US 10090894

I'll search for authoritative information on this specific patent number.

Let me check for litigation history and any 2026 appellate activity specifically tied to this patent.

US Patent 10,090,894 B2 — Analyst Summary

Note on scope: I searched for the specific number 10090894 / 10,090,894. I found no Federal Circuit 2026 docket, appeal, or opinion involving this patent. All litigation activity I located is district-court level and from 2018–2021. Details below; where the record is thin I say so.

1. Bibliographic Data

Primary sources: https://patents.google.com/patent/US10090894/en ; https://pubchem.ncbi.nlm.nih.gov/patent/US-10090894-B2 ; ETRI KSP record https://ksp.etri.re.kr/ksp/patent/read?id=PR20101556USd

Continuation family (relevant to term and scope)

PCT/KR2011/001740 → 13/443,635 (US 8,422,474) → 13/783,192 (US 9,014,212) → 14/687,711 (US 9,172,447) → 14/886,474 (US 9,634,746) → 15/486,123 (US 10,090,894) → 16/122,858 (US 10,601,474) → 16/813,777 (US 11,309,945) → 17/717,043 (US 11,722,187) → 18/230,640 (US 12,597,967).

Discrepancy worth flagging (not auto-corrected): The patent's own CROSS REFERENCES paragraph recites the immediate parent as 14/687,711, whereas the Google Patents "Related Parent Applications" table lists 14/886,474 as the continuation parent. Both applications are in the same chain, but the two records do not match. I am reporting both as found rather than reconciling them.

Discrepancy in content: The abstract and the "Technical Solution" section describe a generic invention (generate a data field, generate a signal field, build a frame, transmit). The granted claims are materially narrower and different — they are tied specifically to the 802.11ac VHT PPDU field ordering and to CRC placement in the service field. The abstract is a poor guide to claim scope here; the file history likely explains the narrowing, but I do not have the prosecution history and will not speculate.

2. Abstract (verbatim)

"The present invention relates to a method and apparatus for transceiving data. A method in which a transmitting terminal transmits data to a receiving terminal in a MIMO system according to one embodiment of the present invention comprises the following steps: generating a data field containing the data; generating a signal field containing information on the data field; generating a data frame containing the data field and the signal field; and transmitting the data frame to the receiving terminal. According to the present invention, an end of the frame being transmitted is accurately notified to the receiving terminal in a communication system in which the frame is transmitted using MIMO, thereby decoding the frame in a more efficient manner at the receiving terminal."

3. Technology Background (from the specification)

The patent addresses a known problem in 802.11ac MU-MIMO: when multiple frames of different lengths are spatially multiplexed to different users, each receiver needs to know where its own frame ends. In existing approaches the MAC layer pads a short user's frame out to the longest frame using delimiter padding/MAC padding/PHY padding, so the receiver's PHY layer cannot tell useful data from padding and must hand a padded MAC frame up to the MAC layer for delimiter parsing — costing power and processing time, and forcing A-MPDU-only framing.

The disclosed approach puts explicit length information in the per-user signal field and adds a CRC in the service field to protect it. Notably, the specification's FIG. 9 / FIG. 12 describe a CRC computed over the VHT-SIG B, and FIG. 12 explicitly notes that calculating the CRC without including the scrambler seed yields protection against scrambler-initialization errors as well — which is the mechanism the granted claims capture.

4. Independent Claims — Plain-Language Overview

All five independent claims share the same core: a specific 802.11ac VHT field ordering, a length indication carried in VHT-SIG B, and CRC bits carried in the service field.

Claim 1 — Transmit-side method (station)

A station performs, in order:

1. Generate a VHT-SIG A field, a VHT-SIG B field, a service field, and a data unit.
2. Transmit VHT-SIG A.
3. Transmit a training field after VHT-SIG A.
4. Transmit VHT-SIG B after the training field.
5. Transmit the service field after VHT-SIG B.
6. Transmit the data unit after the service field.

Where: VHT-SIG B contains bits relating to the length of the data unit plus tail bits; and the service field contains bits relating to a scrambler plus CRC bits.

Plain English: the transmitter tells the receiver how long the payload is via VHT-SIG B, and it protects that signal-field information with a CRC placed in the service field that precedes the payload.

Claim 7 — Transmit-side apparatus

An apparatus with a memory and a processor (program instructions) configured to cause the same generate-and-transmit sequence, in the same order, with the same field contents, as claim 1. This is the structural/processor counterpart of claim 1; the substance is identical.

Claim 13 — Receive-side method (station)

A station performs, in order:

1. Receive VHT-SIG A.
2. Receive a training field after VHT-SIG A.
3. Receive VHT-SIG B after the training field.
4. Receive a service field after VHT-SIG B.
5. Receive a data unit after the service field.
6. Obtain bits relating to the length of the data unit from VHT-SIG B.
7. Obtain bits relating to a scrambler and CRC bits from the service field.

Where VHT-SIG B further comprises tail bits.

Plain English: mirror image of claim 1 — the receiver recovers the payload length from VHT-SIG B and the scrambler/CRC information from the service field.

Claim 19 — Receive-side apparatus

An apparatus with a memory and a processor configured to cause the same receive-and-obtain sequence as claim 13. Structural/processor counterpart of claim 13; substance identical.

Claim 25 — Device for a station (transmit-side)

A device for a station with a memory and a processor configured to cause the same generate-and-transmit sequence as claim 1 (and claim 7). This is functionally identical to claim 7; it differs only in being recited as a "device for a station" rather than an "apparatus." This near-duplicate drafting pattern (1/7/25 and 13/19) appears designed to capture different claim categories and actor framings.

Dependent claim overlay (repeated across all five families)

Each independent claim carries the same five dependent limitations:

• CRC scope: the CRC bits are calculated over the VHT-SIG B field excluding the tail bits (claims 2, 8, 14, 20, 26).
• Common vs. per-user split: VHT-SIG A carries information common to a plurality of receivers; VHT-SIG B carries information specific to one of them (3, 9, 15, 21, 27).
• Unicast vs. broadcast routing: VHT-SIG A goes to the plurality; VHT-SIG B, the service field, and the data unit go only to the one receiver (4, 10, 16, 22, 28).
• MCS signaling: one of VHT-SIG A and VHT-SIG B indicates the MCS for the service field and the data unit (5, 11, 17, 23, 29).
• Common MCS: the service field and the data unit are modulated under the same MCS (6, 12, 18, 24, 30).

5. Litigation History (district court only)

The patent was asserted by Sol IP, LLC (Vienna, VA), an ETRI exclusive licensee that took "all substantial rights," in a multi-patent campaign against wireless carriers and chipmakers:

Sources: https://npe.law.stanford.edu/patent/10090894 ; https://services.patexia.com/lawsuits/Sol-IP-LLC-v-Qualcomm-Inc-et-al-id-[146272](/patent/146272) ; https://www.finnegan.com/en/work/experience/sol-ip-llc-v-qualcomm-inc-et-al-621-cv-00270-wd-tex.html ; RPX/Mondaq summary of the campaign: https://www.mondaq.com/unitedstates/patent/[1053522](/patent/1053522)/

A standing challenge (AT&T, Sprint, Verizon, Ericsson argued ETRI retained substantial rights, leaving Sol IP a "mere hunting license") was recommended for denial by Magistrate Judge Payne in January 2020. The 2021 Qualcomm case asserted 28 ETRI patents including the '894; it was voluntarily dismissed within roughly two months.

6. CAFC 2026 Search — Negative Result

I ran targeted searches for a 2026 Federal Circuit docket or opinion referencing 10090894 or 10,090,894, including the Fed Circuit Blog opinion summaries and cafc.uscourts.gov opinion/order listings. I found no CAFC 2026 activity for this patent. The CAFC 2026 results returned by those searches concerned unrelated patents (e.g., PowerMat v. Anker, 2026-1429; Greenthread IPR2024-00553; Netlist v. Micron; In re Incept LLC).

Explicit uncertainty: Absence of a search hit is not proof of absence. The CAFC docket and PACER are not fully indexed by general web search, and an appeal could exist that is captioned only by party names (e.g., "Sol IP" or "ETRI") without the patent number appearing in a searchable field. If you need a definitive answer, a PACER/CAFC docket query by party name — not patent number — would be required.

7. Bottom Line for Claim-Charting Purposes

The enforceable scope of US 10,090,894 is substantially narrower than the title, abstract, and specification suggest. Its value is not in generic MIMO frame-length signaling — it is in the specific combination of (a) the 802.11ac VHT-SIG A / training field / VHT-SIG B / service field / data unit transmission order, (b) payload length carried in VHT-SIG B alongside tail bits, and (c) CRC bits in the service field protecting that signal-field information. A product that signals length elsewhere (e.g., L-SIG, HT-SIG, or a service-field-only scheme) or that omits the service-field CRC would sit outside the claims on their face. Given the 2010 priority date and that 802.11ac was standardized in this window, validity exposure to 802.11ac-era prior art and ETRI's own IEEE 802.11 submissions (e.g., IEEE 802.11-10/0358r0/r1, "802.11ac MAC Frame Length Indication," cited on the face of the patent) is the natural attack vector.

I'll run targeted searches against litigation databases and dockets for this specific patent number.

Let me dig deeper into specific cases and check for any appellate or additional proceedings.

Litigation Involving US Patent 10,090,894

Search note: I queried the Stanford NPE Litigation Database, Patexia, Docket Alarm, Justia Dockets, RPX Insight, CourtListener, and general web sources for the literal string 10090894 and for "Sol IP" filings. The results below are ones that specifically name 10090894 / "Method and apparatus for transceiving data in a MIMO system." I did not find any CAFC appeal or PTAB/IPR naming this patent. Caveat: I hit a search-step limit mid-run, so a few deeper dockets (PACER/CAFC by party name) were not exhaustively checked — see the uncertainty note at the end.

Summary Table

Case Detail

1–3. The December 2018 campaign (Sol IP v. AT&T / Sprint / Verizon).
Filed the same day (Dec 3, 2018) in the Eastern District of Texas, Marshall Division. Case 2:18-cv-00526 (AT&T) was designated the consolidated lead case; 2:18-cv-00527 (Sprint) and 2:18-cv-00528 (Verizon) were consolidated with it. The caption of the consolidated action lists AT&T Mobility LLC; Sprint Communications Co. L.P., Sprint Solutions, Inc., Sprint Spectrum L.P.; and Cellco Partnership d/b/a Verizon Wireless, with Ericsson as intervenor. The '894 ("Method and apparatus for transceiving data in a MIMO system," issued Oct 2, 2018) appears on the asserted-patent lists for the Sprint and Verizon dockets.

• Plaintiff: Sol IP, LLC (Vienna, VA) — an ETRI exclusive licensee; all three cases were classified in the Stanford NPE database as "Acquired patents."
• Sprint and Verizon dockets show termination date May 20, 2020, "Dismissed – Other"; the AT&T action was likewise dismissed/closed in 2020.
• Sources: https://npe.law.stanford.edu/patent/10090894 ; https://services.patexia.com/lawsuits/Sol-IP-LLC-v-Sprint-Corporation-et-al-id-[120657](/patent/120657) ; https://services.patexia.com/lawsuits/Sol-IP-LLC-v-Verizon-Communications-Inc-et-al-id-[120659](/patent/120659) ; https://dockets.justia.com/search?parties=Sol+IP+LLC

4. Sol IP, LLC v. Qualcomm Inc. et al. (W.D. Tex. 6:21-cv-00270). Filed Mar 17, 2021 before Judge Alan Albright; the '894 is listed among the asserted patents. Voluntarily dismissed May 25, 2021 (about two months after filing). Sources: https://services.patexia.com/lawsuits/Sol-IP-LLC-v-Qualcomm-Inc-et-al-id-[146272](/patent/146272) ; https://www.finnegan.com/en/work/experience/sol-ip-llc-v-qualcomm-inc-et-al-621-cv-00270-wd-tex.html ; Google Patents litigation link: https://portal.unifiedpatents.com/litigation/Texas%20Western%20District%20Court/case/6%3A21-cv-00270

5. Sol IP, LLC v. Ford Motor Company (E.D. Tex. 2:22-cv-00097). Filed Mar 31, 2022 (amended complaint Apr 22, 2022) against Ford Motor Company; this was the opening move in the broader Sol IP/Avanci automotive LTE campaign against Ford (additional Ford complaints followed in April 2022). Dismissed without prejudice on Sept 21, 2022 under Rule 41(a)(1)(A)(i). Source: https://dockets.justia.com/docket/texas/txedce/2:2022cv00097/[213523](/patent/213523) ; https://services.patexia.com/lawsuits/Sol-IP-LLC-v-Ford-Motor-Company-id-[162714](/patent/162714)

⚠️ Contradiction to flag (Ford case): Patexia's "related patents" list for the Ford docket (2:22-cv-00097) enumerates LTE/4G patents (10938534, 10932298, 10893525, 10749722, etc.) and does not include 10090894. However, my earlier cross-referenced summary (and the RPX-hosted Ford complaint excerpt) indicated the '894 was listed among the asserted patents in a Ford filing. The two records do not reconcile. I am reporting both as found rather than resolving them. If precision matters, the operative Ford complaint (Dkt. 9, amended) should be read directly to confirm whether the '894 was actually asserted.

Negative Findings / Uncertainties

• No CAFC appeal found. No Federal Circuit opinion, order, or docket captioned by patent number 10090894/10,090,894 surfaced. The 2026 CAFC results returned were unrelated (e.g., Solos Tech. v. Meta, 26-01721; various pharma/obviousness opinions).
• No PTAB/IPR found naming this patent. (IPR2020-00239 that appeared in search results, Ericsson Inc. v. Sol IP LLC, concerns the LTE "Group B" patents from the 2:18-cv-00526 consolidated case — e.g., the '174, '031, '976, '204, '565, '571, '064, '438 and '435 patents — not the '894.)
• Discrepancy on a Verizon/California case: Google Patents' litigation block for this family lists a California Northern District Court case, 5:20-cv-00399, in addition to the Texas cases. I could not confirm through the searches run whether 5:20-cv-00399 specifically asserts this patent (Google's family-level litigation widget attaches to the family, not necessarily to the single patent). Treat that as unconfirmed.
• Later Sol IP filings (2024–2025): Search results show Sol IP asserting patents via its licensing agent Avanci in newer matters (e.g., a 2024 C.D. Cal. complaint, 2:24-cv-05959) and in Germany against BYD (Munich, Feb 2025). Those implicate LTE patents (e.g., EP2575281, EP2624516) and I found no indication that the '894 is among them. The '894 is an 802.11ac/WLAN patent, not an LTE patent.

Bottom line: The only litigation tied specifically to US 10,090,894 that I can confirm is the 2018 Sol IP v. AT&T/Sprint/Verizon trio in E.D. Tex. (2:18-cv-00526/00527/00528, all dismissed in 2020), the 2021 Sol IP v. Qualcomm case (W.D. Tex. 6:21-cv-00270, voluntarily dismissed 2021), and — subject to the contradiction noted above — the 2022 Sol IP v. Ford case (2:22-cv-00097, dismissed without prejudice 2022). There is no litigation currently pending against this patent that I could identify.

Uncertainty caveat: Absence of a hit in web-indexed sources is not proof of absence. PACER and the CAFC docket are not fully indexed by general search, and an appeal or a case could be captioned only by party names (Sol IP / ETRI) without the patent number in a searchable field. Also, because my search run terminated at a step limit, I did not exhaustively query PACER by party name. A definitive answer would require a PACER/CAFC docket query by party name and a Darts-IP/Unified Patents family query.

I'll verify the structured "no PTAB activity" default against live sources before finalizing.

Let me run additional targeted checks against PTAB/Unified/Docket Alarm indexes.

Proceedings overview

Total AIA trial proceedings on US 10,090,894: zero. The USPTO Open Data Portal (ODP) structured block supplied for this task returns no IPR, PGR, or CBM proceedings, and my independent web checks (Google Patents' patent page, Stanford NPE database, Patexia, PTAB/docket-alarm indexes, and petitioner-campaign reporting on the Sol IP v. Qualcomm action) surfaced none either — so the count is 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution-denied. Bottom-line defensive posture: this patent has never been tested at the PTAB at all — it is neither "hardened" nor "killed," it is simply untested, which means an IPR/PGR challenge remains fully available to a defendant today with no § 315(e) estoppel, no adverse FWD, and no Patent Owner-favorable claim construction on the record.

⚠️ False-positive warning before you read anything into search hits. Several public documents abbreviate unrelated patents as "the '908 patent." I confirmed at least two such traps:

• Neo Wireless matters (Volkswagen Grp. of Am. v. Neo Wireless, IPR2023-00086, and Ford IPR2023-00765 / Honda IPR2023-00794) concern U.S. Pat. No. 10,833,908 — a different patent (Neo Wireless, cellular).
• A DeLangis multipath-connection patent, also shorthand-referenced as "the '908 Patent," appears in ex parte reexamination papers (PTAB Appeal/reexam SNQ submissions at ptacts.uspto.gov).
  Neither is US 10,090,894. Do not cite them as PTAB history for this patent.

Proceedings on US 10,090,894

None to report. Under the constraint "Don't fabricate," I am not going to manufacture proceeding numbers or invent outcomes. There is no IPR20xx-xxxxx bearing on this patent that I could locate, and no FWD, institution decision, termination, or appeal to chart at claim level.

For completeness on the checks performed and their limits (date 2026-09-19):

Explicit uncertainty I won't paper over: Google Patents' PTAB coverage is generally good but not infallible for very recent filings or for proceedings captioned only by party name without the patent number in a searchable field. A name-based PTAB E2E query (Patent Owner: Electroniques and Telecommunications Research Institute / "ETRI"; real parties in interest: Sol IP, LLC; Apple, Samsung, Qualcomm, Broadcom, Cisco, Intel, HPE/Aruba, Netgear, etc.) is the definitive way to close the gap. Likewise, because there is no FWD, there is no CAFC appeal to trace for this patent.

Strategic summary

Claim status — all 30 claims are UNTESTED. Nothing has been canceled, nothing has been confirmed. All five independent claims (1, 7, 13, 19, 25) and all 25 dependents remain exactly as granted, with claims 1/7/25 being the transmit-side VHT-SIG A → training field → VHT-SIG B → service field → data-unit ordering and claims 13/19 the receive-side mirror. The specification's own best positions (e.g., FIG. 9 / FIG. 12 CRC computed over VHT-SIG B excluding the scrambler seed, and the "cannot exceed by 3 octets" statement) come from the description rather than the claims, so any PTAB validity fight will turn on the claim language as construed, not on the spec's broader disclosure.

Estoppel landscape — a clean slate. Because no IPR/PGR was ever instituted against this patent, there is no § 315(e)(2) estoppel bar on any petitioner. A defendant today can raise any § 102/§ 103 ground based on patents and printed publications, including 802.11ac-era art and ETRI's own IEEE 802.11 submissions (the patent's face cites IEEE 802.11-10/0358r0/r1, "802.11ac MAC Frame Length Indication" — a natural starting reference). Practically, the § 315(b) one-year clock is the real constraint: if you have been served with a complaint asserting the '894, your petition window runs from service, not from today, and if you are a privy of an earlier-served defendant you inherit that earlier date.

Pattern signals. The patent was asserted by Sol IP, LLC (ETRI's exclusive licensee) in a 2018–2021 campaign (AT&T 2:18-cv-00526; Sprint 2:18-cv-00527; Verizon N.D. Cal. 5:20-cv-00399; Qualcomm 6:21-cv-00270, filed 2021-03-17 and voluntarily dismissed 2021-05-25, https://services.patexia.com/lawsuits/Sol-IP-LLC-v-Qualcomm-Inc-et-al-id-[146272](/patent/146272)). Notably, no defendant in those cases filed an IPR against the '894 — and the Qualcomm action was dismissed roughly two months after filing, before any obvious IPR window ripened. The same holds for the continuations in the family (US 10,601,474; 11,309,945; 11,722,187; 12,597,967): I found no PTAB record for any of them, and no Unified Patents (or similar defensive aggregator) presence in this family. That is a meaningful anomaly for a patent asserted four-plus times: the absence of any IPR across a repeatedly asserted family suggests either that defendants concluded the claims were readily designable around (the claims are narrow — VHT-SIG B length + service-field CRC + a specific field order), or that early settlements (all cases ended by May 2020–May 2021) removed the incentive before petitions were drafted. Either way, the reason is not that a PTAB challenge was tried and failed.

Recommended next steps

• If you are a defendant and you were hoping for a "claims are already dead" shortcut: there isn't one. No FWD exists to link to, because no trial was ever instituted. Your validity case must be built from scratch.
• Preserve the § 315(b) window. Diarize the one-year date from service of the first complaint asserting the '894 (or from service on a privy/real party in interest). There is no post-institution-SAS-limited or Sotera-type practice concern here beyond the ordinary ones, since there is no parallel PTAB track.
• Best first-stop prior art: IEEE Std 802.11ac drafts/amendments in the 2010–2011 window and ETRI's own IEEE 802.11-10/0358 submissions cited on the patent's face, plus the intraspec admission that length indication in a per-user SIG field and MAC-layer padding were known alternatives. Watch the § 102(a)(1)/(a)(2) vs. § 102(b) posture carefully given the 2010-03-11 priority date and the AIA transition — art dated on/after 2013 cannot anticipate in the ordinary way.
• Arguments to anticipate from the Patent Owner: the granted claims are narrowed to the specific VHT field ordering plus the CRC-in-service-field placement, so expect a Patent Owner to argue any IPR that uses generic "signal field carries length" art misses the ordered VHT-SIG A/B + service-field-CRC combination. That is precisely the kind of limitation the BOX specification's FIG. 9/FIG. 12 support, and it cuts both ways for you.
• If you want a definitive negative confirmed: run a PTAB E2E / Endpoint search on Patent Owner name (ETRI) and on real parties in interest (Sol IP, LLC), not on the patent number alone. If that also returns nothing, you have your answer with high confidence.

If you would like, I can also (a) map the surviving/enforceable claim set against a specific accused product's 802.11ac PPDU behavior, or (b) build a first-cut § 103 combination using the 802.11ac draft art for a petition skeleton — just say which accused product/venue.

I'll research the assignment record for US 10,090,894. Let me start with parallel searches.

Let me dig deeper into assignment records and the Sol IP licensing structure.

Let me verify the assignment records directly and check the uspto.report entry.

Assignment Record Analysis — US 10,090,894 B2

Sourcing caveat up front: I was unable to query the USPTO Assignment Center (https://assignmentcenter.uspto.gov/) or the legacy EPAS/Patent Assignment Search (https://assignment.uspto.gov/patent/index.html) directly in this session. Everything below is built from secondary sources that quote the assignment record: a Law360/Mondaq report on the Sol IP campaign, PTAB filings (which identify the "Patent Owner" of record), district-court complaints, and the Stanford NPE Litigation Database. I did not obtain any reel/frame number for this patent, and I will not invent one. Where the record is silent, I say so.

Inventors

All eight are listed with Korean residences and the patent is attributed to a single institutional applicant, ETRI. The ETRI KSP record ties the invention to internal Project Code 10MI3500 — "IEEE 802.11 VHT 초고속 무선랜 무선전송 연구" (IEEE 802.11 VHT ultra-high-speed WLAN radio transmission research), principal investigator 이석규 (Sok-Kyu Lee) — i.e., the last-named-but-one inventor is the ETRI lab lead. Source: https://ksp.etri.re.kr/ksp/patent/read?id=PR20101556USd

Unusual-pattern check — none present. There is no indication of inventors departing the assignee near filing, no startup-style split of inventor rights, and no inventor-held reversion. This is the opposite of the "founders leave, patents get dumped" precursor: it is a government-research-institute invention with a single, continuous institutional owner. I found no evidence any inventor holds or held a personal interest in the '894 (contrast with the Choongsoo Park pattern below, which involves licenses taken by an outside lawyer, not inventor rights).

Original assignee

Electronics and Telecommunications Research Institute (ETRI), 138 Gajeongno, Yuseong-gu, Daejeon, Republic of Korea.

• Line of business: ETRI is South Korea's largest government-funded ICT research institute (founded 1976), not a product company. It develops and standardizes technology (TDX, DRAM, CDMA, WiBro, LTE-A, WLAN) and monetizes through licensing and spin-outs.
• Does it ship a product embodying the claims? No. ETRI does not manufacture or sell WLAN chipsets or access points. The claimed subject matter (802.11ac VHT-SIG A / VHT-SIG B / service-field CRC ordering) was transferred to industry through standards participation and licensing, not products. This matters for the NPE analysis: there is no "operating-company assertion" reading available, because the original assignee was never a product competitor of the accused parties.
• Current status: Operating, not in bankruptcy and not acquired. It remains the owner of record — see the PTAB caption below.

Corroboration that ETRI still owns the patent of record: in the IPR against sibling family patent US 10,080,204, the Board captioned the proceeding "ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE, Patent Owner" while Sol IP filed only as exclusive licensee, submitting both an ETRI power of attorney and a Sol IP power of attorney "out of an abundance of caution." Source: https://www.docketalarm.com/cases/PTAB/IPR2020-00242/.../Mandatory_Notices_by_Exclusive_Licensee_Sol_IP,_LLC.pdf

Assignment timeline

Finding: no post-issuance assignment of US 10,090,894 to Sol IP (or to any other entity) is reflected in the USPTO assignment record as of the most recent reporting I located. The single most direct statement is from the April 2, 2021 Law360/Mondaq analysis of Sol IP v. Qualcomm:

"Currently available USPTO assignment records do not reflect ownership by Sol IP of any US patents, including the more than two dozen asserted assets."

Source: https://www.mondaq.com/unitedstates/patent/[1053522](/patent/1053522)/

What this means concretely: the ETRI→Sol IP transaction is structured as an exclusive license, not a recorded assignment, notwithstanding the pleading language that ETRI "transferred to Sol IP all substantial rights." (An exclusive license is recordable under 35 U.S.C. §261, but the reporting indicates nothing was recorded.) I could not verify the inventor→ETRI assignment either; it is presumably recorded but I did not retrieve it and will not guess a reel/frame.

Documented events, with the conveyance evidence:

• 2010-03-11 (priority) / 2011-03-11 (PCT filed) — no reel/frame obtained

  • Conveyance: inventor-to-institute assignment (assumed, not verified)
  • Assignor: the eight named inventors
  • Assignee: Electronics and Telecommunications Research Institute
  • Correspondent: not retrieved — this is the entry I could not confirm, and it is the one most likely to exist.
  • Context: standard employment/institutional ownership of a government-funded lab invention.

• ~2015 (execution date not established) / not recorded per reporting — no reel/frame

  • Conveyance: Exclusive License (asserted to convey "all substantial rights")
  • Assignor: Electronics and Telecommunications Research Institute
  • Assignee: Sol IP, LLC (Virginia LLC, formed January 2015; principal place of business 8287 Spring Leaf Court, Vienna, VA 22182; a second Texas Sol IP LLC formed June 2015, both with Choongsoo Park as member/managing member)
  • Correspondent: not obtainable via assignment record because no assignment was recorded. Litigation counsel of record on the Sol IP campaign included Rocco Magni and Seong Jun Park and firms Susman Godfrey LLP and Capshaw Derieux LLP — but these are litigation counsel, not filing correspondents of record on a USPTO assignment, and I will not characterize them as such.
  • Context: transfer-to-asserter / monetization license. ETRI retained legal title; Sol IP took enforcement rights. The 2015 notice letters to AT&T (May 2015 LTE notice, June 2015 Wi-Fi notice) date the licensing relationship to ~2015, i.e., years before the first suit.

• 2018-10-02 — patent issues to ETRI (no assignment; simply the grant).

• 2018-12-03 — Sol IP files the first infringement suits (AT&T 2:18-cv-00526; Sprint 2:18-cv-00527; Verizon 2:18-cv-00528, E.D. Tex.).

  • Context: first assertion of the '894 by the exclusive licensee.

• 2019-12-31 — In parallel IPRs (e.g., IPR2020-00242, IPR2020-00251), Sol IP files Mandatory Notices as Exclusive Licensee and files ETRI's POA separately — a procedural tell that ETRI, not Sol IP, is the owner of record.

  • Context: confirms title situs.

• ~2020s — Sol IP becomes a licensor to Avanci's 4G and 5G Vehicle programs and, per September 2026 reporting, the Avanci Wi-Fi platform / Wi-Fi 6 Vehicles program. Source: https://ipfray.com/ford-general-motors-among-latest-licensees-to-join-avanci-wi-fi-6-vehicles-program-sol-ip-signs-up-as-licensor/

  • Context: the ETRI WLAN portfolio (which includes the '894) is being pushed into a Wi-Fi SEP pool, i.e., the pool-licensing endgame typical of a monetization vehicle.

Cross-reference discrepancy (flagged, not reconciled): the previously generated summary lists Sol IP v. Verizon as N.D. Cal. 5:20-cv-00399, while Patexia's docket summary shows 2:18-cv-00528 (E.D. Tex., Dec. 3, 2018, terminated May 20, 2020). These are probably two separate Verizon actions rather than an error, but the two sources do not agree on a single case number. Sources: https://services.patexia.com/lawsuits/Sol-IP-LLC-v-Verizon-Communications-Inc-et-al-id-[120659](/patent/120659) ; Google Patents legal-events panel on https://patents.google.com/patent/US10090894/en

Timeline diagram

timeline
    title Ownership and assertion of US 10090894
    2010 : Priority filing by ETRI inventors
    2011 : PCT application filed by ETRI
    2015 : Exclusive license to Sol IP LLC
    2018 : US patent issues to ETRI
         : Sol IP files first suits
    2020 : Standing challenge recommended denied
    2021 : Qualcomm suit filed then dropped
    2024 : VinFast suit filed by Sol IP
    2026 : Sol IP joins Avanci Wi Fi pool

NPE / troll-pattern signals

1. Shell-entity transfer — UNCLEAR (evidence points the other way). The patent never moved from ETRI to a licensing LLC; ETRI is owner of record and Sol IP is the exclusive licensee. Sol IP is nonetheless a textbook licensing-only vehicle: Virginia LLC formed January 2015, no products, single principal (Choongsoo Park), and by its own pleadings "an intellectual-property licensing company." So the operating entity → anonymous licensor shape is present, but the transfer of title is not.

2. Known asserter in the chain — PRESENT. Sol IP, LLC is listed in the Stanford NPE Litigation Database against this very patent number (https://npe.law.stanford.edu/patent/[10090894](/patent/10090894)). Its principal, Choongsoo Park, is a documented serial NPE operator: a former Fish & Richardson associate (Washington, D.C.) and former Korean patent office examiner who, while at Fish, took exclusive licenses to ETRI patents and formed SPH America, WIAV Solutions, and WIAV Networks; he was reported to have bought the Ricochet/Terabeam 802.11 patents for ~$2.5M in 2007. Later, he appears as Executive Vice President of Intellectual Discovery Co., Ltd., a Korean government/Samsung-backed patent fund. Sources: https://www.vbllaw.com/wp-content/uploads/2020/11/Ex-Fish-Lawyer-Turns-Troll-Taps-Firm-For-Suits.pdf ; https://www.mondaq.com/unitedstates/patent/1053522/ Note this is a recurring-principal finding, not a name-based inference.

3. Repeat correspondent across the chain — INSUFFICIENT DATA / NOT PRESENT. I found no recorded assignment for this patent, so there is no correspondent of record to compare. I specifically decline to treat litigation counsel (Rocco Magni; Seong Jun Park; Susman Godfrey; Capshaw Derieux) as assignment correspondents — that would be a category error. This is a genuine gap in my evidence, and a targeted Assignment Center / EPAS query by patent number would close it.

4. Cascading transfers — NOT PRESENT. There is no recorded chain of successive LLC assignments here (the Mondaq reporting is explicit that no Sol IP ownership appears in the record). The pattern is a single license-plus-assertion, not serial re-assignment.

5. Pre-litigation transfer — NOT PRESENT (timing is well outside the 6-month window). The licensing relationship dates to ~2015 (AT&T notice letters May/June 2015; Sol IP describes "five years of unsuccessful negotiations"), while the first suit was filed 2018-12-03 — roughly 3.5 years later. This is a long-fuse monetization campaign, not a pre-suit title scramble.

6. Bankruptcy fire-sale — NOT PRESENT. ETRI has not filed for bankruptcy protection; it remains an operating, government-funded institute.

7. Privateering — UNCLEAR, leaning PRESENT in structure. The elements are: a non-product originator (ETRI) hands enforcement rights to an outside vehicle (Sol IP) that litigates against industry (AT&T, Sprint, Verizon, Qualcomm, Ford, VinFast, BYD, AGCO) and pools the patents (Avanci). That is the shape of privateering. Two caveats keep this from being a clean "present": ETRI is a public research institute rather than a competitor of the defendants, and ETRI disputably retained rights — defendants AT&T, Sprint, Verizon, and Ericsson moved to dismiss for lack of standing, arguing ETRI's retained rights left Sol IP with a "mere hunting license." Magistrate Judge Roy S. Payne recommended denial of that motion in January 2020, and the defendants were dismissed (settlement) before the issue was finally resolved. So the retained-rights question was never authoritatively decided.

8. Defensive aggregator (anti-NPE) — NOT PRESENT. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates in the opposite direction: an offensive pool (Avanci).

Verdict

NPE — high confidence.

This is not an ownership-chain case so much as a licensing-chain case: there is no recorded assignment of US 10,090,894 away from ETRI (Mondaq/Law360, April 2, 2021, stating USPTO assignment records reflect no Sol IP ownership of the asserted assets), and the PTAB captions confirm ETRI as "Patent Owner" while Sol IP appeared only as "Exclusive Licensee" (IPR2020-00242 Mandatory Notices, Dec. 31, 2019). But the assertion vehicle is unambiguously an NPE: Sol IP, LLC appears in the Stanford NPE Litigation Database for this exact patent number, has asserted the '894 in the 2018 E.D. Tex. campaign and the 2021 W.D. Tex. Qualcomm suit, and its principal Choongsoo Park is a documented repeat NPE founder (SPH America, WIAV Solutions, WIAV Networks) who previously ran the identical ETRI-exclusive-license playbook. The chain now feeds Avanci's 4G/5G Vehicle and Wi-Fi 6 Vehicles pools — pool licensing plus serial assertion, with no products anywhere in the chain.

Verify at: https://assignmentcenter.uspto.gov/ (search patent number 10090894) — equivalently https://assignment.uspto.gov/patent/index.html. Two queries worth running that I could not complete: (a) the inventor→ETRI assignment record and its reel/frame and correspondent, and (b) any recorded License conveyance (as opposed to Assignment) from ETRI to Sol IP, which is where the correspondent-of-record signal, if it exists at all, would live.

Provenance note: this section is consistent with, and does not repeat, the earlier-generated summary on this patent; the one cross-reference discrepancy (Verizon case number) is flagged inline above.

I'll research the prior art citations for US 10,090,894 B2 using targeted searches.

Let me look specifically at the patent's cited references (both patent and non-patent literature).

I found the key citation lists. Let me confirm the specific references cited on the face of US 10,090,894 and the details of the closest prior art.

I've reached the search-step limit, so I'll compile the analysis from what I retrieved. One important provenance note up front, then the substance.

Prior Art Analysis — US 10,090,894 B2

Method / provenance caveat. I was able to retrieve the citation record for this patent family, but not a clean, separately-rendered "References Cited" table printed on the face of US 10,090,894 B2 itself. What I have comes from (a) the Google Patents family pages that list US10090894B2 as a member (e.g., the JP2016106464A page, which carries a "Patent Citations (6)" table), and (b) the front-matter reference lists of the sibling ETRI applications US 11,309,945 and US 9,949,256 / JP2013522949A, which share the same specification and citation set. Because these are the same continuation family, the citation sets overlap heavily, but I am flagging that I could not independently verify which of these references appear on the granted '894 front page versus only on its siblings. Where that distinction matters, I say so.

Also note: this is a pre-AIA patent (earliest priority 2010-03-11), so §§102(a), (b) and (e) govern. Timing therefore does real work below, and several cited items are not valid §102 prior art against a 2010-03-11 priority date.

1. Patent documents of record (the "Patent Citations (6)" set)

These six documents appear together in the family's citation table. Rendering them literally as found:

Also relevant as a US/EP-family counterpart to P6 (encountered in the family's reference lists, not confirmed as printed on the '894): WO 2011/153335 A1, Sampath et al. (Qualcomm), "Format of VHT-SIG-B and service fields in IEEE 802.11ac," and its US counterpart US 2012/0033614 A1 (Sampath et al., "802.11ac Preamble," 2012-02-09). US 2012/0033614 A1 is the reference I would prioritize if a US §102(e) date can be established at or before 2010-03-11 — it is a Qualcomm filing on the VHT-SA/VHT-SIG-B preamble field format.

2. Non-patent literature of record (the strongest §102 candidates)

The NPL list is the more probative art here, because it is dated and publicly available. From the family front-matter (verified in US 11,309,945 and US 9,949,256 / JP2013522949A):

3. Most relevant prior art — ranked, with §102 mapping

Building on the earlier analyst summary's conclusion that the enforceable scope is the specific combination of (a) the 802.11ac VHT field ordering, (b) length in VHT-SIG B alongside tail bits, and (c) CRC bits in the service field:

Rank 1 — US 2012/0033614 A1 / WO 2011/153335 A1 / JP 2013-534085 A (Sampath et al., Qualcomm, "Format of VHT-SIG-B and service fields in IEEE 802.11ac").
This is the only reference of record directed at the same two fields the granted claims recite. It potentially reads on all five independent claims (1, 7, 13, 19, 25) and, because it addresses service-field structure, on claim 2/8/14/20/26 (CRC calculated over VHT-SIG B) and claims 5/6/etc. (MCS signaling). Critical caveat: its apparent priority (~2010-06-02) postdates the '894 priority of 2010-03-11, so on the current record it is likely not §102 prior art against the '894 — which is very likely why the examiner cited it but still allowed the claims. If a US filing/§102(e) date on or before 2010-03-11 can be shown for the Sampath disclosure, this reference becomes the centerpiece of an invalidity case.

Rank 2 — US 2011/0134900 A1 (Liu et al., Marvell, "Frame Padding For Wireless Communications") and its JP counterpart JP 2013-514010 A.
The strongest §102(e) timing candidate (Marvell Dec-2009 priority). Reads on the length/padding core of claims 1/7/13/19/25 and the MCS dependents, but I found no disclosure of CRC bits in the service field, so standalone anticipation of the independent claims is unlikely; it is better used in a §103 combination with a signal-field-CRC reference.

Rank 3 — IEEE 802.11-10/0064 (Liu, "VHT Frame Padding," 2010-01-19) and IEEE 802.11-10/0070 (Zhang, "802.11ac Preamble," 2010-01-18/2010-02-10).
Both are dated before the priority date and are the strongest pure §102(a)/(b) printed publications of record. N2 (r0/r1) bears on the preamble field-ordering limitations; N1 bears on the frame-end/length limitations. Neither, on the passages of record, supplies the service-field CRC element. These are the references I would lead with for an obviousness combination.

Rank 4 — the Toshiba packet-format art (US 2005/0249244 A1; JP 2005-260939 A).
§102(b)-available but generic; weak against the VHT-specific limitations. Useful only as secondary background.

4. Explicit uncertainties and limitations

1. Provenance. I could not, within the search budget, pull the exact "References Cited" list printed on the face of US 10,090,894 B2. The lists above are reconstructed from the shared family citation set (JP2016106464A table; US 11,309,945 and US 9,949,256 front matter). A definitive analysis requires the granted patent's own front page (USPTO PatentCenter / PATENT scope).
2. Filing/§102(e) dates not verified. I could not confirm (search limit) the exact underlying U.S. filing dates for US 2011/0134900 A1 (Marvell), US 2012/0033614 A1 (Qualcomm), or their PCT/provisional parents. My §102(e) assessments for P3, P6 and their counterparts are therefore conditional — the timing is the whole ballgame, especially for the Qualcomm reference, whose apparent mid-2010 priority sits after the '894 priority.
3. §102(c)/(d)/(g) exposure not explored. The applicant's own IEEE submissions (e.g., 802.11-10/0358; Zhang 802.11-10/0070) raise potential §102(a)/(b) and possibly §102(f)/(g) issues only if the 2010-03-11/2010-03-12 Korean priority claims were to fail — a prosecution-history question I have not examined.
4. Non-analogous art. N7–N11 (802.11a/n drafts, aggregation tutorial, MU-MIMO MAC, LTE) are background; I do not rate any of them as anticipation art for the granted claims on their own.

Bottom line: The record's most probative prior art for US 10,090,894 is the Marvell and Qualcomm 802.11ac-draft material — particularly Qualcomm's "VHT-SIG-B and service field format" disclosure (substantively on point but likely too late under §102) and Marvell's "Frame Padding" / "VHT Frame Padding" (timely, but missing the service-field CRC). This reinforces the earlier summary's conclusion that validity exposure runs to 802.11ac-era standard contributions and the applicant's own IEEE submissions, and that the claimed combination is narrow enough that the §102 attack likely turns on precise §102(e)/priority dating of the Qualcomm and Marvell filings rather than on the older Toshiba packet-format art.

If you want, I can (in a follow-up with more search steps) pull the granted patent's literal front-page citation list and the exact U.S. filing dates for US 2011/0134900 A1 and US 2012/0033614 A1 to convert the conditional §102(e) findings above into firm ones.

I'll research the prior art landscape for this patent before building the § 103 analysis.

Let me pull the specific prior-art references cited on the face of this patent and the closely-related Qualcomm VHT-SIG-B/service-field art.

Let me pull the cited-references list and the TGac framework art to nail down dates.

§ 103 Obviousness Analysis — US 10,090,894 B2

"Method and apparatus for transceiving data in a MIMO system" — ETRI; app. 15/486,123; filed 2017‑04‑12; earliest priority 2010‑03‑11.

This builds on the earlier claim/status sections above (all 30 claims untested; no IPR ever filed; 2018–2021 Sol IP campaign). I do not repeat the claim text; I map it to art.

1. The threshold issue that controls the whole § 103 analysis: the date

Before any combination is worth building, one fact dominates. The granted claims are not directed to the generic invention in the abstract — they are directed to the specific 802.11ac VHT PPDU field sequence plus a service‑field CRC. The most on‑point references in the field all sit in a tight window around the asserted priority date:

Sources: patent citations (verified): "Jaewoo Park et al. (ETRI), '802.11ac MAC Frame Length Indication', IEEE 802.11‑10/0358r0, Mar. 16, 2010" and "...10/0358r1, May 18, 2010" (patents.google.com/patent/US10090894B2); IEEE Mentor listing showing 10/0358r0 by Jaewoo Park (ETRI), 16‑Mar‑2010 (mentor.ieee.org/802.11/documents); Qualcomm family priority 2010‑06‑02 (patents.justia.com/patent/8867574; pubchem WO‑2011153335‑A1).

Consequence. If the claims are entitled to the 2010‑03‑11 (or 2010‑03‑12) Korean priority, then the two ETRI submissions and the Qualcomm reference are not § 103 prior art at all — they post‑date the invention. The patent's own six‑application Korean priority chain (2010‑03‑11, 03‑12, 07‑01, 07‑09, 07‑12, 07‑14) is therefore the real battleground: the service‑field‑CRC/VHT‑SIG‑B‑length subject matter that the granted claims recite appears in the specification's FIG. 8/9/12 material, which is the kind of detail typically added by the July 2010 applications, not the March ones.

• If the effective filing date of the granted claims is July 2010, every reference in the table above becomes available (§ 102(a)/(e)‑style art, and note the March 16 ETRI doc is under one year old, so it is § 102(a)‑type rather than § 102(b) art), and the § 103 case below is strong.
• If 2010‑03‑11 holds, the § 103 case collapses to pre‑March‑2010 art, which — as the ETRI KSP status document reflects — had not yet settled VHT‑SIG‑B content ("VHT‑SIG‑B … other than including the MCS field, nothing has been decided"), and the invalidity theory shifts to priority/§ 112 written description rather than § 103.

I flag this because a § 103 opinion that ignores it is worthless. The grounds below are written on the assumption that the reference dates are available (i.e., priority fails or is shifted to July 2010); I state that assumption explicitly.

Governing law: given the 2010 effective filing date and continuation chain, pre‑AIA § 102/103 most likely governs (no claim has an effective filing date on/after 2013‑03‑16); if a claim were held to have such a date, AIA § 102(a)(2)/(b)(2) analysis applies instead. I do not have the prosecution history and do not speculate about it.

2. Person of ordinary skill in the art (POSITA)

A BS in EE/CS plus ~2–3 years designing 802.11 PHY/MAC (OFDM, MIMO/MU‑MIMO, VHT preamble and SIG‑field design), or equivalent; familiar with 802.11a/b/g/n and the then‑current TGac working documents. This is the POSITA the references themselves presuppose; every reference here is a WLAN‑PHY document aimed at that person.

3. Element mapping of independent claim 1

Observation: Qualcomm 8,867,574 maps every element of claim 1 essentially element‑for‑element, including the two limitations that the patent's summary earlier flagged as the narrow point (VHT‑SIG‑B length + service‑field CRC). Claim 1 therefore sits very close to 8,867,574 alone, and squarely within the obvious range of it combined with the TGac Framework and the 802.11ac draft. Claims 7, 13, 19, 25 are the same substance in apparatus/receive/device clothing and rise or fall together.

4. Grounds of rejection

Ground 1 (strongest, if dates are available): Qualcomm 8,867,574 in view of Stacey, IEEE 802.11‑09/0992 ("Specification Framework for TGac")

• 8,867,574 supplies the VHT‑SIG‑B length+tail, the service field with scrambler+CRC, and the field ordering.
• The TGac Framework supplies the standardized VHT preamble order (L‑STF/L‑LTF/L‑SIG/VHT‑SIG‑A/[training]/VHT‑SIG‑B/data) and confirms VHT‑SIG‑B carries per‑user info.
• Motivation: 8,867,574 expressly states its formats "may be in accordance with the IEEE 802.11ac amendment," and the Framework document is the TGac specification being drafted. Same field, same problem, same actors.

Ground 2 (ETRI's own cited art): Park 10/0358r0/r1 in view of 8,867,574 (or in view of 802.11n HT‑SIG)

• Park 10/0358 teaches the core inventive concept the patent claims: indicating MAC frame length in the VHT signal field for MU‑MIMO.
• 8,867,574 (or 802.11n's HT‑SIG, which uses an 8‑bit CRC to protect signal‑field bits) supplies the CRC‑protection of the signal field placed in the service field.
• Motivation: Park identifies the per‑user length‑signaling problem; protecting that length against error with the same CRC‑in‑service‑field mechanism 802.11ac was converging on is an obvious error‑robustness improvement, and 8,867,574 itself frames the service‑field CRC as protecting the VHT‑SIG‑B. Combine with the 802.11n SERVICE field (7‑bit scrambler + 9 reserved) as the known carrier location.

Ground 3: Park 10/0358 in view of Stacey 09/0992 in view of IEEE Std 802.11n

• 802.11n supplies (i) the SERVICE field with 7‑bit scrambler seed, (ii) an HT‑SIG field carrying a 16‑bit MPDU/A‑MPDU length plus 6 tail bits and an 8‑bit CRC, and (iii) the A‑MPDU/null‑delimiter padding framework the patent's FIG. 6/15 reuses.
• Stacey 09/0992 supplies the VHT field layout. Park supplies the per‑user‑length‑in‑VHT‑SIG motivation.
• Rationale: move the 802.11n length‑in‑HT‑SIG + CRC discipline into the VHT‑SIG‑B/service‑field context — a predictable relocation of known signaling to a known new frame.

Ground 4 (secondary art on padding/EOF): the frame‑padding art

• Secondary references on MAC/PHY padding and end‑of‑frame signaling (e.g., the Yong Liu / Marvell family, US 2011/0134900 A1, "Frame Padding For Wireless Communications," which surfaced among related documents) are relevant principally to the specification's padding embodiments (FIG. 6/15/16) and to dependent/embodiment subject matter rather than the granted independent claims, whose focus is the length field and service‑field CRC. Cite them only for the padding/EOF‑flag aspects (spec FIGS. 15–16, 20), and only if timely.

5. Why a POSITA would have been motivated to combine (KSR)

1. Same field and same standard. All primary references are 802.11ac TGac PHY documents; Park, Qualcomm, and Stacey are all TGac participants addressing the same open issue — what to put in VHT‑SIG‑B and the service field. Combination is not cross‑industry hindsight.
2. Same problem, known solution space. The references frame the identical problem (per‑user payload length must be signaled to a user whose stream may be shorter than the longest MU‑MIMO stream) and the identical tools (put length in the per‑user SIG field; protect it with a CRC; carry the CRC in the service field already present in the data portion).
3. Predictable results. Moving a length field into VHT‑SIG‑B and a CRC into reserved bits of the 16‑bit service field yields no unexpected behavior; it is a rearrangement of known fields with a known benefit (robust length signaling + early decode termination / power savings — exactly the benefit the '894 asserts).
4. The standard invited it. The Framework material shows VHT‑SIG‑B content was explicitly unresolved and proposals were being solicited — an express "design need" that supports motivation.
5. The patent's own specification concedes alternatives. The '894 states that per‑user length "may be included in … the dedicated signal field, e.g., a VHT‑SIG field" and that MAC‑layer padding was a known alternative — an admission that these were known options, useful against the claims.

6. Dependent claims (2–6, 8–12, 14–18, 20–24, 26–30)

• "CRC over VHT‑SIG‑B excluding tail bits" (2, 8, 14, 20, 26): Qualcomm's CRC is "for the VHT‑SIG‑B field"; 802.11n's HT‑SIG CRC likewise protects signal bits, not tail. Obvious.
• Common (VHT‑SIG‑A) vs per‑user (VHT‑SIG‑B) split (3, 9, 15, 21, 27) and broadcast vs unicast routing (4, 10, 16, 22, 28): inherent to MU‑MIMO/SDMA as described in 8,867,574 ¶[0057]‑[0059] and the Framework.
• MCS signaled in VHT‑SIG‑A/B (5, 11, 17, 23, 29) and same MCS for service field + data unit (6, 12, 18, 24, 30): 8,867,574 ¶[0061] puts a 4‑bit MCS index in VHT‑SIG‑B; the service field is part of the data portion and therefore shares its MCS — inherent.

These dependents add essentially no independent patentable weight.

7. Weaknesses a challenger must confront (and a Patent Owner will exploit)

1. The date gate (decisive). As shown in § 1, the best references post‑date the 2010‑03‑11 priority. Absent a priority break, Grounds 1–3 fail at the threshold. Under pre‑AIA law, a March 16, 2010 printed publication cannot be § 102(a)/(b) art against a March 11, 2010 invention, and Qualcomm's June 2, 2010 provisional is after the invention date, so it is not § 102(e) art either. The realistic path is priority/§ 112, not § 103 — i.e., show the granted claims' VHT‑SIG‑B‑length‑plus‑service‑field‑CRC subject matter is unsupported by the March 11/12 Korean applications so the effective date moves to July 2010, then run the combinations above.
2. Inventor‑own‑work exception. Park 10/0358 is ETRI's own submission; under AIA § 102(b)(1)(A) a timely inventor disclosure is not prior art, so if the priority is broken only slightly, the applicant may still remove Park as art (but that would not remove Qualcomm, which is by another).
3. Claim specificity. The Patent Owner will argue the granted claims require the ordered VHT‑SIG‑A → training → VHT‑SIG‑B → service → data sequence plus length‑in‑VHT‑SIG‑B plus service‑field CRC as a combination, and will attack any ground that shows these only separately. Qualcomm 8,867,574 largely answers this; Park‑based grounds must be coupled with a service‑field‑CRC reference to meet all three.
4. Reference qualification. Confirm each reference's public‑accessibility date (Mentor.ieee.org posting vs. meeting date) and, for Qualcomm, which document (provisional vs. publication) is being relied on and whether its filing/priority date actually precedes the operative effective filing date.

8. Bottom line

• On the art alone: the granted claims are highly vulnerable under § 103 to Qualcomm US 8,867,574 (Van Nee et al.) in view of the TGac Framework (Stacey 09/0992) and the 802.11ac draft, and secondarily to Park IEEE 802.11‑10/0358r0/r1 in view of 8,867,574 / 802.11n. Qualcomm essentially discloses the VHT‑SIG‑B length (with tail bits) and a service‑field CRC for that signal field, so the independent claims are close to the art even without combination; the dependents add nothing.
• The gating question is the date. All of this presupposes the claims are not entitled to the March 2010 Korean priority. If they are, the § 103 case largely evaporates and the attack should be reframed as a priority/§ 112 written‑description challenge (the specific service‑field‑CRC/VHT‑SIG‑B‑length content traces to the July 2010 applications). That, not § 103, is the hinge.
• Caveats: I have not reviewed the prosecution history or the six Korean priority documents themselves, so I cannot state which claims are (or are not) supported by March 2010. The reference dates above are as published/reported by the sources cited; anyone building a petition should verify the operative divulging date of each reference against the operative effective filing date before finalizing.