US 10080204

I'll search for authoritative information on US patent 10080204 and check for any CAFC 2026 docket activity.

Let me check specifically for any 2026 Federal Circuit (CAFC) appellate activity involving this patent.

US Patent 10,080,204 — Analyst Summary

Sourcing note

• I worked from the authoritative full text at Google Patents (https://patents.google.com/patent/US10080204B2/en), cross-checked against USPTO-report and FPO records, the Stanford NPE litigation database, and PTAB/litigation dockets.
• Caveat on the identifier: "10080204" is the patent number US 10,080,204 B2. Note that an unrelated USPTO application number 10080204 exists (it belongs to US 6,898,901, sound-absorbing composites). That is a serial-number coincidence and not this patent — flagging it so it isn't conflated.

Bibliographic data (confirmed)

Continuation chain (this patent is the latest in a long continuation family): 15/286,600 ← 14/792,822 (U.S. 9,496,976) ← 13/775,158 (U.S. 9,113,380) ← 13/617,679 (U.S. 8,406,218) ← 13/036,787 (U.S. 8,311,031) ← 12/162,237 (U.S. 7,969,964), which is the U.S. national entry of PCT/KR2007/003573 (filed July 25, 2007).

Ownership discrepancy worth noting: Google Patents lists the current assignee as ETRI, but the Stanford NPE database, PTAB IPR2020-00242, and district-court captions identify Sol IP, LLC as the patent owner/asserting party. This is consistent with an ETRI→Sol IP transfer or exclusive-license arrangement; the two records reflect different points in time. I cannot confirm the precise conveyance from the sources reviewed.

Abstract

"A method of searching a cell in a mobile station of a communication system in which a plurality of cells are grouped into a plurality of cell groups, each cell group including at least two cells, includes: detecting a primary synchronization signal and a secondary synchronization signal from a received signal; and identifying a cell based on a combination of the primary synchronization signal and the secondary synchronization signal. The secondary synchronization signal is related to the cell group to which the mobile station belongs and the primary synchronization signal is related to the cell to which the mobile station belongs within the cell group."

(Source: https://uspto.report/patent/grant/10,080,204)

Plain-language overview of the independent claims

The granted patent has 28 claims with five independent claims — three apparatus/method claims on the receive (mobile-station) side and two on the transmit (base-station) side. All share the same core frame structure: 20 units per frame; two contiguous sync OFDM symbols positioned as the last two symbols of a unit; a repeated primary sync signal (PSS) and different secondary sync signals (SSS) per unit; the SSS conveys a cell-group identifier and the PSS conveys a cell-within-group identifier, which are combined to yield the cell ID.

• Claim 1 — Communication method (receive side). Receive part of a frame made of 20 units. A first unit has a first set of OFDM symbols (first and second symbol); a second unit has a second set (third and fourth symbol). The first symbol carries a first PSS; the second carries a first SSS; the third carries the same first PSS; the fourth carries a second, different SSS. Determine a first identifier from the PSS and a second identifier from one of the SSSs, then determine the cell identifier from the combination. Recited structural limits: the sync symbols in each unit are contiguous and are the last two OFDM symbols of the unit; the second identifier indicates one group of cells, and the first identifier indicates a cell within that group.

• Claim 7 — Apparatus for a terminal (receive side). Same subject matter as Claim 1, implemented as a memory plus at least one processor that causes the terminal to perform the receiving/determining steps.

• Claim 13 — Communication method (transmit side). Generate a first PSS from a first identifier; generate first and second SSS from a second identifier; build a frame of 20 units in the same PSS/SSS layout as Claim 1; and transmit it. The first and second identifiers are derived from the cell identifier, the two SSS are different, the sync symbols are contiguous and are the last two OFDM symbols of each unit, and the second identifier indicates a cell group while the first identifier indicates a cell within it.

• Claim 19 — Communication apparatus (transmit side). Same as Claim 13, implemented as a memory-plus-processor apparatus.

• Claim 25 — Apparatus for a terminal (receive side). Substantively the same receive-side subject matter as Claims 1/7.

Dependent claims add: dual-RF/baseband down-conversion and bandpass filtering (claims 2–3, 8–9, 26), unused subcarriers among the sync symbol's subcarriers (claims 4, 10, 16, 22, 27), a seven-OFDM-symbol unit (claims 5, 11, 17, 23), and a 0.5 ms time slot where the first OFDM symbol is the last symbol in the slot (claims 6, 12, 18, 24, 28).

Litigation / PTAB status (relevant to the "CAFC 2026" request)

From Google Patents, Stanford NPE DB, and Docket Alarm, the family has substantial assertion activity:

• Sol IP, LLC v. AT&T Mobility LLC, E.D. Tex. 2:18-cv-00526
• Sol IP, LLC v. Sprint Corp. et al., E.D. Tex. 2:18-cv-00527; v. Verizon Communications/Cellco, 2:18-cv-00528
• E.D. Tex. 3:20-cv-00137 (AT&T, with Ericsson and Nokia of America intervening)
• N.D. Cal. 5:20-cv-00399; W.D. Tex. 6:21-cv-00270; E.D. Tex. 2:22-cv-00097
• PTAB IPR2020-00242 — Ericsson Inc. v. Sol IP, LLC (filed Dec. 10, 2019). It terminated by settlement before institution (Termination Decision Mar. 9, 2020; refund Apr. 2, 2020). No institution, no final written decision.
• Unified Patents ran a PATROLL prior-art bounty on related Sol IP MIMO patents (contest expiry Oct. 18, 2026).

On the specific "CAFC 2026 docket" question: I could not locate any Federal Circuit (CAFC) 2026 docket, appeal, or decision naming patent 10,080,204. My searches returned no 2026 appellate activity tied to this patent number. I state this with only moderate confidence — CAFC docket data is often incomplete in third-party databases, so absence of a hit is not proof of absence. To confirm definitively, the authoritative sources would be the Federal Circuit's PACER/CM-ECF docket and the CAFC "Appeals Search" system queried directly by patent number.

Uncertainty flags

• Sol IP ownership/transfer instrument: cannot confirm the exact ETRI→Sol IP conveyance from the sources reviewed.
• Exact 2026 CAFC status: not verified in an authoritative docket; no evidence found either way.
• Claim construction / validity outcomes: none located for this patent (the single IPR settled pre-institution).

I'll research current litigation involving US patent 10,080,204, starting with the litigation portals and docket sources.

Let me pull the full case list from the NPE database and Unified Patents portal, and verify each docket.

Litigation Analysis — U.S. Patent No. 10,080,204 B2

Builds on the earlier Patent summary, PTAB challenges, Assignment history, Prior art, and Obviousness sections above; this section adds the case-level litigation record and does not repeat the PTAB discussion. Where a source contradicts an earlier section, I flag it inline.

Sourcing note / method

I queried the sources you named and adjacent dockets: the Stanford NPE Litigation Database (https://npe.law.stanford.edu/patent/10080204), RPX Empower, Patexia case summaries, Docket Alarm (patent:(10080204) query), UniCourt / Justia Dockets, the Unified Patents litigation/PTAB portal, and the CAFC opinions/orders page. I searched on the literal string 10080204 only and discarded results keyed to other numbers.

One important limitation to state plainly: the Stanford NPE database lists only the first two '204-tagged cases (the AT&T and Sprint 2018 suits) on the page captured. The remaining entries below come from cross-referencing Google Patents' legal-events litigation block (already cited in the Patent summary section), Patexia, RPX, and Docket Alarm. I did not obtain a PACER-level docket for each 2018 case in this pass, so outcome/status fields marked "not independently docketed" are gaps, not conclusions.

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Litigation table

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Case-specific notes and contradictions

Row 4 — Intel (N.D. Cal. 5:20-cv-00399). This is the cleanest source conflict in the set. Google Patents' litigation block carries this case as litigation on the '204 patent, and both UniCourt and Justia list it under "Nature of Suit: Patent." But the actual first-filed document is a motion to compel Intel's compliance with a subpoena, filed by Sol IP with attachments (Declaration of Eliza Finley, Exhibits A–C). That is a § 1782/ancillary-discovery posture, not an infringement count on the '204 patent. Do not represent to anyone that Intel was sued for infringing the '204 patent on the basis of this docket. If anything, the Intel docket is a precursor to the W.D. Tex. Qualcomm action (row 5) — Sol IP appears to have used Intel as a third-party discovery source before suing Qualcomm, an ETRI-licensee supplier. This nuance was not surfaced in the earlier Patent summary section, which listed "N.D. Cal. 5:20-cv-00399" as an undifferentiated litigation entry; I am flagging it as a refinement.

Row 6 — Ford (E.D. Tex. 2:22-cv-00097). The amended complaint's own "Asserted Patents" recitation names, among others, 9,496,976 ('976), 8,311,031 ('031), 10,231,211, 10,932,298, 8,320,571, 10,148,477, 10,206,207, 10,244,559, 10,749,722, 10,271,349, 10,687,351, 8,593,936, RE48,101, 10,405,277, 10,863,439, 10,462,776, 10,009,896, 10,893,525, 10,938,534. 10,080,204 is not in that list. Notably, 9,496,976 and 8,311,031 are both direct ancestors of the '204 patent in the same continuation chain (per the Patent summary section's chain: 15/286,600 ← 14/792,822 [U.S. 9,496,976] ← 13/775,158 [U.S. 9,113,380] ← 13/617,679 [U.S. 8,406,218] ← 13/036,787 [U.S. 8,311,031]). So the Ford case asserts sibling/ancestor family members, not the '204 patent itself, at least in the amended complaint. This is exactly the family-level assertion pattern the PTAB challenges section predicted ("expect assertion of sibling claims"). The Google Patents tag is best explained as a patent-family mapping artifact. Flagging explicitly because it contradicts an undifferentiated reading of the earlier section.

Sprint / Verizon / AT&T (rows 1–3). These are the assertions catalogued by the Stanford NPE Litigation Database (asserter category "Acquired patents") — the authoritative confirmation that '204 was actually asserted in the 2018 wave. Filing date 2018-12-03 for all three is corroborated by Patexia (Sprint and Verizon pages both show "Filing Date Dec 3, 2018"). Their disposition ties to the Mar 2020 Ericsson settlement described in the PTAB challenges section — the IPR2020-00242 termination record expressly states the settlement resolved the E.D. Tex. actions 2:18-cv-00526, -00527 and -00528 and that stipulations of dismissal were filed. So rows 1–3 are settled/dismissed, but the settlement terms are confidential (37 C.F.R. § 42.74(c) request granted) and I could not retrieve the individual dismissal orders.

2026 Honda / Volkswagen suits. The Assignment history section mentions Sol IP suits against Honda and Volkswagen in 2026 (sourced to a GreyB article) and lists Nelson Bumgardner counsel. I could not verify in this pass (a) that those 2026 suits name the '204 patent specifically, or (b) their case numbers/venues. Those assertions appear to be on other Sol IP / ETRI patents (the Ford complaint similarly asserted a different asset set). Treat '204's inclusion in the 2026 Honda/VW actions as unverified.

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Federal Circuit (CAFC) check — specific to this patent

You asked me to check CAFC. I searched the CAFC opinions/orders and docket sources for an appeal naming 10,080,204. Findings:

• No Federal Circuit appeal, order, or decision naming patent 10,080,204 was located. The only recent CAFC result surfacing under a "Unified Patents" query was IdeaHub Inc. v. Unified Patents, LLC, No. 2024-1684 (Rule 36 judgment, April 10, 2026), which arises from PGR2022-00044 and has nothing to do with the '204 patent — I include it only to show the search was run and that this is a false positive, not a hit.
• There is a structural reason no CAFC appeal exists: the only PTAB proceeding on this patent (IPR2020-00242) was dismissed pre-institution (Termination Decision 2020-03-09, per Docket Alarm). A pre-institution dismissal is not appealable — there is no final agency action on the merits. And the district-court actions were resolved by settlement/stipulated dismissal, which are likewise not appealable (no adverse final judgment).
• Confidence: moderate-to-high that there is no '204 CAFC appeal, but not certain. CAFC docket coverage in third-party databases is incomplete, and I did not query the CAFC's own CM/ECF / "Appeals Search" system directly by patent number in this pass. To close this definitively, query PACER CM-ECF for the Federal Circuit and the CAFC Appeals Search by patent number.

This is consistent with — and corroborates — the Patent summary section's statement that it "could not locate any Federal Circuit (CAFC) 2026 docket, appeal, or decision naming patent 10,080,204."

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Related proceeding (not civil litigation, listed for completeness)

Ericsson Inc. v. Sol IP, LLC, IPR2020-00242, USPTO PTAB, filed 2019-12-10, terminated by settlement before institution 2020-03-09 (panel: Droesch, Howard, Jefferson). Patent Owner of record includes Sol IP, LLC and Electronics and Telecommunications Research Institute. This is a PTAB trial, not an Article III case, and is covered in depth in the PTAB challenges section — I list it here only because Unified Patents' portal cross-indexes it under the '204 litigation record, and because it is the mechanism by which the carrier suits (rows 1–3) were resolved.

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Summary of what is verified vs. open

Verified (asserted against the '204 patent specifically):

• Sol IP, LLC v. AT&T Mobility LLC, E.D. Tex. 2:18-cv-00526, filed 2018-12-03 — settled/dismissed.
• Sol IP, LLC v. Sprint Corporation et al., E.D. Tex. 2:18-cv-00527, filed 2018-12-03 — settled/dismissed.
• Sol IP, LLC v. Verizon Communications Inc. et al., E.D. Tex. 2:18-cv-00528, filed 2018-12-03 — settled/dismissed.
• Sol IP, LLC v. Qualcomm Inc. et al., W.D. Tex. 6:21-cv-00270, filed 2021-03-17 — voluntarily dismissed 2021-05-25.

Open / unverified:

• Whether 10,080,204 itself was pleaded in N.D. Cal. 5:20-cv-00399 (Intel) — the docket is a subpoena motion, and E.D. Tex. 2:22-cv-00097 (Ford) — the asserted-patent list omits '204.
• E.D. Tex. 3:20-cv-00137 (AT&T/Ericsson/Nokia) — carried from a prior section; not re-verified.
• The 2026 Honda and Volkswagen actions — not verified as to this patent.
• Any Federal Circuit activity — none found; not confirmed against the CAFC's own docket system.

Bottom line: the patent has a real but dated assertion history — a three-case Dec 2018 carrier wave (AT&T, Sprint, Verizon) that resolved via the Mar 2020 Ericsson settlement, plus a 2021 Qualcomm case voluntarily dismissed. Both other "litigation" entries that third-party portals attach to this patent are artifacts (an ancillary Intel subpoena matter and a Ford complaint that asserts sibling/ancestor patents, not '204). There is no CAFC appeal on this patent. Verify rows 1–3 and the two open district dockets at PACER, and the (empty) CAFC history at the Federal Circuit's CM-ECF/Appeals Search, before relying on any of this in a diligence memo.

I'll start by pulling the structured PTAB data and cross-checking against the patent record's litigation entries.

The search surfaced a real proceeding the ODP missed: IPR2020-00242 (Ericsson v. Sol IP). Let me get its petition details, panel, and the surrounding Ericsson/Sol IP IPR cluster.

Now let me pin down the petition grounds, the docket page, and check for any later IPRs on this patent or its continuations.

Proceedings overview

One AIA trial proceeding is on file against US 10,080,204 — and it was never instituted. It was dismissed pre-institution on 2020-03-09 in view of a confidential settlement, so the count is: 1 total, 0 active, 0 claims canceled, 0 claims sustained, 1 settled/dismissed, 0 institution denials. (Note the source conflict: the USPTO ODP "PTAB proceedings on file" block for this prompt returns nothing. Docket Alarm, RPX, Patexia and Law360 all index IPR2020-00242 on this patent, petitioner Ericsson Inc. — the ODP miss is a known artifact for petitions dismissed before institution. Treat the proceeding as real and flag it in any diligence memo.)

Bottom line for a defendant: the patent has not been tested on the merits at the PTAB. All claims of the '204 patent remain presumptively valid and, critically, zero IPR estoppel attaches — because § 315(e) estoppel only arises after a final written decision, and no FWD exists. That cuts both ways: the patent is unhardened (no PTAB panel has blessed it), but the one petitioner who tried bought its way out, so there is no free roadmap. The honest defensive posture is "claims are wholly untested and every prior-art ground is still legally available, but the last challenger with a $4M+ incentive to run a full IPR settled instead."

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IPR2020-00242 — Ericsson Inc. v. Sol IP, LLC (Patent Owner of record: Electronics and Telecommunications Research Institute)

• Type: Inter Partes Review
• Filed: 2019-12-10
• Status: Terminated — Settlement Before Institution (Docket Alarm document label: "Settlement Before Institution: Termination Decision Document," 2020-03-09). Plain English: the Board dismissed the petition on the parties' unopposed motion without ever deciding whether to institute. There is no institution decision and no Final Written Decision.
• Judge panel: Kristen L. Droesch, Trevor M. Jefferson, Scott B. Howard (per Docket Alarm's panel listing; the consolidated termination decision in the companion case IPR2020-00251 is captioned to the same three APJs)
• Petition grounds: Not verifiable from the sources retrieved. I could not pull the petition PDF itself, so I will not state claimed claim numbers or § 102/§ 103 grounds — please read the petition on PTAB E2E before relying on anything here. What is indexed is the exhibit set, which indicates the art Ericsson assembled: 3GPP TS 25.211 v6.7.0 (2005-12), TS 25.214 v6.7.1 (2005-12), TR 25.814 v0.5/v1.0.3/v1.2.2, a series of 3GPP RAN1 Tdoc contributions (R1-051357, R1-060072, R1-060812, R1-061144, R1-062990, R1-070650, R1-071768), Bahl, Cell searching in WCDMA (2003), English translations of Korean applications 10-2007-0006230 and 10-2007-0074705, US Provisional 60/745,250, the '204 file history, and a declaration by Dr. Alexander Haimovich (Ex. 1001). Treat the R1 exhibit list with caution — Docket Alarm aggregates exhibits across the Ericsson/Sol IP batch, so individual exhibits may not map one-to-one to this petition.
• Institution decision: none. The Board never reached the merits. The termination decision states the proceeding "is in its preliminary phase, Patent Owner has not yet filed a Preliminary Response, and we have not yet reached the merits ... by issuing a decision on institution."
• Final Written Decision: none issued.
• Settlement / termination: 2020-03-09 consolidated termination/dismissal covering the Ericsson batch (Appendix lists IPR2020-00237, -00238, -00239 and companions; the same motion paper is filed in IPR2020-00240, -00241, -00242, -00244, -00249, -00250, -00251, -00252 and -00253 — twelve substantively identical papers filed 2020-03-02). The terms are confidential — the parties jointly requested the settlement agreement be treated as business confidential under 37 C.F.R. § 42.74(c) and kept separate from the patent file; the request was granted. What is public: the settlement resolved the disputes (including the Ericsson-side E.D. Tex. actions 2:18-cv-00526, -00527 and -00528), stipulations of dismissal were filed, and the Board cited the "strong public policy reasons to favor settlement." A notice of refund issued 2020-04-02.
• Appeal: none. A pre-institution dismissal is not appealable (no final agency action on the merits).
• Defensive value: Low as precedent, high as intelligence. You cannot cite this proceeding for anything claim-level. What you can use: (1) Ericsson — a sophisticated, well-funded, directly-exposed defendant/intervenor — built thirteen petitions including one against this patent and chose to pay to settle rather than litigate institution; that is a market signal about the strength of the art package, not a validation of the patent. (2) Because the case died before institution, no estoppel and no adverse claim construction exists; nothing here binds or burdens your own IPR. The most valuable artifact is the exhibit list, which is a free, court-tested starting point for your own prior-art search (3GPP RAN1 contributions + WCDMA cell-search literature + the two Korean applications).

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Strategic summary

Claim status. No claim of US 10,080,204 has ever been adjudicated by the PTAB. Canceled: none. Sustained: none. Untested: all. There is no narrowed, surviving claim set to map — the patent you would face today is the patent as granted (issued 2018-09-18 from Application 15/286,600, filed 2016-10-06, priority 2006-07-25). Do not let anyone tell you a particular claim "already survived an IPR"; it did not, and no claim has been invalidated either.

Estoppel landscape. This is the single most defendant-favorable fact in the file. § 315(e)(2) estoppel requires a final written decision; IPR2020-00242 never got past the preliminary phase, and the Board dismissed it under 37 C.F.R. § 42.72 without an institution decision. Result: Ericsson (and its privies) is not estopped from filing a fresh IPR on any ground, and neither is anyone else. There is no § 315(a)/(b) time-bar or estoppel web to navigate. Practically, the entire prior-art universe — including the 3GPP and Korean-application art Ericsson assembled — remains available to you, both at the PTAB and in district court. The flip side: you also get no benefit from any prior petitioner's work product beyond the public exhibit list.

Pattern signals. The petitioner was a defensive supplier (Ericsson, intervening in Sol IP's carrier suits), not a defensive aggregator — Unified Patents does not appear in the chain, and the Unified Patents link on the Google Patents page is just a litigation-data portal reference to the same IPR2020-00242. Ericsson launched a thirteen-petition salvo on 2019-12-10 (IPR2020-00237/-00238/-00239/-00240/-00241/-00242/-00244/-00249/-00250/-00251/-00252/-00253) against the Sol IP / ETRI portfolio and then settled the whole thing roughly three months later, dismissing all thirteen on 2020-03-09 and taking fee refunds. That is a "buy peace, don't buy precedent" strategy — likely driven by the commercial relationship with the carriers it supplies. Sol IP/ETRI, for its part, has not been dragged into any PTAB merits proceeding on this patent since, even though the patent was re-asserted in N.D. Cal. (5:20-cv-00399, 2020), W.D. Tex. (6:21-cv-00270, 2021) and E.D. Tex. (2:22-cv-00097, 2022). No Federal Circuit appeal exists because there was nothing to appeal. Also note the family is live: continuations have issued as US 11,363,547 and US 12,284,620, with a further publication US 2025/0159620A1 — expect assertion of sibling claims, and consider that a merits challenge to this patent may be strategically less useful than challenging the sibling that is actually asserted.

Caveat on scope. I verified the existence, petitioner, panel, filing date and disposition of IPR2020-00242 from secondary dockets (Docket Alarm, RPX, Patexia, Law360). I could not retrieve the petition itself, so the challenged claim list and the statutory grounds are unverified — I have deliberately not guessed at them. Verify against PTAB E2E (https://ptacts.uspto.gov/ptacts/) and the consolidated termination decision before filing anything.

Recommended next steps

1. Do not represent to a court or an adversary that this patent has been "IPR-tested." It has not. The correct framing in a litigation hold or IPR-avoidance memo is: "one petition filed 2019-12-10, dismissed 2020-03-09 pre-institution on settlement, no institution decision, no FWD, no estoppel."
2. Pull the petition and the 2020-03-09 termination decision from PTAB E2E. Docket pointers: Docket Alarm IPR2020-00242 record; Law360 case page, "Terminated"; Unified Patents PTAB entry. Confirm the challenged claims and grounds — that is the only gap in this report.
3. Reuse Ericsson's exhibit list as your prior-art seed set. The 3GPP RAN1 Tdocs, the WCDMA cell-search literature, and the two Korean applications were curated by counsel with full discovery into Sol IP's infringement contentions (note Ex. 1025, "ATT Complaint," and Ex. 1026, "Sol IPs 1st Amd Infringe Discl" — Ericsson had the infringement theory in hand when it selected art).
4. If you are in a § 315(b) window, move. One year from service of the complaint; the absence of any prior FWD means no estoppel and no § 325(d) "same art previously presented" headwind beyond prosecution history.
5. Watch the sibling patents. US 11,363,547 (from App. 16/114,224) and US 12,284,620 / US 2025/0159620A1 (from App. 17/719,398 and 19/021,188) are separate patents with their own IPR clocks. Budget for a family-level, not patent-level, strategy.

I'll research the assignment record for US 10080204, starting with the primary sources and cross-referencing litigation/NPE directories.

Critical finding: this patent was asserted by Sol IP, LLC (an NPE). Let me dig into the Sol IP chain and assignment specifics.

Let me look for the recorded assignment specifics (reel/frame, correspondent) and Sol IP's structure.

Ownership & Assignment Analysis — US 10,080,204 B2

Data-limitation note up front: I could not retrieve a recorded-assignment hit for this patent in the USPTO Assignment Center / assignment.uspto.gov index. The strongest secondary reporting (Mondaq, 2 Apr 2021) states expressly that "Currently available USPTO assignment records do not reflect ownership by Sol IP of any US patents, including the more than two dozen asserted assets." Google Patents legal events likewise list ETRI as both original and current assignee, and the patent's own front page names ETRI only. I did not invent reel/frame numbers to fill the gap — none are cited below because none were verifiable. The "chain" here is built from litigation records and the parties' own pleadings, not from recorded assignments.

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Inventors

All seven are listed on the face of US 10,080,204 with Electronics and Telecommunications Research Institute (ETRI) as the sole assignee (no third-party co-assignee appears):

Pattern notes:

• The application (15/286,600) was filed 2016-10-06 but carries an earliest priority of 2006-07-25 — a 10-year continuation chain. The same family has been kept alive into 2025 (US20250159620A1), which is the signature of a long-horizon licensing asset, not an abandoned filing.
• I could not verify departure dates for the individual inventors or whether any left ETRI within 12 months of filing; no reliable source surfaced. I am explicitly not asserting an inventor-departure signal.
• The inventor roster is unchanged across the continuation family — consistent with a single originating research group rather than an assembled/acquisition portfolio.

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Original assignee

Electronics and Telecommunications Research Institute (ETRI), Daejeon, South Korea.

• Primary line of business: Government-funded ICT/electronics R&D institute (founded 1976); a major contributor to 3GPP/TTA standards and a heavy filer of wireless SEPs. It is a research and technology-transfer organization — it does not manufacture or ship products embodying the claims.
• Product-embodying status: No. ETRI monetizes the patent by licensing/transferring rights, not by selling base stations or handsets. Its patents have been declared essential to LTE via the Telecommunications Technology Association of Korea (TTA), per Sol IP's own complaints.
• Current status: Operating. Not acquired, dissolved, or in bankruptcy. Google Patents lists ETRI as current assignee — i.e., title apparently never left ETRI.

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Assignment timeline

No recorded assignment post-dating issuance was found in the Assignment Center index for this patent. The original inventor→ETRI assignment (routine for corporate/government filings) is probable but was not retrievable, and no assignment to Sol IP, LLC appears of record. Google Patents legal events show no assignee change and list ETRI as current assignee.

The operative relationship is instead an exclusive license characterized by the parties as a transfer of "all substantial rights":

• Executed on an unverified date (in force by mid-2015, before the first suit) / not recorded — Reel/frame not found
  • Conveyance: Exclusive license (styled by plaintiff as transfer of "all substantial rights")
  • Assignor: Electronics and Telecommunications Research Institute (ETRI)
  • Assignee: Sol IP, LLC (Virginia LLC)
  • Correspondent: not retrievable — no recording corresponds to this transfer, so there is no correspondent of record to capture. (Flag: the absence of a recorded correspondent is the finding — the arrangement was deliberately left off the assignment record.)
  • Context: transfer-to-asserter via exclusive license — Sol IP pleads it "holds an exclusive license to the Asserted Patents from" ETRI, "which transferred to Sol IP all substantial rights in those patents."

Standing caveat (recorded in litigation, not an assignment): In Sol IP v. AT&T et al. (E.D. Tex.), defendants argued ETRI retained substantial rights, leaving Sol IP "a mere hunting license." Magistrate Judge Roy S. Payne recommended denying the motion to dismiss in Jan 2020 — but the fact that title stayed with ETRI is exactly why no assignment record exists.

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Timeline diagram

Recorded assignments are absent, so the diagram tracks the ownership/assertion milestones that are actually verifiable.

timeline
    title Ownership of US 10080204
    2006 : Earliest priority date
    2015 : Sol IP LLC formed in Virginia
         : ETRI notice letters sent
    2016 : Continuation filed at USPTO
    2018 : Patent issued to ETRI
         : Sol IP sues AT and T Sprint Verizon
    2019 : Ericsson files IPR2020-00242
    2020 : IPR settled before institution
    2021 : Sol IP sues Qualcomm over ETRI patents
    2026 : Sol IP sues Honda and Volkswagen

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NPE / troll-pattern signals

1. Shell-entity transfer — PRESENT (via exclusive license, not recorded title). Sol IP, LLC is a Virginia LLC formed January 2015, with Choongsoo Park listed as member (a second Sol IP entity was formed in Texas in June 2015 with Park as managing member). Park is a former Fish & Richardson associate and an EVP of Intellectual Discovery Co., Ltd. The entity is licensing-only, holds no products, and per plaintiff's own pleading "is an intellectual-property licensing company." Caveat: title appears to remain with ETRI, so this is a functional shell-vehicle transfer rather than a recorded §261 assignment.

2. Known asserter in the chain — PRESENT. Sol IP, LLC appears as an NPE in the Stanford NPE Litigation Database (asserter category "Acquired patents") for this patent, and Unified Patents describes these assets as "owned by ETRI and asserted by Sol IP, LLC, an NPE," with active PATROLL prior-art contests. Assertion venues: Sol IP v. AT&T Mobility (E.D. Tex. 2:18-cv-00526), v. Sprint (2:18-cv-00527), v. Verizon (2:18-cv-00528), v. Qualcomm (W.D. Tex. 6:21-cv-00270), plus E.D. Tex. 2:22-cv-00097 and N.D. Cal. 5:20-cv-00399 per Google Patents.

3. Repeat correspondent across the chain — UNCLEAR / NOT DETERMINABLE. No recording correspondent exists to compare, because nothing was recorded. Litigation counsel is not the same signal as a recording correspondent, but for completeness: Susman Godfrey LLP and Capshaw Derieux LLP (2018–19 carrier suits); Nelson Bumgardner Albritton / Nelson Bumgardner Conroy — Brent N. Bumgardner, John P. Murphy, Timothy E. Grochocinski, Christopher Granaghan — in the 2026 Honda and VW suits. I could not tie any name to a US PTO recording, so I am not calling this signal.

4. Cascading transfers — NOT PRESENT. No chain of successive LLC-to-LLC assignments in <24 months. There is a single exclusive-license relationship with ETRI, not a serial flip through nominally unrelated assignees.

5. Pre-litigation transfer — NOT PRESENT (on the available dates). ETRI's May/June 2015 notice letters (alleged in the E.D. Tex. complaint) and the January 2015 Virginia LLC formation show the licensing arrangement was in place ~3.5 years before the first Dec 2018 suit — not a within-6-months flip. I could not retrieve the exact execution date of the license, so this is a negative finding on the narrow 6-month test only.

6. Bankruptcy fire-sale — NOT PRESENT. ETRI is a solvent government research institute; no Chapter 7/11 and no court-supervised patent sale.

7. Privateering — PRESENT. ETRI — a standards body member (TTA) that declared these LTE patents essential — routed enforcement to Sol IP, a licensing-only NPE, which sues ETRI's standards implementers (AT&T, Sprint/Deutsche Telekom, Verizon, Ericsson, Nokia, Qualcomm, Intel, Ford, VinFast, BYD, and in 2026 Honda and VW). Sol IP also appears as an Avanci licensor representing ETRI's patent package. This is the classic operating/standards-body-to-NPE outsourcing pattern.

8. Defensive aggregator — NOT PRESENT. The chain does not terminate at RPX, AST, LOT, Unified, or OIN. Unified Patents is challenging these patents (IPR2020-00242, PATROLL contests) — i.e., it is adverse, not a successor owner.

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Verdict

NPE — high confidence.

Two or more strong signals are present despite the missing assignment record: (i) Sol IP, LLC is affirmatively catalogued as an NPE asserter by both the Stanford NPE Litigation Database and Unified Patents, and is the plaintiff in Sol IP v. AT&T Mobility (E.D. Tex. 2:18-cv-00526), v. Sprint (2:18-cv-00527), v. Verizon (2:18-cv-00528), and v. Qualcomm (W.D. Tex. 6:21-cv-00270); and (ii) this is a textbook privateering arrangement in which the original assignee ETRI — an operating standards body that declared the patent LTE-essential — pushed enforcement to a licensing-only Virginia LLC whose principal is a former Fish & Richardson associate, with Sol IP also appearing as an Avanci licensor. The unusual wrinkle is that no assignment was ever recorded — title stayed with ETRI while "all substantial rights" moved to Sol IP by exclusive license, which is itself an evasion-of-record pattern and the subject of the defendants' standing challenge.

Verify directly at the USPTO Assignment Center (search by patent number 10080204 or app 15/286,600): https://assignmentcenter.uspto.gov/ — and cross-check the (empty) assignee-change history on Google Patents legal events: https://patents.google.com/patent/[US10080204B2](/patent/US10080204B2)/en

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Sources: USPTO Assignment Center (assignmentcenter.uspto.gov) / assignment.uspto.gov — no Sol IP record located; Google Patents US10080204B2 legal events (ETRI listed as current assignee); Mondaq, "Sol IP Sues Qualcomm Over 28 ETRI Patents" (2 Apr 2021) — plaintiff pleading language and "no USPTO assignment records" statement; Stanford NPE Litigation Database, patent 10080204; Unified Patents PATROLL contest pages and News & Views for Sol IP; Docket Alarm IPR2020-00242 (Ericsson Inc. v. Sol IP, LLC, terminated on settlement 9 Mar 2020); Patexia case summaries 2:18-cv-00526/00527/00528; GreyB, "Sol IP Sues Honda and Volkswagen" (2026); RPX litigation document 14683004 (E.D. Tex. complaint).

I'll research the USPTO record and the front-page citations for US 10,080,204.

Prior-Art Analysis — U.S. Patent No. 10,080,204

0. What the USPTO lookup returned, and one critical sourcing gap

I ran the lookup against the patent-number record for 10,080,204 and restricted results strictly to that patent. The record matches what previous sections established: US 10,080,204 B2, "Cell search method, forward link frame transmission method, apparatus using the same and forward link frame structure", App. No. 15/286,600, filed 2016-10-06, granted 2018-09-18, priority 2006-07-25, assignee ETRI.

Gap you need to know about before you rely on anything below. The authoritative full text I have for this patent (the Google Patents fetch in the prompt) is truncated and image-stripped — it contains the description, classifications and definitions, but it does not contain the front-page (56) References Cited block (the "U.S. PATENT DOCUMENTS / FOREIGN PATENT DOCUMENTS / OTHER PUBLICATIONS" list). My repeated attempts to retrieve that specific block for 10080204 in this session returned either the same truncated text or irrelevant patents that are not this patent (e.g., US 10,823,818; US 11,842,495; US 9,614,097; EP 2,486,877 A1; the "Myr/Spriestersbach/Himmelstein" list from an unrelated PTAB petition). Per the operating rule, I am not going to present any of those as citations of '204 — they aren't, and importing them would be exactly the kind of number-drift error you told me to avoid.

So I am splitting this answer into two parts:

• Part A — the prior art that is verifiably of record against US 10,080,204 (from the IPR2020-00242 exhibit set, which is the actual prior-art record for this patent), with § 102 mapping.
• Part B — the exact front-page (56) list, which I could not retrieve and which you must pull directly from the USPTO before filing anything. I give the precise retrieval path.

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Part A — Prior art verifiably of record against US 10,080,204

The strongest, most defensible prior-art record for this patent is the exhibit set of IPR2020-00242 (Ericsson Inc. v. Sol IP, LLC), filed 2019-12-10. I confirmed the following exhibits by name and number from the Docket Alarm docket for that proceeding (https://www.docketalarm.com/search/?q=&fname_q_search_within=Searching+within+IPR2020-00242&f=...):

The previous Obviousness section additionally identified, from the broader Ericsson/Sol IP exhibit aggregation, R1-051357, R1-061144 (CHTTL, RAN1 #45, Shanghai, May 8–12, 2006), R1-061186, TS 25.214 v6.7.1 (2005-12), Bahl Cell searching in WCDMA (2003), and the English translation of KR 10-2007-0074705 — I flag that these carry the same aggregation caveat the prior section raised (Docket Alarm pools exhibits across the thirteen-petition batch, so any single exhibit may not map one-to-one to the '204 petition).

Reference-by-reference, with § 102 mapping

(1) R1-061144 — Chunghwa Telecom Labs (CHTTL), "Three-Step Initial Cell Search and System Acquisition for E-UTRA," 3GPP TSG RAN WG1 #45, Shanghai.

• Citation: 3GPP TSG-RAN WG1 Meeting #45, Tdoc R1-061144, Shanghai, China.
• Date: May 8–12, 2006 (pre-dates the 2006-07-25 priority ✔).
• Description: Proposes two consecutive SCH symbols "allocated at the last two OFDM symbols of the 10th and 20th sub-frame"; uses GCL sequences for the SCH; derives the cell ID from "the combination of two consecutive GCL sequences within the SCHs"; the first SCH symbol uses only even-numbered subcarriers (creating a time-domain repeat detected by delay-and-correlate); the 1st/2nd GCL sequences are common to all cells while the 3rd/4th carry cell-ID information.
• § 102 exposure: This is the only single reference that plausibly anticipates the independent claims. It discloses the contiguous two-symbol sync placement at the end of a unit (element C), a repeated/common primary sequence paired with a cell-information-carrying secondary sequence (element D), and cell ID = combination of the two sequences (element E). Potentially anticipates claims 1, 7, 13, 19, and 25 — if and only if the granted claims do not require (a) a 20-unit frame per se and (b) a strict cell-group-vs-cell-within-group distribution between the two sequences. R1-061144 uses two sync blocks per frame (subframes 10 and 20), whereas the '204 spec describes five sync blocks/frame, so a five-sync-block limitation would likely defeat pure anticipation and push the ground to § 103.

(2) R1-060072 / R1-061186 — NTT DoCoMo, "SCH Structure and Cell Search Method for E-UTRA Downlink," 3GPP RAN1.

• Citation: 3GPP TSG-RAN WG1, Tdoc R1-060072 (RAN1 #44, Denver, c. Feb. 2006), later revised as R1-061186 (RAN1 #45, Shanghai, May 2006).
• Date: Feb. 2006 (R1-060072) / May 2006 (R1-061186) — both pre-date the priority ✔.
• Description: Hierarchical P-SCH + S-SCH; a small set of P-SCH sequences identifies the cell ID within a group; the S-SCH identifies the cell group ID; two-step search (P-SCH first, then S-SCH).
• § 102 exposure: Does not alone anticipate — it is not an OFDM frame-structure disclosure with the 20-unit/0.5 ms layout. It is § 103 material, supplying the one element R1-061144 arguably lacks (the group/in-group partition). Best characterized as the secondary reference in an obviousness ground, not an anticipation reference.

(3) 3GPP TR 25.814 — "Physical Layer Aspects for Evolved UTRA."

• Citation: 3GPP TR 25.814 (versions v0.5, v1.0.0, v1.0.3, v1.2.2).
• Date: v0.5 and v1.0.x bracket the priority date (✖/✔); v1.2.2 is post-date ✖.
• Description: Defines the E-UTRA 10 ms radio frame of twenty 0.5 ms subframes, with 7 OFDM symbols per subframe (short CP) or 6 (long CP).
• § 102 exposure: Potentially anticipates only the narrow structural dependent claims — i.e., claims 5, 11, 17, 23 (seven-OFDM-symbol unit) and the 0.5 ms slot basis of claims 6, 12, 18, 24, 28 — and only if those claims are read to require nothing more than the subframe/symbol numerology. It does not anticipate any independent claim (it lacks the sync-signal layout and identifier combination).

(4) 3GPP TS 25.211 v6.7.0 (2005-12) and TS 25.214 v6.7.1 (2005-12) — WCDMA physical channels.

• Citation: 3GPP TS 25.211 v6.7.0, Dec. 2005; 3GPP TS 25.214 v6.7.1, Dec. 2005.
• Description: WCDMA P-SCH/S-SCH definitions — PSC for slot sync; SSC code word (15 positions, 64 code words) → scrambling-code group + frame boundary.
• § 102 exposure: No anticipation. These are DS-CDMA, direct-sequence, time-domain-multiplexed channels; the '204 claims recite an OFDM symbol / subcarrier frame, so no single WCDMA reference discloses every claimed element. § 103 material only, as the motivation source for the hierarchical group/in-group split. (The '204 specification itself concedes these "cannot be applied to the OFDM forward link.")

(5) US Provisional Application No. 60/745,250 (Ex. 1010).

• Citation: U.S. Provisional App. No. 60/745,250, filed April 2006.
• § 102 exposure: A provisional is not itself published, so it is not a § 102(a)(1)/(b) printed publication. It can operate as § 102(e) (pre-AIA) / § 102(a)(2) (AIA) art only through a later published application/patent that claims benefit of it, and only as to subject matter the provisional actually supports. I could not verify its contents, so I will not assert which claims it could anticipate. Treat the § 102(e) window as a hypothesis to check, not a finding.

(6) Korean applications KR 10-2007-0006230 (Ex. 1007) and KR 10-2007-0074705.

• Citation: Korean App. 10-2007-0006230 (filed 2007-01-19); KR 10-2007-0074705 (filed 2007-07-25).
• § 102 exposure: None against the 2006-07-25 priority date — both were filed after it, and they are the patentee's own later applications. Ericsson's presence of these in the exhibit set signals their use as priority-defect evidence (proving what the 2006 Korean application does not support), not as § 102 art. Keep them out of any § 102 chart; they belong in the § 103/priority argument.

(7) R1-051357, R1-060812, R1-062990, R1-070650, R1-071768 — subsequent RAN1 contributions.

• Dates: R1-051357 (Oct. 2005 ✔); R1-060812 (c. spring 2006, needs confirmation); R1-062990, R1-070650, R1-071768 are all post-2006-07-25 ✖.
• § 102 exposure: The three post-date documents cannot anticipate the '204 claims on a 2006 priority date. They become available only if the claims are pushed to a 2007 effective filing date — in which case they open up the entire PSS/SSC design corpus and become the highest-leverage § 103 path (see the prior Obviousness section, § 8).

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Part B — What I could NOT verify: the front-page (56) citation list

I want to be unambiguous, because this is the literal thing you asked for:

I was unable to retrieve the "(56) References Cited" list — the U.S. patent documents, foreign patent documents, and other publications cited on the face of US 10,080,204 — in this session. The Google Patents fetch in the prompt is truncated before that block, and my searches for it surfaced only unrelated patents. I am therefore not listing any "patent citations for 10080204" that I have not verified, because doing so from an unverified source is precisely the failure mode you instructed me to avoid.

There is a substantive reason this matters here: for a continuation with a 10-year chain, the front-page (56) list of the issued '204 patent reflects the IDS the applicant filed in 2016 — not the 2007-era art. The applicant-controlled citations are therefore likely less probative than the art a real challenger would use. The prior Obviousness section already noted that the family's own IDS cites the 2007 RAN1 corpus (NTT DoCoMo R1-071628; Qualcomm R1-072093; Ericsson R1-072448; Nortel R1-072368; Huawei R1-072326) and 3GPP TS 36.211 — those are applicant-cited references and would normally appear in the (56) list. That is a lead, not a verified citation.

To retrieve the authoritative (56) list, pull it directly from:

1. USPTO Patent Public Search / Patent Center — enter patent number 10080204 (or App. No. 15/286,600) at https://ppubs.uspto.gov/pubwebapp/ and open the "References Cited" tab; and https://patentcenter.uspto.gov/ for the filed IDS (PTO/SB/08) forms, which give the applicant-cited set with examiner consideration.
2. The grant PDF at patentimages.storage.googleapis.com/.../US10080204.pdf (front page, columns 1–2) — the (56) block is printed there verbatim.
3. The published application US 2017/0026922 A1 (https://patents.google.com/patent/US20170026922), whose front page carries the pre-grant (56) list for the same application.
4. PTAB E2E (https://ptacts.uspto.gov/ptacts/), IPR2020-00242, Exhibit 1005 — the '204 file history — which reproduces the IDS and the examiner's considered citations.

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Two things that look like prior art but are not

1. Forward citations ("Cited By") are not prior art here. My search surfaced lists including US 2008/0043702 A1 (Samsung), US 11,018,794 / US 10,341,037 (LG Electronics / Wild Guard), US 9,438,397 / US 8,971,305 (Qualcomm, "Pseudo-random sequence mapping"), US 10,219,236 / US 9,733,805 (LG, "Method of performing cell search"), and KR 10-1099344 B1 (Qualcomm, "Secondary synchronization codebook for E-UTRAN"). Every one of these is a 2007-or-later document citing '204's family from the future. They are not § 102 prior art against a 2006-07-25 priority date. Do not let these drift into a prior-art chart — they are validity-relevant only as evidence of the crowded post-2006 art, if at all.
2. The unrelated "Myr / Spriestersbach / Himmelstein / Ekerborn / Haberman" patent list that appeared in my first search is from a different PTAB petition on a different patent. It has nothing to do with '204. Disregard.

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Bottom line on § 102

• Independent claims 1, 7, 13, 19, 25: the only serious § 102 candidate on this record is R1-061144 (CHTTL, May 2006), and even that depends on claim construction — specifically whether the granted claims require a five-sync-block / 20-unit frame and a strict group-vs-in-group split between the two sequences. If they do, R1-061144 drops to § 103 (combined with R1-060072/R1-061186 + TR 25.814). No other single reference anticipates any independent claim. The WCDMA standards (TS 25.211/25.214) and TR 25.814 are § 103 references only, because neither discloses the sync layout and identifier combination in an OFDM frame.
• Dependent claims: TR 25.814 can come close to anticipating the 7-symbol claims (5, 11, 17, 23) and the 0.5 ms slot claims (6, 12, 18, 24, 28) if read narrowly; R1-061144 can come close to anticipating the "unused subcarriers" claims (4, 10, 16, 22, 27) via its even-subcarriers-only first SCH symbol.
• Post-date references (R1-062990, R1-070650, R1-071768, TR 25.814 v1.2.2, the two Korean applications) are not § 102 art on a 2006 priority date. Their value is entirely as priority-defect evidence opening the 2007 RAN1 corpus — which is where the strongest invalidity theory lies.

Confidence: High on the identity, exhibit numbers and dates of the IPR2020-00242 references; Moderate on exact meeting dates for R1-060072, R1-060812, R1-062990, R1-070650 and R1-071768 (marked "c." above — confirm against the 3GPP FTP server); High that the front-page (56) list could not be retrieved and must be pulled from the sources in Part B. Do not cite any of the "Cited By" or unrelated-patent documents above as prior art against this patent.

I'll research the prior art identified in the IPR2020-00242 exhibit set and the field's background art before building the § 103 analysis.

The R1-061144 contribution is directly on point. Let me retrieve the actual granted claim text and the IPR petition grounds, plus the other key references.

Obviousness Analysis — U.S. Patent No. 10,080,204 Under 35 U.S.C. § 103

Scope and sourcing note

This analysis builds on the earlier sections of this report (bibliography, claim overview, litigation, and PTAB history) and does not repeat them. It is grounded in the prior art actually assembled against this patent — principally the IPR2020-00242 exhibit set and the references cited on the face of the '204 family — which is the closest thing on this record to a "Prior Art section."

Two limitations I must flag up front, because they bound my confidence:

1. I could not retrieve the IPR2020-00242 petition body. The challenged-claim list and asserted statutory grounds are therefore unverified. The Haimovich declaration (Ex. 1001) that I retrieved is captioned to the '204 patent but, in the excerpt available, states he was asked about "claims 9, 10, and 16 would have been anticipated and/or obvious." That is a dependent-claim subset and may be a partial declaration — I will not assume the petition's scope from it. Treat the petition scope as an open item.
2. I did not retrieve the full granted claim text in this pass. The element-level mapping below relies on the claim characterization in the previously generated Patent summary section. If the granted text differs materially from that characterization, the mapping must be re-run.

Reference dates are checked against the July 25, 2006 priority date (KR 10-2006-0069800), with the priority-defect caveat discussed in §8.

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1. The legal framework applied

Under Graham v. John Deere, 383 U.S. 1 (1966), I resolve: (a) scope and content of the prior art; (b) differences between the prior art and the claims; (c) level of ordinary skill; and (d) objective indicia. Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), a combination is obvious where the elements were known, the combination yields predictable results, and there is an articulated reason — including "a finite number of identified, predictable solutions" (the "obvious to try" rationale, KSR at 421) — to combine. Critically for this patent, the field here is a standards-development field. Where multiple vendors were converging on a single committee-driven design, the KSR "design incentives and other market forces" rationale (and its "obvious to try" corollary) applies with unusual force: the prior art is literally a series of competing proposals solving the same stated problem in the same forum.

Level of ordinary skill (POSITA). Consistent with Dr. Haimovich's articulation in IPR2020-00242 Ex. 1001 ¶28, a POSITA would hold an undergraduate degree in EE, CS, or Computer Engineering (or equivalent) plus roughly 2–4 years of experience in OFDM/wireless system design, and would be familiar with WCDMA cell-search (3GPP TS 25.211/25.214), the E-UTRA study item (3GPP TR 25.814), and the RAN1 contributions driving the E-UTRA SCH design. This is a modest skill level in a highly active, well-documented art.

What the claims require (per the previous section's characterization). Stripped to elements, all five independent claims (1, 7, 13, 19, 25) share:

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2. The prior-art universe (the "Prior Art section" as actually populated)

The references fall into three families. I list them with what each is and a date check against 2006-07-25.

(a) E-UTRA SCH-structure contributions (the core art)

(b) E-UTRA frame-structure / system art

• 3GPP TR 25.814, Physical Layer Aspects for Evolved UTRA — defines the E-UTRA 10 ms radio frame of twenty 0.5 ms subframes, with 7 OFDM symbols per subframe (short CP) or 6 (long CP). Versions v0.5 and v1.0.0/v1.0.3 bracket the priority date; v1.2.2 is post-date. The v0.5 and v1.0.x versions are before ✔ and supply elements A and the 7-symbol dependent claim.

(c) WCDMA cell-search art (the "known-solution" backdrop)

• 3GPP TS 25.211 v6.7.0 (2005-12) and TS 25.214 v6.7.1 (2005-12) — the WCDMA P-SCH/SSC physical-channel definitions: PSC for slot sync, SSC code word (15 positions, 64 code words) → scrambling-code group + frame boundary. Before ✔
• Bahl, Cell searching in WCDMA (2003) — tutorial on the three-step WCDMA cell search, code-word detection, cyclic shifts, 64 code groups → 512 scrambling codes. Before ✔
• Wang & Ottosson, Cell Search in W-CDMA, IEEE JSAC vol. 18 no. 8, pp. 1470–1482 (Aug. 2000) — the canonical hierarchical cell-search reference; the SSCH code-word / hypothesis-test machinery (64 code words × 15 shifts) that the '204 specification itself recites. Before ✔
• *Tanno et al., Fast Cell Search Algorithm for Overlay System…, IEICE Trans. Commun. vol. E88-B no. 1, pp. 159–169 (Jan. 2005)* — OFCDM fast cell search. Before ✔
• US Provisional 60/745,250 (filed April 2006) — cited as an exhibit; before ✔ (content unverified here).

Reading the universe as a whole: the four elements of the monopoly that matter — (i) a 20-unit / 0.5 ms frame, (ii) two contiguous sync symbols placed in the last two OFDM symbols of a unit, (iii) a repeated primary sequence paired with a varying secondary sequence, and (iv) cell-ID = combination of a group identifier (secondary) and an in-group identifier (primary) — each appear in this set, and the first two appear together in a single reference (R1-061144).

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3. Ground 1 (primary): R1-061144 alone, or in view of TR 25.814

Why this is the strongest ground. R1-061144 discloses, in one document:

• Element C — "two consecutive SCHs are allocated at the last two OFDM symbols of the 10th and 20th sub-frame." Contiguity and the last-two-symbols placement are literally recited.
• Element B/D(partial) — a first SCH symbol whose sequence is common to all cells (i.e., repeated/identical) and a second SCH structure carrying per-cell information.
• Element E(partial) — "The combination of two consecutive GCL sequence within the SCHs is employed for cell ID identification." That is element E's "cell ID = combination" limitation, verbatim in substance.
• Element G(partial) — the first SCH symbol uses only even-numbered subcarriers, leaving the odd subcarriers unused and creating a time-domain repeated structure detected by a simple delay-and-correlate. This maps to the dependent "unused subcarriers among the sync symbol's subcarriers" limitation and supplies the design rationale for it.

Difference from the claims, and why it is obvious. R1-061144 does not, on the retrieved text, expressly split the identifier into a cell-group part (from the secondary) and a cell-within-group part (from the primary). That is the only substantive gap. It is closed by R1-060042/R1-061186 (DoCoMo), which expressly teaches the hierarchical split — P-SCH sequence → cell ID within group, S-SCH → cell group ID — and by the WCDMA background art, where the identical hierarchical split is the defining feature of three-step cell search (SSC code word → scrambling-code group, PSC → slot timing within the group; TS 25.211/25.214; Bahl; Wang & Ottosson). A POSITA reading R1-061144 against the DoCoMo proposal in the same RAN1 meeting would find the group/in-group partition a simple substitution of one known element for another yielding a predictable result — exactly the KSR rationale (a)–(d).

Finally, TR 25.814 supplies element A (20 × 0.5 ms units per 10 ms frame) and the "7 OFDM symbols per unit" dependent limitation, and supplies the reason the sync symbols sit at the end of the unit (the CP-length ambiguity problem the '204 specification itself discusses).

Reason to combine (articulated): all three documents address the same problem — "define an E-UTRA downlink SCH that a UE can acquire in two/three steps" — and were authored into the same working group at the same meetings for the same standard. There is an express design incentive (reach a single committee-standardized SCH) plus a finite set of identified, predictable solutions (hierarchical P-SCH/S-SCH with group/ID split). KSR at 417, 421; In re Fulton/In re Geisler teaching-away analysis is inapplicable because none of these references criticizes the combination.

Result: claims 1, 7, 13, 19, 25 (all five independents) obvious over R1-061144 in view of R1-060042/R1-061186 and TR 25.814. If the granted claim text does not require the group/in-group split to be distributed between the two sequences in a particular way, R1-061144 alone may anticipate — that is a claim-construction question I cannot resolve without the petition and the full claim text.

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4. Ground 2: R1-061144 + R1-061117 (patentee's own contribution) + Sharp R1-061681

The ETRI contribution R1-061117 is a particularly damaging admission. It is the patentee's own RAN1 submission comparing one-SCH and two-SCH schemes and the two-step P-SCH/S-SCH acquisition. Under § 103, an applicant's own pre-critical-date publication is prior art against it (subject to the § 102(b) grace-period / § 102(a)(1) analysis for the AIA-vintage claims). A POSITA seeking to implement the two-SCH scheme of R1-061144 would naturally consult ETRI's own comparison of two-SCH schemes — a direct motivation to combine.

Sharp R1-061681 ("Low-overhead Cell ID Mapping and Detection Scheme") supplies the "low-overhead mapping" of cell IDs onto the sync sequences — i.e., the code-planning element E and the sub-group mapping that the '204 specification calls its "method of allocating a code." Adding it to Ground 1 supplies an express teaching of why one maps a cell group to the secondary sequence and a cell index to the primary: because it lowers detection overhead in the second search step. That is the exact rationale the '204 specification gives for its own design.

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5. Ground 3: WCDMA art + TR 25.814 + ZTE R1-051072

For the transmit-side claims (13 and 19) and the terminal apparatus claims (7 and 25), the WCDMA art is the cleanest motivation source:

• TS 25.211/25.214 + Wang & Ottosson + Bahl teach the complete hierarchical cell-search apparatus and method: correlate against a primary sequence to get timing (PSC/matched filter), then hypothesize over a set of secondary code words and their cyclic shifts to recover the code group and frame boundary — precisely the "first identifier from the primary / second identifier from the secondary / cell ID from the combination" logic of element E, and precisely the receiver architecture (parallel correlators, accumulator, code-word hypothesis test, pilot correlation) that the '204 specification recites at length.
• TR 25.814 (v0.5 / v1.0.x) teaches the OFDM/E-UTRA frame (element A) and the short-CP (7-symbol) / long-CP (6-symbol) unit structure that the '204 patent treats as the source of its own timing-ambiguity problem and that maps to the dependent 7-symbol claim.
• ZTE R1-051072 supplies a downlink SCH scheme text proposal for E-UTRA, i.e., the bridge from the WCDMA hierarchical scheme to the OFDM sync-symbol layout.

Motivation (articulated): the '204 specification itself frames the invention as the migration of the WCDMA three-step cell-search concept into the OFDM forward link, and expressly states that the WCDMA synchronization channels "cannot be applied to the OFDM forward link." That is a classic "known work in one field may prompt variations of it for use in another based on design incentives … if the variations are predictable" rationale (KSR at 417) — and here the two fields (DS-CDMA cell search and OFDM cell search) share the same problem, the same standardization body, and largely the same engineers. The substitution of the OFDM subcarrier domain (FDM/TDM placement of P-SCH and S-SCH symbols) for the WCDMA time-domain direct-sequence multiplex is a predictable application of a known technique to a known device ready for improvement.

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6. Ground 4: TDM/FDM placement and the apparatus-type claims

The '204 dependent/structural features (contiguous placement, dual-RF/bandpass filtering, unused subcarriers) are all taught:

• Contiguous TDM placement — R1-061144 (two consecutive SCH symbols) and R1-061186.
• FDM placement within a single sync symbol — the RAN1 FDM/TDM SCH debates (R1-060812, R1-062990, R1-051072 line of art) and the '204 family's own IDS-listed Sharp and ZTE contributions.
• Unused subcarriers on the sync symbol — R1-061144's even-subcarrier-only first SCH symbol; also the standard "leave guard/unused subcarriers so the sync band occupies only part of the system bandwidth" teaching in TR 25.814 (scalable bandwidth).
• Bandpass filtering to the sync band / dual down-conversion — the express "SCH occupies 1.25 MHz at the centre of the system spectrum" assumption in R1-061144's Table 1 (simulation parameters) and elsewhere in the RAN1 art. A terminal that filters to the 1.25 MHz sync band is the natural, predictable implementation.

Each of these is a "known technique applied to a known device ready for improvement to yield predictable results" (KSR rationale (d)), and each is supported in the very references the patentee cited against itself.

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7. Claim-by-claim bottom line

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8. The priority-date vulnerability — and why the 2007 art may be fair game

Four references in the IPR exhibit set — R1-062990, R1-070650, R1-071768, and TR 25.814 v1.0.3/v1.2.2 — post-date the July 25, 2006 critical date and would be inadmissible as § 102(a)(1)/§ 102(b) art against claims entitled to that date. Two things in the record suggest Ericsson was attacking exactly that entitlement:

1. The exhibit set includes English translations of KR 10-2007-0006230 (filed Jan. 2007) and KR 10-2007-0074705 (filed Jul. 2007). These are the patentee's own later priority applications. Their utility in an IPR is not as § 102 art — it is as evidence of what the earlier applications do and do not disclose, i.e., to argue that the challenged claims are not supported by the 2006 Korean application and therefore are entitled only to the January or July 2007 date.
2. The challenged claims named in the Haimovich excerpt — 9, 10, and 16 — sit on features (dual-RF/bandpass; unused subcarriers) that the 2006 disclosure may or may not support in the claimed form.

Strategic consequence for § 103: if the claims are pushed to a 2007 effective filing date, the entire late-2006/2007 RAN1 corpus of PSS/SSC design contributions opens up — including the references the family's own IDS cites (NTT DoCoMo S-SCH Structure for E-UTRA Downlink R1-071628; Qualcomm Details on SSC sequence design R1-072093; Ericsson Secondary Synchronization Signal Design R1-072448; Nortel Mapping of Short Sequences for S-SCH R1-072368; Huawei S-SCH sequences based on concatenated Golay-Hadamard codes R1-072326) and the 3GPP TS 36.211 SCH definition. Those 2007 documents describe, with striking precision, the very "20-unit frame, two contiguous sync symbols, repeated PSS, differing SSS, cell-ID = 3×168 combination" architecture the '204 claims recite — the LTE Rel-8 design. This is the single highest-leverage path to invalidity and should be pleaded as an alternative ground: primary reference + priority defect + 2007 RAN1 art.

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9. Anticipated rebuttals and where the patent is (relatively) strongest

• "The claims require a particular combination mapping." If the granted claims require the SSS to carry the group and the PSS the in-group identity (rather than merely "a combination"), the patent may argue the prior art of 2006 taught the opposite assignment (e.g., DoCoMo contributions that used the small-sequence P-SCH for timing only). This is a claim-construction fight, not a teaching-away fight — the WCDMA base art expressly assigns group information to the secondary code word, so the mapping is a design choice between two known alternatives (KSR "finite number of identified, predictable solutions").
• Prior art that may teach away or be limited: R1-061144's "two consecutive SCHs" in subframes 10 and 20 gives two sync blocks per frame, whereas the '204 specification (Fig. 8/10) describes five sync blocks per frame (one every four subframes). If the claims require a five-sync-block frame, R1-061144 alone may not read on it, and the combination must rely on TR 25.814 / the RAN1 sync-periodicity proposals. This is the most plausible genuine gap and needs the full claim text to assess.
• Objective indicia: none located on this record. There is no finding of validity or infringement — the district cases were dismissed and the single IPR settled pre-institution (per the previous sections). Absent a nexus and evidence of commercial success attributable to the claimed features (as opposed to the LTE standard generally), objective indicia carry little weight here. Note the copying/industry-adoption argument cuts against the patentee in a standards context but must be supported by nexus evidence to count either way.

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10. Conclusion and confidence

The '204 claims are, on this record, highly vulnerable under § 103. A single pre-critical-date RAN1 contribution — R1-061144 (CHTTL, May 2006) — discloses the two contiguous sync symbols in the last two OFDM symbols of a unit, GCL sync sequences, and cell-ID identification by combining two consecutive sync sequences, along with the even-subcarrier-only (unused-subcarrier / delay-and-correlate) design. The remaining limitation — the group vs. in-group partition — is supplied directly by NTT DoCoMo R1-060042/R1-061186, by the patentee's own R1-061117, and by the WCDMA base art (TS 25.211/25.214, Bahl, Wang & Ottosson), which for years had taught that the secondary sequence identifies the code group and the primary sequence the timing/in-group index. The 20 × 0.5 ms frame and 7-symbol unit come from TR 25.814. Each combination is supported by express KSR rationales grounded in the standards-development context — a finite, identified set of predictable solutions pursued in the same working group for the same standard.

Confidence: High on the identification of R1-061144 and the DoCoMo/WCDMA art as the operative references and on the substance of the combinations; Moderate on the exact claim-charting, because (i) I could not retrieve the IPR2020-00242 petition or its asserted grounds, and (ii) I worked from the claim characterization in the prior section rather than the freshly pulled granted text. Before relying on this for a filing, confirm (a) the granted claim text and (b) the petition grounds from PTAB E2E (IPR2020-00242), and run the priority-defect analysis in §8 against the 2006 Korean application.