings

None. No IPR, PGR, or CBM proceeding number exists for US 6,417,801 that I can identify or that the USPTO ODP record reports. Per instructions, I am not inventing proceeding numbers or FWD outcomes to fill the section template. The per-proceeding subsections below are therefore inapplicable.

Flagged non-AIA challenge — verify before relying

Ex parte reexamination request, reportedly filed by SiRF (2008) — proceeding number NOT verified

• Type: Pre-AIA ex parte reexamination (35 U.S.C. §§ 301–307 as then in force) — not an AIA trial; outside the scope of the PTAB block, but the only post-issuance validity challenge to the '801 that surfaced in my research.
• Reported timing: contemporaneous trade press (GPS World, 2008-08-07/08) states SiRF "had asked the USPTO reexamine four patents that are the subject of an infringement suit Broadcom has brought against SiRF in federal court," one day before the ALJ's 2008-08-08 infringement ruling. Source: https://stage.gpsworld.com/consumer-oemnewsitc-says-sirf-infringes-six-broadcom-patents-2974/ and https://www.kipo.go.kr/club/front/menu/bbs/view.do?clubId=dispute&menuId=3&curPage=203&messageId=13495 ("SiRF … has reportedly filed with the U.S. Patent Office to gain a reexamination of the contested patents").
• Status: Unknown / unconfirmed. The press reports are secondhand ("reportedly") and do not identify a reexamination control number or which four of the six patents were involved. I could not confirm that a reexamination request on the '801 was actually filed, granted, or that any certificate issued.
• Negative evidence worth weighing: the patent's Google Patents record shows kind code B1 and no reexamination certificate (an ex parte reexam that changes claims would appear as a C1 kind code / "REEXAM" event). The listed legal status is "Expired – Lifetime," with no reexamination event in the transaction history. That is consistent with either (a) no reexam request ever being filed against the '801, or (b) a request filed and denied. Do not treat the 2008 reexamination as a validity determination in either direction.
• Defensive value (if it happened at all): nil in 2026. It is pre-AIA, non-appealable to the CAFC in a way that produced no published decision, and produced no claim cancellation visible in the record.

The real validity/adjudication record (outside the PTAB framework)

Since no PTAB FWD exists, the only adjudicated validity holding on this patent comes from the ITC/CAFC track — and it favored the patent owner:

• ITC Inv. No. 337-TA-602, instituted 2007-05-07: Google Patents' source text records institution on 2007-05-07 (Federal Register 72 FR 25777). ALJ Carl C. Charneski's Initial Determination (2008-08-08) found SiRF infringed all six asserted patents — including the '801 — and that they were not invalid and not unenforceable. Per the CAFC opinion, the ALJ "found infringement of claims 1, 2, and 11 of the '801 patent." Commission Final Determination 2009-01-15: violation as to all six patents; limited exclusion and cease-and-desist orders issued. Source: https://www.federalregister.gov/documents/full_text/xml/2010/12/07/2010-30617.xml
• CAFC No. 2009-1262, SiRF Technology, Inc. v. ITC, 601 F.3d 1319 (Fed. Cir. 2010-04-12): affirmed in all respects. The court expressly analyzed the '801's method claims and held they satisfied the then-governing Bilski machine-or-transformation test because "a GPS receiver is a machine and is integral to each of the claims." Source: https://www.courtlistener.com/opinion/[1320748](/patent/1320748)/sirf-technology-inc-v-international-trade-commission/

Caveat, stated plainly: the CAFC's § 101 analysis in SiRF v. ITC is not an invalidity shield. It applied the 2010 Bilski framework, which was superseded by Mayo/Alice (2012/2014). No post-Alice court or the PTAB has ever passed on the '801's claims. If a demand letter arrives today, the patent's § 101 vulnerability is untested, not resolved.

Strategic summary

Claim status: everything is UNTESTED at the PTAB. No claim of US 6,417,801 has been canceled by the Board, and none has been sustained by the Board either. The four independent claims — 1 (position and time from a bad clock), 17 (time alone given position), 28 (grid search + a-posteriori residual rejection for integer-ms ambiguity), and 33 (mobile-device/server system) — plus all 31 dependents remain in the exact text as issued. Contrast this with the usual "claims 1–5 are canceled" posture: here there is no PTAB narrowing, so any theory built on Claim 1 is not pre-empted by estoppel or by a Board holding — but it also means the patent owner has no favorable PTAB precedent to lean on.

Estoppel landscape: empty, in both directions. Because no petitioner ever filed, there is no § 315(e)(2) estoppel binding anyone, and no § 325(e)(2) estoppel either. A hypothetical defendant today would face no IPR estoppel bar, but would also gain no benefit from an invalidating FWD, because none exists. The practical constraint is different and more decisive: the patent's term expired 2020-11-17 ("Expired – Lifetime"), so there is no forward-looking infringement exposure. Any suit now would be a damages-only claim for past conduct within the 35 U.S.C. § 286 six-year lookback, which reaches back only to roughly late 2020 — a window of days-to-weeks after expiration for which the market had already transitioned to Broadcom/Avago GNSS products and their competitors' own designs.

Pattern signals. No defensive aggregator (Unified Patents, RPX, etc.) ever filed against the '801 — Unified merely maintains an informational portal page (https://portal.unifiedpatents.com/patents/patent/US-[6417801](/patent/6417801)-B1). The patent owner (Global Locate → Broadcom → Avago) never had a PTAB appeal to pursue because it was never a party to an AIA trial. The invalidity fight, such as it was, was litigated entirely in ITC § 337 + district court + a reported 2008 reexamination filing — all pre-AIA. The patent family is also unusually deep in continuations/continuations-in-part sharing the 2000-11-17 priority date (e.g., US 6,734,821; US 6,937,187; US 7,245,253; US 7,554,487; US 8,692,712; US 10,520,606), so a 2026 challenger to related Broadcom/Avago portfolio members should look to those siblings — several of which did spawn later prosecution and are more recent, and one of which (US 6,937,187) is a continuation-in-part of the '801.

Recommended next steps

1. If you receive a demand letter citing US 6,417,801: check the expiration first. Term ran from 2000-11-17, expired 2020-11-17 (Google Patents legal status: "Expired – Lifetime"). There is no live injunctive or ongoing-royalty theory. The only possible claim is past damages inside the § 286 window, and even that window is nearly closed.
2. Do not rely on a PTAB record — there is none. Nothing at https://ptacts.uspto.gov/ptacts/ (PTAB E2E / PTAB Center) for this patent. If you need to be certain, run a party-name search in PTAB E2E for "Global Locate," "Broadcom," and "Avago Technologies International Sales Pte" and a patent-number search on 6,417,801; my ODP-based review and public-source review both come back empty.
3. IPR is not legally barred but is commercially pointless. There is no statutory prohibition on an IPR petition against an expired patent, but with no live assertion and no term remaining there is no relief to win. If you nonetheless need a validity opinion for a warranty, indemnity, or licensing negotiation, the productive frame is § 102/§ 103 art plus a modern § 101 analysis — not the 2010 Bilski-era holding in SiRF v. ITC.
4. Verify the 2008 reexamination before citing it. FOIA/PatentCenter the '801's file wrapper for any 2008-era reexamination request. If a request was filed and denied, that denial is a weak (non-precedential) validity datapoint; if no request was filed, the press reports were simply imprecise. Either way, report it as unverified, not as an IPR analogue.
5. If you're being asserted on a sibling patent from the same family (e.g., US 6,734,821, US 6,937,187, US 7,554,487, US 10,520,606), the analysis inverts: those have later expiration dates and, on the record surfaced here, likewise no PTAB proceedings — so they are equally un-narrowed and equally open to an IPR built on the prior art cited against the '801 in the ITC (e.g., US 6,064,336 to Loomis; US 6,215,442 to Loomis; US 6,150,980 to Krasner — all listed in the '801's cited-art set on the Unified Patents portal).

Sources: Google Patents full text for US 6,417,801 (authoritative, provided in prompt) · Unified Patents patent portal: https://portal.unifiedpatents.com/patents/patent/US-6417801-B1 · SiRF Tech., Inc. v. ITC, No. 2009-1262 (Fed. Cir. 2010-04-12): https://www.courtlistener.com/opinion/1320748/sirf-technology-inc-v-international-trade-commission/ · ITC enforcement/termination notice, 75 Fed. Reg. (2010-12-07): https://www.federalregister.gov/documents/full_text/xml/2010/12/07/2010-30617.xml · GPS World, "ITC Says SiRF Infringes Six Broadcom Patents": https://stage.gpsworld.com/consumer-oemnewsitc-says-sirf-infringes-six-broadcom-patents-2974/ · PTAB E2E / PTAB Center: https://ptacts.uspto.gov/ptacts/

I'll research the assignment record for this patent before reconstructing the chain.

Assignment & Ownership Reconstruction — US 6,417,801 B1

Scope note. The authoritative full text supplied in this session already encodes the USPTO assignment events (under "Images … Assignments" / Google Patents legal events). What it does not contain is reel/frame numbers or correspondents of record, and I could not retrieve those from the USPTO Assignment Center via the tools available to me. Where I cannot verify a field I say so rather than fill it in. Nothing below is an invented reel/frame.

Inventors

Departure pattern: none. Van Diggelen did not leave around the filing. Public profiles (Inside GNSS "Human" profile) show he continued at Global Locate through the TomTom ONE XL / Hammerhead chip and iPhone 3G programs, then became VP Technology and a Broadcom Fellow after Global Locate was acquired. This is the ordinary "inventor assigns to employer and stays" pattern — not the within-12-months departure that often precedes a portfolio fire-sale.

Original assignee

Global Locate, Inc. — the entity named on the issued patent (original assignee per Google Patents; recorded address history: 208 Harristown Road, Glen Rock, NJ 07452 → 3190 S. Bascom, Suite 260, San Jose, CA 95124 → 5300 California Avenue, Irvine, CA 92617, i.e., Broadcom's HQ address).

• Primary business: GPS / assisted-GPS (A-GPS) technology. It designed GPS baseband chips — the Hammerhead chip powered the TomTom ONE XL PND and the iPhone 3G, and it ran a global reference network for A-GPS assistance data. It is the archetypal "operating company that actually ships" for this patent, and the specification's client/server architecture matches its commercial server-assisted A-GPS service.
• Product embodying the claims: Yes. The claims describe exactly the server-side "time-free" position/time solve that Global Locate's A-GPS service and chipset implemented.
• Current status: No longer independent. Acquired by Broadcom Corporation (deal announced 2007); the recorded US assignment of this patent to Broadcom is dated 2015-09-16, and a corresponding EP-family deed of assignment is dated 2015-10-16 — see the discrepancy flag below. Global Locate survives today as a Broadcom/Avago group entity; the ultimate recorded holder of this patent is Avago Technologies International Sales Pte. Ltd.

Discrepancy flag (vs. the earlier generated summary): the prior summary listed a four-link chain (Global Locate 2001 → Broadcom 2015 → Avago General IP 2017 → Avago International Sales 2018). The authoritative source also records a 2016-02-11 security agreement in favour of Bank of America as collateral agent and a 2017-02-03 release of that security interest — two extra links that belong in the ownership picture. Conversely, the earlier summary's implication that the Global Locate→Broadcom assignment corresponds to the 2007 deal is imprecise: the 2007 event was a corporate acquisition, while the 2015 recordation is a later intercompany consolidation of the patent title. I am flagging, not silently correcting.

Assignment timeline

Data limitation, stated plainly: the USPTO Assignment Center / Patent Assignment Search records for this patent do exist (they are reflected in the Google Patents legal-events listing reproduced in the authoritative text). However, I was unable to retrieve reel/frame numbers, execution dates, or correspondents of record for any of them through the sources available in this session. Every "Reel/Frame" field below is therefore marked not retrieved. This is a genuine evidence gap, not a finding that no assignment was recorded.

• 2001-03-21 (recorded) — Reel/Frame not retrieved

  • Conveyance: Assignment ("ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignor: Frank van Diggelen
  • Assignee: Global Locate, Inc.
  • Correspondent: not retrieved (so no recurrence test possible)
  • Context: Original inventor-to-employer assignment, recorded ~4 months after the 2000-11-17 filing — routine employer practice, not a distress transfer.

• 2015-09-16 (recorded; execution date disputed — see note) — Reel/Frame not retrieved

  • Conveyance: Assignment ("ASSIGNMENT OF ASSIGNORS INTEREST")
  • Assignor: Global Locate, Inc.
  • Assignee: Broadcom Corporation
  • Correspondent: not retrieved
  • Context: Internal reorg / consolidation — Global Locate title folded into the Broadcom parent. The parallel EP record (GB/EP register) gives a deed of assignment dated 2015-10-16, registered 2015-11-26, in favour of Broadcom Corporation, and an address change of Global Locate from Glen Rock, NJ to 5300 California Ave, Irvine, CA. Flag: the US recordation (2015-09-16) predates the EP execution date (2015-10-16); one of the two dates is being reported under a different convention. I cannot resolve which without the reel/frame images.

• 2016-02-11 — Reel/Frame not retrieved

  • Conveyance: Security Agreement ("PATENT SECURITY AGREEMENT")
  • Assignor: Broadcom Corporation
  • Assignee: Bank of America, N.A., as Collateral Agent
  • Correspondent: not retrieved
  • Context: Securitization — the patent pledged as collateral under Broadcom's financing arrangements, recorded 10 days after the Avago/Broadcom merger closed (2016-02-01). Not a change of beneficial ownership.

• 2017-02-01 — Reel/Frame not retrieved

  • Conveyance: Assignment ("ASSIGNMENT OF ASSIGNOR'S INTEREST")
  • Assignor: Broadcom Corporation
  • Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
  • Correspondent: not retrieved
  • Context: Internal reorg — post-merger transfer of patent assets into the Avago/Broadcom IP-holding subsidiary.

• 2017-02-03 — Reel/Frame not retrieved

  • Conveyance: Release ("TERMINATION AND RELEASE OF SECURITY INTEREST IN PATENTS")
  • Assignor: Bank of America, N.A., as Collateral Agent
  • Assignee: Broadcom Corporation
  • Correspondent: not retrieved
  • Context: Lien discharge/refinancing — the 2016-02-11 pledge is released two days after the IP transfer above, consistent with a coordinated refinancing/reorg.

• 2018-10-04 — Reel/Frame not retrieved

  • Conveyance: Merger ("MERGER (SEE DOCUMENT FOR DETAILS)")
  • Assignor: Avago Technologies General IP (Singapore) Pte. Ltd.
  • Assignee: Avago Technologies International Sales Pte. Limited
  • Correspondent: not retrieved
  • Context: Internal reorg — absorbing merger of the IP-holding entity into the group sales entity.

• 2018-11-05 — Reel/Frame not retrieved

  • Conveyance: Correction ("CORRECTIVE ASSIGNMENT TO CORRECT THE EFFECTIVE DATE OF MERGER…")
  • Assignor: Avago Technologies General IP (Singapore) Pte. Ltd.
  • Assignee: Avago Technologies International Sales Pte. Limited
  • Correspondent: not retrieved
  • Context: Correction of record only — fixes the effective date of the 2018-10-04 merger; no change in beneficial ownership.

Timeline diagram

timeline
    title Ownership of US 6417801
    2000 : Filed by van Diggelen
    2001 : Assigned to Global Locate Inc
    2002 : Patent issued
    2007 : Broadcom acquires Global Locate
    2015 : Title to Broadcom Corporation
    2016 : Pledged to Bank of America
    2017 : To Avago General IP Singapore
         : Pledge released
    2018 : Merged into Avago International Sales
    2020 : Patent term expires

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. No operating→licensing-only-LLC hop appears anywhere in the record. Every assignee is part of an operating group: Global Locate, Inc. (chip maker) → Broadcom Corporation → Avago Technologies General IP (Singapore) Pte. Ltd. → Avago Technologies International Sales Pte. Limited. The Avago names are IP/sales subsidiaries of a ~$30B operating semiconductor group, not single-purpose Delaware/Texas assertion vehicles. Caveat: I could not confirm registered-agent addresses or membership structure because the reel/frame images were unavailable.

2. Known asserter in the chain — NOT PRESENT. No assignee matches Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg entity. The only plaintiff that ever enforced this patent is Broadcom/Global Locate itself, against a competitor (SiRF) — the inverse of the NPE pattern.

3. Repeat correspondent across the chain — UNCLEAR (evidence unavailable). The correspondent of record is the single most diagnostic field for a shell chain, and I could not retrieve it for any of the seven entries. So the recurrence test cannot be run. Recording is flagged, not scored.

4. Cascading transfers — PRESENT, but intra-group and benign on the evidence available. Seven recordations span 2001–2018, with four inside 18 months (2015-09-16, 2016-02-11, 2017-02-01, 2017-02-03) and a fifth ten days later in the sequence. The tell that distinguishes a benign reorg from a shell cascade is common principals/addresses: here the recurring party is Broadcom Corporation itself (assignee 2016-02-11 and 2017-02-03; assignor 2017-02-01) and the Avago entities are the same corporate family post-merger. That reads as corporate housekeeping, not manufactured anonymity. Shared-correspondent confirmation remains unavailable (see #3).

5. Pre-litigation transfer — NOT PRESENT. The assertion against SiRF (ITC Inv. No. 337-TA-602; Cal. C.D. Cal. No. 8:06-cv-01216, filed 2006) was brought by Global Locate/Broadcom, which had owned the patent since the 2001-03-21 recordation — five years before the first suit. Every later assignment (2015 onward) postdates the litigation. There is no within-6-months assignment timed to enable an assertion.

6. Bankruptcy fire-sale — NOT PRESENT. No assignor or assignee in the chain is a debtor that sold patents in Chapter 7/11 proceedings. Global Locate was acquired (2007), not liquidated; Broadcom and Avago were solvent acquirers. No analogue to Kodak/Nortel/Polaroid/Sun.

7. Privateering — NOT PRESENT. The enforcing party throughout (Global Locate, then Broadcom) was the product-making parent/subsidiary asserting directly, not an operating company handing patents to a third-party NPE to sue on its behalf. The 2017 transfer to Avago General IP (Singapore) occurred seven years after the litigation ended and is a group consolidation, not an assertion vehicle.

8. Defensive aggregator — NOT PRESENT. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It ends at Avago Technologies International Sales Pte. Limited (Avago/Broadcom group). The patent was never neutralised by a defensive aggregator.

Two temporal qualifications worth stating: (a) the patent expired 2020-11-17 (Google Patents: "Expired – Lifetime"), so this file is a historical assertion record, not a live monetisation campaign; and (b) the only adversary ever named is SiRF Technology — a real GPS-chip competitor — which is the defining fact separating this file from an NPE pattern.

Verdict

Operating-company assertion.

Global Locate, Inc. was a GPS silicon and A-GPS service company that shipped the patented technology (Hammerhead chip in the TomTom ONE XL and iPhone 3G), held this patent from the 2001-03-21 inventor assignment, and enforced it directly against a genuine competitor — SiRF — in ITC Inv. No. 337-TA-602, affirmed by the Federal Circuit in SiRF v. ITC, 601 F.3d 1319 (Fed. Cir. 2010). All post-2015 recordations (2015-09-16 to Broadcom; 2016-02-11 Bank of America security agreement; 2017-02-01 to Avago General IP (Singapore); 2017-02-03 release; 2018-10-04 merger and 2018-11-05 correction) are intra-group corporate consolidations, securitization, and record corrections inside the Broadcom/Avago organisation, with no shell entity, no NPE, and no third-party asserter. Confidence is tempered by one unresolved evidence gap: no reel/frame numbers or correspondents of record could be retrieved, so the repeat-correspondent signal could not be tested either way.

Verify the records at the USPTO Assignment Center / Patent Assignment Search:

• https://assignment.uspto.gov/patent/index.html#/patent/search — search "6417801"
• https://assignmentcenter.uspto.gov/ (same underlying records)

I'll search for the prior-art citations associated with US 6,417,801 and any litigation record identifying which references were asserted against it.

The first pass returned mostly forward citations. Let me pull the backward "Patent Citations" list (prior art cited within the '801 patent) and the invalidity contentions from the ITC/CAFC record.

Good — this surfaced the ITC record. Now I need the actual front-page "References Cited" list for the '801 patent and the specific prior-art references litigated (e.g., "Peterson", Rossbach, Sheynblat).

Prior Art Analysis — US 6,417,801 B1 ("Method and apparatus for time-free processing of GPS signals")

0. Scope correction you need before reading further

A critical orientation point that changes what "the citations for 6417801" can mean: under 35 U.S.C. § 102 (pre‑AIA, which governs here because the application was filed 2000‑11‑17), an anticipating reference must predate the 2000‑11‑17 priority date. Anything that cites the '801 patent is therefore, by definition, too late to anticipate it. The '801 patent's own "Cited By (120)" list records later patents that cite the '801 — those are potential § 102 art against those patents, not against the '801.

What I could and could not retrieve (please read as a limitation, not a finding):

• The authoritative Google Patents full text supplied in the user message contains the inventor, claims, specification, family, assignments, classifications and the forward citation list ("Cited By (120)"), but not the front‑page backward "Patent Citations" (References Cited) list for US 6,417,801.
• My live searches were terminated by a step limit before I could pull that backward list or the examiner's PTO‑892/PTO‑1449 from application 09/715,860.
• Therefore I am not able to enumerate "each patent citation for 6417801" as printed on the face of the patent, and I will not reconstruct that list from memory. A reconstructed list of cited references would be indistinguishable from fabrication. Section 6 tells you exactly where to obtain it.

What I can do — and what follows — is (a) report the citation data that is grounded in the authoritative text I was given, (b) report the prior art that was actually litigated against these claims, with citations and URLs, and (c) give a claim‑by‑claim § 102 framework keyed to the four independent claims (1, 17, 28, 33) and the three claims asserted at the ITC (1, 2, 11).

Refinement to the earlier section (not a contradiction): the earlier summary left unresolved which proceeding USITC Publication 4137 belongs to. The document itself resolves this: it is the ALJ's Initial Determination in Inv. No. 337‑TA‑602, Certain GPS Devices and Products Containing Same, bearing "Issued: August 8, 2008" and containing a dedicated section "VI. U.S. Patent No. 6,417,801 (the '801 Patent)". Treat the priority‑dispute testimony quoted from it as ITC‑record evidence, not as a court finding.

1. Citation data grounded in the provided authoritative text

These are the references in the supplied full text. Direction matters for § 102.

Representative forward citations (all post‑date 2000‑11‑17, hence not § 102 art against the '801): US 2003/0107513 A1 (Abraham, "determining time in a satellite positioning system," pub. 2003‑06‑12); US 6,670,916 B2 (Seiko Epson, "position calculation from calculated time," 2003‑12‑30); WO 2004/011957 A1 (Global Locate, "instantaneous Doppler measurements," 2004‑02‑05); US 2004/0142701 A1 (Abraham, oscillator frequency, 2004‑07‑22); US 2005/0206559 A1 (van Diggelen, "absolute time‑of‑day in a mobile‑assisted satellite positioning system," 2005‑09‑22); EP 2,081,040 A2 (Broadcom, 2009‑07‑22); US 2008/0303713 A1 (Han, "Navigational positioning without timing information," 2008‑12‑11); US 2009/0002226 A1 (Mo, "Position and time determination under weak signal conditions," 2009‑01‑01); US 7,936,642 B1 (Atheros, "High sensitivity GPS‑assisted time source," 2011‑05‑03); WO 2012/093146 A1 (Rx Networks, 2013‑10‑03).

2. The prior art that was actually litigated against these claims — the most probative record

This is where the genuine § 102 content for the '801 lives.

Proceeding: ITC Inv. No. 337‑TA‑602, Certain GPS Devices and Products Containing Same. Complaint filed by Global Locate 2007‑04‑30; instituted 2007‑05‑07 (72 FR 25777). Broadcom added as complainant 2008‑02‑05.

Prior‑art pleadings and expert reports (these name the references asserted against the '801 claims):

Asserted claims of the '801: claims 1, 2 and 11 (per the ALJ's Initial Determination and the CAFC opinion).

Outcome — this is the operative § 102 conclusion on the record: ALJ Initial Determination (Aug. 8, 2008) found no asserted claim of the '801 patent invalid; the Commission affirmed (Final Determination, Jan. 15, 2009; FR notice E9‑1428); the Federal Circuit affirmed in SiRF Technology, Inc. v. ITC, No. 2009‑1262, 601 F.3d 1319 (Fed. Cir. Apr. 12, 2010). The § 101 challenge (machine‑or‑transformation, Bilski) was rejected; validity was upheld.

Plain implication for your § 102 question: in the only adversarial record in which the '801 claims were tested, no reference was shown by clear and convincing evidence to anticipate claims 1, 2 or 11. Any new § 102 theory must therefore displace a fully litigated and twice‑affirmed validity determination.

3. The closest art classes the '801 had to distinguish (admitted background)

The '801 specification contains its own characterization of the state of the art — useful as a § 102 "admission" anchor:

• "All GPS Aiding, thus far invented, requires accurate external knowledge of the absolute time… required to an accuracy of between 1 millisecond and 10 milliseconds."
• "no traditional GPS receivers solve for absolute time error[,] instead relying on the fact that they know absolute time to the required accuracy (of 10 milliseconds or better)."
• "Therefore, a need exists in the art for a method and apparatus that processes GPS signals without using absolute time."

Analytical consequence for § 102: the SnapTrack/Krasner aided‑GPS family (e.g., US 5,945,944; US 5,841,396; US 5,874,914; US 5,781,156) supplies absolute time externally. It therefore cannot anticipate claim 1, which requires computing absolute time by updating an estimate of absolute time as an unknown. That distinction (supplied time vs. solved‑for time) is the fault line any § 102 reference must cross, and the specification's own text is the admission that the prior art sat on the "supplied" side of it.

4. Prior art named in later USPTO proceedings where the '801 itself is prior art

Two P‑TACTS petitions concerning a later Global Locate patent (referred to in the petitions as the "'104 Patent") list the '801 as Ex. 1010 and combine it with other art. These petitions are useful because they contain an expert's element‑by‑element articulation of what the '801 teaches — and, importantly, identify reference(s) that predate the '801 and were argued to be equivalent to it:

• "Peterson" (Ex. 1026) — characterized in the petition as predating van Diggelen by "about four years," and as teaching a formulation of position + time from TOAs "modulo 1 ms" with a matrix whose columns are direction cosines plus a column of radial velocities divided by the speed of light, with two time variables (gross/fine) equivalent to the '801's t_S and t_C. The pin cite given is "at 1323," which is consistent with a conference‑proceedings pagination. I could not verify the full bibliographic identity (author, venue, exact date) of "Peterson" within the available steps — treat it as the single most promising § 102 candidate for claims 1/2/17 pending verification.
• "Beser" (Ex. 1004) — argued to supply the additional satellite measurements (e.g., GPS + GLONASS) that the '801's five‑unknown solve requires.
• "Rossbach" and "Sheynblat" (Exs. in the first declaration) — named as background art in the same petition.
• Full citations for Beser, Rossbach and Sheynblat, and the venue/date for Peterson, are not verified in this analysis.

Note also that these petitions target a different, later patent in the same portfolio and post‑date the '801's expiry; they say nothing about the '801's own validity, but they do show how a challenger would frame the '801's elements.

5. Claim‑by‑claim § 102 framework

Claim 28 is the most § 102‑exposed of the four independently, because it is drafted at the level of a search‑and‑reject algorithm rather than the five‑state solve, and because its dependents deliberately broaden the permitted a‑priori error. The specification itself frames it broadly: "It will be understood by those skilled in the art that even if the absolute time is available at the GPS receiver, the process of integer ambiguity resolution has traditionally required an initial estimate of position close enough to the true position… The current invention provides a novel means of computing the correct integers without requiring an accurate initial estimate of position." That is the inventive point to attack or defend.

6. How to close the gap I flagged (concrete next steps)

1. USPTO PatentCenter, application 09/715,860 → "References Cited" / PTO‑892 and PTO‑1449 — this is the authoritative face‑of‑patent prior‑art list the task asks for.
2. Google Patents "Patent Citations" tab for US6417801B1 (the section omitted from the supplied text): https://patents.google.com/patent/US6417801/en
3. ITC EDIS, Inv. No. 337‑TA‑602 → exhibits: Respondents' Prior Art Notice (2008‑02‑15), First Supplemental Corrected Notice (2008‑03‑04), and the Heppe invalidity reports (2008‑02‑25 / 2008‑04‑04) — these name the exact references asserted against claims 1, 2, 11.
4. USITC Pub. 4137 (ALJ Initial Determination, 2008‑08‑08): https://www.usitc.gov/intellectual_property/documents/pub4137.pdf (see § VI on the '801 patent).
5. CAFC No. 2009‑1262: http://cafc.uscourts.gov/opinions-orders/09-1262.pdf
6. Final Determination notice: https://www.govinfo.gov/content/pkg/FR-2009-01-23/pdf/E9-1428.pdf
7. P‑TACTS petitions 1524049 and 1524601 — to identify "Peterson," "Beser," "Rossbach," "Sheynblat" precisely.

7. Explicit uncertainties and non-corrections

• Not retrieved / not asserted: the full front‑page "References Cited" list for US 6,417,801. I did not reproduce it from memory.
• Unverified: exact bibliographic citations for Peterson, Beser, Rossbach and Sheynblat; the characterization of those references rests on petition text located via search, not on the references themselves.
• Unverified as face‑of‑patent citations: US 5,945,944, US 5,841,396, US 5,874,914, US 5,781,156 — I present them as the archetype of the admitted "GPS Aiding" background, not as references the examiner cited against the '801.
• Typographical anomalies preserved as printed, not corrected: claim 2 "The method oc claim 1"; claim 17 "pluarlity"; "pseudoreanges" in claim 1; and the claim‑18 dependency on claim 1 rather than claim 17. Per your standing instruction I have not auto‑corrected these. The claim‑18 anomaly also means, for § 102 purposes, that claim 18 is a second copy of claim 2 — two independent anticipation targets with identical scope.
• No live 2026 activity: term expired 2020‑11‑17 ("Expired – Lifetime"), so the only decisions of record remain the 2008–2010 ITC/CAFC sequence. No § 102 holding adverse to the '801 exists in that record.
• Legal framing caveat: the claim/art mapping in § 5 is an analytic framework, not a conclusion of law. I have not compared the '801 claim language element‑for‑element against any reference's disclosure; that requires the actual texts of the references listed in § 6.

I'll first try to retrieve the actual "References Cited" / prior-art listing from the Google Patents page, since the version provided to me is truncated before that section.

Good leads. Let me pull the ITC's invalidity analysis of the '801 patent and the actual cited references.

Let me try to pull the ITC's specific invalidity analysis for the '801 patent and the examiner-cited references.

Obviousness Analysis — U.S. Patent 6,417,801 B1 under 35 U.S.C. § 103

0. Evidentiary caveat up front (please read before relying on this)

Two housekeeping points that materially affect the analysis:

1. The "Prior Art section" of the page you directed me to is not present in the text I was given. The fetched Google Patents text (https://patents.google.com/patent/US6417801/en) ends mid-way through the "Cited By (120)" table; there is no "References Cited" / "Patent Citations" list and no Non-Patent Citations list for the '801 patent itself. I therefore could not verify the face-of-patent citations (the examiner-cited art). Rather than fabricate them, I reconstructed the prior-art universe from three checkable sources: (a) the admitted background art inside the '801 specification itself, (b) the ITC record in Certain GPS Devices and Products Containing Same, Inv. No. 337-TA-602 (USITC Pub. 4137), and (c) the surrounding A-GPS literature. Anything I could not verify is flagged.

2. The patent's own admission problem. Under In re Wyers/KSR principles, the '801 specification's background section is itself usable prior art for what it admits was known. It admits a great deal — see §4 below.

Contradiction flagged against the previously generated sections: the earlier Litigation Summary states the ITC asserted claims were "Claims 1 and 17." The ITC Initial Determination (Pub. 4137) actually finds infringement of "claims 1, 2 and 11 of U.S. Patent No. 6,417,801." Claim 17 does not appear in that infringement finding. I am reporting the ID text as ground truth and flagging the earlier summary as inconsistent.

1. Statutory framework and the dispositive threshold issue

The application was filed 2000-11-17, so pre-AIA § 103(a) governs.

The single most important fact for a § 103 analysis is the invention date, because it defines the prior-art cutoff:

That April 11, 2000 date knocks out the two closest references in the record:

• Syrjarinne, "Time Recovery Through Fusion of Inaccurate Network Timing Assistance with GPS Measurements," Proc. 3rd Int. Conf. on Information Fusion, Paris, July 10–13, 2000 — the most on-point "time-free/time-recovery" reference in the ITC record. Published after the April 2000 invention date, so not § 102(a) art; less than one year before filing, so not § 102(b) art; not a U.S. filing, so not § 102(e) art. Not prior art to the '801.
• RX Networks' '670-provisional / Dr. Chansarkar's "overdetermination procedure" (filed Sept. 15, 2000) — postdates both conception and diligent reduction to practice; the ITC found no corroborated earlier conception/reduction/diligence by Chansarkar. Fails § 102(g).

This is why SiRF lost. Any § 103 combination must be built only from art predating April 11, 2000, and the best art simply isn't available.

2. Person of Ordinary Skill in the Art (POSITA)

A bachelor's degree in EE, aerospace, or CS (or equivalent), plus 2–4 years in GPS/satellite-navigation receiver design — or a master's plus 1–2 years. The POSITA is presumed to know:

• PN-code correlation and sub-millisecond pseudorange measurement (the '801 spec admits this is known: "At very low signal levels the PN pattern may still be observed … These measured time delays are called 'sub-millisecond pseudoranges'");
• the linearized (Taylor-series) least-squares PVT solution and the ICD-GPS-200 navigation message;
• assisted-GPS / server architectures (Krasner et al.);
• the satellite range-rate bound of ≈ ±800 m/s and its consequence that 1 ms of time error ≈ 0.8 m of range error.

3. Independent claims under review

The asserted/litigated set per the ID was {1, 2, 11}.

4. Graham factor 1 — scope and content of the (verified) prior art

Not prior art (or unverifiable): Syrjarinne (July 2000); RX '670 provisional (Sept. 2000); Stroia thesis (Oct. 2001, post-filing); any examiner-cited references (list not present in the page I was given).

5. Graham factor 2 — the actual differences

Conventional GPS already solves for receiver clock bias (column 4, c, "well known in the art" per the '801 spec). The '801's asserted novelty is the joint treatment of:

1. absolute time error as a fifth unknown state (t_S), and
2. the fifth sensitivity column ∂ρ/∂t_S = −ρ̇ (range rate), computable from ephemeris.

Everything else — the a-priori position, the a-priori time, the ephemeris, the sub-ms pseudoranges, the fault model, the server/client split — is admitted to be known.

6. Proposed § 103 grounds

Ground A — Claim 33 (and claim 1 via claim 33): Krasner A-GPS + standard overdetermined estimator (Spilker/ICD-GPS-200) + cell-ID aiding

Motivation (KSR): FCC E-911 location mandates created market pressure to locate handsets on AMPS/TDMA networks that carry no precise time — a problem the '801 specification expressly admits. Krasner supplies the mobile-measures/sub-ms-pseudoranges/server-computes architecture; Spilker/ICD-GPS-200 supplies the linearized estimator into which one more state can be added; cell-ID supplies the a-priori position. The POSITA would recognize that an estimator with a new unknown simply needs one more independent measurement — the classic "overdetermined solution" condition, and would expect position accuracy of ~10 m given the 0.8 m/ms bound.

Ground B — Claim 1: adding a fifth state to the four-state PVT solution

Motivation: (i) The applicant's own admission that "traditional GPS receivers treat the common mode error as an unknown that must be solved for, along with position" shows a state-space extension was known practice. (ii) The 800 m/s maximum range rate is a closed-form, predictable relationship, so the POSITA would expect the first-order Taylor expansion to converge (the spec itself says "typically very few iterations are required"). (iii) The specification admits the first four matrix columns are "well known in the art" and that linearization via Taylor series is "just one example." Under KSR, combining a known estimator with a known physical sensitivity (the range rate, already computed for Doppler/velocity work — cf. Global Locate's own later WO 2004/011957) is a predictable, finite-solution improvement.

Ground C — Claim 17: computing absolute time from pseudoranges + a position estimate

Motivation: Solving for time given position is the algebraic inverse of the classic "five satellites/four states" clock-bias problem. Syrjarinne's independent time-recovery work (even though post-dating the invention date) evidences that this was a recognized objective; the Schuchman time-position-ambiguity teaching supplies the mechanism.

Ground D — Claim 28: grid search + a-posteriori residual rejection

Motivation: Schuchman teaches resolving time-position ambiguity using prior knowledge of position. Adding the routine engineering step of testing a solution by its post-fit residuals (standard RAIM / goodness-of-fit practice) to validate the integer-ms choice is a combination of familiar elements with predictable results. The "snap into place" behavior is nothing more than the least-squares solution converging once the correct integers are chosen.

Ground E — Claims 6–14, 19–27: the mathematical model

The '801 specification concedes the disputed scope: "the first three columns of the matrix H are well known in the art"; "the fourth column … is also standard in the art"; altitude pseudo-measurements and removing known parameters "is standard in the art." Those claims rise or fall with claim 1.

The reference-satellite single-difference trick (FIG. 3, steps 310–322)

Cancelling the common-mode term t_C by differencing against a reference satellite is textbook single-differencing in GPS processing. Once the model of claim 1 is accepted, this is routine.

7. Graham factor 3 — secondary considerations and the actual outcome

This is where the hypothetical case collapses:

• The record refutes it. The ITC ALJ's Final ID (Aug. 8, 2008) found the '801 not invalid and not unenforceable; the Commission affirmed (Jan. 15/27, 2009). The Federal Circuit affirmed in SiRF Technology, Inc. v. ITC, 601 F.3d 1319 (Fed. Cir. Apr. 12, 2010) (No. 2009-1262). SiRF, with Dr. Heppe's invalidity reports and a full Notice of Prior Art, failed to carry the clear-and-convincing burden.
• The best art is disqualified by the April 11, 2000 invention date (§ 1 above).
• Nexus evidence: the ITC found a domestic industry satisfied as to the '801; Global Locate's implementation (LTO/Indoor GPS chips in TomTom devices) was the accused-infringing domestic industry; SiRF ultimately redesigned around the exclusion order. That is non-trivial evidence of technical merit, and it is precisely the argument that defeated the obviousness case in the ITC.

8. Additional claim-drafting anomalies worth flagging (not corrected)

Consistent with the earlier-flagged claim-18 issue, and per the "do not auto-correct" rule:

• Claim 11 reads "The method of claim 4, wherein one or more of the updates is assumed known…" — but claim 4 (a bare dependency on claim 1) introduces no "updates"; the "updates" concept first appears in claim 10 (via 9 ← 6). The literal dependency on claim 4 is anomalous.
• Claim 35 depends on the system of claim 33 and recites "the position estimate is a position of a radio tower," whereas the tower-aiding concept is introduced as a method step in claim 15.
• Claim 2 ("method oc claim 1") and claim 17 ("pluarlity") carry the printing errors already noted.

These anomalies matter for § 103 because claims 2 and 11 were the actually adjudicated claims and their scope depends on resolving these dependencies.

9. Bottom line

1. A competent challenger could construct a KSR-style obviousness case against claim 1 by combining (a) Krasner-type server A-GPS measuring sub-millisecond pseudoranges, (b) the Spilker/ICD-GPS-200 linearized estimator that already solves for clock bias as an unknown, and (c) the admitted known problem of cellular networks lacking precise time — with the range-rate sensitivity ∂ρ/∂t = −ρ̇ as a predictable, closed-form addition. Grounds A, B and D above are the strongest framings; Grounds C and E are weaker (they largely duplicate the admitted art).

2. But that case would very likely fail on this record, for three independent reasons: (i) the closest art (Syrjarinne, July 2000; RX '670, Sept. 2000) postdates the proven April 11, 2000 conception and is therefore not § 102(a)/(b)/(e)/(g) art; (ii) the "add-one-more-state" argument does not confront the specific insight — that the absolute-time residual is linearly sensitive to the range rate — which no pre-April-2000 reference in the verified record supplies; and (iii) the ITC and the Federal Circuit affirmatively held the claims not invalid after full adversarial testing.

3. I am explicitly flagging uncertainty as to the examiner-cited "References Cited" list, which was absent from the source page. If that list is supplied, the obviousness attack should be re-run against it specifically — particularly with respect to claims 2 and 11, which carry the anomalous dependencies above.

4. Practical note: the patent expired 2020-11-17. Any modern § 103 analysis is therefore hypothetical (valuation, family-member scope, or a later member such as US 6,734,821 / US 6,937,187) rather than an invalidity defense to a live infringement claim.

Sources: Google Patents US 6,417,801 B1 · USITC Pub. 4137, Certain GPS Devices and Products Containing Same, Inv. No. 337-TA-602 (Commission Opinion, Jan. 27, 2009) · CAFC No. 2009-1262, SiRF Tech., Inc. v. ITC, 601 F.3d 1319 (Fed. Cir. 2010) · FindLaw opinion text · PTAB preliminary guidance citing van Diggelen '801 as a secondary reference · Unified Patents record for US 6,417,801 B1