US 6009088

I'll search for this specific patent number and any CAFC 2026 docket references.

The first result is unrelated (a different '908 patent in a Texas case). Let me run additional targeted searches to verify the specific patent and check for CAFC involvement.

Let me do two final checks for any CAFC/PTAB/invalidity proceedings specifically naming this patent.

US Patent 6,009,088 — Search Results and Summary

Search notes (USPTO / CAFC 2026 dockets)

• I searched for the exact number 6009088 and variants (US6009088A, "6,009,088", "patent 6009088") in connection with the USPTO and the CAFC.
• No CAFC 2026 (or any recent) docket, appeal, IPR, or litigation referencing this specific patent was found. Multiple search hits returned different patents ending in "‑088" (e.g., 9,745,088, 6,467,088, 8,235,088, and a "‘908 patent" in a Texas case); none relate to US 6,009,088. Given that the patent lapsed in December 2011 for non-payment of maintenance fees, the absence of recent Federal Circuit activity is expected.
• The bibliographic and technical data below come from the authoritative Google Patents record for US6009088A (fetched 2026-09-09, supplied in the prompt), which matched a secondary Searchlight Law mirror. I could not directly query the USPTO's own database in this session, so treat the bibliographic fields as high-confidence but USPTO-verified status as not independently re-confirmed here.

Summary of US 6,009,088

Abstract (paraphrased closely): To let a user transmit packet data to a desired counterpart on a virtual network spanning a wireless circuit-switched network and a LAN without manually handling address conversion between the physical-network address and the virtual-network address, an exchange (10a) performs the address conversion needed to establish a communication channel between terminals using a conversion table. The system couples a wireless circuit-switched network (wireless mobile/personal station 30a, wireless connection equipment 20a, exchange 10a) to a LAN (40a) through a TA (60a) and router (50a).

Plain-language overview of the invention: The patent bridges two addressing worlds: the wireless PBX world routes by telephone/extension numbers (circuit-switched, connection-oriented), while the LAN/Internet world routes by packet addresses such as IP addresses (connectionless). Rather than having the user manually dial the right number for a given IP destination, the system stores a correspondence table that maps packet addresses ↔ telephone numbers. A special "IP/extension-number conversion" call triggers the conversion automatically, establishing a physical (circuit) channel over which IP packets then flow. Three placement options are taught for the table — in the exchange (PBX), in the wireless personal station (PS), or in the LAN-side control unit (router/TA) — and each is extended to a multi-PBX roaming scenario.

Independent claims (all 6 claims are independent)

• Claim 1 (single system; table in the exchange): A system with a wireless personal station (assigned a telephone number), wireless connection equipment, an exchange controlling it, a control unit (connected to the exchange) that controls packet-data transmission through the LAN, and a LAN terminal assigned a packet address independent of the telephone scheme. The exchange routes by telephone number and the control unit by packet address. Key limitation: the exchange holds the correspondence table and converts packet address → telephone number to set up the channel between the wireless personal station and the LAN terminal.
• Claim 2 (single system; table in the personal station): Same architecture as claim 1, except the wireless personal station holds the correspondence table and performs the packet-address → telephone-number conversion to establish the channel.
• Claim 3 (single system; table in the control unit): Same architecture, except the control unit (the LAN-side router/TA element) holds the table and performs the conversion to establish the channel.
• Claim 4 (multi-system; table in the exchange): A plurality of the above systems in which the exchanges are interconnected and the control units are interconnected, so a personal station of one system can communicate with a control unit of another system through its own or another system's equipment (roaming). The exchange holds the correspondence table and performs the conversion.
• Claim 5 (multi-system; table in the personal station): As claim 4, but the wireless personal station holds the table and converts the packet address to the telephone number.
• Claim 6 (multi-system; table in the control unit): As claim 4, but the control unit holds the table and converts the packet address to the telephone number.

In short: claims 1–3 are the single-PBX variants distinguished only by where the address-conversion table resides (exchange vs. personal station vs. control unit); claims 4–6 repeat that three-way distinction for the interconnected, roaming multi-system embodiment.

Uncertainty statement

• I did not access the USPTO or CAFC databases directly; searches were conducted via general web search, which returned no CAFC 2026 docket entries for patent 6,009,088. If you need a definitive docket check, the CAFC's PACER/CM-ECF and the USPTO Patent Center should be queried directly for application 08/875,510 and any associated case numbers.
• The assignee field reflects NTT Mobile Communications Networks Inc. at issue (with NTT Docomo Inc. listed as the current assignee by Google Patents); Google's assignment/legal-status annotations are not a legal determination.

Based on my searches, I have not found any litigation involving US Patent 6,009,088.

Summary of search results

I searched multiple queries combining the patent number (6009088, "US 6009088", "6,009,088") with terms like litigation, lawsuit, infringement, docket, Unified Patents, and assignee (NTT Docomo / NTT Mobile Communications Networks Inc.).

• Several searches returned no results at all.

• The searches that did return results surfaced only unrelated patents that happen to end in "088", including:

  • 6,467,088 (Uniloc / software reconfiguration — the Microsoft v. Uniloc case and Uniloc v. Apple matters);
  • A Nuance Communications '088 patent (speech recognition, Nuance Communications Inc. v. Tellme Networks Inc.); and
  • Various other non-matching "'088" patents in PTAB caselists.

  None of these involve US 6,009,088, and I have disregarded them per your instruction not to return results for similar numbers.

Answer

No known litigation (district court, CAFC, ITC, or PTAB trial proceeding) involving US Patent 6,009,088 was identified in my searches.

That conclusion is consistent with the patent's record, which shows no litigation-related events:

• Patent: US 6,009,088 — "Mobile wireless data communications system"
• Assignee: NTT Mobile Communications Networks Inc. (later NTT Docomo Inc.)
• Filing date: Dec. 20, 1996 (priority Dec. 26, 1995)
• Grant date: Dec. 28, 1999
• Legal status: Expired — lapsed for failure to pay maintenance fees effective Dec. 28, 2011 (reminder mailed Aug. 1, 2011; last maintenance fee paid in 2007). Its anticipated statutory expiration was Dec. 20, 2016.

The only post-issuance legal events on the file history are an assignment, a certificate of correction, and maintenance-fee/lapse entries — no litigation. My confidence that there is no reported or readily indexed litigation is fairly high given the absence of any docket hits; however, I could not exhaustively verify every PACER/Recap district-court docket, so I cannot absolutely rule out an obscure, unreported case that left no public web trace. If you want, I can run further targeted docket searches (e.g., RPX, DocketNavigator, or LexisNexis-style litigation databases) to which I don't currently have access.

Proceedings overview

Total AIA trial proceedings on file: 0. The USPTO Open Data Portal ingest lists no IPR, PGR, or CBM proceedings for US 6009088, and web searching surfaced no older or recently-filed petitions either. The bottom-line defensive posture is not IPR-based at all: US 6009088 lapsed for non-payment of maintenance fees on 2011-12-28 and reached its full 20-year term on 2016-12-20 — it is an expired, unenforceable patent, so the absence of PTAB challenges is exactly what you would expect for a dead patent that no one is actively asserting with a viable damages claim.

There are therefore no proceedings to profile individually (no petitions, no institution decisions, no Final Written Decisions, no settlements, no CAFC appeals).

Strategic summary

Claim status — CANCELED vs. SUSTAINED vs. UNTESTED. None of the six claims (independent claims 1–6; the patent has no dependent claims) has ever been challenged in an AIA trial, so all claims are formally UNTESTED by the PTAB. That label is academic, though: the more controlling fact is the patent's life-cycle status. Per the USPTO legal-events record on the patent, the maintenance-fee reminder was mailed 2011-08-01, the patent lapsed for failure to pay maintenance fees on 2011-12-28 (formal "FP" lapse entry dated 2012-02-14, effective 2011-12-28), and the full statutory term expired 2016-12-20 (20 years from the 1996-12-20 US filing date). The recorded status is "Expired - Fee Related." That status is not revivable at this point, and it means no injunctive relief and no ongoing-damages exposure exists today; any theoretical damages claim would be limited to infringing acts before expiration and within the § 286 six-year lookback — and would face the reality that the patent owner (NTT Docomo lineage, through NTT Mobile Communications Networks) let the patent die rather than pay the 8th-year fee.

Estoppel landscape. Because no IPR/PGR/CBM was ever filed, there is no § 315(e)(2) estoppel barring any party — and, importantly, a defendant who was not a petitioner in an AIA proceeding is never estopped at the PTAB in any event. For a defendant facing assertion today, all prior-art grounds (anticipation under pre-AIA § 102, obviousness under § 103, and § 112 issues) remain fully available in district court, unconstrained by any IPR record. The practical defenses, however, are not validity-driven: they are (1) expiration (no remedy for post-2016 conduct, and the patent died by non-payment in 2011), and (2) standing/claim-chilling — a demand letter premised on a patent that lapsed for non-payment nine years before its term even ended should be treated accordingly.

Pattern signals. There are none: no serial petitioner, no Unified Patents or defensive-aggregator chain, no patent-owner PTAB aggressiveness to study. The complete silence across USPTO ODP and public web sources is itself the signal — this is a 1990s wireless-PBX/LAN integration patent (inventors Taguchi, Kobayashi, Fujima, Tanaka, Hirono; assigned to NTT Mobile Communications Networks / now NTT Docomo) that issued in 1999, was cited by a handful of later NTT-adjacent and third-party filings, and was allowed to expire. It never attracted an IPR because it was never a live litigation asset during the AIA era.

Recommended next steps

• Do not file an IPR; there is nothing to gain and the patent is expired. PTAB practice permits petitions against expired patents in narrow circumstances, but the Board routinely exercises discretion against them, and here the patent died by maintenance-fee lapse in 2011 — there is no active right to extinguish and estoppel risks would be pure downside. If you are a defendant receiving a demand letter citing US 6009088, your response should lead with expiration, not validity:
  • The USPTO record shows "LAPS: Lapse for failure to pay maintenance fees" (2011-12-28) and "FP: Lapsed due to failure to pay maintenance fee, Effective date 20111228" — see the legal-events section of the Google Patents record for US6009088A (https://patents.google.com/patent/US6009088A).
  • Full term expired 2016-12-20 ("Anticipated expiration" on file).
  • Consequence: no prospective relief of any kind; at most a time-barred or damages-limited historical claim, which the demand should be pressed to particularize if it is not simply withdrawn.
• If the patent is being asserted anyway, preserve your defenses in the responsive pleading: unenforceability/expiration, no damages post-expiration, and (if the pleadings reach validity) reserve all § 102/§ 103/§ 112 grounds — none are estopped.
• No active PTAB milestones exist to track. The only "milestone" of record is historical: maintenance fee lapse effective 2011-12-28. Nothing is pending at the PTAB, and no CAFC appeal exists because no FWD was ever issued.

Verification note: The "no proceedings" conclusion rests on (a) the structured USPTO ODP block in this prompt, which returns zero AIA trials as of the most recent ingest, and (b) live web searches for PTAB/CAFC activity on US6009088 / application 08/875,510, which returned no IPR, PGR, CBM, FWD, or appeal records. The only "6009088" hits online are an unrelated Japanese patent of the same number (a permanent-magnet motor patent) and generic PTAB news — neither concerns this patent. I did not locate a PTAB E2E docket page for this patent to link because none exists.

I'll start by attempting to retrieve the USPTO assignment records for US 6009088 through web searches, then cross-reference with the Google Patents legal events already in the record.

The generic searches returned no assignment data. Let me search specifically for the known assignment (reel 008780/frame 0770 from the Google Patents legal events) and any NTT Docomo name-change recordings.

The Assignment Center interface itself isn't directly crawlable via web search. Let me check mirror databases (FreePatentsOnline, patentdocs) and search for any NTT Docomo name-change recordings on this patent family.

I've hit the step limit for tool calls, so I'll now answer from the available evidence. Important honesty caveat up front: the USPTO Assignment Center is a scripted interface that general web search cannot query directly, so I could not pull correspondent-of-record or verify zero additional recordings first-hand. What follows is reconstructed from the authoritative Google Patents record supplied in the prompt (which reproduces USPTO legal-event and reassignment data) plus the searches run above. No additional recorded assignments, litigation, or NPE filings surfaced in any search.

Inventors

All five named inventors assigned their interest to NTT Mobile Communications Network Inc. on the sole recorded assignment (reel 008780/frame 0770), which identifies their employer at the time of filing:

• Tsutomu Taguchi
• Shinji Kobayashi
• Yoshiki Fujima
• Kazushige Tanaka
• Masahiko Hirono

Employer at filing: NTT Mobile Communications Network Inc. (the NTT DoCoMo group company; renamed NTT DoCoMo, Inc. in 2000). Unusual patterns: none observed — this is a conventional employer-assignment at prosecution stage (executed 1997-06-04, i.e., after the 1996-12-20 US filing, standard practice), not a post-issue departure or portfolio fire-sale tell. I could not determine individual inventors' post-filing departures from public sources in this session.

Original assignee

• Entity named on the issued patent: NTT Mobile Communications Networks Inc. (Google's "current assignee" field lists NTT Docomo Inc., consistent with the 2000 corporate rename).
• Primary line of business: Mobile/cellular telecommunications operator (Japan) — a large operating carrier, not a licensing entity.
• Product embodiment: Unclear from public record. The claims concern wireless-PBX/LAN data communication bridging (IP-address↔extension-number conversion). NTT's PHS/mobile business plausibly practiced related technology, but I found no public product documentation tying a specific NTT product to these claims.
• Current status: Operating — NTT Docomo, Inc. remains one of Japan's largest mobile carriers (NTT Group subsidiary). This patent itself lapsed for non-payment of maintenance fees effective 2011-12-28, with formal expiration recorded 2012-02-14.

Assignment timeline

Only one recorded assignment appears in the Google Patents legal-events/reassignment data, and no post-issuance conveyance of any kind (assignment, merger, security interest, license, or name change) is listed there. Searches of the open web surfaced no additional USPTO assignment records for this patent.

• 1997-06-04 (executed) / recorded 1997-07-29 — Reel 008780/Frame 0770
  • Conveyance: Assignment (assignment of assignors' interest)
  • Assignor: Tsutomu Taguchi, Shinji Kobayashi, Yoshiki Fujima, Kazushige Tanaka, Masahiko Hirono
  • Assignee: NTT Mobile Communications Network Inc.
  • Correspondent: Not available from the sources accessible in this session (Google's record does not reproduce the cover-sheet correspondent; the USPTO Assignment Center must be queried directly to retrieve it).
  • Context: Standard employment/prosecution assignment from the five inventors to their employer — the original-assignee grant, not an acquisition or transfer.

No post-issuance assignments were found. That absence is itself a finding: it indicates the patent stayed with NTT Mobile Communications Network / NTT Docomo from grant (1999-12-28) until lapse (2011-12-28) and was never sold, pledged, or licensed-of-record. The only later legal events are a 2001-09-25 certificate of correction, maintenance-fee payments in 2003 and 2007, and the 2011 lapse. Caveat: I could not query the Assignment Center directly, so a recorded NTT Mobile Communications Network → NTT DoCoMo name change or any other filing cannot be definitively ruled out; however, no such record appears in the Google legal-events feed and none surfaced in any search.

Timeline diagram

timeline
    title Ownership of US 6009088
    1995 : Priority filed in Japan
    1996 : US application filed
    1997 : Assigned by inventors to NTT
    1999 : Patent issued
    2001 : Certificate of correction
    2003 : Maintenance fee paid year 4
    2007 : Maintenance fee paid year 8
    2011 : Lapsed for nonpayment
    2012 : Patent expired

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No recorded transfer from NTT to any LLC, "IP Holdings," licensing entity, or registered-agent address. The only conveyance is inventors → NTT (reel 008780/0770, recorded 1997-07-29), i.e., the original employer assignment. No evidence of any shell in the chain.

2. Known asserter in the chain — not present. Neither the original nor current assignee (NTT Mobile Communications Network / NTT Docomo) appears on any public NPE list (Acacia, Marathon, IV, Wi-LAN, Conversant, etc.), and no litigation by any entity was found naming this patent.

3. Repeat correspondent across the chain — not present / unclear. Only one recorded assignment exists, so there is no chain in which a correspondent could recur. The correspondent of record for reel 008780/0770 was not retrievable from the sources available; no attorney name associated with this patent appeared in any NPE-assertion database search.

4. Cascading transfers — not present. There are no consecutive assignments through chained LLCs — indeed, no post-issuance assignments at all.

5. Pre-litigation transfer — not present. No infringement suit naming US 6,009,088 was found (see litigation summary in the prior section), and the only assignment predates issuance by 2.5 years.

6. Bankruptcy fire-sale — not present. NTT Docomo has never been in bankruptcy; the patent lapsed for non-payment of maintenance fees (reminder 2011-08-01; lapse 2011-12-28) rather than being sold in any insolvency proceeding.

7. Privateering — not present. No transfer of the patent to any third-party enforcer, and no SEC/8-K or Patent Progress/EFF evidence of NTT funding assertions against competitors through an NPE.

8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at NTT Docomo, an operating company, by lapse/expiration rather than by defensive acquisition.

Verdict

Insufficient data — no records beyond the original assignment were found, and the USPTO Assignment Center could not be queried directly in this session to certify a zero post-issuance assignment count or retrieve correspondent data.

That said, every affirmative data point points away from an NPE pattern: the sole recorded assignment is the 1997 inventors-to-employer grant (reel 008780/0770), the patent remained with NTT Docomo — a large operating carrier — until it lapsed for unpaid maintenance fees in 2011, and no litigation, LLC transfer, or asserter involvement surfaced anywhere. Verification link for a definitive chain-of-title pull: https://assignmentcenter.uspto.gov/ (search Patent Number 6009088).

I have the authoritative citation lists from the patent record. Let me now retrieve details on the remaining cited references — the Japanese family citations, the Swedish and Finnish applications, and the Fujitsu electronic-exchange LAN reference — to give accurate descriptions.

I have enough to answer, though I hit the tool-call limit before I could retrieve full text of several Japanese-language citations. I'll flag confidence levels accordingly. Note that I could not query USPTO's databases directly in this session; the citation data below comes from the authoritative Google Patents record for US6009088A (supplied in the prompt) plus the web searches run above, and the examiner/ITC identifiers are read literally per your rule.

Prior Art Analysis — US Patent 6,009,088 ("Mobile wireless data communications system")

0. Scope note and framework

Target: US6009088A, application 08/875,510, filed 1996-12-20, priority 1995-12-26 (JP 7-339664 → PCT/JP1996/003724 → WO97/23977). Because the application was filed before the AIA, pre-AIA § 102 governs.

• § 102(b) critical date: more than one year before 1996-12-20 → any reference patented or published before 1995-12-20 is a statutory bar.
• § 102(a)/(e) reference date: the invention date, presumed 1995-12-26 (Japanese priority). U.S. patents by others filed in the U.S. before 1995-12-26 (and whose disclosures support the cited subject matter) are § 102(e) art even if they issued later; U.S. patents issued before 1995-12-20 are also § 102(b) art.

Claim structure reminder (all six claims are independent). Every claim requires: (i) a wireless personal station (PS) with a telephone number under a single telephone-number scheme; (ii) wireless connection equipment (CS); (iii) an exchange controlling the CS and routing by telephone number; (iv) a control unit (router/TA) connected to the exchange, controlling packet-data transmission through the LAN by packet address; (v) a LAN terminal with a packet address independent of the telephone scheme; and (vi) a correspondence table mapping packet address → telephone number, used to convert the packet address to a telephone number in order to establish a communication channel between the PS and the LAN terminal. The only structural variable across claims 1–3 (and across 4–6) is where the table resides:

Anticipation requires every element in a single reference, so the decisive question for each citation is whether it discloses the circuit-switched, telephone-number-routed wireless exchange + packet-address-routed LAN split and the address→telephone-number conversion table in the claimed node.

1. The reference cited on the face of the U.S. patent (examiner citation)

1.1 US5726984A — Norand Corporation

• Full citation: US 5,726,984 A, "Hierarchical data collection network supporting packetized voice communications among wireless terminals and telephones," inventors Kubler et al., assignee Norand Corporation.
• Dates: Priority 1989-01-31 (chain of continuing applications); U.S. grant/publish 1998-03-10.
• § 102 status: Not § 102(b) (issued 1998-03-10, after the 1995-12-20 bar date). Potentially § 102(e) to the extent its disclosure is supported by U.S. applications filed before 1995-12-26 (the family traces to 1989-01-31). This is the reference the examiner placed on the face of the patent, most plausibly under § 102(e).
• Description: A premises communication network with a hardwired backbone network and a wireless network in which portable terminals exchange both voice and data packets; stationary network devices (which may be PCs with attached telephones) convert between analog voice and voice packets, and route packets between the telephone side and the wireless terminals without distinguishing voice vs. data packets. It is fundamentally a packet-routed premises network (spanning-tree routing, polling), not a circuit-switched PBX system.
• Claim analysis: Discloses the general "wireless terminals + telephones + LAN/wired network data communication" concept and packet transport, but does not disclose: a PBX-type exchange that routes by telephone number, a control unit routing IP/packet addresses through a LAN, or a correspondence table converting a packet address to a telephone number to establish a circuit channel. The packet/telephone "conversion" it does is analog↔digital voice coding, not address translation.
• Anticipation conclusion: Does not appear to anticipate any of claims 1–6 standing alone. Its value is as background and for obviousness combinations (e.g., with a wireless-PBX art). Confidence: high, based on the claim text retrieved (FreePatentsOnline/USPTO mirrors).

2. Family citations (cited during WO97/23977 / EP0812085 / JP prosecution — "Family Cites Families")

2.1 US5159592A — International Business Machines Corp. (C. E. Perkins)

• Full citation: US 5,159,592 A, "Network address management for a wired network supporting wireless communication to a plurality of mobile users," inventor Charles E. Perkins, assignee IBM.
• Dates: Filed 1990-10-29; granted/published 1992-10-27.
• § 102 status: § 102(b) (issued >1 year before 1995-12-20) and § 102(a)/(e).
• Description: Couples a wireless LAN to a wired TCP/IP network through a local gateway, and provides a global gateway that maintains a pool of "pseudo-IP" network addresses. A mobile unit requesting service is assigned a pseudo-IP address; the global gateway buffers and routes packets addressed to that pseudo-address to the mobile unit. The invention's whole point is that the IP layer address of a mobile user is dynamically managed so that a mobile's identity is associated with a network address.
• Claim analysis: This is the closest of the U.S. citations to the "map a mobile identity/terminal to a packet (IP) address to enable communication with a mobile user on a LAN" concept. However, it operates on a wireless LAN / wired IP network (connectionless, packet-routed), with no circuit-switched PBX, no CS, no extension-number routing by an exchange, and no telephone-number addressing at all. There is no IP↔telephone-number conversion table, and no channel establishment triggered by dialing a converted extension number.
• Anticipation conclusion: Does not anticipate claims 1–6 (missing the telephone-number-scheme PS, the number-routing exchange, and the packet-address→telephone-number table). Highly relevant to claim 3/6's control-unit-side address management idea in an obviousness combination. Confidence: high.

2.2 JPH05207072A — NEC Corporation

• Full citation: JP H05-207072 A, "Method and device for automatic call issuance" (自動発呼方法及び装置), assignee NEC.
• Dates: Priority 1991-11-30; laid-open 1993-08-13.
• § 102 status: § 102(a)/(b) as a printed publication (published 1993-08-13, before the bar date).
• Description (limited information): Based on the title and available indexing, it concerns automatically placing a call (automatic call origination) — plausibly, automatically dialing a pre-stored destination number when a data-sending request occurs. This is conceptually near the claimed "special number + convert to extension number → establish channel" trigger, but I could not retrieve the full text in this session.
• Claim analysis: If the disclosure shows automatic dialing of a telephone number derived from or associated with a data-addressing request (rather than manual dialing), it bears on the conversion/trigger feature common to all six claims. But there is no evidence it discloses the full wireless-PBX-plus-LAN architecture or the table locations.
• Anticipation conclusion: Unlikely to anticipate any full claim on its own; potentially relevant to the "automatic establishment of a circuit call for data" element. Confidence: low — description inferred from title/abstract only; do not rely on this without retrieving the Japanese document.

2.3 JP2943478B2 — Matsushita Electric Industrial Co.

• Full citation: JP 2943478 B2 (laid-open family of JP H05-…), "Computer network management method and apparatus," priority 1992-01-30; granted 1999-08-30 (laid-open ~1993).
• § 102 status: The laid-open publication (if pre-1995-12-20) would be § 102(a)/(b) art; the granted Japanese patent itself post-dates the bar.
• Description (limited): Computer-network management — terminal/network management on a LAN; no evidence in the record of a wireless PBX or telephone-number conversion.
• Claim analysis: No disclosed correspondence between packet addresses and PBX telephone numbers for channel establishment that I can verify.
• Anticipation conclusion: Not identified as anticipating any claim. Confidence: low (no full text retrieved).

2.4 JP2826416B2 — NEC Corporation

• Full citation: JP 2826416 B2, "Connection router between local area networks," priority 1992-06-05; granted 1998-11-18.
• § 102 status: Potential § 102(a)/(b) if the pre-grant laid-open publication predates 1995-12-20 (likely, given priority 1992).
• Description (limited): A router interconnecting LANs (LAN-to-LAN connection router). LAN routing only.
• Claim analysis: Relevant only to ordinary LAN routing; does not address wireless personal stations, PBX exchanges, or IP↔telephone-number conversion.
• Anticipation conclusion: Not anticipatory. Confidence: low-to-moderate (title-based).

2.5 JP3076676B2 — Anritsu Corporation

• Full citation: JP 3076676 B2, "Remote bridge," priority 1992-07-10; granted 2000-08-14.
• § 102 status: Potential § 102(a)/(b) via its laid-open publication (~1994, before the bar date).
• Description (limited): A remote bridge for interconnecting LANs over a distance.
• Claim analysis: No wireless-PBX / telephone-number conversion content identified.
• Anticipation conclusion: Not anticipatory. Confidence: low (title-based).

2.6 JPH06105384A — Fujitsu Limited (electronic-exchange LAN management)

• Full citation: JP H06-105384 A, "LAN management system for electronic exchange" (電子交換機におけるLAN管理システム), inventors Yamato, Ito, assignee Fujitsu; priority 1992-09-21; laid-open 1994-04-15. (U.S. counterpart: US5384766A, "LAN management system in electronic switching apparatus," granted 1995-01-24 — independently § 102(b) art.)
• § 102 status: § 102(a)/(b) (published 1994-04-15 and, via the U.S. counterpart, patented 1995-01-24 — both before the bar date).
• Description: An electronic (telephone) exchange integrating voice/low-speed telephone terminals and high-speed LAN terminals on multiplexed subscriber lines. The exchange stores the association between the low-speed (telephone) terminal and the high-speed (LAN) terminal on each line and, using that stored association, manages/monitors both the circuit-switched traffic and the LAN traffic from a common maintenance platform. (Description confirmed via the retrieved US5384766 text.)
• Claim analysis: This is the family citation closest to the claimed hybrid exchange: one node (the electronic exchange) that has a stored correspondence between the telephony side and the LAN side, i.e., a form of "correspondence table" linking a telephone-identity to a LAN/data terminal. But it lacks: a wireless personal station and cell station; the packet-address (IP) → telephone-number conversion used to establish a channel between the PS and a LAN terminal; and the three-way placement of the table (exchange/PS/control unit) that differentiates claims 1–6.
• Anticipation conclusion: Does not anticipate claims 1–6 on its own. It is, however, one of the strongest pieces of family-cited art for the exchange-side stored association element of claims 1 and 4 in an obviousness combination. Confidence: moderate-to-high (US counterpart full text reviewed).

2.7 US5796727A — International Business Machines Corp. (Harrison/Jaepel)

• Full citation: US 5,796,727 A, "Wide-area wireless LAN access," inventors C. G. Harrison, D. Jaepel, assignee IBM.
• Dates: Filed 1993-04-30; granted/published 1998-08-18.
• § 102 status: § 102(e) (U.S. filed 1993-04-30, before 1995-12-26); also § 102(g). Not § 102(b) (issue date after the bar).
• Description: Lets a mobile PC equipped with a cellular-telephone modem take part in an establishment LAN. A cellular system (MTSO/MSC) provides point-to-point links between mobile stations and a Mobile Data Service Controller (MDSC); a Wide-Area Bridge (WAB) bridges LAN MAC frames between the wired establishment LAN and the cellular infrastructure, with link/stream managers and "shadow PC" functions maintaining the LAN session while the mobile roams. Data (LAN MAC frames) ride over the circuit-oriented cellular telephone network, and the system supports voice as well.
• Claim analysis: This is the closest overall architecture among the U.S. citations: a circuit-oriented wireless (cellular) telephone network interworking with a LAN so mobile data terminals can communicate with LAN terminals, including roaming between switching offices. What it lacks for claims 1–6: (i) it bridges MAC-layer LAN frames and does not route by a telephone/extension number at an exchange while separately routing by IP/packet address at a control unit; (ii) there is no correspondence table that converts a packet address into a telephone number to place the call (the WAB/MDSC do protocol/link adaptation, not IP→extension-number translation for call setup); (iii) the table-placement distinctions of claims 2/5 (PS) and 3/6 (control unit) are absent.
• Anticipation conclusion: The most plausible § 102(e) anticipation threat to the preamble/general architecture of claims 1 and 4, but on the record it does not disclose the "packet address converted to telephone number via correspondence table to establish the channel," which is the crux of all six claims. Not anticipatory standing alone; strong obviousness anchor. Confidence: high (specification reviewed via EP0622924/PTAB exhibit and USPTO mirrors).

2.8 JP2502468B2 — International Business Machines Corp.

• Full citation: JP 2502468 B2, "Communication control method for a local wireless communication system having a plurality of wireless mobile stations," priority 1993-09-30; granted 1996-05-29.
• § 102 status: Potential § 102(a)/(b) if laid-open before 1995-12-20 (likely, priority 1993).
• Description (limited): A wireless local communication system with multiple wireless mobile stations — communication control (e.g., access control, registration/handoff) among wireless mobile stations under base stations.
• Claim analysis: Discloses wireless-mobile-station communication control, but nothing in the available record shows a PBX extension-number ↔ IP-address conversion table or a LAN-terminal destination.
• Anticipation conclusion: Not anticipatory of claims 1–6 based on available information. Confidence: low (no full text).

2.9 SE9304119D0 — Ericsson GE Mobile Communications (now Ericsson)

• Full citation: SE 9304119 D0, "Devices and mobile stations for providing packet data communication in digital TDMA cellular systems," filed 1993-12-10 (PCT family: WO95/16330 → EP0683963; U.S. counterpart US5590133A, filed 1994-12-09, granted 1996-12-31).
• § 102 status: Swedish filing/publication 1993-12-10 → § 102(a)/(b) as a foreign printed publication if publicly available before 1995-12-20; the U.S. counterpart was filed 1994-12-09 → § 102(e).
• Description: The GPRS-precursor architecture: shared packet-data channels (PDCH) in a TDMA (GSM-type) cellular system; a packet-data controller in each MSC controls access; a packet-data router per MSC routes IP packets to/from the MSC area; a backbone interconnects routers and interworking functions (IWF) to external IP/X.25 networks. Notably, the PD controller translates an MS's IP address to IMSI (subscriber identity) and maintains routing tables keyed by IP address with HLR interrogation for roaming. Confirmed in detail via US5590133 text retrieved above.
• Claim analysis: Discloses (i) a mobile station with a telephone-network identity; (ii) an MSC-side node that translates between an IP/packet address and a cellular subscriber identity (IMSI); (iii) routing of packet data between the mobile network and external IP networks through IWFs; and (iv) roaming across MSCs. It is the family citation with the clearest "convert packet address → network identity at the network node" teaching. However, it is a shared-packet-channel (packet-data) system — routing is done packet-by-packet by PD routers, not by establishing a circuit channel through a PBX exchange based on converting an IP address into a telephone/extension number, and there is no wireless-PBX/LAN terminal arrangement as claimed. The conversion is IP→IMSI for packet routing, not IP→telephone-number for circuit setup.
• Anticipation conclusion: Potentially the strongest § 102(e)/102(b) threat to the address-translation concept of claims 1 and 4 (table at the exchange/network node) as part of an obviousness case, but not a clean anticipation of any of claims 1–6 given the circuit-channel-establishment and PBX/LAN architecture differences. Confidence: moderate-to-high on content (via US5590133); the anticipation gap analysis is my own.

2.10 FI940093A0 — Nokia Mobile Phones Ltd.

• Full citation: FI 940093 A0, "Foerfarande Foer oeverfoering av data och datagraenssnittenhet" ("Method for transferring data and a data interface unit"), filed/priority 1994-01-10.
• § 102 status: § 102(a)/(b) if publicly available before 1995-12-20 (likely, filed 1994-01-10).
• Description (limited): A method for transferring data and a data-interface arrangement for a mobile phone/data terminal context (title translation). Full text not retrieved.
• Claim analysis: No verifiable disclosure of the claimed PBX/LAN correspondence-table architecture.
• Anticipation conclusion: Not identified as anticipatory. Confidence: low.

3. Summary table — citation → claims

4. Bottom line

1. No single cited reference appears to anticipate any of claims 1–6. Every claim is an independent system claim whose crux is the combination of (a) a circuit-switched wireless exchange routing by telephone number, (b) a LAN-side control unit routing by packet address, and (c) a correspondence table that converts a packet address into a telephone number to establish the physical channel, with the table located in the exchange (claims 1/4), personal station (claims 2/5), or control unit (claims 3/6). None of the retrieved references discloses that exact three-part combination, and none discloses table placement in a PS (claims 2/5) at all.

2. Most relevant references, ranked:

   • US5796727A (IBM) — closest architecture (wireless circuit/cellular system + LAN data access + roaming), § 102(e) as of 1993-04-30. Biggest threat to claims 1/4 if the "conversion table" limitation could be read onto its bridging/address handling — on my reading it cannot, but this is the reference I would scrutinize hardest in an invalidity analysis.
   • SE9304119D0 / US5590133A (Ericsson) — closest address-translation-at-the-network-node teaching (IP→IMSI/HLR routing), § 102(e) as of 1994-12-09; strong for claims 1/4 combinations, but a packet-data system rather than circuit-channel establishment.
   • US5159592A (IBM/Perkins) — closest IP-address management for wireless mobile users teaching; supports the packet-address side of the system.
   • JPH06105384A / US5384766A (Fujitsu) — closest exchange-with-stored-telephony↔LAN-association teaching; supports the correspondence-table side of claims 1/4.

3. Confidence caveats: For the Japanese/Swedish/Finnish documents I could verify titles, dates, assignees, and (for Fujitsu, Ericsson) full-content via U.S./EP counterparts, but I could not retrieve full text of JPH05207072A, JP2943478B2, JP2826416B2, JP3076676B2, JP2502468B2, or FI940093A0. Their descriptions and non-anticipation conclusions rest on titles/index data and should be re-verified against the documents themselves before being relied on. I also could not query USPTO examiner's search history (the PTO's internal search report was not in the supplied record); the "citations" analyzed here are those printed on the patent and its WO/EP/JP family members.

4. Practical note for further work: Because claims 1–6 differ only by table location, the strongest § 102 invalidity strategy would target the table-in-the-exchange claims (1 and 4) with US5796727 and/or SE9304119/US5590133, and the table-in-the-control-unit claims (3 and 6) with US5159592 combined with a PBX-coupling reference — but those would be § 103 obviousness arguments, not § 102 anticipation, given the element gaps identified above.

I'll ground the § 103 framework with a few targeted searches on the legal standard and the address-translation state of the art as of the 1995 priority date, then build the obviousness analysis on the Prior Art section already produced.

Obviousness Analysis — US 6,009,088 under 35 U.S.C. § 103

Note on a source conflict (flagged per instructions): the system header states today's date is 2026-09-10, while this task states April 26, 2026. I treat the operative date as irrelevant to the merits (the patent is expired and the governing law is pre-AIA); I flag the discrepancy only because the operating rules require it. Nothing in the analysis turns on which date is correct.

This section builds on the Prior Art analysis already produced (reference descriptions, § 102 status, and the conclusion that no single cited reference anticipates any of claims 1–6). The question here is the complementary one: whether the combined teachings render the claims obvious. The short answer is yes, with high confidence for claims 1, 3, 4, and 6; moderate/low confidence for claims 2 and 5.

1. Governing framework

Statute. The application (08/875,510) was filed 1996-12-20, before the AIA. Pre-AIA § 103(a) applies: obviousness is judged as of the invention date (presumed 1995-12-26, the JP priority date). The Graham v. John Deere factors control:

1. scope and content of the prior art;
2. differences between the prior art and the claims;
3. level of ordinary skill in the art; and
4. secondary considerations.

The KSR overlay. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), governs the motivation-to-combine inquiry and is decisive here. KSR held the Federal Circuit's TSM test "too rigid," and endorsed (i) predictable results ("[t]he combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results," 550 U.S. at 416), (ii) commonsense inference, (iii) design incentives and market forces, and (iv) — directly on point — the "known problem" rationale: "One of the ways in which a patent's subject matter can be proved obvious is by noting that there existed at the time of invention a known problem for which there was an obvious solution encompassed by the patent's claims." Id. at 420. See the practitioner summaries at Lexology (KSR summary) and Martindale/Kilpatrick (KSR summary).

Design-choice rationales. MPEP § 2144.04 permits a "design choice" or "rearrangement of parts" rationale where the art shows the parts in some arrangement and the difference is only their placement — subject to the caveat that criticality of a specific limitation, if demonstrated, defeats a bare rearrangement theory (In re Japikse, 181 F.2d 1019; In re Kuhle, 526 F.2d 553). This is directly applicable because claims 1–3 (and 4–6) differ only by where the table sits.

Interesting framing point — the claims are self-limiting admissions. All six claims are drafted in two-part ("characterized in that") form. The pre-characterizing portion — the wireless personal station, cell station, exchange routing by telephone number, the LAN-side control unit routing by packet address, and the LAN terminal with a packet address "independent of the telephone number scheme" — is thus presented by the patent itself as the known context, with the alleged invention residing solely in the correspondence table and the packet-address→telephone-number conversion. That drafting choice narrows the § 103 dispute to a single limitation (where the table lives and what it does), which is exactly the kind of limitation most vulnerable to a design-choice / predictable-results attack.

2. Level of ordinary skill (Graham factor 3)

A POSITA at the 1995 priority date most plausibly had: a bachelor's degree in electrical engineering, computer science, or equivalent, plus 2–4 years of experience in one or more of (a) private-branch-exchange / wireless-PBX telephony (PHS/cordless, RCR STD-28 generation), and (b) data networking (Ethernet, TCP/IP, routers, ARP). This was an integration role — the patent itself is an integration invention — so the hypothetical artisan is a systems engineer comfortable with both the circuit-switched telephony world and the connectionless IP world. Nothing about any asserted feature requires a higher level of skill, and no reference turns on exotic technology.

3. Claim construction of the decisive limitation

Every claim reduces to one contested limitation: "a correspondence table in which the packet address is made correspond to the telephone number," used to "convert the packet address to the telephone number ... in order to establish a communication channel between said wireless personal station and said terminal equipment connected to said LAN."

Three construction points materially strengthen the obviousness case, and all come from the patent's own specification (not from hindsight):

1. The patent equates the extension number with the physical-layer address. The spec states the necessary mapping is between "an address (IP address) used in an IP layer" and "an address (Ethernet address in the LAN, and extension number in the wireless PBX system) used in a lower physical layer." The patent thus treats the extension number as functionally the data-link-layer analog of an Ethernet address. Converting an IP address to a data-link address via a table is the definition of ARP (RFC 826, 1982) — i.e., the claimed conversion is the telephony analogue of a routine, decades-old LAN function.

2. The conversion is expressly optional in the disclosed operation. For the M-DTE→DTE case, the spec says the H-PBX "may send the connection request directly and unconditionally to the TA without referring to the incoming IP address information contained in the conversion table." Under MPEP § 2144.04, an applicant who has not demonstrated criticality of a limitation cannot rely on that limitation to defeat a design-choice/routine-optimization rationale — and here the patent affirmatively describes the table lookup as bypassable.

3. The problem was expressly known and admitted. The Background admits the prior art mapping was performed "by man as an addresser of the data. Therefore, the operation was troublesome," and admits "loaming between PBX" mobility was already realized. Under KSR's "known problem" rationale, this is a textbook predicate for obviousness.

Additionally, RFC 1631 (Network Address Translator, May 1994) — a printed publication predating the 1995-12-20 § 102(b) bar date (see RFC Editor) — discloses placing a translation table at a router/border node between two address domains and translating packet addresses at that boundary, explicitly noting the advantage that it "can be installed ... without changes to routers or hosts." Its co-author, P. Francis, NTT (the patent's own assignee's laboratory), was working on exactly this problem. NAT is not IP→telephone-number translation, so it is not anticipatory, but it supplies powerful motivation and technical grounding for the control-unit-side placement of claims 3/6.

4. The overarching motivation to combine (applies to every combination below)

All of the cited references sit in the same field of endeavor — interworking a wireless (circuit-oriented) telephony environment with a wired, packet-oriented LAN — and the motivation to combine them arises from a single, articulated problem admitted in the patent's own Background: how to let a data terminal on one side reach a data terminal on the other without a human manually reconciling two address systems. This is exactly the KSR "known problem with an obvious solution" scenario, and it does not require the references to address the identical problem as the patent (KSR permits looking to any relevant art and to market/design pressures).

5. Combination families by claim group

5.1 Claims 1 and 4 — table in the exchange (strongest attack)

Primary combination: US 5,796,727 (IBM, "Wide-Area Wireless LAN Access," filed 1993-04-30) + JP H06-105384 A / U.S. 5,384,766 (Fujitsu, "LAN management system in electronic switching apparatus") + SE 9304119 D0 / U.S. 5,590,133 (Ericsson, packet data in TDMA cellular).

Element-by-element:

Articulated reasoning. (a) IBM teaches the complete wireless-LAN interworking architecture including roaming. (b) Fujitsu teaches that a telephone exchange can hold a stored correspondence linking a telephony terminal to a LAN terminal — the precise physical locus of claim 1's table. (c) Ericsson teaches that a network node can hold an address-translation table mapping a packet address to a network/subscriber identity, with roaming lookup — the precise mathematical content of claim 1's conversion. A POSITA seeking to automate the admitted manual mapping would combine (b)'s locus with (c)'s content on (a)'s architecture. Result is predictable: table lookup and call routing are routine switching functions, and the exchange already stores subscriber/location data (the patent says so itself: "initial registration data," "location registration data"). No new technology is required; no unexpected result is asserted.

Claim 4 adds only interconnection of exchanges and control units and roaming. This is the least burdensome part of the case: IBM '727 and Ericsson '133 both expressly disclose roaming across switching nodes, and the patent admits "loaming between PBX" was known. The two-part claim form admits the multi-PBX architecture as context.

5.2 Claims 3 and 6 — table in the control unit (strong, and aided by RFC 1631)

Primary combination: US 5,159,592 (IBM/Perkins, "Network address management for a wired network supporting wireless communication to a plurality of mobile users") + US 5,796,727 (IBM) + RFC 1631 (NAT) / US 5,590,133 (Ericsson).

• US 5,159,592 is the key reference: it places address management for mobile users in local/global gateways — i.e., at the network boundary node — maintaining and assigning packet addresses for mobile units. The patent's own specification defines the claim's "control unit" as follows: "the routers and the TA have the role which a control unit has, for controlling the transmission of packet data through the LAN." That express definition makes the Perkins gateway and the claim's control unit the same class of node.
• RFC 1631 supplies the well-known engineering practice of putting a translation table at a router to bridge two address formats, and the recognized advantage of doing so transparently "without changes to hosts or routers." Combined with the admitted problem, this is a direct motivation to host the IP↔extension-number table at the router/TA.
• US 5,796,727 supplies the wireless-PBX-to-LAN architecture and roaming.

Articulated reasoning. Routers already perform address resolution at layer boundaries (ARP); NAT (RFC 1631, May 1994) generalized that to cross-domain address translation in a table. Placing the IP↔telephone-number table at the router/TA is the natural boundary placement, avoids modifying the PBX and PS, and concentrates administration — the same "install without changing hosts" advantage NAT expressly touts. Predictable result; no asserted criticality. For claim 6 the same reasoning applies, with the multi-system interconnection supplied by US 5,796,727/US 5,590,133 and the patent's admitted PBX-roaming.

The NTT connection is worth noting: RFC 1631's co-author was at NTT Software Lab — the assignee's own organization — which undercuts any argument that the translation-at-a-router concept was remote from the inventors' field.

5.3 Claims 2 and 5 — table in the wireless personal station (weakest attack)

Combination: any of the above systems + US 5,159,592 / US 5,726,984 (Norand) for terminal-side/lookup-capable mobile units + the design-choice rationale.

No cited reference stores the address-conversion table in the mobile station itself, so this family must rest on:

• Predictable variation / design choice (KSR + MPEP § 2144.04). The claims differ from claims 1/3 only by the location of a known lookup table. Distributing a lookup table from a network node to an endpoint to trade network signaling for terminal memory is a classic, predictable engineering trade-off.
• The patent's own disclosure supports the equivalence. For the PS-side variant the spec says the PS "converts the incoming IP address to a corresponding extension number using the conversion table and sends a connection request including the extension number as in the case with a voice communication." That is, the PS does what any mobile already does — originate a call — and the only addition is a local table lookup. That the patent elsewhere treats the PS-, PBX-, and router-side placements as interchangeable (claims 1–3) is itself evidence that the placement yields no asserted difference in function or result.
• Motivation from the multi-system claims (5). A PS that carries its own table can initiate a converted call even when roaming into a system whose exchange lacks the table, which supplies a concrete reason (a design incentive) to move the table to the terminal for the claim-5 roaming scenario.

Honest assessment: this is the family most likely to survive a validity challenge, because the applicant can point to (i) no explicit teaching of a personal-station-resident IP→number table and (ii) functional differences in who initiates the conversion and when. A § 103 attack on claims 2/5 would likely require an expert declaration on what terminal-resident address caching/translation a POSITA would have routinely implemented, plus a secondary reference showing endpoint-side address tables. The challenger's clear-and-convincing burden is highest here.

6. KSR rationale matrix

7. Secondary considerations (Graham factor 4) — likely absent or weak

• Commercial success / licensing / copying / industry praise: no evidence found in the record or in the earlier searches. The patent was never litigated and lapsed for non-payment (2011-12-28).
• Long-felt but unmet need: the patent asserts the manual burden was "troublesome," but the art (Perkins 1992; RFC 1631, 1994; Ericsson 1993) shows the problem was being actively addressed before the priority date — which weakens rather than strengthens a long-felt-need narrative.
• Failure of others: none identified.
• Unexpected results / nexus: none asserted. The patent presents the three table locations as interchangeable embodiments, which is affirmative evidence of predictability — the enemy of a non-obviousness position.
• Teaching away: none identified. US 5,796,727's MAC-frame bridging might be argued to steer away from IP-layer translation, but that is a weak "different solution," not a teaching away (In re Fulton: mere disclosure of an alternative is not teaching away).

8. Limits, gaps, and confidence

1. This is a § 103, not a § 102, case. As established in the Prior Art section, no single reference discloses the claimed combination. Any challenge must be a combination/reasoning case built on two or three references plus the admitted prior art.
2. Full-text gaps. JPH05207072A, JP2943478B2, JP2826416B2, JP3076676B2, JP2502468B2, and FI940093A0 were not retrieved in full in the earlier work; I do not rely on them, and a final invalidity contention should re-verify them against the originals. My conclusions rest on US 5,796,727, US 5,159,592, US 5,590,133, US 5,384,766/JP H06-105384, RFC 1631, and US 5,726,984, which were verified at least in substance.
3. The routing target differs across references. Ericsson translates IP→IMSI, not IP→telephone/extension number; Fujitsu stores a telephony↔LAN association without packet-address conversion. Claim 1 requires the target to be a telephone number. The bridge is straightforward — the claim's own preamble requires the exchange to route by telephone number, so the target of translation must be a number — and the patent's own spec equates the extension number with a physical-layer address, but a defendant should expect the patentee to press this gap.
4. Claims 2/5 (PS-side table) are the vulnerable-to-the-patentee corner, as explained above.
5. Presumption of validity / clear and convincing evidence applies in litigation (§ 282); in a reexamination-type setting the standard is lower. Because the patent is expired and unenforceable, the practical value of this analysis is retrospective (pre-lapse damages and defensive posture) — but the § 103 merits are unaffected by expiration.

9. Bottom line

The through-line is simple: the alleged invention is the automation of a mapping the patent itself admits was previously done by hand, implemented by putting a known lookup table at one of a finite number of known network nodes, using known address-translation techniques (ARP/NAT) on a known wireless-PBX-plus-LAN architecture that already supported roaming. That is the paradigm of predictable results from familiar elements under KSR, reinforced by the claim's two-part form (which concedes the architecture) and the specification's own statement that the conversion table need not even be consulted. Claims 1, 3, 4, and 6 should be considered plainly obvious over the combinations above; claims 2 and 5 are more defensible but still vulnerable on a design-choice/predictable-variation theory.

Key sources: US6009088A Google Patents record · US5590133A · RFC 1631 (NAT), May 1994 · KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) · KSR practitioner summary · MPEP §§ 2144.03–2144.04 (In re Japikse, In re Kuhle, In re Chu).