US 11825558

I'll verify against live sources before summarizing.

Verdict on the searches

I could not find any CAFC 2026 docket or USPTO PTAB/IPR proceeding naming U.S. Patent No. 11,825,558 specifically. What I did find is a dense set of E.D. Tex. and UPC litigation involving Wilus Institute of Standards and Technology over sibling Wi‑Fi 6 EDCA/Wi‑Fi patents (e.g., U.S. 11,116,035, 10,313,077, 10,687,281, 11,470,595, 11,159,210), plus a Google Patents "Family has litigation" flag on the '558 family (Darts‑IP family 61562552). No litigation hit was tied to the number 11,825,558 itself. Everything below treats the number literally and flags where I am inferring.

1. Bibliographic data (US 11,825,558 B2)

Abstract: the authoritative text I was given does not include the printed abstract, and I did not retrieve a verbatim copy from a primary source, so I am not quoting one. The inventive summary is the "Definitions"/object statement in the specification: "An object of an embodiment of the present invention is to provide a wireless communication method using enhanced distributed channel access and a wireless communication terminal using the same," implemented via a transceiver + processor that switches between a general ("first") EDCA parameter set and an MU ("second") EDCA parameter set based on whether the base terminal triggers the terminal's multi‑user uplink participation. Treat that as a faithful paraphrase, not the literal abstract.

2. What the patent is about

The '558 disclosure is IEEE 802.11ax (HE / Wi‑Fi 6) uplink‑OFDMA channel‑access behavior. Under EDCA, a station picks a random backoff within a contention window and waits an AIFS before transmitting, the CWmin/CWmax/AIFS being set per access category (AC). When an AP schedules a station for UL MU (trigger‑based) transmission, that station is expected to defer, so the spec defines a separate, deliberately less aggressive MU EDCA parameter set. The patent family addresses: when to switch into the MU parameter set, when to switch back out (the "second parameter set timer" / MU EDCA timer), what to do with the backoff timer and CW value at the switch, and what an EDCA queue should do when its backoff timer hits 0 with an empty queue.

3. Plain‑language overview of the independent claims

⚠️ Flag first: the authoritative text supplied to me contains the specification, figures list and the "Definitions" claim‑summary block, but the numbered claim set of 11,825,558 was truncated. The overview below is built from the '558 specification's own claim‑summary language. Live search results reproduce claim language that matches it almost verbatim from U.S. 11,116,035 (a sibling Wilus Wi‑Fi 6 EDCA patent, whose claims 1 and 8 were quoted in the Wilus v. HP joint claim construction chart, E.D. Tex. 2:24‑cv‑00752, Dkt. 195‑1, and in PTAB petition materials). I therefore present the independent claims as an apparatus claim (appearing as claim 1) and a mirror‑image method claim (appearing as claim 8), and label the numbering as inferred rather than verified for '558.

Independent apparatus claim (inferred: claim 1) — "wireless communication terminal"

• A terminal (transceiver + processor) that accesses a channel according to the priority of data it wants to send to a base wireless communication terminal (i.e., ordinary EDCA contention).
• The processor switches the parameter set used for channel access from a first parameter set to a second parameter set based on whether the base terminal triggers the terminal's multi‑user uplink transmission participation (i.e., whether the AP schedules it for UL MU; practically, whether a trigger frame addresses it).
• It transmits a trigger‑based PPDU to the base terminal, and sets a second parameter set timer depending on whether an immediate response to an MPDU in that trigger‑based PPDU is received.
• When the MPDU does not request an immediate response, the timer is set when transmission of the trigger‑based PPDU ends; when the MPDU does request an immediate response, the timer is set for the access category of the MPDU for which the response is received.
• When the second parameter set timer expires, the application of the second parameter set is terminated (fall back to normal EDCA).

Independent method claim (inferred: claim 8) — "operation method of a wireless communication terminal"
The method counterpart: receive a trigger frame (in the family version, one that triggers OFDMA uplink), transmit the trigger‑based PPDU, switch the parameter set from first to second based on whether the base terminal triggers MU uplink participation, set the second parameter set timer per the immediate‑response rule above, terminate the second parameter set when the timer expires, access the channel per data priority and the parameter set, and transmit the data.

Dependent‑claim subject matter (from the '558 claim summary): MPDU is a QoS data frame; obtaining the timer period from a beacon frame; parameter set comprising CWmin and CWmax; random integer in the CW → backoff timer → channel access based on backoff timer and slot time; capping CW at CWmax; multiple EDCA queues per access category, with no operation at a slot boundary when the queue is empty and its backoff timer is 0 (with variants: maintaining the backoff timer at 0, re‑drawing a backoff while preserving other EDCAF state, or re‑initializing the EDCAF).

4. Litigation / docket posture (as found, not as asserted by me)

• Google Patents applies a "Family has litigation" flag with a Darts‑IP link (family 61562552) — i.e., the family is litigated, but the flag is not a per‑patent assertion of '558.
• Wilus litigation activity I found in E.D. Tex. involves different patent numbers: 10,313,077 / 10,687,281 / 11,470,595 / 11,159,210 (vs. Samsung, 2:24‑cv‑00752) and the '035 patent, U.S. 11,116,035 (vs. HP/Askey, 2:24‑cv‑00752‑JRG), including a Feb.–June 2026 permanent‑injunction and partial‑final‑judgment fight and a Feb./Mar. 2026 meet‑and‑confer record.
• UPC Mannheim proceedings (UPC_CFI_1152/2025, UPC_CFI_452/2025) name Wilus against ASUSTeK/ASUS entities and Ninepoint GmbH, over e.g. EP 3 849 157.
• A Unified Patents post (dated Sept. 8, 2026 in the retrieved result — note this is after the April 26, 2026 date you gave me, so treat the date with caution) concerns a different Wilus patent, U.S. 12,150,105, not '558.
• No CAFC 2026 appeal docket and no PTAB/IPR naming 11,825,558 was located.

5. Explicit uncertainties

1. Verbatim claim set of 11,825,558 — not retrieved. Claim numbering (1 = apparatus, 8 = method) is inferred from the identical claim language in U.S. 11,116,035 as reproduced in E.D. Tex. briefing; the actual '558 numbering could differ.
2. Verbatim abstract — not retrieved from a primary source; not quoted.
3. Assignee — Google warns its assignee list may be inaccurate; the record shows SK Telecom as original assignee with subsequent Wilus assignments/license and a 2025 corrective assignment (agreement date corrected from Nov. 1, 2022 to Aug. 31, 2020). "Current assignee = Wilus" is the listed status, not a legal conclusion.
4. Priority date 2016‑09‑07 is Google's own labeled assumption; I did not verify the underlying §119/§120 chain (the application is plainly a later continuation‑type filing given the 2022 filing date).
5. I found no litigation or CAFC proceeding that specifically names 11,825,558; absence in these searches is not proof that none exists.

I'll search for litigation involving US patent 11825558 across patent litigation databases and court records.

Let me search more specifically for the patent owner's litigation activity.

Let me search directly for the patent number as it would appear in litigation filings and databases.

Bottom line

I could not identify any litigation — district court, Federal Circuit/CAFC, ITC, PTAB, or UPC — in which U.S. Patent No. 11,825,558 ("Wireless communication method using enhanced distributed channel access, and wireless communication terminal using same") is specifically named as an asserted, challenged, or otherwise litigated patent.

Every search I ran for the literal number (11825558, 11,825,558, US11825558B2) returned patent-document pages (Google Patents, PubChem patent record, Golden wiki), not docket entries, complaints, IPR petitions, or case lists. The instruction "do not return results for similar numbers" matters here: many of the hits I got were for other patents in the same Wilus/SK Telecom Wi-Fi 6 family (e.g., the European application 17 824 568.4, Japanese 2020-125358/125359), which are different instruments and not evidence of '558 litigation.

So: no known litigation involving US 11,825,558 on the record available to me. I want to be explicit that this is a negative finding, not a certification — see the caveats at the end.

Important context: the patent's owner is litigious, but on other patents

US 11,825,558 is owned by Wilus Institute of Standards and Technology Inc. (originally assigned to SK Telecom Co., Ltd. and Wilus; priority date 2016-09-07; app. 17/979,767; granted 2023-11-21). Wilus is a licensor in the Sisvel Wi-Fi 6 (802.11ax) patent pool and has run an active multi-front enforcement campaign since 2024. That campaign appears to have been waged on sibling/related patents, not on '558. Unity of family does not equal assertion, and I found no pleading, claim chart, or docket that maps '558 into any of these suits.

Wilus enforcement matters I did find (none assert '558)

Non-litigation challenges (PTAB/CRU) — also not '558:

• Unified Patents ex parte reexamination of US 12,166,587 — request granted by CRU 26 Feb. 2026.
• Unified Patents ex parte reexamination of US 10,651,992 — filed 24 Jul. 2026.
• Samsung IPRs against a dozen Wilus asserted patents (referenced in Wilus's discretionary-denial briefing); none identified as directed to '558.

Caveats on this negative finding

1. Search-tool limitation. My results came from open web indexing. I was not able to query the RPX/Unified Patents litigation portals, PACER, or Darts-IP directly with the literal string for '558 before exhausting my search budget. A Darts-IP "Global patent litigation dataset" link appears on the Google Patents page for '558 (family 61562552), which is a family-level litigation indicator, not proof that '558 itself is asserted.
2. Complaints often assert a subset of a portfolio. Wilus's complaints typically list several patents; '558 could plausibly be added to a future suit (or an existing one) without my having captured the amended pleading.
3. Date discrepancy. The user message states the current date as 26 April 2026, but my search results include items dated well after that (e.g., the 24 Jul. 2026 Unified reexamination request, the 24 Aug. 2026 TP-Link complaint, May 2026 UPC orders). I have reported those items with their stated dates rather than suppressing them, but you should treat any post-April-2026 item as potentially outside the intended knowledge cutoff.
4. Do not treat this as legal clearance. If you need a definitive litigation-clearance statement for '558, the reliable route is a Darts-IP / RPX / Lex Machina search on the exact patent number plus a PACER and PTAB (P-TACTS) docket search, which I could not fully execute here.

If you can authorize a further round of targeted searching (or provide a Darts-IP/RPX export), I can try to close the remaining gap — specifically whether '558 has been asserted in any amended Wilus pleading or in the E.U./U.K. parallel actions against ASUS and others.

I'll verify the ODP default against public sources before drafting.

The Wilus/Samsung IPRs surfaced are on different patents. Let me check directly whether the '558 patent itself has any proceeding.

Let me run a final targeted check to make sure no '558-specific petition exists.

AIA Trial Proceedings — US 11,825,558 B2

Verification note: I checked the structured ODP block (canonical, per your instruction) and ran four independent web searches targeting the patent number directly ("11,825,558" combined with IPR/PGR/Samsung/HP/Askey/Wilus), plus searches of the broader Wilus PTAB campaign. No petition, institution decision, FWD, or appeal naming U.S. Patent No. 11,825,558 was found. Candidly: my search is not a substitute for a PTAB E2E / Docket Navigator party-and-patent query, and a very recently filed 2026 petition not yet indexed would not surface. But for the practice purposes below, the working assumption is zero AIA trials on the '558 patent.

Proceedings overview

Total AIA trial proceedings on US 11,825,558: 0 — 0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution-denied. Bottom line for a defendant: there is no PTAB record to lean on and no estoppel to exploit — the patent is untested, not hardened. That cuts both ways: no claim has been canceled, but equally, no petitioner has spent the money to take a shot, and every invalidity ground is still on the table for whoever files first.

{No proceedings to enumerate}

Because there is no proceeding, I am deliberately not generating the per-proceeding template headings — filling in petitioner names, panels, or ground tables would require fabrication. The only accurate entry is:

• Proceedings naming the '558 patent: none on file per ODP; none found via public search as of 2026-09-28.

Why the absence is not evidence the patent is strong

This is the most important analytical point, and it is a trap for the unwary defendant.

1. The '558 patent does not appear to be in Wilus's asserted set. The Wilus Institute of Standards and Technology v. HP/Samsung/Askey EDTX campaign (lead case No. 2:24-cv-00752-JRG-RSP, Judge Rodney Gilstrap) asserts a defined group of Wi-Fi 6 patents. Samsung's own filing identifies the IPR'd patents as U.S. Patent Nos. 10,313,077; 10,687,281; 11,470,595; 11,159,210; 11,116,035; 11,516,879; 11,700,597; and 11,129,163. The January 2025 cases (No. 2:25-cv-00069-JRG-RSP) add U.S. Patent No. 11,664,926. 11,825,558 appears in none of those lists — only in an evidence exhibit ("Excerpts from U.S. Patent No. 10,911,186") that happens to sit alongside it in the record.

Samsung sues (or IPRs) what Wilus asserts. No assertion → no IPR is the expected equilibrium, not proof of validity.

2. The '558 patent is squarely in the family that is under coordinated attack. Per the '558 specification, the patented subject matter is the MU EDCA parameter set, the MU EDCA timer, and the trigger-based PPDU / M-BA immediate-response machinery (the FIG. 14 option1/option2 timer embodiments). That is the same disclosure family as the '035 and '879 patents, whose claims recite verbatim: "when a MAC protocol data unit (MPDU) included in the trigger-based PPDU does not request an immediate response, set a second parameter set timer for an access category of the MPDU when the transmission of the trigger-based PPDU ends…" — quoted in the EDTX Markman briefing at cases.justia.com (2:24-cv-00752, Dkt. 212). Those two sibling patents have both been instituted for trial (IPR2025-01043 → US 11,116,035, filed 2025-05-29, instituted 2025-11-07; IPR2025-01044 → US 11,516,879, filed 2025-05-29, instituted 2025-11-07, per Samsung's Notice of Institution of IPR Petitions, Dkt. 224, filed 2026-02-10). If those petitions succeed, the same prior art is very likely to map onto '558's claims — meaning the family is under fire even though this particular continuation is not.

3. Family posture. '558 was filed 2022-11-03 as US 17/979,767, granted 2023-11-21, priority date 2016-09-07, current assignee Wilus Institute of Standards and Technology Inc. (exclusive license from SK Telecom Co., Ltd.; original assignee SK Telecom + Wilus). Anticipated expiration: 2037-09-07 — a long tail for assertion. Related continuations include US 18/384,678 (→ US 12,193,116 B2) and US 19/010,192 (→ US 2025/0133631 A1), i.e., Wilus is still building prosecution runway on top of this disclosure.

Cross-proceeding context: the Wilus Wi-Fi 6 family (NOT proceedings on '558)

These are provided only as landscape for your § 315(e)(2) and prior-art planning. None of them estops anyone as to '558. Dates are as recited in Samsung's Dkt. 224 exhibit table (a party filing, so verify against PTAB E2E before relying).

Pattern signals observed:

• Same petitioner, mass-filed: Samsung Electronics Co., Ltd. is the petitioner across the family, filing ~May–June 2025 with Fish & Richardson as counsel. Art is Wi-Fi/802.11ax-based obviousness (e.g., Josiam, Bharadwaj, Chu, Zhang-810 referenced in the briefing).
• Patent owner fights hard at the threshold: Wilus (Russ August & Kabat: Reza Mirzaie, Neil A. Rubin, Philip X. Wang, Linjun Xu) filed POPRs, per-patent requests for discretionary denial under Fintiv and § 325(d), and requested Director Review of every institution grant. Those Director Review requests were denied on 2026-02-04 (IPR2025-00934/0935/0936/01043/01044/01069, Paper 20; cited as an exhibit in IPR2026-00105).
• No defensive aggregator in the chain. I found no Unified Patents, RPX, or similar non-practicing challenger. All '558-family challenges trace to commercial defendants (Samsung primarily; Wilus also faces Askey and HP in EDTX, and parallel FRAND litigation in Germany/UPC, e.g., Wilus v. Asus, LG München I, 7 O 5007/25).
• No FWDs yet on any family patent, so there is no claim-cancellation precedent anywhere in this family to cite.

Strategic summary

Claims status on '558: entirely UNTESTED. No claim — independent or dependent — has been canceled, confirmed, or construed in an AIA proceeding. There is no FWD to quote and no certificate of cancellation. If a demand letter from Wilus cites '558, you cannot answer it with "those claims are already dead." You can, however, note that the identical disclosure is being tried before the Board in IPR2025-01043 and IPR2025-01044, and that a stay or a wait-and-see posture may be rational if your accused products overlap with the Wi-Fi 6 EDCA trigger/MU-EDCA timer features.

Estoppel landscape: essentially wide open. Because no IPR/PGR on '558 has reached a final written decision, § 315(e)(2) estoppel does not attach as to '558 by anyone — not against Samsung, not against HP, Askey, or their privies. Every prior-art ground remains available: printed publications under § 102(a)(1)/(a)(2), patents, 802.11ax/TGax submissions and meeting minutes, and — critically — system prior art and public-use evidence that cannot be raised in an IPR at all (that is exactly the gap the petitioners exploited in the Caltech/Apple line). If you are a defendant on '558, the practical consequence is inverted from the usual: you are not boxed in by someone else's petition, and you should be careful not to assume the family's estoppel applies to you. Conversely, if you file first and lose at FWD, you personally forfeit the § 102/§ 103 printed-publication grounds you raised or reasonably could have raised.

Timing and validity leverage. The family's instituted trials carry statutory FWD deadlines roughly one year from institution — i.e., late 2026 into 2027 for the November 2025 and February 2026 institutions. If a family FWD cancels or narrows the '035/'879 MU-EDCA-timer claims, expect that result to be leveraged immediately in any '558 negotiation, and expect Wilus to distinguish on continuation-specific claim language. Watch the EDTX stay fight (Samsung's Dkt. 176 motion, updated by Dkt. 224) as a leading indicator of how Judge Gilstrap treats this campaign.

Recommended next steps

1. Run the authoritative check before committing. Query PTAB E2E (https://ptab.uspto.gov) and Docket Navigator / Docket Alarm by patent number 11,825,558 — not by party. A party-level query on "Wilus" returns dozens of results across the family and will mask the fact that '558 is absent. This is the single highest-value five-minute task here.
2. If you are a defendant: there is no FWD to quote and no canceled claim to weaponize. Your invalidity case is unconstrained by estoppel, so build it on the full prior-art universe — including § 102(a)(1) "known or used" and public-use/system art that no IPR petitioner can reach. Pull the file histories of the sibling patents now in trial (IPR2025-01043, IPR2025-01044) and monitor them; their expert declarations (e.g., Dr. R. Michael Buehrer's work for Samsung, referenced at IPR2025-00988) are a ready-made roadmap.
3. If you are evaluating a license: the '558 patent runs to 2037-09-07, so its term is the tail of the portfolio. Price it against the family's litigation and IPR risk, not against its standalone merits.
4. If no proceeding appears after a proper PTAB E2E query: report that plainly. The absence is a signal about assertion strategy, not patent strength — the patent is an unasserted continuation whose twins are already at the Board. Say so; do not let the absence be read as a clean bill of health.

Sources consulted:

• USPTO Open Data Portal "PTAB proceedings on file" block (canonical; zero proceedings returned)
• PTAB petition files at ptacts.uspto.gov (Samsung v. Wilus family petitions, IPR2025-00988, -01110, -01165 etc.)
• Wilus Institute of Standards and Technology Inc. v. HP Inc., E.D. Tex. 2:24-cv-00752 — https://www.courtlistener.com/docket/69161107/wilus-institute-of-standards-and-technology-inc-v-hp-inc/ (Dkt. 176 stay motion; Dkt. 212 Markman; Dkt. 224 Notice of Institution of IPR Petitions, filed 2026-02-10)
• Samsung's IPR status table, Ex. filed at 2:24-cv-00752 Dkt. 303

Confidence: High that no indexed proceeding exists; moderate-to-high overall given the targeted searches. Any conclusion here should be refreshed against PTAB E2E immediately before it is relied on in a filing.

I'll reconstruct this chain from primary sources. Let me pull the assignment records, litigation, and entity background.

Ownership & Assignment Reconstruction — US 11,825,558 B2

Patent: US 11,825,558 B2 — Wireless communication method using enhanced distributed channel access, and wireless communication terminal using same
App.: 17/979,767 (filed 2022-11-03) · Pub.: US 2023/0055982 A1 · Granted: 2023-11-21 · Earliest priority: 2016-09-07 · Anticipated expiry: 2037-09-07
Google Patents legal-events flag: "Family has litigation" (Darts-IP family 61562552)

Source-access note (read first): The USPTO Assignment Center was not directly queryable in this session. Reel/frame values below are those that appear verbatim in litigation exhibits that reproduce the USPTO Patent Assignment Cover Sheets, plus the reel/frame expressly cited inside the corrective-assignment record text on Google Patents. Where a reel/frame was not recoverable, I say so rather than supply a number. No assignment is asserted here that is not traceable to a recorded document.

Inventors

Pattern assessment — no fire-sale precursor. The classic warning sign (all inventors leaving the original assignee within 12 months of filing) is not present. All four inventors are Wilus personnel, and the lead inventor is still Wilus's CEO and its declarant in 2025 PTAB proceedings. The unusual feature is the opposite: the inventors' employer was only one of two named assignees at filing, with SK Telecom Co., Ltd. named alongside Wilus as original assignee (Google Patents "Original Assignee" data). Samsung's pleadings confirm Wilus's IEEE delegates "are listed as inventors on these patent applications," i.e., inventive activity is Wilus-side, while SK Telecom's interest appears to arise from a commercial/portfolio arrangement rather than from employment of the inventors — consistent with the exclusive-license-then-assignment sequence documented below.

Original assignee

SK Telecom Co., Ltd. (KR) and Wilus Institute of Standards and Technology Inc. (KR), jointly — per the issued patent's front-page assignee data.

• SK Telecom Co., Ltd. — KRX-listed mobile carrier (operating). Its products/network services implement Wi-Fi, but SK Telecom is not a Wi-Fi silicon or handset vendor; it is a standards contributor and SEP holder (named in Sisvel's Wi-Fi pool as a licensor, alongside Wilus). Status: operating.
• Wilus Institute of Standards and Technology Inc. — South Korean R&D lab founded 2012, based at 5F 216 Hwangsaerul-ro, Bundang-gu, Seongnam-si, Gyeonggi-do. Per CEO Kwak's sworn declaration: "a leading independent R&D lab… over 700 technical contributions" to 3GPP, IEEE 802.11 and MPEG; a portfolio of "more than 3,500 patents across 9 SEP portfolios"; licensing "through participation in market-leading patent pools." Wilus's stated business is R&D plus patent licensing — it does not ship products embodying the claims. Status: operating as a licensing/assertion entity. Unified Patents describes Wilus as "an entity of Good Day to Invent, Inc." (group-structure reference; I did not independently verify the Korean corporate registry).

Current assignee of record: Wilus Institute of Standards and Technology Inc., sole. (Google Patents current-assignee field, consistent with the 2024 SK Telecom→Wilus assignment.)

Assignment timeline

Records below are ordered by recording date. Reel/frame is given only where evidenced; two entries are recorded events whose reel/frame I could not retrieve.

1. 2022-12-18 (recorded) — Reel 062152/0001

• Conveyance: License (recorded as "LICENSE (SEE DOCUMENT FOR DETAILS)"; the underlying instrument is an Exclusive License, per the later corrective assignment)
• Assignor: SK TELECOM CO., LTD.
• Assignee: WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.
• Correspondent: Not recovered.
• Context: Internal/commercial portfolio restructuring — SK Telecom grants Wilus an exclusive licence over the jointly-filed Wi-Fi 6 family; agreement date later corrected to 2020-08-31, i.e. the arrangement predates this continuation's 2022-11-03 filing.
• Reel/frame basis: the 2025-02-26 corrective assignment states the document was "PREVIOUSLY RECORDED ON REEL 62152 FRAME 1." This is the only SKT→Wilus recording in the pre-2024 record, so the citation maps to this entry. Treat the mapping as a high-confidence inference, not a verbatim read of the cover sheet.

2. 2023-09-06 (recorded) — reel/frame not retrieved

• Conveyance: Assignment of assignors' interest ("ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)")
• Assignors: AHN, Woojin; KO, Geonjung; KWAK, Jinsam; SON, Juhyung
• Assignees: WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC. and SK TELECOM CO., LTD.
• Correspondent: Not recovered.
• Context: Confirmatory/late-recorded inventor→company assignment executed at or around filing, blanket-writing the four inventors' rights to the two co-applicants. Note this was recorded after the 2023-11-21 grant, i.e. after the 2022 licence recording — an ordering worth noting because the assignment chain and the licence chain run in opposite directions in time.

3. 2024-06-20 (recorded), executed 2024-05-27 — Reel 067790/0700

• Conveyance: Assignment (Patent Assignment Cover Sheet)
• Assignor: SK TELECOM CO., LTD. (execution date 05/27/2024 as printed on the cover sheet)
• Assignee: WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC. (address block on the cover sheet: Seongnam-si, Gyeonggi-do, KR)
• Correspondent: Not recovered from the text I could access. The cover sheet as reproduced in litigation carries a USPTO customer number ("508611892") in the signature/customer block; the attorney or firm name is not visible in the available extract. Do not treat Wilus's litigation counsel (Russ August & Kabat; Bird & Bird; Ampersand) as the assignment correspondent — these are separate roles and I have no evidence linking them to the recording.
• Context: Title consolidation / transfer-to-licensing-entity. This is the operative event that made Wilus sole owner of the patent and extinguished the operating co-owner (SKT). It was produced in litigation as Exhibit C to the Hoffman Declaration supporting Wilus's opposition to Samsung's motion to dismiss for lack of statutory standing — i.e. the assignment exists in the record specifically to prove Wilus's standing to sue.
• Basis: E.D. Tex. document text reproducing the cover sheet with "REEL: 067790 FRAME: 0700"; Hoffman Decl. ¶5 ("a true and correct copy of the June 20, 2024 Patent Assignment Cover Sheet… at Reel 067790"). The '558 patent's identifiers (17/979767 · 20230055982 · 11825558) also appear in a Wilus v. HP exhibit alongside the same reel, indicating this patent is within the conveyed schedule.

4. 2025-02-26 (recorded) — reel/frame not retrieved (it is the corrective instrument; its own reel is not printed in the legal-events text)

• Conveyance: Correction — "CORRECTIVE ASSIGNMENT TO CORRECT THE AGREEMENT DATE OF THE EXCLUSIVE LICENSE NOVEMBER 1, 2022 WRITTEN IN THE RECORDED AGREEMENT SHOULD BE CORRECTED TO AUGUST 31, 2020. PREVIOUSLY RECORDED ON REEL 62152 FRAME 1."
• Assignor: SK TELECOM CO., LTD.
• Assignee: WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.
• Correspondent: Not recovered.
• Context: Administrative cleanup of the 2022 licence recording (see entry 1). Harmless on its face; relevant analytically because it shows SKT's exclusive licence to Wilus was in place from 2020-08-31, well before this application was filed.

If the Assignment Center shows no further entries beyond these four, that is itself the finding: the chain terminates at Wilus Institute of Standards and Technology Inc. as sole owner, with no downstream defensive aggregator and no further shell hop.

Timeline diagram

timeline
    title Ownership of US 11825558
    2012 : Wilus founded as South Korean R and D lab
    2016 : Earliest priority filing for the family
    2020 : SKT grants Wilus exclusive license
    2022 : Continuation application filed
         : Exclusive license recorded to Wilus
         : Application published as US 20230055982
    2023 : Inventor assignments recorded
         : Patent US 11825558 granted
    2024 : SKT executes assignment of its interest
         : Assignment recorded at reel 067790
         : Wilus files HP suit in East Texas
    2025 : Corrective assignment recorded by SKT
         : Wilus sues Samsung in East Texas
    2026 : Samsung settles via Sisvel pool license

NPE / troll-pattern signals

1. Shell-entity transfer — Present, in non-standard form.
The patent did move out of sole operating-company control: the 2024-05-27/2024-06-20 assignment (reel 067790/0700) transferred SK Telecom's interest to Wilus, leaving a licensing-only assignee that ships no products. However, the classic shell tells are absent: Wilus is not a Delaware or Texas single-member LLC, is not at a registered-agent service address (it gives a real Seongnam-si office), has operated continuously since 2012, employs the named inventors, and files to standards bodies. This is a licensing specialist, not a vacant shell. Also note the direction of travel: Wilus was a co-original-assignee from filing, so this is consolidation of a joint portfolio — not a mid-life dump into a newly formed vehicle.

2. Known asserter in the chain — Present.
Wilus Institute of Standards and Technology Inc. is not on the legacy NPE lists you supplied (Acacia, Marathon, IV, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Round Rock, etc.), but it is tracked as a high-frequency asserting entity by Unified Patents, which maintains a dedicated district-court litigation page for Wilus and has filed ex parte reexamination requests against its patents (e.g. U.S. 10,931,396, request 90015488, granted 2025-10-14). Wilus's enforcement record includes E.D. Tex. actions against HP (2:24-cv-00752) and Samsung (2024 and a 2025-01-23 complaint), plus Askey and ASUS (Munich Regional Court 2025-04-16 and UPC Mannheim 2025-06-19). Wilus's CEO declaration in IPR2025-00988 quantifies the model: ~3,500 patents across 9 SEP portfolios, "hundreds of licenses," pre-suit licensing letters to Samsung dated 2022-04-08 and 2023-01-18. That is a litigation-backed licensing programme, not incidental enforcement.

3. Repeat correspondent across the chain — Unclear / data gap.
I could not recover the named correspondent on any of the four recordings, including reel 067790/0700. This is the single most important missing data point for your purpose. What is visible on the reel 067790 cover sheet is the assignee address block and a USPTO customer number (508611892), with no attorney name in the accessible extract. I will not name a correspondent without the record. Action item: pull reel 062152/0001, 067790/0700, and the 2023 and 2025 recordings from Assignment Center and compare the correspondent field across the SKT–Wilus family (US 10,313,077; 10,687,281; 11,470,595; 11,159,210; 11,129,163; 11,700,597; 11,116,035; 11,516,879; 11,664,926; 10,931,396) — if one firm name recurs across all of them, that recurrence is the finding, and it is the one signal here I cannot yet grade.

4. Cascading transfers — Not present as defined.
There are three SKT→Wilus recordings in ~26 months (2022-12-18 licence, 2024-06-20 assignment, 2025-02-26 correction), but they run between the same two counterparties and do not chain through successive LLCs; there is no shared-correspondent-address pattern to detect, and no evanescent intermediary. Churn, yes; cascading shell ladder, no.

5. Pre-litigation transfer — Present (moderate).
The assignment conveying SKT's interest was executed 2024-05-27 and recorded 2024-06-20, immediately preceding Wilus's 2024–2025 enforcement campaigns (HP, E.D. Tex. 2:24-cv-00752; Samsung, incl. the 2025-01-23 complaint). The cover sheet was then deployed as Exhibit C to Wilus's opposition to Samsung's motion to dismiss for lack of statutory standing — the textbook use of a freshly recorded assignment to manufacture a clean standing record. Caveat: I could not confirm that US 11,825,558 itself has been asserted in any complaint. Its appearance in Wilus v. HP exhibits relates to the assignment schedule, not to an infringement claim chart. Do not report the '558 patent as asserted without checking the complaints directly.

6. Bankruptcy fire-sale — Not present.
No Chapter 7/11, no trustee sale, no judicial auction. SK Telecom is a going concern; Wilus has been continuously operating since 2012. The SKT→Wilus transfer is a negotiated portfolio disposition, not a distress sale.

7. Privateering — Unclear.
Directionally tempting but not cleanly supported. SK Telecom is a Korean carrier and a direct competitor of Samsung, and it transferred its interest in this Wi-Fi 6 family to Wilus, which then sued Samsung, HP, ASUS and Askey. That is the privateering shape. But SK Telecom is itself a named licensor in the Sisvel Wi-Fi 6 / Wi-Fi Multimode pools alongside Wilus, and the two have co-filed this portfolio from the start — so SKT is monetising in its own name too, which undercuts the "operating company hiding behind a proxy" reading. Grade as unclear pending evidence of a licence-back or revenue-share term in the 2024 assignment.

8. Defensive aggregator — Not present.
The chain does not terminate at RPX, AST, LOT, Unified Patents or OIN. To the contrary, Unified Patents is the challenger of Wilus patents. Sector-side resolution came through a licensing pool (Sisvel), not a defensive aggregation — Samsung simultaneously took a Sisvel Wi-Fi Multimode licence and became a pool licensor, resolving the E.D. Tex. Wilus–Samsung litigation (announced 2026-07-14).

Verdict

NPE — high confidence.

Two strong signals converge on the same entity. First, the chain terminates in a licensing-only assignee with no products: the 2024-05-27 execution / 2024-06-20 recording at reel 067790/0700 moved SK Telecom's interest to Wilus Institute of Standards and Technology Inc., which is now sole owner of a patent it does not practise. Second, Wilus is a recognised high-frequency asserter — tracked by Unified Patents, which has petitioned for reexamination of its patents (90015488, granted 2025-10-14), with E.D. Tex. campaigns against HP (2:24-cv-00752), Samsung, Askey and ASUS, and a stated portfolio of ~3,500 SEPs licensed through pools and litigation. A third, weaker signal supports it: the assignment was executed within months of the 2024 enforcement wave and was filed as a standing exhibit against Samsung's statutory-standing motion.

Two important qualifications. (a) This is a SEP-licensing NPE, not a shell mill — Wilus is a genuine, 14-year-old R&D lab with 700+ standards contributions, the inventors on payroll, and FRAND commitments; the "troll" label is contestable even though the NPE taxonomy fits. (b) The chain has no cascading LLC hops and no bankruptcy element, and the correspondent field — the strongest available tell — could not be recovered, so my confidence rests on the assignee's business model and litigation profile rather than on the recording-pattern forensics you asked me to prioritise.

Verify at: https://assignmentcenter.uspto.gov/ (search by patent 11,825,558 or application 17/979,767) · mirror: https://assignment.uspto.gov/patent/index.html · patent record: https://patents.google.com/patent/US11825558/en · litigation/assertion profile: https://www.unifiedpatents.com/insights/2025/10/15/another-wilus-wi-fi-patent-challenge-instituted

Two data gaps worth closing before this memo is relied on: (1) correspondent of record on reels 062152/0001 and 067790/0700 and on the 2023 and 2025 recordings; (2) confirmation of whether the '558 patent appears as an asserted patent in any Wilus complaint, as distinct from appearing in an assignment exhibit.

I'll search USPTO and related sources for the specific patent number 11825558 and its cited references.

Let me pull the specific citation lists for 11,825,558 from patent databases.

Prior-Art Analysis — U.S. Patent No. 11,825,558

0. Two corrections/updates to the previously generated sections

(a) The abstract is now retrieved. The earlier section said the printed abstract was not available. A secondary record (Golden wiki mirror of the patent) reproduces it, and it matches the specification's "Definitions" object statement verbatim-ish, including the OCR-duplicated phrase:

"Provided is a wireless communication terminal that communicates wirelessly. The wireless communication terminal includes a transceiver and a processor for processing a radio signal received through the transceiver or a radio signal to be transmitted through the transceiver. The processor accesses a channel according to according to a priority of data to be transmitted to the base communication terminal by the wireless communication terminal."

I flag the duplicated "according to" because it is literally in the source and I am not auto-correcting it. Source: https://wiki.golden.com/wiki/US_Patent_11825558_Wireless_communication_method_using_enhanced_distributed_channel_access%2C_and_wireless_communication_terminal_using_same-DZY6VYA

(b) Date contradiction, flagged per instructions. Your task header says "Current Date: April 26, 2026," while the system date on my side is 2026-09-28. I have therefore treated 2026-04-26 as the cutoff for "live" status and have not relied on anything post-dating it.

(c) Near-miss identifiers excluded. Per your instruction, I discarded results that are not US 11,825,558: the EPO "Ref document number: 11825558 / Country of ref document: EP" appearing in WO 2012/036730 (an unrelated plural-component dispensing-gun PCT), and unrelated patents 11,826,262 / 11,825,558-adjacent numbers, and "179797670" (a mangled rendering of application 17/979,767 on a wiki mirror).

1. Search result for the specific number

Critical limitation on this task, stated up front: I was not able to retrieve the printed front-page "(56) References Cited" list of 11,825,558 itself. The authoritative full text you supplied is truncated immediately after the "Definitions"/claim-summary block — it contains the specification and figure list but omits the References Cited section and the numbered claim set. My live searches returned the patent's IDS/prosecution content (PubChem record) and citing patents, but not '558's own cited-reference table. So the inventory below is assembled from co-family and directly-related Wilus patents whose IDS lists are publicly visible (U.S. 11,116,035; 11,523,464; 12,120,744), all of which share inventors, specification and 2016 KR priority. Treat this as a high-confidence proxy, not a verbatim transcription of '558's front page. Where I cannot verify a reference's subject matter, I say so rather than guess.

2. Reference inventory (proxy list from the co-family '035 / '464 / '744 records)

Group A — same-family / self references (NOT prior art)

§102 effect: These cannot anticipate or render obvious. Same inventors + common ownership → excepted under §102(b)(2)(C) (and §102(b)(1)(A) as the inventors' own disclosures).

Group B — third-party U.S. patents/publications appearing in the family IDS

Retrieved verbatim from the "Referenced Cited" table of U.S. 12,120,744 (https://patents.justia.com/patent/12120744), which lists the Wilus family together with the third-party art:

Group C — foreign patent documents in the same list

CN 102859895 (Jan. 2013); CN 103379554 (Oct. 2013); CN 104066091 (Sep. 2014); CN 105142207 (Dec. 2015); CN 105830506 (Aug. 2016); EP 3 270 646 (Jan. 2018); EP 3 412 107 (Dec. 2018); JP 2015-50650 (Mar. 2015); JP 2018-509024 (Mar. 2018). Subject matter not verified for each.

Group D — non-patent literature (the legible, high-value portion)

This is where the real §102 fight is, because it is all IEEE TGax material dated around the priority date:

1. IEEE 802.11-16/0998r0–r3, "2 sets of EDCA parameters" (Laurent Cariou et al.) — r0/r1 July 2016; r2/r3 Sep. 12, 2016, slides 1–32.
2. IEEE 802.11-16/1180r0, "Proposed spec text for MU EDCA parameters" — Sep. 2016. This document appears on the face of the co-family U.S. 11,116,035 (archive.org copy of the '035 front page, E.D. Tex. 2:24-cv-00752).
3. "Resolution for CID 9058 and 90750/90751 — Proposed spec text for MU EDCA parameters," IEEE P802.11, Sep. 2016 (Cariou et al.).
4. IEEE 802.11-16/1220r1, "MU Mode EDCA Control," Ahn, Jin Soo et al., Sep. 14, 2015 (as printed in the retrieved record — I note the year literally; the 16/xxxx numbering implies 2016, but I am not auto-correcting). Slides 1–10.
5. IEEE 802.11-2012, Part 11: Wireless LAN MAC and PHY Specifications — the baseline EDCA/EDCAF text.
6. WO 2016/112146 — asserted by Wilus in the Samsung action as prior art that predates Cariou (E.D. Tex. 2:24-cv-00752, Dkt. 348, filed 03/23/26, "Ex. C").

3. §102 analysis — which references actually matter

Because '558 has a 2016-09-07 earliest priority (with a KR chain running through 2017-02-20: KR 2016-0114822 → 0116877 → 0116965 → 0117898 → 0122488 → 0147189 → KR 2017-0022227, per the EP 3 512 289 B1 priority list), it is an AIA patent. The controlling questions are §102(a)(1) (publicly available before the effective filing date) and §102(a)(2) (U.S. patent/application effectively filed before that date).

Claim-numbering caveat (carried forward and still unremedied): '558's numbered claims remain truncated in my source. I use the previously-flagged inferred structure — independent apparatus claim (1) and mirror method claim (8) — and label every mapping as inferred.

Bottom line on §102: I do not find a reference that anticipates the independent claims on its face. The realistic invalidity theory is §103 over Cariou's IEEE 16/0998 + 16/1180 in view of IEEE 802.11-2012 — which is exactly the theory Samsung is running in E.D. Tex. 2:24-cv-00752, and which Wilus is contesting on the ground that the Cariou submissions "lacked critical operational details." Note that Samsung's challenge leans toward a derivation/inventorship theory (that Cariou conceived the MU-EDCA inventions) rather than pure §102 art; the record shows Dr. Ahn testified there was "no collaboration in making of the technology itself" (Ahn Dep. 37:14-22).

4. Additional candidates found in search but NOT confirmed as citations of '558

Two items surfaced that are topically on point but are not established to be on '558's face, so I list them separately rather than folding them into the §56 analysis:

• US 2006/0215686 A1, "Communication method for accessing wireless medium under enhanced distributed channel access" — adaptive CWmin/CWmax update announced in beacons. Directly relevant to the CW/backoff dependent claims, but it is a 2006 publication with no confirmed link to '558's citation list.
• US 10,911,186 B2 (Wilus) — appears as Exhibit 9 to Dkt. 488 in the HP action; a family-adjacent Wilus patent, not prior art.

5. Explicit uncertainties (do not treat as verified)

1. '558's own "References Cited" list was not retrieved. Everything in §2 is a proxy from co-family records. This is the single largest limitation of this analysis.
2. '558's numbered claim set is still truncated in my authoritative source. All claim mappings are against the inferred 1 = apparatus / 8 = method structure flagged in the prior section.
3. Descriptions for Group B and Group C references are unverified. I did not retrieve their specifications and have not invented subject matter for them.
4. US 2017/0245261's effective U.S. filing date is unverified, which is dispositive for whether it is §102(a)(2) art.
5. The Sep. 7, 2016 priority date is Google's labeled assumption. The KR priority chain extends to Feb. 20, 2017, so different claims may carry different effective dates — which changes the §102 status of every September-October 2016 IEEE document.
6. "Sep. 14, 2015" for IEEE 802.11-16/1220r1 is reproduced literally from the retrieved record; the 16-series numbering implies 2016, but I have not corrected it.
7. Litigation probing found no docket naming 11,825,558 itself. Confirmed live Wilus activity is under sibling numbers: Wilus v. HP, E.D. Tex. 2:24-cv-00752-JRG (Dkts. 301-7, 340-3, 348, 488-4) and the Samsung action, with the '035 and '879 patents in suit.

I'll research the prior-art landscape relevant to the '558 claims before building the §103 analysis.

Good — I've found the PTAB/IPR record for a sibling patent and the prior-art shortlist. Let me drill into the specific references and whether '558 itself was challenged.

I now have the actual '558 claim language. Let me confirm the assertion record for '558 itself and lock down the remaining references.

Obviousness Analysis — U.S. Patent No. 11,825,558 B2 under 35 U.S.C. § 103

Note on scope / what I used for "Prior Art." The fetched Google Patents text for '558 in my working set contains the specification, figure list and the "Definitions" claim‑summary block, but not the printed claim set and not the "References Cited / Similar Documents / Cited By" tables. I therefore reconstructed the prior‑art universe from three grounded sources: (a) the references cited on the face of the '558 family during prosecution — Cariou 0998 (IEEE 802.11‑16/0998r0, "2 Sets of EDCA Parameters," Jul. 2016) and Cariou 1180 ("Proposed spec text for MU EDCA parameters," Resolution for CID 9058 and 9075, IEEE P802.11, Sep. 1, 2016), per the Justia family listing (https://patents.justia.com/patent/[12193116](/patent/12193116)); (b) the prior‑art election and obviousness‑combination lists served in the co‑pending Wilus v. HP/Samsung consolidated litigation, E.D. Tex. 2:24‑cv‑00752 (Ex. 4, Dkt. #185‑5, https://www.courtlistener.com/docket/69161107/185/5/); and (c) the PTAB petitions against the sibling patents (e.g., https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557875](/patent/1557875)/). Where I rely on Tier‑2 art whose status depends on the '558 effective filing date, I flag it.

0. Correction to the earlier‑generated section (explicit flag)

The prior section stated that the '558 claim set was truncated and inferred that claim 1 = apparatus and claim 8 = method. A litigation exhibit now supplies what is on its face claim 1 verbatim:

"1. A wireless communication terminal that wirelessly communicates with a base wireless communication terminal … transmit, to the base wireless communication terminal, a trigger‑based physical layer protocol data unit (PPDU) using the transceiver, switch a parameter set … from a first parameter set to a second parameter set based on whether the base wireless communication terminal triggers a multi‑user uplink transmission participation …, when a MAC protocol data unit (MPDU) included in the trigger‑based PPDU does not request an immediate response, set a second parameter set timer for an access category of the MPDU when the transmission of the trigger‑based PPDU ends, when the MPDU … requests the immediate response, set the second parameter set timer for the access category of the MPDU for which immediate response is received, when the second parameter set timer expires, terminate an application of the second parameter set, and access a channel according to a priority of data … and the parameter set."
— reproduced in Dkt. #301‑7 (https://archive.org/download/gov.uscourts.txed.[232954](/patent/232954)/gov.uscourts.txed.232954.301.7.pdf)

That text tracks the '558 "Definitions" block word‑for‑word, so it is almost certainly a '558‑family claim (I could not confirm the exhibit caption attaches to '558 rather than the closely related '879 patent — treat the literal number as unverified). It contradicts the "claim 8 = method" inference; the numbering should be re‑verified against the printed patent. The dependent text quoted in the same exhibit ("The MPDU … is a QoS data frame"; "obtain information indicating a period of the second parameter set timer from the beacon frame") confirms dependents 2 and 3 as previously summarized.

1. Element breakdown of claim 1

Dependents (per the '558 specification's own claim‑summary): 2 QoS data frame; 3 beacon‑frame‑sourced timer period; 4 random integer in CW → backoff timer → channel access on backoff timer + slot time, with CW capped at CWmax; 5–7 plurality of AC‑classified EDCA queues, and at a slot boundary where the queue is empty and its backoff timer = 0: perform no operation (variant: hold backoff at 0; variant: re‑init the EDCAF and set CW = CWmin, QSRC/OLRC initialized).

2. Person of ordinary skill and the state of the art as of the effective date

A POSITA here is a MAC‑layer 802.11 engineer (B.S. E.E./C.S. + ~3 yrs. WLAN MAC experience) actively tracking TGax drafts. Critically, every element A–G was the subject of an open, publicly documented IEEE 802.11 TGax work item in mid‑2016, and the "empty queue / backoff = 0" ambiguity in dependent claims 5–7 was an identified, discussed open issue (see §5 below).

Priority friction (applies to every ground). Google lists priority as 2016‑09‑07 (its own labeled assumption). Elements B–E and the MU EDCA concept map onto HE (802.11ax), whose D1.0 was published November 2016 — after that date. Samsung's petitions therefore attack the priority chain directly ("complex factual findings as to the effective filing date of both the asserted art and the challenged patents," https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557813](/patent/1557813)/). I therefore split grounds by tier.

3. The prior art

Tier 1 — on its face before 2016‑09‑07 (the strongest ground):

Tier 2 — contingent on the effective filing date landing later than 2016‑09‑07:

4. Ground 1 (principal): Cariou 1180 + Cariou 0998 + Kim '476 (or Zhou ‑Cherian) — § 103(a)

Element coverage

• A/B/G — Cariou 1180/0998 presuppose non‑AP HE STAs contending for the medium in the CP; D1.0 §§27.5.2.2–27.5.2.3 (and Seok 166/Merlin 500 for pre‑2016 availability) supply the TB‑PPDU: "A Trigger frame allocates resources for and solicits one or more HE TB PPDU transmissions."
• C — Cariou 1180's switch‑in event is receipt of "a basic variant Trigger frame" naming the STA; Cariou 0998 frames it as the SU→MU transition. This is element C almost verbatim.
• F — Cariou 1180: the STA "can switch back to the legacy EDCA parameters" on timeout; Cariou 261/HE3 add per‑AC timers, so the "for an access category" qualifier is met.
• E1 — Cariou 261 ¶¶[0019]–[0021], [0047], [0054]–[0061] and HE3 (timer launched upon successful UL MU transfer / upon ACK) teach setting the MU timer off the immediate response for the ACs that were actually acknowledged.
• D1 — Kim '476 (and Zhou/Cherian) teach UL MU transmissions whose MPDUs carry No‑Ack ACK policies; where no response is coming, the only coherent reference event is the end of the TB‑PPDU transmission — Kim's ack‑policy tables make the two branches explicit. Samsung maps exactly this way: "Zhou‑Cherian‑Kim renders obvious [1.4]–[1.5] … if no ACK is requested, [it] sets the timer when transmission of the trigger‑based PPDU ends and, second, if an ACK is requested, [it] sets the timer upon receipt of the ACK signal" (Dkt. #179‑24).

Motivation to combine

1. Same field, same problem, known interchangeability. Cariou 0998 and Cariou 1180 are two iterations of one proposal by the same author (and Cariou 1180 was the TGax‑adopted resolution text for the very CIDs Cariou 0998 raised). Combining them is not a "combination" at all in the KSR sense — it is finishing a draft.
2. Predictable result. The parameter set is per‑AC CWmin/CWmax/AIFSN — the same class of data as legacy EDCA. Substituting a more‑restrictive instance of a known parameter class to obtain the known benefit (deferring triggered STAs so the AP's TXOP succeeds) is "use of a known technique … to improve a similar device in the same way" (KSR).
3. The reference itself dictates the variation. Cariou 1180 already fixes a reference event for the timeout ("starts from end of basic variant Trigger"). Selecting the analogous event for the no‑response case (end of TB‑PPDU) and the response case (reception of M‑BA/ACK) is a finite number of identified, predictable solutions yielding the expected result (In re Aller, In re Magna).
4. Art‑recognized need with express motivation. Cariou 1180's rationale — MU EDCA parameters exist so that "the base wireless communication terminal … does not transmit any additional information" and so the AP's channel‑access attempts are not undermined — is the stated reason a POSITA would tighten the timer semantics: an unset/unduly long timer lets an idle STA re‑contend and defeat the very priority the MU set creates.
5. Rationale #1 in the petition record. Samsung's Appendix‑E motivation language — "A POSITA would have recognized that these references are within the same field and directed to similar problems" and "would have had a reasonable expectation of success … applying a known technique to a known system" — is directly on point and mirrors the PTAB's accepted Abraham/Merlin/Grandhi line of reasoning.

5. Ground 2 (contingent on a later effective date): 802.11ax D1.0 + Cariou 1180/0998 + Kim '476

If the claims lose the 2016‑09‑07 priority (the live dispute), D1.0 becomes § 102(a)(1)/(a)(2) art and is a near‑anticipatory primary reference:

• D1.0 §26.2.7: "A non‑AP HE STA that receives a Basic Trigger frame that contains a User Info field addressed to the STA shall update its CWmin[AC], CWmax[AC], AIFSN…" → elements A, B, C, G.
• D1.0 §27.7 / the MU EDCA Parameter Set element → the timer, per‑AC records, and beacon signaling (elements D/E/F and dependent 3).
• §27.5.2.3's "UL MU response scheduling" and the A‑Control‑based solicitation variant also meet the '558 specification's own alternative ("the wireless communication terminal may receive UL MU response scheduling instead of the trigger frame").

Notably, the Wi‑Fi 6 standard is the accused instrument: a German judgment in the parallel action held "claim 1 of the patent in suit is being implemented verbatim by the Wi‑Fi 6 standard" (Dkt. #457‑2). A patent that reads verbatim on a published, consensus standard draft is in an awkward position on § 103 — the same disclosure that proves infringement proves the public state of the art.

6. Ground 3 (alternative primary): Cariou 261 (US 2017/0245261) + Seok 166 + Huawei 185

Cariou 261 alone supplies the architectural core: per‑AC mode switching in response to a trigger ("In response to receiving the trigger frame … the STAs 1‑3 transition to the MU mode"; "the STA that receives a trigger frame … may update its EDCA parameters"), a HEMUEDCATimer delivered in the beacon, degraded per‑AC parameters, and a Preferred‑AC field in the trigger's User Info that ties the mode to specific ACs. Seok 166 adds the UL MU trigger/response rules; Huawei 185 adds the CW‑clamping rules needed for dependents 4–5. Samsung's district‑court theory states the motivation: "a POSITA would have understood and found obvious that when Cherian describes transmitting, to the STA, a trigger frame for 'switching from SU to MU,' it refers to the EDCA parameters switch from a first parameter set (SU parameters) to a second parameter set (MU parameters) based on whether the base wireless communication terminal triggers a multi‑user uplink transmission participation" (Dkt. #301‑7).

7. Dependents — element mapping

Claims 5–7 are the clearest KSR case in the patent: the four EDCAF slot‑boundary behaviours are an expressly enumerated, closed set, and the reference documents themselves flag the empty‑queue/zero‑backoff case as needing a rule. Selecting "Do nothing" — or, in the alternatives, re‑invoking the backoff procedure while leaving CW/QSRC unchanged — is "the product … of ordinary skill and common sense," with an evident design reason (do not double CW on a non‑failure, so as not to penalise a station that merely ran out of queued data). Baron '989 supplies the same insight from the opposite direction.

8. Anticipated patent‑owner rebuttals, and why they are weak

1. "Cariou only discloses general concepts." This is Wilus's own litigation position ("Cariou's submissions … only discuss general MU‑EDCA concepts"; "the specific operational rules" were Wilus's contribution — Dkt. #439). It is a concession that Cariou 1180/0998 teach elements A, B, C, F and G, leaving only the response‑conditional timer as the point of novelty. Obviousness of the remainder then turns on Kim '476/Zhou/Cherian — a much narrower and more vulnerable defensive position than "no reference teaches two parameter sets."
2. Priority. Wilus's strongest argument is temporal: D1.0 (Nov. 2016), Cariou 261, Kim '476, Cherian 264 and HE3 all post‑date 2016‑09‑07. But Cariou 0998 (Jul. 25, 2016) and Cariou 1180 (Sep. 1, 2016) are before it and are cited on the family's face — a ground built only on those two plus pre‑2016 IEEE/US art avoids the priority fight entirely.
3. Teaching away. There is none. Cariou 1180 expressly invites refinement of when the timer starts ("timeout starts from end of basic variant Trigger"); the 11‑17/0987 comment thread expressly asks for the empty‑queue rule. Neither reference criticises the claimed design.
4. Secondary considerations. Adoption by the Sisvel Wi‑Fi 6 pool and settlements with HP/Askey show industry uptake, not non‑obviousness: the nexus runs to the standard, and the standard's own draft is the prior art. Wilus's § 282/§ 101/§ 112 counter‑attacks in the parallel case (Dkt. #106) do not rebut the § 103 mapping.
5. Enforceability/unenforceability, joint inventorship. Samsung's undeclared‑subject‑matter and Cariou‑as‑co‑inventor theories (Dkt. #348) are separate from § 103, but note the tension: Wilus arguing Cariou's contributions were "well‑known concepts" simultaneously strengthens the obviousness case.

9. Bottom line

(a) Strongest § 103 ground. Cariou 1180 (IEEE 802.11‑16/1180r1) in view of Cariou 0998, further in view of Kim '476 (or Zhou 023/Cherian 264) for the response‑conditional timer branches, and optionally IEEE 802.11‑2016 + Huawei 185 for dependents 3–5 and the EDCAF slot‑boundary rules. Independent claim 1's only non‑trivial element — setting the MU timer for the AC of the MPDU at TB‑PPDU end when no response is requested, and at immediate‑response reception when one is — is a binary design choice dictated by the MPDU's own ACK policy, a choice the primary reference already frames by fixing a reference event for the timeout.

(b) Alternative grounds. (i) 802.11ax D1.0 + Cariou 1180 + Kim '476' — strongest if the effective filing date is pushed past Nov. 2016 (D1.0 §26.2.7 is close to anticipatory of element C). (ii) Cariou 261 + Seok 166 + Huawei 185. (iii) Baron '989 (US 10,700,989) + IEEE 802.11‑2016 for claims 5–7.

(c) Confidence. Medium‑high on claim 1 (the element‑by‑element mapping is corroborated by an actual, fully briefed § 103 record in a parallel case involving the same specification and the same references). High on claims 2–7. The binding uncertainties are: the effective filing date (Tier‑1 vs. Tier‑2 art), the literal claim numbering of '558 (unverified — the claim 1 text I quote comes from a litigation exhibit that may be captioned to a sibling), and the fact that Cariou 0998/1180 were before the Examiner, so any ground must be framed as the Examiner having overlooked the specific response‑conditional timer branch, not the two‑set concept.