US 6295286

I'll search for the specific patent number 6295286 in the USPTO and CAFC records.

Let me check for any CAFC litigation records involving this patent and verify the USPTO bibliographic data.

Let me do one final check specifically for CAFC 2026 docket appearances.

Summary of U.S. Patent No. 6,295,286

Bibliographic data (verified against USPTO/Google Patents records):

• Title: Method for indicating a multi-slot channel in a TDMA radio system
• Patent / Publication No.: US6295286B1
• Application No.: US 08/836,969
• Inventor: Jussi Rajala
• Original Assignee: Nokia Mobile Phones Ltd. (later assigned through Nokia Corporation to Vringo Infrastructure Inc. / Vringo, Inc.; Google Patents lists "Current Assignee" as Vringo Infrastructure Inc.)
• Filing date: November 24, 1995
• Priority date: November 25, 1994 (Finnish application FI945540; PCT/FI1995/000651 → WO1996017447A1)
• Issue date: September 25, 2001
• Legal status: Expired – Lifetime (maintenance fees paid through the 12th year; anticipated expiration shown as 2015-11-24; Google's family data flags the family as having litigation, but I found no specific CAFC 2026 docket entry for this patent number)

Abstract (condensed): A method for indicating a multi-slot channel in signaling to a radio terminal in a TDMA radio system without increasing the amount of signaling versus normal single-slot channel assignment. An element of the normal signaling message that describes the channel is transformed into a code that identifies the channel as a multi-slot channel and sets the number of successive slots included; the element that normally indicates the timeslot is reused to indicate the first slot of the multi-slot channel. In the GSM embodiment, the 5-bit CHT element (channel type and subchannel) is replaced with a code whose first two bits ("11") mark a multi-slot channel and whose remaining three bits set the slot count; the TN (timeslot number) element indicates the first timeslot.

Claims overview: The patent has 5 claims — one independent claim (claim 1) and four dependent claims (claims 2–5). No other independent claims exist.

• Claim 1 (independent): A method for indicating a multi-slot channel in signaling to a TDMA radio terminal, where a normal radio channel uses one timeslot per frame, and channel assignment uses a message containing a first element identifying one timeslot and at least one second element describing the channel. The method comprises (a) to assign a multi-slot channel, replacing at least one second (channel-describing) element with a code that (i) identifies the channel as multi-slot and (ii) defines the number of timeslots in the multi-slot channel, and (b) using the first (timeslot-indicating) element to point to a certain timeslot (e.g., the first) among those included timeslots. In short: signal multi-slot allocation by repurposing/overloading the existing channel-type field with a multi-slot count code, and reuse the ordinary timeslot field as the starting slot — no extra signaling messages needed.

• Claim 2 (dependent): The second (replaced) element is the one defining the channel type.

• Claim 3 (dependent): Limits the method to a GSM system, where the message includes a Channel Description Information Element containing a TN element (timeslot) and a CHT element (channel type and subchannel); the CHT element is replaced with the multi-slot code and the TN element indicates the first successive timeslot of the multi-slot channel.

• Claim 4 (dependent): In the CHT element's five bits, the two first bits identify the multi-slot channel and the three remaining bits set the number of successive timeslots.

• Claim 5 (dependent): The two identifying bits are "11."

Plain-language takeaway: The invention avoids the overhead of sending a separate channel-description message per timeslot when a mobile needs several consecutive TDMA slots for higher data rates. Instead, it overloads the existing channel-type/subchannel field (CHT in GSM) with a special code — reserved bit pattern "11" plus a 3-bit count — so the same single assignment message conveys "N consecutive slots starting at timeslot TN." Because GSM frames have 8 slots, 3 bits (8 values) suffice for the slot count.

Uncertainty / caveats: My searches of the USPTO records and CAFC 2026 dockets did not surface any pending 2026 Federal Circuit appeal docketed under this specific patent number (the Google Patents "family has litigation" flag and the Darts-ip link indicate past family litigation, but I could not confirm any CAFC 2026 matter for patent 6295286 itself). The bibliographic details above come from the authoritative Google Patents/USPTO-sourced record supplied in the prompt, which matched the live search results. I could not independently verify current USPTO assignment-chain status beyond the events shown in the record (Nokia Mobile Phones → Nokia Corp. → Vringo Infrastructure Inc., with security-interest transfers involving Vringo, Inc. and Iroquois Master Fund).

I'll search for litigation records involving US patent 6295286.

Let me search more specifically for litigation databases and the Vringo/Nokia patent assertion campaigns.

Let me search the Unified Patents litigation portal and other specific sources for this patent number.

I was unable to complete additional searches (step limit reached), but here is what I was able to confirm — and, importantly, what I could not confirm.

Bottom line

I did not identify any specific, docketed litigation that names US Patent 6,295,286 as an asserted patent. My searches did not surface a case number, plaintiff, or defendant tied to this patent. I am flagging this as a negative finding, not a positive one — it reflects the limits of my search, not proof that no such case exists.

What I did confirm (and why it may or may not relate to this patent)

1. Google Patents' litigation flag (from the authoritative record in the prompt). The patent-page metadata shows a "Family has litigation" flag with a link to Darts-ip family tracking (family=8541870). This is a family-level flag, not a case caption. It indicates that some member of the global family (e.g., the DE, GB, FR, SE, FI, CN, KR, JP, WO siblings) has appeared in a tracked litigation dataset. It does not establish that US 6,295,286 itself was asserted, and it gives no plaintiff, defendant, jurisdiction, case number, or date.

2. Vringo Infrastructure's acquisition of the Nokia portfolio. This patent's assignment chain runs Nokia Mobile Phones → Nokia Corporation → Vringo Infrastructure Inc. (effective 2012‑09‑10), with later security-interest transfers to Vringo, Inc. and Iroquois Master Fund, L.P. Vringo Infrastructure acquired a large Nokia wireless-infrastructure SEP portfolio in August 2012 and launched assertion campaigns against ZTE (globally) and others.

3. But the Vringo cases I could actually identify assert different patents. The high-profile Vringo/I‑P Engine matters — against Google, AOL, IAC Search & Media, Gannett, and Target (E.D. Va., Judge Raymond A. Jackson; case 2:11‑cv‑00512‑RAJ‑TEM, filed Sept. 15, 2011) and against Microsoft (S.D.N.Y., settled for $1M in 2013) — asserted US 6,314,420 and US 6,775,664 (the Lycos search patents), not US 6,295,286. The ZTE assertions I saw referenced EP 1,808,029 (Romania) and other FRAND/SEP matters, again not this patent.

So the widely reported "Vringo litigation" is a false lead for this particular patent number — those suits involve different patents in the portfolio. I want to be explicit about that so you don't mis-attribute the Google/Microsoft/ZTE cases to 6,295,286.

Caveats on my process

• I searched general web sources and the Unified Patents portal documentation, but I could not directly query the Unified Patents litigation case list, PACER, or Darts-ip for the exact string "6295286," so I cannot rule out a case that exists only in those databases.
• The prompt directs me to interpret identifiers literally and not auto-correct them. Accordingly, I did not treat any case involving similarly numbered patents (e.g., 6,292,xxx or family members) as involving 6,295,286.
• Note a date discrepancy to flag: the task header states "Current Date: April 26, 2026," while the system context date is 2026‑09‑10. I did not find any 2026 Federal Circuit docket entry for this patent in either framing.

Recommended next steps for a definitive answer

If you need a verified negative or a full case list, these are the authoritative sources to pull directly:

• Unified Patents Portal → Litigation → Case List, filter by patent number 6295286 (also shows PTAB/IPR history).
• PACER / CourtListener (RECAP) search on "6,295,286."
• Darts-ip family ID 8541870, following the specific link the patent record provides.
• USPTO PatentCenter / Assignment for the full assignment chain (transfers do not by themselves indicate litigation, but the security-interest events can correlate with enforcement activity).

Honest conclusion: On the evidence available to me, I found no confirmed litigation specifically involving US 6,295,286. The only litigation indicator is the Google Patents family-level "has litigation" flag pointing to Darts-ip family 8541870 — which I could not resolve into a case caption, party list, jurisdiction, case number, or date. I would not represent to a client that this patent has been litigated without first checking the sources above directly.

I'll verify the canonical "no proceedings" result against live sources before writing.

PTAB / AIA Trial Analysis — U.S. Patent No. 6,295,286

Verification note up front: This report is built on the canonical structured block in the prompt (USPTO Open Data Portal: no AIA trial proceedings on file for US 6,295,286), cross-checked against live web sources. My live searches returned zero hits tying this patent number to any IPR, PGR, or CBM docket, any PTAB Final Written Decision, or any Federal Circuit appeal. I have deliberately not generated proceeding numbers, panel rosters, or outcomes, because doing so would require fabrication. Where I could not verify something, I say so.

Proceedings overview

Total AIA trial proceedings on US 6,295,286: ZERO — 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution-denied.

The bottom-line defensive posture is therefore neither of the prompt's two archetypes. This patent is not "hardened" by surviving IPRs (it has never been tested at the Board, so there is no PTAB claim-construction record, no FWD to leverage, and no § 315(e) estoppel working in anyone's favor). But it is also not a dead letter to be avoided — quite the opposite: with a priority date of 1994-11-25 and a statutory expiration of 2015-11-24 (12th-year maintenance fee paid 2013-03-21, per the Google Patents legal-events record), the patent has been expired for roughly a decade. A demand citing it in 2026 has no prospective-infringement theory and, as explained below, almost certainly no recoverable past-damages theory either.

Why there are no per-proceeding entries

There is nothing to populate the ### {PROCEEDING_NUMBER} — {Petitioner} v. {Patent Owner} template with. The absence is explainable on the timeline rather than by accident:

• The AIA trial regime (IPR/PGR) began 2012-09-16. This patent had already been in force for ~17 years by then and expired 2015-11-24, leaving a practical ~3.2-year window in which it could have been challenged while it still had commercial life.
• In that window, the operating entity that acquired the Nokia portfolio — Vringo Infrastructure Inc. (assignment effective 2012-09-10, per the record) — was litigating against Google, Microsoft and ZTE, but the patents actually in suit were different Nokia/other assets (e.g., US 6,314,420 and US 6,775,664 in Vringo v. Google; and the five Vringo patents ZTE sought ex parte reexamination on in February 2015: US 7,558,283, US 6,081,534, US 7,126,940, US 5,689,252, US 7,724,720). US 6,295,286 appears in none of those campaigns based on my searches.
• I found no evidence of an ex parte reexamination, reissue, or Director Review touching this patent either (lower confidence on reexam — I did not exhaustively query the reexam database).

Cross-reference check against the earlier section

The prior summary flagged that the Google Patents family record (family ID 8541870) carries a "Family has litigation" marker and a Darts-ip link, while also noting that no specific 2026 CAFC docket was found for this patent number. I confirm that distinction and want to make it explicit: a family-level litigation flag is not a PTAB proceeding and is not proof that US 6,295,286 itself was ever asserted. The Darts-ip link is attached to the worldwide family (which includes WO1996017447A1, GB2295525B, DE19543253A1, FR2727591B1, SE508766C2, FI99076C, CN1084985C, KR100351604B1, AT407318B, ES2113810B1, NL1001744C2, AU695635B2, JPH10510111A), and family-level litigation data commonly reflects foreign counterpart actions. I could not verify any U.S. district court complaint asserting US 6,295,286. Treat that as unconfirmed, not as disproven.

Strategic summary

Claim status of US 6,295,286 (claims 1–5):

So: canceled = none; sustained = none; narrowed by amendment = none; untested = all five. All five claims carry the § 282 presumption of validity in the abstract, but that presumption has never been litigated at the Board for this patent.

Estoppel landscape: There is no § 315(e)(1)/(2) estoppel anywhere on this patent, because there has been no petitioner, no institution, and no FWD. No party is barred from raising any § 102/§ 103 ground. Conversely — and this is the practical point — there is no favorable estoppel or canceled claim to hand a defendant either. § 325(d) and Fintiv/§ 314(a) discretionary-denial arguments are irrelevant here; there is no parallel ITC or district court track to weigh.

Fresh-challenge availability, and why it doesn't matter: Nothing on the face of the statute prevents filing an IPR against an expired patent (the Board applies Phillips-style construction in expired-patent IPRs), and absent a served complaint more than one year earlier there is no § 315(b) bar. But two things blunt the value: (i) the accused-acts window is gone — the patent could only be infringed by acts on or before 2015-11-24, and under 35 U.S.C. § 286 damages reach back only six years from filing, which closed around 2021-11-24; and (ii) a PTAB win on an expired patent buys a declaratory-style record, not freedom to operate. If a demand letter arrives citing claims 1–5, the cheapest and strongest response is the expiration/limitations argument, not a $300k+ IPR.

Pattern signals: No repeat petitioner (there are no petitioners at all). No PTAB appeal history, hence no Vringo Infrastructure v. Google-style CAFC appeal traceable to this patent number. I found no evidence of a defensive aggregator such as Unified Patents filing on this patent. The only portfolio-defense activity I could document in the relevant timeframe is ZTE's February 2015 ex parte reexamination requests against five different Vringo patents, plus the German and Chinese invalidation proceedings noted in press coverage — none involving 6,295,286.

Recommended next steps

If you are a defendant or demand-letter recipient on US 6,295,286:

1. Lead with expiration and § 286. The patent expired 2015-11-24 (Google Patents legal-events: anticipated expiration, 12th-year fee paid 2013-03-21). There is no prospective injunctive exposure and the past-damages tail closed ~2021-11-24. Ask the asserting party to identify the accused acts, the accused products, and the good-faith basis for a claim whose enforcement window has lapsed.
2. Do not default to an IPR. There is no claims-canceled FWD to cite (nothing to quote — I will not invent one), and there is no active PTAB matter with trial-stage milestones to track (no institution-decision deadline, no oral hearing, no 1-year FWD due date, because no petition exists).
3. If you nonetheless need a PTAB record (e.g., for settlement leverage, a co-pending DJ, or to moot a nuisance claim), the challenge would be a straightforward § 102/§ 103 IPR on claims 1–5. The natural starting art is already in the patent's own IDS/citation list — EP 0 399 611 A2 (the specification's own admitted prior art), WO 94/08431 A1, EP 0 605 312 A1, US 5,515,379, WO 95/31878 A1, and US 5,577,024. Note the one-year § 315(b) clock starts on service of a complaint, not a demand letter.
4. Preserve the record of your verification. Print/save the Google Patents record showing expiration and the ODP "no proceedings" result, so the assertion can be rebutted on day one.

Where to independently re-verify (all public):

• PTAB E2E / Patent Trial Appeal Board docket search: https://ptab.uspto.gov — search "6295286" and "US 6,295,286" in the Proceedings tab.
• USPTO Open Data Portal (AIA trial proceedings API), the canonical source for this report: https://data.uspto.gov (search endpoint for trial proceedings by patent number).
• Google Patents record (used for bibliographic and legal-events data): https://patents.google.com/patent/US6295286/en
• Darts-ip family-litigation link from the Google Patents page (family 8541870) — for tracing the family-level litigation flag to its actual cases; treat any hit here as a lead to confirm patent-number-to-case mapping before relying on it.
• CourtListener / Federal Circuit docket search: https://www.courtlistener.com — for any § 319 appeal of an FWD (none found) and for district court complaints asserting 6,295,286.

Confidence and limits: High confidence that no AIA trial proceeding exists on US 6,295,286 — the USPTO ODP structured block is canonical and my live searches returned nothing contradicting it. Medium confidence that the patent was never asserted in a U.S. district court case (I could not rule out a complaint that is not well indexed). Lower confidence on negative results for ex parte reexamination and foreign counterpart litigation, which I did not exhaustively query. If any of these surface in your own docket check, the analysis above should be updated — and if a reexam certificate issued that canceled or narrowed claims, that would materially change the defensive posture.

I'll verify the assignment chain and identify the recorded correspondents and any litigation context before writing.

Inventors

Unusual-pattern check: No inventor-departure pattern. There is only one inventor, and he assigned to his employer. The only mildly notable timing is that the assignment was executed 1997-06-23 and recorded 1997-08-04 — roughly 19 months after the 1995-11-24 filing date. That lag is consistent with routine national-phase/PCT paperwork (PCT/FI1995/000651 entered the US as 08/836,969), not with a fire-sale signature. No evidence of an inventor exit within 12 months of filing.

Original assignee

Nokia Mobile Phones Limited (Finland) — named as assignee on the issued patent (Reel 008678/0213).

• Primary line of business: Design and manufacture of GSM cellular handsets and related radio infrastructure. Yes, it shipped products embodying the claims — this patent is a GSM air-interface signalling patent (CHT/TN channel-description fields), and Nokia was among the largest GSM terminal/infrastructure vendors. Multi-slot operation (HSCSD, later GPRS/EDGE) is precisely the functionality the claim enables on Nokia hardware.
• Current status: Nokia Mobile Phones Limited ceased to exist as a separate entity — it was merged into Nokia Corporation with legal effect 2009-09-11, recorded at USPTO on 2012-08-30 (Reel 028878/0811). Nokia Corporation divested its Devices & Services business to Microsoft (2014), but retained its patent portfolio; Nokia remains an operating company.
• Corporate lineage downstream: Vringo, Inc. (which became the parent of the patent-holding subsidiary) was renamed FORM Holdings Corp. on 2016-05-06, and that corporate shell subsequently became XpresSpa Group, Inc. / XWELL, Inc. Google Patents presently lists the "Current Assignee" as Vringo Infrastructure Inc.

Assignment timeline

Data-completeness caveat (important for the "correspondent" column below): The authoritative record supplied for this analysis (Google Patents, which mirrors USPTO assignment data) reproduces the reel/frame, conveyance, assignor, assignee, execution and recording dates, but it does not expose the attorney/agent "correspondent of record" for any of the six filings. I was unable to retrieve the Assignment Center correspondent fields (my search budget was exhausted before I could pull the underlying reel images). I therefore mark correspondents as not retrieved rather than guessing. This is a genuine gap, not a finding of "no correspondent."

1. Executed 1997-06-23 / recorded 1997-08-04 — Reel 008678/0213

• Conveyance: Assignment (assignment of assignors' interest)
• Assignor: Jussi Rajala (inventor)
• Assignee: Nokia Mobile Phones Limited (Finland)
• Correspondent: not retrieved from the record available to me
• Context: Routine inventor-to-employer assignment of a PCT national-phase application; executed ~19 months post-filing, typical paperwork lag.

2. Executed 2009-09-11 / recorded 2012-08-30 — Reel 028878/0811

• Conveyance: Merger
• Assignor: Nokia Mobile Phones Limited
• Assignee: Nokia Corporation (Finland)
• Correspondent: not retrieved
• Context: Internal corporate reorganization — upstream merger of the handset subsidiary into the parent; no change of beneficial control.

3. Executed 2012-09-10 / recorded 2012-09-24 — Reel 029010/0345

• Conveyance: Assignment of assignors' interest
• Assignor: Nokia Corporation
• Assignee: Vringo Infrastructure Inc. (New York)
• Correspondent: not retrieved
• Context: Portfolio sale / transfer to an asserter. Part of the publicly reported Patent Purchase Agreement dated 2012-08-09 under which Vringo, Inc. paid $22 million for >500 patents and applications (109 issued US patents), with Nokia retaining a paid-up field-of-use license, a 35% share of gross revenue above $22M, and a right to re-acquire the portfolio for a nominal amount if Vringo sued Nokia. (SEC Form 8-K, Vringo, Inc., event date 2012-08-10; payment made 2012-08-10.) The Nokia→Vringo record was executed one day after the announced closing.

4. Executed 2015-05-04 / recorded 2015-05-05 — Reel 035585/0371

• Conveyance: Security Interest (pledge of collateral, incl. patents)
• Assignor: Vringo Infrastructure, Inc.
• Assignee/secured party of record: Vringo, Inc. (New York)
• Correspondent: not retrieved
• Context: Securitization / collateral pledge tied to Vringo's May 2015 debt financing (8-K filed 2015-05-04, with Security Agreement and Patent Security Agreement exhibits). Patents pledged as loan collateral — a distress marker, not an ownership change.

5. Executed 2015-04-04 / recorded 2015-05-08 — Reel 035624/0710

• Conveyance: Assignment of Security Interest
• Assignor: Vringo, Inc.
• Assignee: Iroquois Master Fund, L.P. (New York)
• Correspondent: not retrieved
• Context: Transfer of the secured position to a distressed-debt fund — the lender's collateral position moved to Iroquois Master Fund. Note the recorded execution date (2015-04-04) precedes the execution date of the underlying security interest (2015-05-04), so the two 2015 filings were recorded as a coordinated package within four days.

6. Executed 2016-04-06 / recorded 2016-04-07 — Reel 038380/0956

• Conveyance: Release by Secured Party
• Assignor: Silicon Valley Bank (releasing secured party)
• Assignee/beneficiary of release: Vringo, Inc.
• Correspondent: not retrieved
• Context: Lien release after debt repayment. Consistent with Vringo/FORM's 2016 disclosures that, following repayment of the Amended Notes, "all liens on the Company's assets, including intellectual property, were released." Not an ownership transfer — the patent simply returned to an unencumbered state.

Note on subsequent activity: There is no recorded assignment after 2016-04-07 and no transfer to any defensive aggregator. Critically, the patent expired 2015-11-24 (20-year term from the 1995-11-24 US filing date), which is why the chain terminates in lien clean-up rather than further monetization sales.

Timeline diagram

timeline
    title Ownership of US 6295286
    1994 : Priority filing in Finland
    1995 : US and PCT filing 08/836969
    1997 : Rajala assigns to Nokia Mobile Phones
    2001 : Patent issued as US 6295286 B1
    2009 : Nokia Mobile Phones merges into Nokia Corp
    2012 : Nokia merger recorded reel 028878
         : 500 patent portfolio sold to Vringo
         : Assignment recorded reel 029010
         : Vringo asserts Nokia portfolio in litigation
    2015 : Patent expires at end of 20 year term
         : Patents pledged as loan collateral reel 035585
         : Collateral position sold to Iroquois reel 035624
    2016 : Lender lien released reel 038380

NPE / troll-pattern signals

1. Shell-entity transfer — PRESENT (qualified). The patent moved from operating company Nokia to Vringo Infrastructure Inc., a patent-holding/licensing subsidiary, per Reel 029010/0345 (executed 2012-09-10). The qualifying nuance: this is not an anonymous single-member Delaware LLC with a registered-agent address — the parent, Vringo, Inc., was a publicly listed company (AMEX/NASDAQ: VRNG) that in its own SEC filings described its business as "the innovation, development and monetization of mobile technologies and intellectual property," and after 2016 repositioned/rebranded as FORM Holdings and later XpresSpa Group. So the licensing-only character is documented, but the "hidden shell" tells (masked ownership, service address) are absent.

2. Known asserter in the chain — PRESENT (strong). Vringo is expressly on the public NPE/asserter list cited in this task. Assignee per Reel 029010/0345. Vringo's assertion activity is well documented: it litigated against Google over Lycos-origin patents (ad-insertion) and against ZTE — including a UK suit filed 2012-10-08 grounded on patents from the very Nokia portfolio acquired in August 2012. Caveat: I could not confirm US 6,295,286 specifically appears in any Vringo complaint, and ZTE's 2015 US re-examination requests targeted five other Vringo patents (US 7,558,283; 6,081,534; 7,126,940; 5,689,252; 7,724,720) — none of which is this patent. The asserter identity is confirmed; this patent's individual assertion history is not.

3. Repeat correspondent across the chain — UNCLEAR (data gap). The assignment data available to me does not include the correspondent of record for any of the six entries. I cannot confirm or deny a recurring filing attorney across Reels 008678/0213, 028878/0811, 029010/0345, 035585/0371, 035624/0710, 038380/0956. Per the task's own standard ("a single appearance is not a finding — the signal is recurrence"), this must be scored unclear pending retrieval of the reel images from the Assignment Center.

4. Cascading transfers — WEAK / PARTIAL PRESENT. Two clusters: (a) the 2012 pair — Nokia merger recorded 2012-08-30 (Reel 028878/0811) and the Nokia→Vringo sale recorded 2012-09-24 (Reel 029010/0345), 25 days apart; and (b) the 2015 pair — pledge recorded 2015-05-05 (Reel 035585/0371) and assignment of that security interest recorded 2015-05-08 (Reel 035624/0710), 3 days apart. However, cluster (b) concerns security interests, not ownership, so I do not count it as cascading ownership transfers through chained LLCs. Cluster (a) is a merger plus a sale, not a chain of purpose-built shell entities. Score: weak.

5. Pre-litigation transfer — UNCLEAR. The Nokia→Vringo assignment executed 2012-09-10 (Reel 029010/0345) and Vringo's UK ZTE complaint was filed 2012-10-08, i.e. within ~4 weeks — textbook pre-assertion timing at the portfolio level. But I cannot tie US 6,295,286 itself to that or any complaint, so the signal does not attach to this patent.

6. Bankruptcy fire-sale — NOT PRESENT. Neither Nokia nor Nokia Mobile Phones filed for bankruptcy; Nokia's 2012 patent sale was an asset-monetization step during restructuring. No Chapter 7/11 proceeding is evidenced for Vringo Inc./FORM Holdings in the material reviewed (its 2015–2016 distress manifested as secured lending and an impairment write-down of the patent asset group on 2016-05-06, not a bankruptcy estate sale).

7. Privateering — PRESENT (strong). The 2012 sale is a textbook privateering structure: Nokia, an operating company, transferred the portfolio to a dedicated licensing/assertion entity while retaining a non-exclusive, fully paid-up license for its own products, a 35% royalty on gross revenue above $22M, and a re-acquisition right triggered if Vringo sued Nokia. Nokia thus kept economic upside from Vringo's assertions while insulating itself from countersuit. Assigned via Reel 029010/0345; documented in Vringo's SEC Form 8-K (Patent Purchase Agreement dated 2012-08-09). Vringo's subsequent UK assertion campaign against ZTE on portfolio patents is the predicted downstream conduct.

8. Defensive aggregator (anti-NPE) — NOT PRESENT. The chain never reaches RPX, AST, LOT Network, Unified Patents, or OIN. The last ownership-affecting event is the 2012 transfer to Vringo Infrastructure; the 2015–2016 entries are a pledge, an assignment of that pledge to Iroquois Master Fund, L.P. (a distressed-debt fund, Reel 035624/0710), and a release (Reel 038380/0956). The patent was not neutralized by a defensive buyer — it simply expired 2015-11-24.

Verdict

NPE — high confidence.

Three independently sufficient signals attach to the record: (i) a known asserter is in the chain — the patent was assigned to Vringo Infrastructure Inc. by Reel 029010/0345 (executed 2012-09-10), and Vringo is a documented IP-monetization plaintiff; (ii) transfer to a licensing-only holder — the same reel moved the asset from operating company Nokia into Vringo's patent-holding subsidiary, whose parent's SEC filings describe an IP-monetization business model; and (iii) privateering — the 2012 Patent Purchase Agreement left Nokia with a field-of-use license, a 35% royalty share above $22M, and a re-acquisition right, i.e. the operating company retained upside from the buyer's assertion activity (matching the strong "NPE — high confidence" bar of 2+ strong signals). Offsetting context that keeps this from being a "pure shell" case: the recipient was a publicly traded asserter, and the patent expired 2015-11-24, so the post-2015 entries — the pledge to Iroquois Master Fund, L.P. (Reel 035624/0710) and the release by Silicon Valley Bank (Reel 038380/0956) — are collateral clean-up, not further monetization. The repeat-correspondent signal is unresolved because the correspondent fields were not retrievable from the record I had.

Verify against: USPTO Patent Assignment Search and Assignment Center — search patent 6295286, then pull the reel images for 008678/0213, 028878/0811, 029010/0345, 035585/0371, 035624/0710, 038380/0956 to capture the correspondents and close the one unresolved signal.

I'll search the USPTO and patent databases for US 6,295,286 and its cited references.

Let me gather details on the remaining cited references.

I've reached my search-step limit, so I'll now compile the prior-art analysis from the authoritative patent record (which contains the complete USPTO citation list for 6,295,286) plus the reference data I was able to retrieve. One flag up front: my searches were step-limited, so full-text descriptions could not be pulled for every reference — I mark those where I'm relying on the title/abstract and the patent's own characterization.

Prior-Art Analysis — US 6,295,286

0. Confirmation of the target patent

The number in the request resolves to a single, distinct document — do not conflate it with neighbors (e.g., 6,292,xxx, or family members GB2295525, FI99076, WO1996017447):

The record lists 10 backward patent citations ("Patent Citations (10)" and "Citations (10)"). These are the references below. (The record also shows forward "Cited By" documents and 4 "Family Cites Families" items; those are not §102 art against this patent's claims and are addressed at the end.)

1. The 10 cited references at a glance

(* = marked "Cited by examiner" in the record.) The §102(b) critical date is one year before the US filing, i.e. 1994-11-24 (foreign priority under §119 does not move the §102(b) date).

2. The single key limitation everything turns on

Claim 1 requires, in combination:

• (a) a TDMA channel normally = one timeslot/frame;
• (b) an assignment message containing a first element indicating one timeslot and at least one second element describing the channel;
• (c) replacing the second (channel-describing) element with a code that both identifies the channel as multi-slot and defines the number of timeslots; and
• (d) using the first (timeslot) element to indicate a certain slot (the first) of the multi-slot set.

Claims 2–5 narrow this to (2) the second element being the channel-type element; (3) GSM's Channel Description IE with TN + CHT, CHT replaced by the code, TN = first successive slot; (4) within CHT's 5 bits, first two bits = multi-slot flag, last three = count; (5) the two bits = "11."

The distinguishing feature is not "allocate multiple slots," but "overload an existing channel-description field so the single, ordinary assignment message carries the multi-slot meaning — with zero added signalling." That is what the references must disclose to anticipate.

3. Reference-by-reference analysis

3.1 EP 0399611 A2 — Philips Electronics UK Ltd.

• Full citation: EP 0399611 A2, "A communications system for data transmission over a time division duplex frequency channel"; GB priority 8912175 (1989-05-26); published 1990-11-28; granted as EP 0399611 B1 (1996-02-14). Corresponding US 5,200,956.
• Description: TDMA cordless/duplex system. Normally one duplex voice channel (one forward + one reverse slot per frame) per transaction. For high data rates it assigns additional duplex voice channels in parallel, selected via a per-station map store of channel usage/quality, and relinquishes them after the burst. Details of usable channels "may be included in the signalling portion of a message."
• §102 analysis: This is the reference the patent itself discusses in its Background — and the patent expressly distinguishes it: the reference "basically does not allow for assignment of successive physical channels," and its signalling is "extra signalling for additional data transmission, apart from normal operation." No disclosure of replacing a channel-describing element with a multi-slot code, nor of reusing the timeslot element as the start slot. Does not anticipate claim 1 (or 2–5). Relevant as §103 background on "assign several channels quickly for high-rate data."

3.2 US 5,239,545 A — Motorola (Buchholz) [examiner-cited]

• Full citation: US 5,239,545, "Channel access control in a communication system"; filed 1990-11-05; issued 1993-08-24; Motorola, Inc. (inventor Dale R. Buchholz).
• Description: RF TDMA system in which user modules send access requests to a control module; the control module assigns a small or large data channel plus "the corresponding number of required timeslots," depending on packet/fragment size, on a FIFO basis.
• §102 analysis: Discloses signalling a number of timeslots and allocating multiple slots. But the count rides in a request/grant mechanism, not in a channel-description element that is replaced by a code identifying the channel as multi-slot; there is no first-element/second-element structure as claimed and no "TN = first slot" reuse. Does not anticipate claim 1. §103-relevant to the "number of timeslots" concept.

3.3 US 5,257,257 A — Nokia Mobiltelefoner Ab

• Full citation: US 5,257,257, "Method of controlling the operation of a packet switched CDMA communication network for controlling the operation of transmitters and receivers"; filed 1991-04-05; issued 1993-10-26.
• Description: Packet-switched CDMA network control of transmitters/receivers.
• §102 analysis: Different multiple-access scheme (CDMA, not TDMA) and not concerned with a TDMA channel-description element or multi-slot TDMA channel coding. Does not anticipate any claim. Background only.

3.4 WO 1994008431 A1 — Motorola

• Full citation: WO 1994008431 A1, "Method of allocating channels in multirate channel environment"; priority 1992-09-25; published 1994-04-14.
• Description: Allocation of channels in an environment supporting multiple data rates (title/abstract basis; full text not retrieved within my search budget).
• §102 analysis: Multirate channel allocation is adjacent art, but nothing retrieved shows the claimed field-replacement code mechanism (a channel-type element carrying both the multi-slot identity and the slot count, with the timeslot element giving the start). No anticipation of claim 1. §103-relevant at most.

3.5 WO 1994010767 A1 — Telefonaktiebolaget LM Ericsson

• Full citation: WO 1994010767 A1, "A method of effecting random access in a mobile radio system"; priority 1992-10-26; published 1994-05-11.
• Description: Random-access procedure for a mobile radio system (title basis).
• §102 analysis: Concerns uplink access, not the content/encoding of a multi-slot channel-assignment description. No anticipation. Background.

3.6 EP 0605312 A1 — Alcatel N.V.

• Full citation: EP 0605312 A1, "Method of high rate information transmission by multiple block allocation, method and device for reception"; priority 1992-12-30; published 1994-07-06.
• Description: High-rate transmission by allocating multiple blocks (i.e., multiple slots/blocks) to a connection (title basis).
• §102 analysis: Conceptually close on "multiple-slot/block high-rate allocation," but there is no retrieved disclosure of the specific claimed signalling — replacing a channel-describing element with a code that both marks multi-slot and encodes the count, with the timeslot element as the start. No anticipation of claim 1; §103 candidate.

3.7 US 5,577,024 A — Nokia Mobile Phones Ltd. [examiner-cited]

• Full citation: US 5,577,024, "Multiple access radio system"; filed 1993-07-08; issued 1996-11-19; assignee Nokia Mobile Phones Ltd. (§102(e) art as of 1993-07-08).
• Description: A multiple-access radio system (full text not retrieved within my search budget).
• §102 analysis: Same-assignee background art on multiple-access radio design; nothing retrieved shows the CHT/TN field-overloading of claims 1/3–5. No anticipation of claim 1 on the record available. Flagging honestly that I could not read the full specification.

3.8 US 5,515,379 A — Motorola, Inc. [examiner-cited]

• Full citation: US 5,515,379, "Time slot allocation method"; filed 1993-10-18; issued 1996-05-07; Motorola (§102(e) art as of 1993-10-18).
• Description: A communication unit sends a first packet either requesting n time slots or multiple packets; the allocator assigns the n time slots "substantially contiguous in time" (or contiguous slots until the message completes). Distinguishes slotted/reservation ALOHA and aims to cut the delay of one-slot-per-frame allocation.
• §102 analysis: This is the strongest §102(e) reference on the "successive contiguous slots + n-count" concept. However, the count is carried in a separate reservation-request packet, not by replacing a channel-describing element of a channel-assignment message with a multi-slot code, and there is no first-element/second-element structure with the timeslot element repurposed as the start slot. Does not anticipate claim 1. §103-relevant (contiguity; number-of-slots signalling). It cannot reach claims 3–5 (GSM CHT/TN bit coding) at all.

3.9 WO 1995012931 A1 — Telefonaktiebolaget LM Ericsson

• Full citation: WO 1995012931 A1, "Digital control channels having logical channels for multiple access radiocommunication"; priority 1993-11-01; published 1995-05-11.
• Description: Digital control channels carrying logical channels for multiple-access radiocommunication (title basis).
• §102 analysis: Relates to control-channel/logical-channel structuring, not to the encoding of a multi-slot traffic-channel description. No anticipation. Note the timing: published 1995-05-11, after the 1994-11-25 priority date, so it cannot be §102(b) art and is §102(a)-type only if it predates the applicant's actual invention date — it does not predate the claimed priority.

3.10 WO 1995031878 A1 — Nokia Telecommunications Oy ⚠️ closest on substance

• Full citation: WO 1995031878 A1, "Method and arrangement for high-speed data transmission in a TDMA mobile telecommunications system"; FI priority 942190 (1994-05-11); international filing 1995-05-10; published 1995-11-23. Family: US 6,005,857; EP 0772944 (B1); AU 688903 B2.
• Description (retrieved text): Assigns a mobile station two or more (adjacent) time slots in the same frame for high-speed data by splitting a high-speed signal into lower-speed signals each carried in its own slot (claims 1–2). Critically, it states: "the present assignment command can easily be expanded to cover the addressing of at least two time slots… Due to the fact that all the channels addressed are of the same type of channel, TCH/F, the message can be limited to describe the type of the first channel and then the total number of channels required. In such a case, the message would be rather short and simple." It also references the GSM 04.08 Channel Description Information Element and the "Mode of first/second channel" fields.
• §102 analysis — the pivotal timing point: On substance, this reference comes closest to claim 1 (contiguous multi-slot allocation; describing the type of the first channel plus a total channel count; express GSM Channel Description IE context). But it is disqualified as §102 art on the dates. Its publication (1995-11-23) and its international filing date (1995-05-10) are both after the 1994-11-25 priority date of US 6,295,286, and even its §102(e) date (international filing date for a US-designating, English-language WO) is after that priority. It therefore cannot anticipate claims 1–5 under §102(a), (b), or (e) unless the applicant were denied its foreign priority and forced to an invention date after 1995-05-10. Its proper role is as §103 background (and it is not "self" art — Nokia Telecommunications Oy is a different entity from the applicant, Nokia Mobile Phones Ltd.).
• Note the contrast: this reference describes a message limited to "the type of the first channel and then the total number of channels," whereas claim 1 (and claims 3–5) require replacing the channel-type element itself with a code whose bits both flag multi-slot and carry the count. That structural difference is what keeps even this reference from reading on the claims.

4. Most relevant prior art — ranking

1. WO 1995031878 A1 (Nokia Telecommunications Oy) — closest on substance (contiguous multi-slot; first-channel-type + total count; GSM Channel Description IE context). Disqualified by date.
2. US 5,515,379 A (Motorola) — n contiguous time slots allocated on request; §102(e) art from 1993-10-18. Closest qualifying reference on multi-slot allocation, but the count is in a request packet, not an overloaded channel-description field.
3. EP 0605312 A1 (Alcatel) — "multiple block allocation" for high-rate transmission.
4. US 5,239,545 A (Motorola) — assigns a number of timeslots based on packet size. [examiner-cited]
5. EP 0399611 A2 (Philips) — parallel multiple duplex channels for fast data; expressly distinguished in the patent's own Background.
6. US 5,577,024 A (Nokia) — same-assignee multiple-access background. [examiner-cited]
7. WO 1994008431 A1 (Motorola) — multirate channel allocation.
8. WO 1994010767 A1 (Ericsson) — random access.
9. WO 1995012931 A1 (Ericsson) — digital control channels/logical channels.
10. US 5,257,257 A (Nokia) — CDMA packet network control (different access scheme).

5. Bottom line on §102

• No cited reference anticipates claim 1, the only independent claim. The references collectively disclose multi-slot/contiguous-slot allocation and number-of-slots signalling, but none discloses the claimed mechanism: replacing the channel-describing element (e.g., GSM CHT) with a code that both identifies the channel as multi-slot and encodes the number of successive timeslots, while reusing the timeslot element (e.g., TN) to indicate the start slot in the otherwise-unchanged assignment message.
• Claims 3–5 (GSM-specific: CHT replaced by the code; TN = first slot; 5-bit CHT with "11" + 3-bit count) are not anticipated by any reference here — they recite a concrete GSM encoding with no counterpart in the cited art.
• The citations functioned as §103 / background art. The examiner-cited items (§3.2, §3.7, §3.8) and the closest non-qualifying item (WO 1995031878) all stop short of the field-overloading limitation.
• Watch the dates when reusing this list post-AIA/AIA-transition: WO 1995031878 (1995-11-23), WO 1995012931 (1995-05-11), and the two 1996-issued US patents (5,515,379; 5,577,024) interact differently with §102(a)/(b)/(e) versus §102(a)(1)/(a)(2) analysis.

6. Caveats

• My reference-by-reference full texts for WO 1994008431, WO 1994010767, EP 0605312, WO 1995012931, and US 5,577,024 were not retrievable before my search budget was exhausted; those descriptions rest on the titles/abstracts and the patent's own characterization, and are flagged as such. Descriptions for EP 0399611, US 5,239,545, US 5,515,379, and WO 1995031878 are grounded in retrieved text.
• I did not auto-correct any identifier; every number above is reproduced literally from the US 6,295,286 record.
• §102 characterizations are analytical, not legal conclusions. The forward "Cited By" documents (e.g., Samsung 6,725,046; Qualcomm 9,173,197) and the four "Family Cites Families" items (WO 1987006082, FR 2689346, GB 2270815, JP 3212169) are not prior art against this patent's claims and are excluded from the §102 analysis above.
• Minor date inconsistency to re-flag from the earlier sections: the task header states "Current Date: April 26, 2026," while the system context shows 2026-09-10; this does not affect the prior-art dates above.

I'll research the cited prior art references to ground the obviousness analysis. Let me pull details on the key references.

Good — I have strong material on several references. Let me pull the remaining ones.

Obviousness Analysis — U.S. Patent 6,295,286 (35 U.S.C. § 103)

Building on the earlier summary and litigation sections (claim set, priority chain, Nokia→Vringo assignment, and the "no confirmed US litigation" finding). This section does not repeat those; it addresses § 103 only, using the references listed in the "Prior Art" / "Patent Citations" / "Family Cites Families" sections of the Google Patents page.

1. Legal framework and timing

• Governing law: Pre-AIA § 103 (application filed 1995-11-24; priority 1994-11-25). The Graham v. John Deere factors apply, informed by KSR Int'l v. Teleflex (2007) and MPEP §§ 2141–2145.
• Critical dates:
  • Invention / foreign priority: 1994-11-25 (FI 945540).
  • U.S./international filing date: 1995-11-24.
  • § 102(b) critical date (filing − 1 year): 1994-11-24.
• PHOSITA: A B.S.-level electrical engineer with ~2–5 years in digital cellular system design, familiar with TDMA frame structure and, for claims 3–5, with the GSM 04.08 air-interface signalling specification (v4.5.0, June 1993), which is itself a printed publication cited inside the references below.

Statutory status of the cited art (as date-qualified):

⚠️ Flag on the strongest-looking reference. WO1995031878A1 (Nokia) published 1995-11-23, and its international filing date is 1995-05-10 (PCT/FI1995/000248) — both after the '286 priority date of 1994-11-25. Under pre-AIA § 102(e) (Hilmer), a foreign priority application does not supply the reference date. It appears it may not qualify as § 103 prior art at all, despite being cited on the face of the '286 record. I therefore present the case two ways: (A) with WO'878 as art, and (B) without it, using only the solidly-qualified references.

2. What each qualifying reference discloses

US5515379A — Motorola, "Time slot allocation method"
A TDMA unit sends a request packet that "identifies the number of time slots necessary"; the allocator "allocates the n-time slots substantially contiguous in time." It expressly discloses both (i) a code identifying a multi-slot allocation and (ii) contiguous/successive slots — the two concepts claim 1 turns on.
Sources: https://patents.google.com/patent/[US5515379](/patent/US5515379) ; https://FreePatentsOnline.com/[5515379](/patent/5515379).html

EP0399611A2 — Philips, TDD/TDMA communications system
Same problem, same field: "it is not unusual for a secondary station … to generate batches of data … at rates in excess of 32 kbits/sec," therefore "assign more than one duplex voice channel to a data transaction so that data transmission can be in parallel duplex voice channels." It discloses that details of the assigned channels, and the number of channels required, are carried in "the signalling portion of a message communicated by the … primary station to the … secondary station." This is the reference the '286 background itself characterizes as signalling the channel count, but as extra signalling and without successive physical channels.
Sources: https://patents.google.com/patent/EP0399611A2 ; http://data.epo.org/gpi/EP0399611B1

EP0605312A1 — Alcatel, high-rate transmission by multiple block allocation
A user is allocated several adjacent blocks that are concatenated into a "super-block"; a signalling element before the frame carries "the number of adjacent blocks concatenated in the super-block concerned." Option (c) is decisive for claim 1/4: "a simple signaling information K, M before each super-block … the receiving equipment is then provided to interpret this signaling." That is a short code whose value defines how many adjacent (successive) blocks/slots are concatenated — structurally identical to the claimed "11nnn" code.
Sources: https://patents.google.com/patent/EP0605312A1/en ; http://data.epo.org/gpi/EP0605312B1

WO1994008431A1 — Motorola, channel allocation in a multirate environment
Teaches requesting a full-, half-, or quarter-rate channel and assigning a traffic channel "having the characteristics requested," i.e., encoding the resource magnitude in the channel-setup request/assignment.
Sources: https://patents.google.com/patent/WO1994008431A1/en ; https://uspto.report/patent/grant/[5471645](/patent/5471645)

WO1995031878A1 — Nokia Telecommunications Oy (high-speed data in TDMA)
With the caveat in § 6, its US counterpart US6005857 states verbatim:

"The present assignment command can easily be expanded to cover the addressing of at least two time slots … For addressing more than two time slots, a new message must be determined. Due to the fact that all the channels addressed are of the same type of channel, TCH/F, the message can be limited to describe the type of the first channel and then the total number of channels required."

This sits directly on claim 1 (repurpose the channel-describing field to carry type-of-first channel + count) and on claim 2 (the replaced element "describes the channel type"). It also confirms the GSM assignment command / Channel Description Information Element framework that claims 3–5 presuppose.
Source: https://uspto.report/patent/grant/[6005857](/patent/6005857) ; claims at https://worldwide.espacenet.com/publicationDetails/claims?CC=WO&NR=[9531878A1](/patent/9531878A1)

GSM 04.08 v4.5.0, June 1993 (cited within WO'878/US6005857)
Supplies the CHT (5-bit channel type/subchannel) and TN (3-bit timeslot) fields and the CHT code table reproduced in the '286 patent (00001, 0001T, 001TT, 01TTT). Any CHT code beginning with "1" was unused — making "11nnn" a free bit pattern.

3. Claim 1 — element mapping and combinations

Combination I (primary, all references solidly qualified): EP0399611A2 + US5515379A + EP0605312A1.

• EP'611 supplies the problem and motivation (high-rate data needs >1 slot) and the notion of signalling channel count in a message.
• US'379 supplies n-slot coding and contiguous allocation.
• EP'312 supplies encoding the number of concatenated adjacent blocks as a short signalling code interpreted by the receiver.

Combination II (alternative): WO1994008431A1 + US5515379A + EP0399611A2.

• WO'431 supplies rate/channel-magnitude signalling; US'379 supplies the count/contiguity; EP'611 supplies the multi-channel high-rate motivation.

Combination III (if WO'878 qualifies): WO1995031878A1 + US5515379A (and optionally GSM 04.08). Here the primary reference literally describes "the type of the first channel and then the total number of channels required," making claim 1 nearly anticipated in substance and plainly obvious in law.

4. Claims 2–5 (GSM-specific)

• Claim 2 (replaced element = channel-type element): disclosed by WO'878 ("describe the type of the first channel") and inherently by GSM CHT, which is the channel-type/subchannel field.
• Claim 3 (GSM CDIE with TN + CHT; CHT replaced; TN = first slot): the CDIE structure and CHT/TN fields come from GSM 04.08 v4.5.0 (June 1993) and are reproduced in WO'878/US6005857. Combining that baseline with the multi-slot count teaching of US'379/EP'312 yields claim 3.
• Claim 4 (2 leading CHT bits = mode; 3 trailing bits = count): pure obvious design choice (MPEP § 2144.04.VI). The CHT field is already 5 bits partitioned as a mode-prefix + argument; the unused patterns 1xxxx are available; 3 bits is exactly enough to count a slot in an 8-slot GSM frame — the patent itself concedes this ("Three bits can be used to indicate eight different values, which is enough … in a GSM system in which a frame contains eight timeslots").
• Claim 5 (the two bits are "11"): selecting "11" over the equally free "10" has no identified functional consequence and no unexpected result. Arbitrary selection among two workable, equivalent alternatives does not confer patentability (KSR; In re Kubin).

5. Motivation to combine (articulated reasons)

1. Same field, same problem. All references are TDMA multi-slot/rate allocation; EP'611 and WO'878 both target high-rate data services — the very stimulus the '286 background identifies.
2. Same assignee/lineage for the GSM-specific art. WO'878/US6005857 and US5577024A are Nokia work on the same GSM assignment signalling; US5577024A is even assigned to Nokia Mobile Phones Ltd. (the '286 original assignee), supplying a strong "known work in the same system" rationale.
3. Predictable result. Combining an n-slot request/allocation (US'379) with a channel-description signalling field (GSM 04.08) yields nothing more than the expected "tell the terminal how many consecutive slots" — a predictable aggregation of known elements (KSR).
4. Design incentive / market pressure. The '286 background and EP'611 both acknowledge the industry push for higher data rates and the desire to avoid "the delay and time overhead" of separate signalling — a classic KSR design incentive that motivates the claimed repurposing to avoid added signalling.
5. Backward-compatibility pressure favours field reuse over new messages. Because GSM already sent two CDIEs for two half-rate channels, reusing/overloading the existing CHT field is the natural, lower-overhead choice a PHOSITA would pursue.
6. Reasonable expectation of success. Every building block (5-bit coded field, count encoding, contiguous allocation, receiver-side interpretation of a configuration code) is disclosed as working in the art; only routine engineering remains.

6. Non-obviousness defenses and how they would be met

• Teaching away (WO'878 "a new message must be determined"). WO'878 arguably steers toward a new message for >2 slots, which could be argued to teach away from overloading CHT. Rebuttal: the same passage says the existing assignment command "can easily be expanded" and that the message "can be limited to describe the type of the first channel and then the total number of channels required" — a direct lead-in to the claimed solution, not away from it. Also, US'379 and EP'312 independently supply the overloading/coding teaching.
• EP'611 does not assign successive channels. The '286 background concedes this. Rebuttal: the "successive" limitation is supplied by US'379 (contiguous slots) and EP'312 (adjacent concatenated blocks).
• Specific bit pattern ("11"). Rebuttal: obvious design choice with no unexpected result (see § 4).
• § 102(e)/Hilmer date problem for WO'878 (see § 1 flag). If WO'878 is disqualified, the case must rest on Combination I/II, which still covers every claim-1 element; only claim 3's GSM framing then depends on GSM 04.08 alone — which is a pre-1994 printed publication and squarely § 102(b) art.
• § 103(c) common-ownership escape. If WO'878 and the '286 share common ownership (both Nokia entities, arguably subject to assignment to a common parent), WO'878 would be disqualified as prior art under pre-AIA § 103(c) even though it qualifies under § 102(e). This cuts the other way here — it removes a reference — and is worth checking against the assignment record (Nokia Mobile Phones → Nokia Corporation merger).

7. Secondary considerations

No unexpected results, commercial-success, or long-felt-need evidence specific to the claimed coding scheme is presented in the patent. The Vringo acquisition/security-interest events and the Google Patents "family has litigation" flag (Darts-ip family 8541870) are at most weak indicia of value; per the earlier litigation analysis, no confirmed U.S. case asserting 6,295,286 was found, so nexus between any apparent commercial activity and the claims is unproven. If enforcement activity exists, the rebuttal is that the asserted value attaches to the multi-slot concept, which the primary art already discloses, rather than to the CHT overload.

8. Bottom line

Confidence: moderate-to-high that claims 1–5 would be held obvious, contingent on the WO1995031878A1 date question.

1. Strongest case: WO1995031878A1 (Nokia) in view of US5515379A, further in view of GSM 04.08 v4.5.0 — renders claims 1–5 obvious (claim 5 by obvious design choice). Its US counterpart literally recites "describe the type of the first channel and then the total number of channels required."
2. Fallback case, free of the date problem: EP0399611A2 + US5515379A + EP0605312A1 (+ GSM 04.08 for claims 3–5) — renders claims 1–5 obvious, with the high-rate motivation explicit in EP'611 and the "count encoded as a short signalling code" teaching explicit in EP'312.
3. Genuine weaknesses in an invalidity case: (a) the possible § 102(e)/Hilmer disqualification of WO'878; (b) possible § 103(c) common ownership; (c) the "successive slots" limitation rests entirely on US'379/EP'312, not EP'611; (d) claim 5's specific "11" pattern is vulnerable only as an obvious design choice.

Unverified items I am flagging honestly: I could not retrieve the full text of US5577024A, US5239545A, US5257257A, WO1994010767A1, WO1995012931A1, or the four family-cite documents (WO1987006082A1, FR2689346B1, GB2270815B, JP3212169B2), and I did not independently verify the WO1995031878A1 international filing date beyond the 1995-05-10 PCT/FI1995/000248 indication and the 1995-11-23 publication date shown in the record. Those items should be pulled from the original documents before any invalidity contention is finalized.