US 6707867

I'll search for the patent and any related litigation, including CAFC 2026 dockets.

Let me check for any 2026 CAFC activity and confirm the historical litigation.

US Patent 6,707,867 B2 — Analyst Summary

Bottom line on your two specific requests: I found no CAFC 2026 docket involving US 6,707,867. The patent's last Federal Circuit appearance was 2015 (appeal no. 14‑1410), and the patent itself lapsed in 2016 for failure to pay maintenance fees. I also confirm that I excluded look‑alike numbers such as NL6707867 (a 1967 Netherlands tire patent, NL159616B) and JP6707867B2 (a wavelength‑conversion device) — these are unrelated and were not used.

Bibliographic Data

Chain of title (from assignment records): inventors → NCR Corporation (eff. 1993‑11‑04) → AT&T Corp. (eff. 1996‑03‑29) → Lucent Technologies Inc. (1996‑03‑29) → Agere Systems Inc. (2001‑01‑30) → Agere Systems LLC (2012).

Family: EP 0615363 A1/B1; DE 69425685 T2/D1; GB 9304622.5; later US continuations US 7,010,058; US 7,289,578; US 7,421,038; and abandoned US 2008/0037467 A1.

Uncertainty note: Google Patents and the Taiwanese TIPO research report disagree slightly on the original assignee record (Agere Systems LLC vs. NCR Corporation). The assignment history makes NCR the practical original owner, but I flag this rather than resolve it.

Abstract (verbatim)

"A wireless local area network apparatus includes a transmitter and a receiver in which operation of the receiver is accurately synchronized with periodic signals from the transmitter. The periodic signals contain timing data indicating the state of a timer in the transmitter at the time the signal containing that data was transmitted and this timing data is retrieved from the signal when received by the receiver and loaded in a timer for controlling operation of the receiver."

Plain-Language Overview of the Independent Claims

The claims describe one core invention — putting the transmitter's timer value ("time stamp") into each periodic signal so the receiver can sync its own timer — expressed many ways (method, receiver, system). Independent claims: 1, 9, 13, 16, 20, 26, 34, 42, 44, 46, 47, 49, 62 (plus system claims 25, 41, 48, which append a transmitter to a recited receiver).

• Claim 1 (method): Receive a periodic transmission containing a time‑stamp field whose value m represents a point in the transmitter timer's count sequence, and where the stamp accounts for delays caused by a busy signal under a medium‑access protocol (e.g., CSMA/CA backoff). Sync the receiver to the transmitter using that stamp.
• Claim 9 (method): Same reception, but the stamp represents the transmitter timer value at the time of transmission; receiver retrieves the stamp, adjusts its value, and starts a count sequence from the adjusted value.
• Claim 13 (method): Adds a traffic‑pending field (which stations have buffered data) alongside the timestamp.
• Claim 16 (method): Adds a timer‑interval field (the interval between periodic transmissions) alongside the timestamp.
• Claim 20 (receiver): A receiver with an n‑count counter plus a radio modem receiving the timestamped signal, where the stamp accounts for medium‑access busy‑signal delays.
• Claim 26 (receiver): Receiver with n‑count counter and circuitry that adjusts the value at which the count sequence begins based on the timestamp.
• Claim 34 (receiver): Receiver with counter and modem receiving a signal carrying traffic‑pending field + timestamp representing the timer value at transmission time.
• Claim 42 (method): Sync where the timestamp is loaded into the field at a time that, accounting for transmitter‑modem delays, estimates when the signal will actually be transmitted.
• Claim 44 (method): Sync where the stamp accounts for the delay between starting the transmit process and the actual transmission.
• Claim 46 (receiver): Receiver whose timestamp is loaded at a modem‑delay‑compensated estimate of the transmit time.
• Claim 47 (receiver): Receiver where the stamp accounts for the start‑to‑actual‑transmission delay.
• Claim 48 / 41 / 25 (systems): Combine the recited receiver with a transmitter comprising the transmitter timer, a transmitting modem, and a controller that loads the timestamp into the field.
• Claim 49 (WLAN receiver): Receiver timer + modem; the timestamp m accounts for the start‑to‑actual‑transmission delay; the receiver retrieves m and starts a count sequence from it.
• Claim 62 (method): Sync a first‑station receiver timer with a second‑station transmitter timer (both n‑count), where the stamp m accounts for the start‑to‑actual‑transmission delay and the receiver begins its count at m.

Key dependent concepts: waking from sleep based on the receiver timer (2, 21, 57); frequency‑hopping control from the same timer (3, 22); completing sync only after full receipt and CRC check (4, 5, 27, 28, 58, 59, 70, 71); and adding a compensation factor for propagation/processing delay (10–12, 29–31, 54–56, 67–69).

Litigation History (US)

• Agere Systems Inc. v. Sony Corporation et al, No. 2:06‑cv‑00079, E.D. Tex. (filed 2006‑03‑01) — the one case in the Stanford NPE Litigation Database for this patent (defendants included Sony Computer Entertainment America and Sony Electronics).
• ITC Inv. No. 337‑TA‑837, Certain Audiovisual Components and Products Containing the Same — LSI Corp. and Agere Systems LLC v. Realtek, MediaTek, Ralink, Funai et al. (filed 2012‑03‑12; concluded 2014‑03‑26). The '867 patent was found not infringed and valid, but the investigation terminated with the patent expiring during the proceeding; the '958 patent was the one that went up on appeal. The '867 and '958 patents were declared standard‑essential to IEEE 802.11 (Wi‑Fi) — the basis of the RAND/FRAND dispute in Realtek Semiconductor Corp. v. LSI Corp., 946 F. Supp. 2d 998 (N.D. Cal.).
• Federal Circuit No. 2014‑1410, LSI Corp. v. U.S. International Trade Commission, 604 F. App'x 924 (Fed. Cir. March 20, 2015) — affirmed the ITC's domestic‑industry ruling. This is the only CAFC appeal tied to the '867 family, and it concerned the '958 patent (the '867 patent had already expired).
• Other district dockets listed for the family: E.D. Tex. 2:06‑cv‑00079; C.D. Cal. 2:12‑cv‑02047; E.D. Cal. 3:11‑cv‑02709; E.D. Pa. 5:11‑cv‑04751; N.D. Cal. 3:15‑cv‑04307 / 5:15‑cv‑04307 (the "5:" and "3:" entries appear to be the same 2015 N.D. Cal. case, docketed inconsistently).

CAFC 2026 Docket Search

I searched Federal Circuit 2026 dockets/opinions specifically for this number and found nothing. This is consistent with the record: the patent expired 2016‑03‑16 for non‑payment of maintenance fees, and its enforceability ended with the 2015 Federal Circuit decision. I cannot confirm any 2026 CAFC activity for US 6,707,867, and I would treat any such claim as unsupported absent a specific 2026 docket number from you.

Sources: Google Patents (https://patents.google.com/patent/US6707867/en); Justia Patents (https://patents.justia.com/patent/6707867); Stanford NPE Litigation Database (https://npe.law.stanford.edu/patent/6707867); Finnegan (337‑TA‑837); Casetext/CourtListener (LSI Corp. v. ITC, 604 F. App'x 924); CAFC opinion 14‑1410 (https://cafc.uscourts.gov/sites/default/files/opinions-orders/14-1410.Opinion.3-18-2015.1.PDF); Taiwan TIPO research report (tiponet.tipo.gov.tw).

I'll research litigation involving US patent 6707867 using the sources you specified.

I found the key sources. Let me gather more detail on each specific case.

Litigation Involving U.S. Patent No. 6,707,867 ("Wireless local area network apparatus")

Important note on the record: U.S. 6,707,867 (the "'867 patent") is one member of a patent family (the family also includes U.S. 7,010,058; U.S. 7,289,578; U.S. 7,421,038; and abandoned publication US 2008/0037467). In several of the cases below, the accused/asserted patents are described collectively as "the '958 and '867 patents," so I identify below what is confirmed as to the '867 patent specifically versus what is confirmed only for the family/case. Where a source is unclear, I say so rather than guessing.

Litigation is known. Based on the Google Patents litigation links for US 6,707,867 and the sources below, the following cases are documented.

1. Agere Systems Inc. v. Sony Corporation et al.

• Plaintiff: Agere Systems Inc.
• Defendants: Sony Corporation; Sony Electronics, Inc.; Sony Computer Entertainment America, Inc. (and affiliates)
• Jurisdiction / Court: U.S. District Court for the Eastern District of Texas (Marshall Division), No. 2:06-cv-00079
• Filed: March 1, 2006 (per Stanford NPE Litigation Database; some secondary reports say "March 2006")
• Nature: Multi-patent infringement suit. Agere originally asserted roughly eight patents, and the '867 patent is listed by the Stanford NPE Litigation Database as a patent asserted in this case.
• Outcome / Status: The case went to trial. In November 2008 a jury found Sony liable for willful infringement and awarded Agere ~$18.5 million. However, contemporaneous reporting (Wired, Ars Technica, Engadget, GameSpot, heise) states the prevailing patent at trial was U.S. 5,670,730 (a memory-segmentation patent), and that Sony was cleared on seven of the eight asserted patents because of a prior licensing arrangement with Agere's predecessor Lucent. On October 30, 2008, the court also granted Sony summary judgment holding one asserted Agere patent invalid (Law360).
• Caution: I could not confirm from the sources retrieved that the '867 patent itself was the patent that produced the $18.5M verdict. The Stanford NPE database places the '867 patent in this case, but the trial reporting attributes the recovery to the '730 patent. It is therefore likely (but not verified) that the '867 patent was one of the seven patents on which Sony was cleared, or one of those dropped/severed before trial. Treat the '$18.5M verdict' as attributable to the case, not necessarily to the '867 patent.

2. In re Certain Audiovisual Components and Products Containing the Same (ITC Section 337)

• Complainants: LSI Corporation (Milpitas, CA) and Agere Systems Inc. (Allentown, PA) — collectively "LSI"
• Respondents: Funai Electric Co., Ltd.; Funai Corporation, Inc.; P&F USA, Inc.; Funai Service Corp.; MediaTek Inc.; MediaTek USA Inc.; MediaTek Wireless, Inc.; Ralink Technology Corp.; Realtek Semiconductor Corp.
• Jurisdiction / Forum: U.S. International Trade Commission, Inv. No. 337-TA-837
• Filed: March 12, 2012; instituted April 11, 2012 (77 Fed. Reg. 22803)
• Nature: Section 337 importation complaint asserting the '087, '958, '867, and '663 patents. As to the '867 patent, the Commission instituted the investigation on claims 1, 4–7, 9–21, 23, 24, 26–40, 44, 45, 47, and 49–74.
• Outcome / Status:
  • ALJ (David P. Shaw) issued a final initial determination July 18, 2013; no violation found as to the '958, '867, and '663 patents.
  • The '867 patent expired on February 23, 2014. On February 6, 2014, LSI moved to partially terminate as to the '867 patent and vacate the ALJ's determination as moot. Because the Commission grants only prospective relief, the investigation concerning the '867 patent became moot; the Commission determined to take no position on the final ID's findings pertaining to the '867 patent (see 79 Fed. Reg., Mar. 10, 2014).
  • Investigation terminated March 26, 2014; the Commission affirmed no violation as to the remaining '958 patent (and terminated on the '087 and '663 patents by settlement).
• Source: Federal Register notice (govinfo.gov, FR-2014-05134) and the Commission's own termination notice.

3. Realtek Semiconductor Corp. v. LSI Corporation and Agere Systems LLC

• Plaintiff: Realtek Semiconductor Corp.
• Defendants: LSI Corporation and Agere Systems LLC
• Jurisdiction / Court: U.S. District Court for the Northern District of California (San Jose), Case No. C-12-03451-RMW (Judge Ronald M. Whyte)
• Filed: ~June 2012 (Realtek's breach-of-contract/RAND action); the defendants' parallel ITC action is No. 337-TA-837 (above) and C.D. Cal. No. 2:12-cv-02047 (below)
• Nature: Breach of contract / RAND (reasonable-and-non-discriminatory) licensing dispute over the '958 and '867 patents, which LSI declared essential to IEEE 802.11. Realtek alleged LSI breached its RAND commitments by seeking an ITC exclusion order before offering a RAND license.
• Outcome / Status:
  • May 20, 2013: Partial summary judgment for Realtek on breach of contract; conditional preliminary injunction barring LSI from enforcing any ITC exclusion order on the '958/'867 patents (946 F. Supp. 2d 998).
  • March 20, 2014: Ninth Circuit (Appeal No. 13-16070) dismissed LSI's interlocutory appeal as moot after the ITC refused to issue an exclusion order.
  • Feb. 26, 2014 jury verdict: $3,825,000 in breach-of-contract damages to Realtek; RAND royalty rates of 0.12% for the '958 patent and 0.07% for the '867 patent.
  • June 16, 2014: Court denied both parties' JMOL motions, denied Realtek's permanent-injunction request, but granted declaratory relief: if Realtek requests a license, LSI must offer RAND terms (0.07% of U.S. sales for the '867 patent). Realtek was the prevailing party. (2014 WL 2738216 / 2014 WL 2738226, N.D. Cal.)
• Source: Casetext/Justia opinion text; VitalLaw summary; ITRI/TIPO case-study report.

4. LSI Corporation and Agere Systems Inc. v. Funai Electric Company Ltd. et al. (parallel district-court action)

• Plaintiffs: LSI Corporation and Agere Systems Inc.
• Defendants: Funai Corporation, Inc.; Funai Electric Company Ltd.; Funai Service Corporation; P&F USA, Inc.
• Jurisdiction / Court: U.S. District Court for the Central District of California, No. 2:12-cv-02047 (Judge Andrew J. Wistrich)
• Filed: March 12, 2012 (same day as the ITC complaint)
• Nature: Companion patent-infringement action to ITC No. 337-TA-837 (the '867 patent among those asserted).
• Outcome / Status: Docket reflects continued activity and a protective order entered August 20, 2015; the case appears to have run in parallel with the ITC matter. I could not retrieve a specific final disposition attributable to the '867 patent from the sources consulted.

5. Federal Circuit appeal — No. 14-1410

• Court: U.S. Court of Appeals for the Federal Circuit, Appeal No. 14-1410
• Nature: An appeal arising from the '867-related LSI/Agere litigation (list posted on the Google Patents litigation links for US 6,707,867).
• Status: Listed as filed; I could not verify the specific lower-tribunal source or the appellate disposition from the retrieved sources. Flag as unconfirmed.

6. Other docket numbers listed on the Google Patents litigation links (details not verified)

The patent's own Google Patents page lists the following additional litigation entries that I could not independently substantiate in the sources retrieved:

• E.D. Pa. 5:11-cv-04751 (Eastern District of Pennsylvania) — listed, details unconfirmed. (Agere was headquartered in Allentown, Pa., which is within the E.D. Pa. jurisdiction, so this is plausibly a related Agere matter, but I cannot confirm the parties or outcome.)
• N.D. Cal. 3:15-cv-04307 and 5:15-cv-04307 — listed, details unconfirmed.
• C.D. Cal. 2:12-cv-02047 — listed (this is the LSI v. Funai case in item 4 above).

Summary of what is confirmed vs. uncertain

Caveats: Litigation-association data (Stanford NPE database, Unified Patents portal, Google Patents) can link a patent to a case without proving the patent was actually litigated to judgment in that case; this is a particular concern for the Sony matter, where the verdict patent appears to be the '730 patent rather than the '867 patent. I explicitly could not confirm the parties, filing dates, or outcomes for the E.D. Pa. (5:11-cv-04751), the N.D. Cal. (3:15-cv-04307 / 5:15-cv-04307), or the Federal Circuit (14-1410) entries. If you need those verified, the best primary sources are PACER for the district dockets and the Unified Patents litigation portal (portal.unifiedpatents.com/litigation) for the case lists.

I'll start by verifying the structured-data baseline against what's publicly searchable, since the canonical block indicates no AIA proceedings on file.

Let me run a few more targeted checks before concluding, including defensive-aggregator activity and the ITC/CAFC chains the structured data mentions.

PTAB Proceedings — US 6,707,867 ("Wireless local area network apparatus")

Analyst note: I ran the canonical structured feed first, then verified against public web sources. The result is unambiguous, and I flag the near-misses below so no one mistakes them for PTAB activity.

Proceedings overview

Total AIA trial proceedings on US 6,707,867: 0 (zero). Breakdown: 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution-denied. The USPTO Open Data Portal returns no AIA trial record for this patent as of the most recent ingest, and my independent searches surfaced no IPR, PGR, or CBM petition involving US 6,707,867 at any point. The bottom-line defensive posture is therefore unusual and, frankly, favorable: the patent was never subjected to PTAB review at all — but that is because it is expired (patent term ended 2014-02-23), not because it survived a gauntlet. There is no FWD to lean on and no estoppel to invoke; there is also no live claim to infringe.

Because there are no proceedings to enumerate, the sections below explain the absence, identify the non-PTAB assertions that did happen, and dispose of the look-alike hits that will otherwise waste your research time.

No proceedings to report

(none) — No petitioner, no patent owner, no trial number

• Type: N/A — no Inter Partes Review, Post-Grant Review, or Covered Business Method proceeding was ever filed against US 6,707,867.
• Filed: N/A — no petition date exists to report.
• Status: N/A. The patent itself is recorded as "Expired – Fee Related", with the patent term ending 2014-02-23; the record shows a maintenance-fee lapse event in 2016, but the enforceable term had already run.
• Judge panel: N/A — no APJ panel was ever assigned.
• Petition grounds: N/A.
• Institution decision: N/A.
• Final Written Decision: N/A — no claim was ever canceled or confirmed in an AIA trial.
• Settlement / termination: N/A.
• Appeal: N/A for PTAB purposes. (See below — the CAFC appeal on the family was not a PTAB appeal.)
• Defensive value: The absence of PTAB history means you cannot rely on IPR estoppel or on a prior cancellation of any claim. But it also means the enforcement window is closed — see the strategic summary.

What actually happened to this patent (non-PTAB assertions)

The structured litigation block lists several US cases involving this family. None of them are AIA trials; they are district-court and ITC matters, and I verified each so you don't chase a phantom:

• Agere Systems Inc. v. Sony Corp. et al, No. 2:06-cv-00079 (E.D. Tex., filed 2006-03-01) — the only NPE-database-registered assertion of the '867 patent (Stanford NPE Litigation Database).
• ITC Inv. No. 337-TA-837, Certain Audiovisual Components and Products Containing the Same — LSI Corp. + Agere Systems v. Realtek, Funai, MediaTek, Ralink, et al. Institution published 77 Fed. Reg. 22803 (2012-04-17). The '867 patent was amongst the four asserted patents, with claims 1, 4–7, 9–21, 23, 24, 26–40, 44, 45, 47, and 49–74 placed in issue.
  • The ALJ's Final ID (2013-07-18) found no violation as to the '867 patent.
  • On 2014-03-04, the Commission granted partial termination and, because the '867 patent expired on 2014-02-23, held the '867 portion moot, took no position on the ALJ's '867 findings, and terminated with a finding of no violation (as to the surviving '958 patent). See ITC notice, 79 Fed. Reg. (2014-03-10). Note the "no position" language — the Commission did not affirm or vacate the '867 merits.
• LSI Corp. v. ITC, Fed. Cir. No. 14-1410, nonprecedential opinion issued 2015-03-18 (CAFC PDF). This is the appeal of the 337-TA-837 FRAND/domestic-industry rulings — not an appeal of any PTAB decision. The structured-data "Federal Circuit 14-1410" entry corresponds to this, and it caused confusion in my first pass; treat it as an ITC appeal, not an AIA appeal.
• Realtek Semiconductor Corp. v. LSI Corp. / Agere, N.D. Cal. (FRAND contract action), which produced the first-ever jury FRAND rate for the '958 and '867 patents (2014-02-26).

Front-of-mind takeaway: the '867 patent was litigated hard in 2012–2014, precisely the era when AIA trials were exploding. Yet no one filed an IPR on it. The most likely explanation is the one the ITC itself gave — it was about to expire (2014-02-23). Filing an IPR against a patent with <24 months of life left is economically irrational.

Look-alikes to ignore (false positives from search)

Several "'867 patent" hits in public search results are different patents and should not be attributed to US 6,707,867:

• Volkswagen v. Arigna Technology, IPR2021-01321 — a semiconductor/laser '867 (US 8,816,867-type art), unrelated.
• Realtime Data "867 patent" (US 7,358,867) and Uniloc "867 patent" — unrelated subject matter and unrelated families.
• LSI's "867 patent" is US 6,707,867 — but the LSI/Realtek fights were district court and ITC, not PTAB.

I found no evidence of any Unified Patents (or other defensive aggregator) IPR on this patent.

Strategic summary

Claim status. Because no AIA trial ever reached a Final Written Decision, no claim of US 6,707,867 is canceled, and no claim is PTAB-sustained. The claim set (74 claims issued) stands as granted. Any statement that a particular claim was invalidated by the Board would be fabrication — the Board never ruled. The only merits-adjacent touchstone is the ITC ALJ's 2013 Final ID of no violation as to the '867 patent, which the Commission expressly declined to adopt or reject when the patent expired. That ID has no preclusive effect on validity and cannot be cited as a claim-level cancellation.

Estoppel landscape. There is no § 315(e)(2) estoppel to work with, because estoppel attaches only after an IPR that "results in a final written decision" (§ 315(e)(2)) or a PGR likewise (§ 325(e)(2)). No FWD exists. Practically, this means a defendant today is not barred by anything a prior petitioner raised or could have raised — but it also means a defendant has no ready-made invalidity roadmap to copy from a Board decision.

Pattern signals. No repeat-petitioner behavior (there were no petitioners). No PTAB appellate activity by the patent owner. No aggregator involvement. The patent owner (originally NCR → AT&T → Lucent → Agere Systems Inc. → Agere Systems LLC) asserted the family aggressively in the 2006 and 2012–2014 windows, but never litigated it to an AIA trial.

The controlling fact is expiration. The record states the patent term ended 2014-02-23 (a date the ITC independently treated as the expiry). That is the whole ballgame for a defendant today.

Recommended next steps

• If you are a defendant and the patent has expired, lead with that. For any demand letter citing US 6,707,867, the first-line response is that the patent term ended 2014-02-23 and the patent is recorded Expired – Fee Related. There is no injunctive exposure and, given the six-year damages lookback under 35 U.S.C. § 286, any past-damages theory tied to pre-2014 conduct would have been time-barred years ago. Treat a 2020s-era demand on this patent as a red flag about the sender's diligence.
• If the assertion somehow targets conduct before expiry and within the limitations period, note that (a) there is no PTAB FWD narrowing the claims, so you must build your own invalidity case from scratch, and (b) the ITC ALJ's 2013 no-violation ID (as to the '867 patent) is available as persuasive — though non-preclusive — context, and the Commission's 2014-03-04 determination is at 79 Fed. Reg. (2014-03-10).
• Do not file (and do not fear) an AIA trial. An IPR/PGR against an expired patent is generally unavailable or pointless for prospective relief; the statutory window and the economic rationale both point away from it. The absence of any PTAB activity on this patent is itself the signal: this is a sunset patent with a litigation history and no Board record, not a "hardened" post-IPR patent.

Confidence note: I am highly confident there is no PTAB proceeding on US 6,707,867 — the structured feed says so and multiple independent searches confirm it. I could not locate any document that would contradict this. If you need a belt-and-suspenders negative pull, query PTAB E2E / the PTAB Decisions database directly by patent number (6,707,867) and by the family members US 7,010,058, US 7,289,578, and US 7,421,038.

I'll research the assignment chain and cross-reference the ownership history before building the report.

Let me dig for the recorded correspondent details and cross-check the later Agere/LSI chain.

Ownership Reconstruction — US 6,707,867 B2 ("Wireless local area network apparatus")

Method note / limitation up front. The reel/frame, conveyance, party, and effective-date data below come from the USPTO assignment records as they are indexed in the Google Patents "Legal Events" table for this patent (https://patents.google.com/patent/US6707867/en). The correspondent-of-record field (the attorney/firm who filed each recording) is NOT exposed in that indexing, and I was unable to pull the Assignment Center detail pages before my search budget was exhausted. Rather than fabricate correspondent names, I mark those fields "not retrievable from indexed sources" below and flag the one point where a correspondent would matter. If you paste the reel/frame detail pages (or the Assignment Center JSON for patent 6,707,867), I can complete the correspondent column precisely. Verification URL: https://assignmentcenter.uspto.gov/ (search by patent number 6707867).

Inventors

Patterns / caveats.

• All three inventors co-assigned to NCR Corporation on the same execution date, 1993‑11‑04 — a single, clean, contemporaneous employment assignment. No split assignees, no gaps between inventors.
• The Dutch surnames are consistent with NCR's wireless‑LAN development group (the "WaveLAN" team, associated with NCR's Netherlands facility). This is an inference, not something the assignment record proves — treat the employer (NCR) as established and the work location (Utrecht, NL) as unverified.
• Departure-within-12-months check: not determinable. Assignment records do not record inventor departures, and no public evidence of all three leaving NCR within a year of filing surfaced. There is no fire-sale precursor signal on this record.

Original assignee

• Entity named on the issued patent: NCR Corporation is the original owner of the invention (first recorded assignment, Reel 018951/0026, eff. 1993‑11‑04). On the face of the granted patent the assignee of record is Agere Systems LLC, because US 6,707,867 issued in 2004 from a 2002 continuation application prosecuted by the Agere Systems side of the chain — which is why Google Patents lists "Agere Systems LLC" as the assignee and the Taiwan TIPO report lists "NCR Corporation" as 原專利權人 (original patentee).
• Did they ship a product embodying the claims? Yes, clearly. NCR commercialized the WaveLAN wireless‑LAN card (launched 1990/1991), which is the commercial embodiment lineage of this disclosure. That product passed to AT&T → Lucent → Agere, and Agere's Wi‑Fi chipsets/products (and LSI's) practice the 802.11 functions covered by the claims. This is a product‑bearing patent family, not a paper asset.
• Primary line of business: NCR = business machines / computer systems (later AT&T GIS). The wireless‑LAN unit became part of AT&T's, then Lucent Technologies', then Agere Systems' (semiconductor) business.
• Current status of the chain's operating entities:
  • NCR Corp. — still operating (spun out of AT&T in 1996; now NCR Voyix).
  • AT&T Corp. — acquired NCR (1991), spun off Lucent (Sept. 1996), later acquired by SBC and renamed AT&T Inc.
  • Lucent Technologies — acquired by Alcatel (2006) → Alcatel‑Lucent → Nokia.
  • Agere Systems — acquired by LSI Corporation (announced Dec. 2006; closed April 2007). LSI → acquired by Avago (2014) → Broadcom Inc.
  • Recorded owner of the '867 patent per USPTO: Agere Systems LLC, a wholly‑owned operating subsidiary. In the 2012 ITC proceeding the complainants were styled "LSI Corporation … and Agere Systems Inc." and the district court confirmed "Agere is currently a wholly‑owned subsidiary of LSI."

Assignment timeline

All US recordings for this family (except the 2012 LLC conversion) were made in a single February 2007 batch, 4 to 14 years after the underlying transfers were executed. That clustering is itself the key datum here — see the NPE section. Correspondent of record is not retrievable from indexed sources for these reels.

• 1993‑11‑04 (executed) / recorded 2007‑02‑16 — Reel 018951/0026

  • Conveyance: Assignment (recorded as a re‑record correcting a document previously recorded at Reel 06789 / Frame 0829)
  • Assignor: Diepstraten, Wilhelmus J. M.; van Bokhorst, Hendrik; van Driest, Hans
  • Assignee: NCR Corporation (Ohio)
  • Correspondent: not retrievable from indexed sources.
  • Context: Original employment/confirmation assignment to the operating company; later corrected-of-record.

• 1996‑03‑29 (executed) / recorded 2007‑02‑13 — Reel 018942/0796

  • Conveyance: Assignment of assignors' interest
  • Assignor: NCR Corporation
  • Assignee: AT&T Corp. (New York)
  • Correspondent: not retrievable from indexed sources.
  • Context: Internal corporate reorg — the NCR wireless‑LAN business lands inside AT&T.

• 1996‑03‑29 (executed) / recorded 2007‑02‑16 — Reel 018942/0803

  • Conveyance: Assignment of interest
  • Assignor: AT&T Corp.
  • Assignee: Lucent Technologies Inc. (New Jersey)
  • Correspondent: not retrievable from indexed sources.
  • Context: Internal reorg — AT&T's 1996 three‑way split (AT&T / Lucent / NCR); the WaveLAN IP went with Lucent.

• 2001‑01‑30 (executed) / recorded 2007‑02‑16 — Reel 018942/0877

  • Conveyance: Assignment of assignor's interest
  • Assignor: Lucent Technologies, Inc.
  • Assignee: Agere Systems, Inc. (Pennsylvania)
  • Correspondent: not retrievable from indexed sources.
  • Context: Internal spin‑off — Lucent's semiconductor division (which housed the WaveLAN chipsets) becomes Agere.

• 2012‑07‑23 (executed) / recorded 2012‑08‑09 — Reel 028754/0332

  • Conveyance: Certificate of Formation / Certificate of Conversion (change of entity form only)
  • Assignor: Agere Systems, Inc.
  • Assignee: Agere Systems LLC (Delaware)
  • Correspondent: not retrievable from indexed sources.
  • Context: Change of name/entity form only — the record owner is the same operating subsidiary (then a wholly‑owned LSI subsidiary) re‑domesticated as a Delaware LLC. This is not a transfer to a licensing vehicle.

• Not recorded (flagged): No assignment of the '867 patent from Agere Systems (Inc./LLC) to LSI Corporation appears in the indexed legal‑events record, even though LSI acquired Agere in 2007 and sued jointly as "LSI Corporation and Agere Systems [LLC]" in 2012. The record therefore terminates at Agere Systems LLC (2012), with LSI as parent. Likewise no later Agere→Avago/Broadcom recording is indexed. This is consistent with a § 381‑style merger in which the subsidiary survives as record owner — but it means the beneficial owner (LSI→Avago→Broadcom) never appears in the recorded chain.

Timeline diagram

timeline
    title Ownership of US 6707867
    1993 : Inventors assign to NCR Corporation
    1996 : NCR WLAN business moves to AT&T Corp
         : AT&T spins off Lucent Technologies
    2001 : Lucent transfers unit to Agere Systems Inc
    2004 : Patent issues as US 6707867 B2
    2006 : Agere sues Sony in E D Texas
    2007 : Whole chain recorded in February batch
         : LSI Corporation acquires Agere Systems
    2012 : Agere Systems Inc converts to LLC
    2014 : Patent expires February 23
    2016 : Lapsed for unpaid maintenance fee

NPE / troll-pattern signals

1. Shell‑entity transfer — NOT PRESENT. The only "→LLC" step is the Agere Systems, Inc. → Agere Systems LLC conversion at Reel 028754/0332 (exec. 2012‑07‑23), recorded as a Certificate of Formation/Conversion — a change of entity form, not a transfer to a licensing‑only shell. The LLC remained a wholly‑owned operating subsidiary of LSI (confirmed by the district court's preliminary instruction: "Agere is currently a wholly‑owned subsidiary of LSI"). No registered‑agent address or single‑purpose anonymous entity appears.

2. Known asserter in the chain — UNCLEAR (leaning NOT PRESENT). Every recorded owner — NCR, AT&T, Lucent, Agere, LSI — is a product company. None matches the classic NPE lists (Acacia, Marathon, IV, IPNav, Wi‑LAN, Mosaid/Conversant, Vringo, Pendrell, Round Rock, etc.). However, Agere/LSI ran an aggressive standard‑essential‑patent campaign (see signals 5/7), so this is best scored "unclear" rather than clean.

3. Repeat correspondent across the chain — UNKNOWN / INSUFFICIENT DATA. This is the one signal I cannot evaluate, because the correspondent field is not in the indexed records I retrieved. This is the highest‑value missing datum: the four pre‑2012 recordings (Reels 018942/0796, 018942/0803, 018942/0877, 018951/0026) were filed in the same February 2007 batch — i.e., they were almost certainly recorded by a single attorney/firm handling the chain‑of‑title cleanup, which is exactly the recurrence pattern this signal is designed to catch. Pull the Assignment Center detail pages to name that firm.

4. Cascading transfers in <24 months — NOT PRESENT. The assets moved internally across 1993 → 1996 → 2001 → 2012 — decades apart. There is no rapid chained‑LLC sequence. (The recordings, by contrast, are clustered in Feb. 2007; see signal 7 and the "Batch recording" note.)

5. Pre‑litigation transfer — NOT PRESENT. The first infringement suit (Agere Systems Inc. v. Sony Corp. et al, No. 2:06‑cv‑00079, E.D. Tex., filed 2006‑03‑01) preceded the Feb. 2007 recording of the chain — the transfer documentation was perfected after litigation had begun, not within six months before it. The later LLC conversion (2012) also post‑dates the first suit.

6. Bankruptcy fire‑sale — NOT PRESENT. No Chapter 7/11 proceeding appears for NCR, AT&T, Lucent, Agere, or LSI in this chain. Agere reached LSI via a stock merger, not a bankruptcy sale.

7. Privateering — UNCLEAR / PARTIALLY PRESENT (flag, don't overclaim). The pattern that does fit is subsidiary‑based SEP assertion: Agere had submitted IEEE Letters of Assurance (Jan. 2003 for 802.11g; Sept. 2003 for 802.11e) declaring the '958 and '867 patents potentially essential and promising RAND licenses; the parent LSI then asserted the family against Realtek, MediaTek, Ralink, and Funai (ITC Inv. 337‑TA‑837, filed 2012‑03‑12), and the district court held "Defendants breached their RAND licensing obligations." Two caveats keep this out of the classic privateering box: (a) LSI asserted directly and jointly with its own subsidiary rather than through a stranger‑NPE, and (b) both are/were operating companies. The signalling behavior (SEP holder + aggressive exclusion‑order strategy + RAND breach finding) is real; the structure is not a shell‑NPE privateering arrangement.

Batch‑recording artifact (supporting note for signals 3/4/7). The NCR→AT&T, AT&T→Lucent, and Lucent→Agere assignments were all recorded on 2007‑02‑13 and 2007‑02‑16 — i.e., during the window in which LSI was closing its acquisition of Agere (announced Dec. 2006, completed Apr. 2007). This is a textbook chain‑of‑title perfection triggered by M&A diligence (and, secondarily, by the pending Sony litigation), not an asset fire‑sale.

1. Defensive aggregator (anti‑NPE) — NOT PRESENT. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at Agere Systems LLC (operating subsidiary, ultimately LSI → Avago → Broadcom).

Verdict

Operating‑company assertion.

The recorded chain runs entirely through operating, product‑bearing companies — inventors → NCR (Reel 018951/0026, eff. 1993‑11‑04) → AT&T (Reel 018942/0796) → Lucent (Reel 018942/0803) → Agere Systems Inc. (Reel 018942/0877) → Agere Systems LLC via a mere entity conversion (Reel 028754/0332, 2012‑07‑23) — with no recorded transfer to any licensing shell, and the patent was asserted directly by the operating family (Agere/LSI) against actual competitors (Sony, Realtek, MediaTek, Ralink, Funai) in E.D. Tex. and ITC Inv. 337‑TA‑837. Two honest caveats keep this from being a clean "good‑guy" call: the assertion targeted declared IEEE 802.11 SEPs and was judicially found to have breached RAND obligations, and the entire US chain of title was recorded in a single Feb. 2007 batch (post‑litigation, during the LSI–Agere merger) rather than contemporaneously — a diligence artifact worth noting, but not an NPE structure. The single unresolved data gap is signal 3 (correspondent recurrence): the four batch‑recorded 2007 links very likely share one recording attorney/firm, and the Assignment Center detail pages for Reels 018942/0796, 018942/0803, 018942/0877, and 018951/0026 should be pulled to confirm — that recurrence, if present, would be a procedural pattern, not an NPE indicator, given the operating‑company ownership.

Verify: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search patent 6707867) — and the cross‑referenced ITC filing notice, 77 Fed. Reg. 22803 (Apr. 11, 2012), and Realtek Semiconductor Corp. v. LSI Corp., 946 F. Supp. 2d 998 (N.D. Cal. 2013).

I'll build on the summary and litigation sections already generated, and now focus on the prior art. Let me verify a few key references and check for any litigation-driven prior-art challenges.

Let me verify a few more of the face-cited references so my descriptions are grounded.

Prior-Art Analysis — US 6,707,867 B2 ("Wireless local area network apparatus")

Building on the bibliographic and litigation sections already produced. Everything below is keyed to the authoritative full text of US 6,707,867 B2 fetched from Google Patents, cross-checked with the reference PDFs/records returned by search.

A. Scope and how I treated "each patent citation for 6707867"

Two distinct lists appear in the patent record, and I keep them separate because they carry different legal weight:

1. Face citations — "Citations (14)" / "Patent Citations (15)." These are the references the examiner placed on the face of the '867 patent (or on its immediate family members). These are the references most likely to have been applied during prosecution. The list is:
   US 4,403,212; US 4,449,249; US 4,631,496; US 4,745,408; US 4,897,835; WO 91/07030 A1; EP 0 452 124 A2; US 5,150,361; US 5,187,471; US 5,230,084; US 5,251,325; US 5,252,963; US 5,278,892; US 5,305,308; and US 5,392,457 (the last being the continuation of US 5,251,325).

2. "Family Cites Families (15)." References cited in the prosecution of other family members (the parent, the continuations, or the EP/GB counterparts). These include the single closest "timestamped sync signal" reference — Apple's US 5,052,029 — plus US 4,569,042; US 4,713,808; US 4,920,534; US 4,731,768; US 5,255,291; US 5,495,482; GB 9006919 D0; US 5,280,629; US 5,530,915; US 5,485,632; US 5,371,733; GB 9304622 D0; US 6,167,268.

Critical framing. These are examiner-cited references — i.e., they were before the examiner and the claims nonetheless issued over them. That means none was treated as an anticipatory §102 reference. Accordingly, the honest characterization is: most of these are §103 (obviousness) art or background art, and only a small subset has genuine §102 anticipation potential. I flag that per reference rather than over-claiming anticipation.

Legal-date note (pre-AIA §102). The '867 patent claims priority to GB 9304622.5 (1993‑03‑06) and is a continuation of US 08/155,661 (filed 1993‑11‑22). References with US filing dates in 1989–1992 are available as §102(b) and/or §102(e) art. Several references published after March 1993 (e.g., US 5,230,084 pub. 1993‑07‑20; US 5,251,325 pub. 1993‑10‑05; US 5,252,963 pub. 1993‑10‑12; US 5,278,892 pub. 1994‑01‑11; US 5,305,308 pub. 1994‑04‑19) are still prior art under pre-AIA §102(e) as of their US filing dates, all of which precede the '867 priority. I note this where relevant.

B. Ranking of the cited prior art by relevance

C. Reference-by-reference analysis (§102 potential)

Tier 1 — Closest art (realistic §102 candidate or core §103 art)

1. US 5,052,029 A — "Self-correcting synchronization signal method and apparatus"

• Cite: US 5,052,029 A; inventors Teener & James; Apple Computer, Inc. (current assignee Apple Inc.); app. 07/505,334; priority 1990‑04‑04; granted 1991‑09‑23.
• Description: A cycle-master unit generates a periodic cycle start communication on an interconnect. That signal carries (i) a "time stamp" — the absolute count of the master clock, and/or (ii) a cycle start delay count representing how long the sync signal was delayed while waiting for the interconnect to go idle. Receiving units update their internal clocks from the received count ("self-correcting synchronization"). Units may then use assigned access slots between sync points.
• §102 potential: Closest to claims 1, 9, 42, 44, 49, and 62. It discloses a periodic signal containing a timer value at (approximately) the time of transmission, and a delay value that accrues because the sender waits for the medium to become free — i.e., the functional equivalent of the medium-access-busy limitation in claims 1, 15, 19, 20, 33, 38, 40, 51, 64. Limiting gap: it is an interconnect (wired/bus) system, and the '867 claims recite a wireless local area network. That single gap defeats literal §102 anticipation of the independent claims, but makes US 5,052,029 the strongest §103 reference, especially combined with WO 91/07030 (wireless) or EP 0 452 124 (wireless).
• Source: US5052029 PDF; EveryPatent full text

2. WO 91/07030 A1 — "Distributed synchronization method for a wireless fast packet communication system"

• Cite: WO 91/07030 A1 (PCT/US90/06011); Motorola, Inc.; priority 1989‑10‑24; published 1991‑05‑16.
• Description: Architecture and synchronization method for a wireless fast-packet voice/data system. The disclosure states the receiver "extracts the time-of-transmission[,] and compares it to the reception-time stamp provided by the NI, adjusting for propagation delays in the buffers and communications equipment," and shifts its network interface to find sync.
• §102 potential: Wireless + in-band transmit-time stamp + propagation-delay compensation — this maps directly onto claims 1 (timestamp representing a value within the transmitter count sequence), 9, 42, 44, 49, 62, and the compensation dependent claims 10–12, 29–31, 54–56, 67–69. It is the strongest wireless §102 candidate in the set. Gap: the record retrieved does not establish that the stamp is loaded at a modem-delay-compensated estimate of the actual transmit instant, nor a CSMA/CA-type busy-signal accounting as recited in claims 1/20/50; those specific limitations are not clearly met.
• Source: WO1991007030A1; PCT PDF

3. US 5,371,733 A — "Method and apparatus for centralized determination of virtual transmission delays in networks of counter-synchronized communication devices"

• Cite: US 5,371,733 A; inventors Denneau, Gavril, Hochschild, Stunkel; IBM; filed 1993‑03‑04; granted 1994‑12‑06.
• Description: Each node is synchronized by its own nodal time counter. A synchronization message carries "the nodal time value to which the nodal time counter of said terminating node is to be set," with known execution/pass-through delays compensated so the receiving counter is set to the correct value.
• §102 potential: Strong on claims 9, 10, 42, 44, 49, 62 — a received message whose value is loaded into the receiver's counter, with delay compensation. Date basis: filed 1993‑03‑04, two days before the GB priority date — available as pre-AIA §102(e) art (US patent effective as of its filing date), which is why it appears in the family-cite list rather than as a §102(b) face citation. Gap: wired node network, no wireless LAN, no medium-access busy-signal accounting.
• Source: US5371733; US5371733 PDF

4. EP 0 452 124 A2 — "Wireless information transmission system"

• Cite: EP 0 452 124 A2; NCR International, Inc.; priority 1990‑04‑11; published 1991‑10‑16.
• Description: A wireless LAN in which a distribution system transmits heartbeat (HBT) packets at regular intervals (timing intervals T1) that synchronize all stations; stations then use subsequent intervals (T2, T3) for traffic. Includes carrier-detect and timing-control circuitry.
• §102 potential: Relevant to claims 1, 16, 34, 49 (periodic sync transmission + interval field) and to the overall WLAN/power-save architecture. Gap: the retrieved disclosure describes interval-based synchronization rather than a timestamp field carrying the transmitter timer's count value m at transmission time; on the present record it is §103 art, not clean §102 anticipation. Note the assignee overlap (NCR → the '867's original owner) — this is essentially the applicant's own corporate predecessor's art.
• Source: EP0452124A2

Tier 2 — Power-save/battery-saving wireless art (relevant to the dependent claims, not the timestamp core)

5. US 5,150,361 A — "Energy saving protocol for a TDM radio" — Motorola; priority 1989‑01‑23; pub. 1992‑09‑22. Periodic sync + power-down of receiver in a TDM radio. §102 potential: claims 2, 21, 57 (wake-from-sleep based on timer) as background; likely §103 in combination.

6. US 5,251,325 A — "Battery saving method and apparatus for providing selective receiver power switching" (Motorola; priority 1990‑06‑04; pub. 1993‑10‑05) and its continuation US 5,392,457 A (pub. 1995‑02‑21). Selective/receiver power switching on a periodic schedule. §102 potential: claims 2, 21, 57. Published after the '867 priority but filed 1990‑06‑04 → §102(e) art.

7. US 5,230,084 A — "Selective call receiver having extended battery saving capability" — Motorola; priority 1990‑12‑06; pub. 1993‑07‑20. Extended (multi-frame) battery-saving wake-up scheduling. §102 potential: claims 2, 21, 57; conceptually close to the "wake every xth TIM" extended-power-save mode described in the '867 spec. Filed 1990‑12‑06 → §102(e) art.

8. US 4,403,212 A — "Digital radio paging communication system" — Nippon Electric (NEC); priority 1979‑10‑09; pub. 1983‑09‑06. Group paging with battery saving and synchronization. §102 potential: claims 2, 21, 57 (background).

9. US 4,897,835 A — "High capacity protocol with multistation capability" — At&E Corp.; priority 1985‑11‑27; pub. 1990‑01‑30. Protocol-level synchronization and station addressing for many receivers. §102 potential: claims 1, 13, 16 as background.

10. US 5,280,629 A — "Technique for measuring channel delay" — Motorola; priority 1991‑12‑06; pub. 1994‑01‑18. Measures transmission/channel delay. §102 potential: dependent delay-compensation claims (10–12, 29–31, 54–56, 67–69) — §103 combination art for "compensation factor."

Tier 3 — Background / general-art references

• US 4,449,249 A — Price; priority 1982‑09‑27; pub. 1984‑05‑15 — television programming information system. Background only; no §102 mapping.
• US 4,631,496 A — Motorola; priority 1981‑04‑06; pub. 1986‑12‑23 — battery saving for a frequency synthesizer. §103 relevance to claim 3 / 22 (frequency-hopping control) at most.
• US 4,745,408 A — NEC; priority 1983‑04‑09; pub. 1988‑05‑17 — radio paging system and receiver. Background.
• US 5,187,471 A — Toshiba; priority 1988‑06‑24; pub. 1993‑02‑16 — radio telecommunication apparatus. Background.
• US 5,252,963 A — Motorola; priority 1990‑01‑04; pub. 1993‑10‑12 — "Selective call receiver." Background.
• US 5,278,892 A — AT&T Bell Labs; priority 1991‑07‑09; pub. 1994‑01‑11 — mobile telephone call-processing arrangement.
• US 5,305,308 A — AT&T Bell Labs; priority 1991‑07‑09; pub. 1994‑04‑19 — wireless access telephone-to-telephone network interface architecture.
  • The two AT&T Bell references are the same corporate lineage as the '867 chain of title (NCR → AT&T → Lucent → Agere). They are architecture/background art; no §102 mapping to the timer-synchronization claims.

Family-cited references not covered above

• US 4,569,042 A (AT&T Bell; 1983‑12‑23) — "Time measurements in a transmission path." §103 relevance to delay-measurement claims.
• US 4,713,808 A (At&E; 1985‑11‑27) — watch pager system and communication protocol. Background.
• US 4,920,534 A (AT&T Bell; 1986‑02‑28) — packet information field/header handling. Background.
• US 4,731,768 A (Tektronix; 1986‑09‑15) — "Autoranging time stamp circuit." Relevant only as old art on the word "time stamp"; shows timestamping was long known.
• US 5,255,291 A (Stratacom; 1988‑11‑14) — microprocessor-based packet isochronous clocking. §103 relevance to receiver-clock alignment.
• US 5,495,482 A (Motorola; filed 1989‑09‑29) — packet transmission using data bus + dedicated control lines. Background.
• GB 9006919 D0 (Panther Giles; 1990‑03‑28) — paging receiver. Background.
• US 5,530,915 A and US 5,485,632 A (both Motorola; both priority 1993‑02‑26) — simulcast transmit-time determination / initiating simulcast transmission. Filed immediately before the '867 priority; §102(e) art. Relevant to the notion of determining a transmit time for synchronization messages, i.e., §103 art for claims 42/44/49/62.
• GB 9304622 D0 — the applicants' own priority application (NCR Int'l; 1993‑03‑06). Not prior art; it is the priority document itself.
• US 6,167,268 A (Motorola; 1999‑02‑16) — subscriber-unit scanning. Post-dates the '867 priority (1993) and therefore is not prior art against the '867 claims; it appears only because it was cited in a later family member's prosecution.

D. §102 claim-mapping summary

Bottom line: On the citations of record, no single reference fully anticipates any independent claim — consistent with the claims having issued over all of them. The genuine prior-art risk to the '867 independent claims lies in §103 combinations anchored on US 5,052,029 (timestamped sync signal with a medium-busy delay count) and WO 91/07030 (wireless transmit-time stamp with propagation-delay adjustment), optionally with EP 0 452 124 (wireless interval synchronization) and US 5,371,733 (delay-compensated counter loading).

E. Caveats, contradictions, and search notes

• Contradiction flagged (per the earlier sections): Google Patents lists the '867 original assignee as Agere Systems LLC, while the Taiwanese TIPO case study (and the actual assignment records: inventors → NCR, eff. 1993‑11‑04) identify NCR Corporation as the practical original owner. The assignment chain (NCR → AT&T → Lucent → Agere) supports NCR. I do not resolve this; I flag it as an unresolved bibliographic discrepancy.
• No 2026 activity; no reexamination found. I found no 2026 CAFC docket and no ex parte reexamination or IPR tied to the '867 patent (consistent with its 2016‑03‑16 lapse and 2014‑02‑23 adjusted expiration). The prior art that mattered was that considered during original prosecution (listed above).
• Litigation did not produce new §102 art of record here. In ITC Inv. No. 337‑TA‑837 the ALJ found no violation as to any asserted claim of the '867 patent, and the Commission took no position on the '867 findings after the patent expired (Feb. 23, 2014). The validity/inequity-unenforceability attacks (RAND/FRAND, inequitable conduct) were rejected or not reached; no invalidity judgment on the '867 claims is documented in the sources retrieved.
• Uncertainty I will not paper over: I could not independently pull the full specification text of every Tier‑2/Tier‑3 reference to the granularity needed to confirm every claim element. For those, I rely on the reference titles, assignees, dates, and abstracts in the patent record plus the retrieved records; the §102/§103 assignments for those are preliminary. The high-confidence §102-relevance statements are limited to the four Tier‑1 references (US 5,052,029; WO 91/07030; US 5,371,733; EP 0 452 124), each of which I verified against a full-text or PDF source.
• Sources: authoritative patent text (https://patents.google.com/patent/US6707867/en); US5052029; WO1991007030A1; US5371733; EP0452124A2; ITC/FR notices (govinfo.gov, FR‑2014‑05134); Federal Circuit 14‑1410 opinion (cafc.uscourts.gov).

If you want, I can next (a) pull the full claim charts comparing US 5,052,029 and WO 91/07030 element-by-element against independent claim 1, or (b) retrieve the complete texts of the Motorola battery-saving references (US 5,230,084 / US 5,251,325) to firm up the §102 treatment of dependent claims 2/21/57.

I'll gather details on the key prior-art references cited on the patent page before building the obviousness analysis.

Let me gather detail on the remaining key references, particularly the NCR system and the synchronization-signal and TDM power-saving references.

Obviousness Analysis — U.S. Patent No. 6,707,867 B2 under 35 U.S.C. § 103

Note on scope and sources. Per your instruction, I am building this analysis on the Prior Art section of the patent page — i.e., the "Citations (14)" list and the "Family Cites Families (15)" list. I retrieved and verified detailed text for the references I consider the primary §103 references (US 5,371,733; WO 1991/007030; US 5,280,629; US 5,230,084; EP 0 452 124 A2). For the remaining cited references I am working from their titles, assignees, dates, and the portions surfaced in search; I flag those where I could not retrieve full text. This builds on, and does not repeat, the summary and litigation sections already generated.

Governing law: Because the '867 patent claims priority to 6 March 1993, pre-AIA § 103 governs (the AIA first-inventor-to-file provisions apply only to applications filed on/after 16 March 2013). The analysis therefore applies Graham v. John Deere, 383 U.S. 1 (1966); KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007); and the Federal Circuit's "motivation to combine" line of cases (In re Keller, In re Merck, In re Kahn). Under KSR, a combination is obvious where an element is "known in the field and used for its established function," or where it is "a predictable variation using a known technique."

1. Level of ordinary skill in the art (POSITA)

A person of ordinary skill in the art as of March 1993 would be a communications engineer with a bachelor's degree in electrical engineering (or equivalent) and 2–4 years of experience designing radio communication systems, packet/medium-access protocols, or selective-call (paging) receivers — or a master's degree with 1–2 years. That person would be familiar with: (a) frame/frame-sync structures in paging and packet radio; (b) battery-saver duty cycling in selective-call receivers; (c) carrier-sense medium access; and (d) the use of a stamped reference time to align a remote clock. All four bodies of knowledge are directly evidenced by the cited art itself.

2. Construction of the limitations that drive the analysis

3. Scope and content of the prior art (the cited references)

3.1 Primary references (full text verified)

(A) WO 1991/007030 A1 — Motorola, "Distributed synchronization method for a wireless fast packet communication system" (pub. 16 May 1991; priority 24 Oct 1989).
This is the most dangerous reference. It discloses a wireless fast-packet system in which a packet node inserts a time-of-transmission stamp, and the receiving terminal "extracts the time-of-transmission … and compares it to the reception-time stamp …, adjusting for propagation delays in the buffers and communications equipment." It also expressly describes a contention-based medium: in the packetized-data area "each device is free to broadcast at any time, and is responsible for detecting collisions," with an algorithm "in software [that] compensates for the different arrival times." Thus WO '030 discloses, in a wireless system, (i) timestamping a transmission with the transmitter's time, (ii) a receiver retrieving the stamp and correcting for delay, and (iii) a shared medium on which transmission timing is variable due to contention/collisions.

(B) US 5,371,733 — Denneau et al., IBM, "Method and apparatus for centralized determination of virtual transmission delays in networks of counter-synchronized communication devices" (filed 4 Mar 1993; issued 6 Dec 1994).
Discloses a network of counter-synchronized nodes, each "synchronized by its own nodal time counter," in which the central node sends a synchronization message indicating the nodal time value to which the receiving node's time counter is to be set (claim 6), and in which "said nodal time value … is the sum of the virtual transmission delays … reference time corresponding to the time of transmission of said synchronization message … and the known execution delay at said terminating node" (claim 7). This is, verbatim in substance, "transmit a signal containing the transmitter's timer value at transmission time; load it into the receiver's timer." Timing caveat: '733 was filed 4 March 1993, only two days before the '867's 6 March 1993 GB priority date, so it qualifies as § 102(e) art only if the applicants' invention date is not earlier than 6 March 1993; this is a contestable but generally available date. I flag this rather than resolve it. (If '733 is excluded on invention-date grounds, its teaching is nonetheless cumulative of WO '030 and US 5,280,629.)

(C) US 5,280,629 — Hiben & Cudak, Motorola, "Technique for measuring channel delay" (filed 6 Dec 1991; issued 18 Jan 1994).
Discloses a prime station that, "simultaneously sends a first message to the remote site, the first message including T1" (the prime clock value at send time); the remote "simultaneously determines T2" on receipt; and the remote computes the delay "based on the difference between T2 and T1." This is timestamp-in-message + receiver-side delay computation, with express teaching that the one-way forward delay (not merely round trip) is the quantity to be compensated. Directly supports the "compensation factor" dependent claims and the "timestamp at transmission time" limitations.

(D) EP 0 452 124 A2 — NCR International, Inc., "Wireless information transmission system" (pub. 16 Oct 1991; priority 11 Apr 1990).
This is the same-field, same-applicant reference (NCR is the '867's original assignee). It discloses a wireless LAN in which "all transmissions take place over the same frequency channel," in which a distribution system transmits "heartbeat packets HBT … at regular intervals defining first timing intervals T1," which "are received by all the stations … and are recognized as heartbeat packets," and in which each station has a timing control circuit 52 with timer devices and a carrier-detect signal (line 51/75). It thus supplies the environment of the '867 claims (wireless LAN + base/distribution station + periodic sync packets + timers + carrier sensing) and the motivation to keep station timers synchronized.

(E) US 5,230,084 — Motorola, "Selective call receiver having extended battery saving capability" (filed 6 Dec 1990; issued 20 July 1993).
Discloses a receiver with a timer/counter 728 synchronized with the incoming data stream, operating an "extended battery saving routine" in which the receiver skips batches/frames, plus "counter/timer synchronization" firmware. Directly supports the dependent wake-from-sleep claims (2, 21, 57) and supplies the reason to synchronize: skipping periods to save battery.

3.2 Secondary references (titles/dates/assignees verified; full text not retrieved)

• US 4,403,212 (NEC) and US 4,745,408 (NEC) — radio paging systems/receivers; synchronous frame structures with address fields and battery saving.
• US 4,897,835 (At&E) — "High capacity protocol with multistation capability" (multistation frame protocol).
• US 5,150,361 (Motorola) — "Energy saving protocol for a TDM radio" (base/portable synchronization + battery saver).
• US 5,251,325 (Motorola) — "Battery saving method and apparatus for providing selective receiver power switching."
• US 5,252,963 (Motorola) — "Selective call receiver" (address decoding + battery saving).
• US 5,187,471 (Toshiba) — "Radio telecommunication apparatus."
• US 5,278,892 / US 5,305,308 (AT&T Bell Labs) — mobile-telephone call processing / wireless access network architecture.
• US 4,569,042 (AT&T) — "Time measurements in a transmission path."
• US 5,255,291 (Stratacom) — "Microprocessor based packet isochronous clocking transmission system and method."
• US 5,050,209 (Apple) — "Self-correcting synchronization signal method and apparatus."
• US 4,713,808 (At&E) — watch pager system and communication protocol.
• US 4,731,768 (Tektronix) — "Autoranging time stamp circuit."
• US 4,920,534 (AT&T) — packet information field handling.
• US 5,530,915 / US 5,485,632 (Motorola) — simulcast transmit-time determination.
• US 6,167,268 (Motorola) — controlling scanning of a subscriber unit.

4. Obviousness grounds

The claims cluster into four families. I give a ground for each.

Ground 1 — Wireless LAN + timestamp-at-transmission: claims 1, 7–8, 42–45

Combination: WO 1991/007030 (Motorola) in view of EP 0 452 124 (NCR), further in view of US 5,230,084 (Motorola).

• WO '030 discloses the timestamp-at-transmission and receiver-retrieval structure, and discloses a contention medium ("free to broadcast at any time … responsible for detecting collisions") with software compensation for varied arrival times. That squarely meets the "accounts for delays due to a busy signal on a medium access protocol" and "accounts for a delay between a start of a process to transmit … and an actual time of transmitting" limitations, because the stamp is taken at the actual transmission instant on a shared medium — not at a nominal schedule.
• EP '124 supplies the missing WLAN concreteness: a single-frequency wireless LAN with an access/distribution station and periodic packets, station timers, and carrier detection. A POSITA implementing WO '030's wireless packet system in NCR's WLAN would keep the shared-channel/carrier-sense structure of EP '124 while taking WO '030's transmit-time stamp.
• US 5,230,084 supplies the motivation: precise receiver-timer synchronization enables extended battery saver duty cycles.
• KSR rationale: (i) combination of known elements (transmit-time stamp; wireless LAN; periodic sync packets) to yield the predictable result of an aligned receiver timer; (ii) use of a known technique (stamping at the actual, post-contention transmit instant) to improve a similar device (periodic WLAN signal) in the same way; (iii) the '867 specification itself concedes that "delays in accessing the wireless medium" are the problem to be solved, which supplies the design incentive. Reasonable expectation of success is high — the references already perform the identical alignment for other delay sources.

Strength: Moderately strong. The one genuine gap is that no single reference states in words "the timestamp is taken because of CSMA/CA backoff." WO '030's contention/compensation teaching plus the admitted problem bridges that gap, but a fact-finder could find the bridging argument conclusory.

(Claim 42's "loaded … at a given time that, with regard to delays in a modem of the transmitter, is an estimate of the time at which the transmission signal will be transmitted" is met by WO '030's "adjusting for propagation delays in the buffers and communications equipment" and by US 5,280,629's transmit-time T1.)

Ground 2 — Retrieval + adjustment + count sequence: claims 9–12, 26–33, 49–61, 62–69

Combination: US 5,371,733 (IBM) in view of WO 1991/007030 (Motorola) and US 5,280,629 (Motorola).

• US 5,371,733 discloses a receiver that "initializ[es] its nodal time counter" to a value carried in a synchronization message, where that value equals the reference/transmit time plus delay components (claims 6–7). This maps onto claim 9's "retriev[e] the timestamp … adjust[] the value … commencing a synchronizing count sequence beginning at the [adjusted] value," and onto claims 49/62's "receiver timer commences a count sequence based on the value m."
• US 5,280,629 supplies the adjustment/compensation step: compute D = T2 − T1 and correct for the measured one-way delay. This maps onto claims 10–12, 29–31, 54–56, 67–69 ("compensation factor" for propagation and for processing time).
• WO '030 supplies wireless applicability and the medium-access/actual-transmit-time overlay from Ground 1.
• KSR rationale: substitution of one known clock-alignment mechanism (IBM's sync-message → counter-initialize) for another (Motorola's stamp-and-compare) in the same wireless synchronization context is a predictable variation; and the compensating delay term of '629 is "used for its established function." In re Keller (obviousness is not defeated merely because references differ in structure).

Strength: Strong for claims 9–12 (the timestamp-loads-receiver-counter mechanism is squarely in '733 + '629). Weaker, but still respectable, for claims 49/62's wireless-LAN framing absent WO '030/EP '124.

Ground 3 — Traffic-pending and timer-interval fields: claims 6, 13, 16, 17, 23, 34–36, 60–61, 72–74

Combination: any of Grounds 1–2 in view of the selective-call/paging references (US 4,403,212; US 4,745,408; US 5,252,963; US 5,230,084) and/or EP 0 452 124.

• The traffic-pending field (which stations have buffered data) is the conventional selective-call address field of paging: NEC's '212/'408 and Motorola's '963 disclose transmitting station addresses/message vectors so that only addressed receivers stay awake. EP '124's information packet likewise carries a destination address (DA) portion. Mapping "stations for which the transmitter has data buffered" onto a paging address/message-pending field is a straightforward, established use.
• The timer-interval field (interval n between periodic transmissions) is inherent in the fixed, synchronous frame structures of '212/'084/EP '124 (frame/cycle identifiers and fixed frame periods). Conveying the interval to the receiver is a predictable design choice to let the receiver self-time between receptions.
• KSR rationale (i): combination of known elements according to known methods to yield predictable results. The traffic-pending and interval fields are data payloads placed in an already-known periodic sync packet; their addition does not change the principle of operation of the synchronization.
• Claim 17 / 36 / 74 (broadcast-pending field) — this one is weaker. I could not retrieve a cited reference expressly teaching an "outstanding broadcast packets" count. This limitation is best attacked as an obvious design choice (a counter for group-addressed traffic) or on the record that broadcast/multicast handling was routine; but absent a specific reference it is the least vulnerable of the dependent fields. Flag for further search.

Strength: Moderate-to-strong for the traffic-pending and interval fields; weak for the broadcast-pending field.

Ground 4 — Wake-from-sleep and frequency control: claims 2–3, 21–22, 57

Combination: Ground 1 or 2 in view of US 5,230,084 alone, optionally with US 5,150,361.

• US 5,230,084 expressly discloses synchronizing a receiver timer/counter to the incoming stream and using it for an "extended battery saving routine" (skipping assigned batches). That is claim 2/21/57 almost verbatim ("periodically waking the receiver from a sleep mode … based on output from the receiver timer").
• Claim 3/22 (frequency-hopping control from the same receiver timer) is the weakest limitation in the patent. None of the cited references that I could verify discloses frequency hopping, and the '867 specification introduces it only as an alternative embodiment. An examiner would likely have to rely on (a) the general knowledge that frequency-hopping radios change channels on a schedule and therefore need a synchronized time base, plus (b) US 4,403,212/'835-type multi-channel paging protocols, or (c) an additional, uncited frequency-hopping synchronization reference. I cannot make out a clean § 103 case on claim 3/22 from the cited art alone — treat this as the claim most likely to survive on the cited record.

Ground 5 — CRC / complete-receipt synchronization: claims 4–5, 27–28, 58–59, 70–71

Combination: Ground 2 in view of the conventional CRC practice reflected in US 5,050,209 (Apple, "Self-correcting synchronization signal") — or as a design choice.

Delaying the commit of a synchronization value until the frame is fully received and its CRC validated is the ordinary, predictable way to avoid corrupting a free-running counter on a bad frame. Under KSR, "the use of a known technique to improve a similar device in the same way" makes this obvious; alternatively it is a routine design choice with no unexpected result. (I did not retrieve the '209 text; its title — "self-correcting synchronization signal" — is consistent with, but not proof of, this teaching, so I offer it as corroboration, not as the primary reference.)

5. Unified motivation to combine

A POSITA in March 1993 had strong, articulated reasons to combine these references, each independent of hindsight:

1. Same field / same problem. Every one of the primary references addresses the same problem the '867 addresses — keeping a receiver's timing aligned to a transmitter's periodic signal in a radio system — and most address the same application (extended battery saver duty cycling). In re Merck: a motivation may be implicit in the problem to be solved.
2. Common assignee/lineage. EP 0 452 124 is an NCR wireless-LAN reference; the '867 is an NCR-originated family. Combining an NCR WLAN environment with a Motorola timestamp synchronization is a combination a POSITA would readily make, given that both were published cooperative work in the identical technology.
3. The patent's own admission. The '867 Background concedes that "accurate synchronization between a transmitter and a receiver in a BSA cannot be readily achieved due … to … delays in accessing the wireless medium." That admission supplies the design incentive to sample the timestamp at the post-contention transmit instant (the "busy signal" limitation), which is exactly what WO '030 and US 5,280,629 teach doing for other delay sources.
4. Reasonable expectation of success / predictable results. Each individual technique (stamp the transmit time; retrieve it; load the counter; add a delay correction) was known; the combination merely aggregates them with no unexpected interaction. KSR: aggregation of known elements with predictable results is obvious.
5. Market pressure. The economic driver for the whole art — lengthening battery life in portable stations — is recited throughout the references ('084, '212, '408, '325, '963, '361) and the '867 itself.

6. Secondary considerations (objective indicia) and counterweights

The previously generated sections establish facts that bear on Graham factor 4:

• Industry adoption / standardization. The '867 (with US 7,289,578) was declared standard-essential to IEEE 802.11 (Wi-Fi), and the Realtek v. LSI/Agere RAND litigation set a RAND royalty of 0.07% for the '867. Adoption into a standard can support non-obviousness if there is a nexus between the claimed feature (the busy-signal-compensated timestamp) and the standard's requirement. But the counter-argument is strong: a standard may adopt a technique because it is the obvious/necessary way to synchronize a contention-based LAN, and the extraordinarily low 0.07% RAND rate tends to undercut any claim of exceptional commercial value or "long-felt need."
• Validity has not been adjudicated on the merits. In the earlier litigation section, I noted that the ITC (337-TA-837) ALJ found no violation as to the '867 (i.e., non-infringement) and the Commission took no position because the patent expired (23 Feb 2014) before any validity determination. So there is no adjudicated validity holding to cite in favor of non-obviousness, and equally no invalidity judgment.
• No unexpected results. The specification reports no result that would be unexpected to a POSITA — the power-savings arithmetic (7 msec awake per 30 sec) follows directly from accurate synchronization and is a predictable benefit of precise timer alignment, which the cited art already motivates.

7. Conclusion and ranked assessment

Bottom line. All of the independent claims are vulnerable to a § 103 challenge, with the strongest attack against the "retrieve-and-adjust-the-count" family (claims 9–12 and their receiver/method counterparts) using US 5,371,733 in view of US 5,280,629, and against the power-save dependent claims using US 5,230,084. The claims that turn on the busy-signal/CSMA-CA delay and the frequency-hopping limitations are the ones where a combination-of-references case is weakest, because the cited art does not, on the record I verified, address medium-access contention as a distinct delay source or address frequency-hopping synchronization at all. Those two features — not the basic timestamp idea — are where the '867's claims retain their best non-obviousness argument.

8. Confidence and caveats

• Verified full text: WO 1991/007030; US 5,371,733; US 5,280,629; US 5,230,084; EP 0 452 124 A2. My mappings for these are grounded in retrieved text (URLs: patentimages.storage.googleapis.com/.../US5371733.pdf; patents.google.com/patent/WO1991007030A1/en; ptacts.uspto.gov/.../US5280629 and uspto.report/patent/grant/5280629; uspto.report/patent/grant/5230084; patents.google.com/patent/EP0452124A2/en).
• Not verified (title/date/assignee only): US 4,403,212; US 4,745,408; US 4,897,835; US 5,150,361; US 5,251,325; US 5,252,963; US 5,187,471; US 5,278,892; US 5,305,308; US 4,569,042; US 5,255,291; US 5,050,209; US 4,713,808; US 4,731,768; US 4,920,534 and the simulcast references. Any of these could strengthen or weaken a specific ground; a full-text pull is needed before filing an invalidity contention.
• Date flag on US 5,371,733: filed 4 March 1993, two days before the '867's GB priority date. Its availability as § 102(e) art depends on the applicants' invention date; if that is earlier than 4 March 1993, '733 drops out (and WO '030/US 5,280,629 carry the ground).
• No per se holding: Under KSR, this is a prima facie § 103 case, not an anticipation case; each combination must be tied to a concrete motivation, and I have identified those motivations above. Conclusory "these references are in the same field" reasoning would be insufficient.