US 6185535

I'll search for this specific patent number across the requested sources.

US Patent 6,185,535 — Analyst Summary

Search scope note: I ran targeted web searches against Google Patents, USPTO-derived data (uspto.report, PTAB/PTActs), and general litigation/docket sources (CourtListener, Justia Dockets, Docket Alarm, CAFC opinion repositories). No CAFC 2026 docket or Federal Circuit appeal involving US 6,185,535 was located. See the "Litigation / CAFC" section below for what I did and did not find. Everything below is drawn from the patent's own front-page and full-text data; where I relied on a secondary source I say so.

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1. Bibliographic data

International family (all claiming the 1998-10-16 priority): PCT/SE1999/001769 → WO 2000/023985 A1; EP 1129449 A1; JP 2002-528804 A; CN 1158645 C; AU 14220/00 A; BR 9914583 A; MY 117070 A. Notably, no CAFC-relevant US continuation or reissue appears in the family listing.

Markdown caveat: the patent text as fetched renders the numbering as "6185535"; the correct literal identifier for the granted patent is US 6,185,535 B1. I have not altered any digits.

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2. Abstract (as granted)

Voice control of a service application provided to a terminal from a remote server is distributed between the terminal and a remote application part. A relatively low-power ASR in the terminal recognizes portions of user audio input that relate to terminal functions or to functions defined by a predefined markup language. Recognized words may control terminal functions or be converted to text and forwarded to the remote server. Unrecognized portions of the audio may be encoded and forwarded to the remote application part, which includes a more powerful ASR. The remote part may convert recognized words to text for the remote server. In the reverse direction, text received from the remote server may be converted to an encoded audio output signal, forwarded to the terminal, and played over a loudspeaker — i.e., a voice control mechanism replaces the remote server's visual-display output and keyboard input.

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3. Plain-language overview of the independent claims

There are exactly two independent claims.

Claim 1 — the method

A method of controlling a service application that a remote server provides to a terminal, with these ordered steps:

1. Receive an audio input signal representing audio information.
2. Recognize locally: use a first ASR located in the terminal to decide whether the audio contains words defined by a first vocabulary. Anything in the audio that does not correspond to those words is an "unrecognized portion."
3. Act locally if recognized: if the audio contains first-vocabulary words, use a terminal application part of an application protocol service logic to decide what to do with them (e.g., local terminal control or building a response message).
4. Package the leftovers: format the unrecognized portion of the audio for inclusion in a data unit whose structure is defined by a first predefined markup language (the disclosure uses WML data units / MIME types as the worked example).
5. Send it: communicate that data unit to a remote application part over a first digital data link operating under a first application protocol.
6. Handle it remotely: at the remote application part, extract the formatted unrecognized audio from the data unit and use remote application part service logic to decide what to do with it.

The core inventive concept is the split-recognition architecture: the terminal handles only the small, standardized markup-syntax vocabulary, and the hard/unknown audio is shipped as data (not as a voice call) to a remote recognizer/service for handling.

Claim 18 — the apparatus

The apparatus counterpart of claim 1, written in means-plus-function style, covering the same six functional blocks: (a) means for receiving the audio input signal; (b) a first ASR in the terminal determining whether the audio contains words of the first vocabulary, with the non-matching portion being the unrecognized portion; (c) a terminal application part of an application protocol service logic for deciding what to do with recognized first-vocabulary words; (d) means for formatting the unrecognized portion into a markup-language-defined data unit; (e) means for communicating the data unit to a remote application part over a first digital data link using a first application protocol; and (f) the remote application part, comprising means for extracting the unrecognized audio from the data unit plus remote application part service logic to decide what to do with it.

Dependent-claim highlights (context, not independent scope)

• Claims 2/19: audio input is compressed digitally encoded speech.
• Claims 3–5 / 20–22: recognized words select terminal functions, including selecting a current menu item as a response to the remote server, and re-associating a current menu item with a different selection.
• Claims 6–12 / 23–29: the terminal generates a corresponding message (state information, text, or binary data) sent to the remote application part, which may forward it to the remote server over a second digital data link under a second application protocol, which may be the same as the first.
• Claims 13–16 / 30–33: a second ASR in the remote application part tests the unrecognized audio against a second vocabulary; claim 14/31 recites that the first vocabulary exclusively includes markup-language syntax words and the second vocabulary exclusively includes remote-server-associated words. Claim 15/32 covers generating a keyboard-emulation response to the remote server; claim 16/33 covers changing remote application part service logic state.
• Claims 17/34: the reverse direction — the remote part receives text from the remote server, generates a corresponding audio output signal, formats it into a markup-language-defined data unit, sends it to the terminal, and the terminal extracts it and drives a loudspeaker.

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4. What the specification adds (useful for claim construction context)

• The working embodiment divides the system into four logical parts: Terminal Part (TP) 203, Terminal Application Part (TAP) 201, Remote Application Part (RAP) 205, and External Services and Content (ESC) 207. The TAP acts as a "voice-oriented browser" in the terminal; the RAP may be a multi-user WAP application server, a WAP gateway/proxy, or a single-user local server.
• The TAP reference database stores words in three formats: text, TP audio-encoded data, and a feature vector — a concrete enablement of the "first vocabulary."
• The patent explicitly states the first application protocol "may, but need not be" the same as the second.
• Stated advantages: no voice channel need be established (audio is carried as MIME-typed digital data), no text-to-speech module is needed in the terminal, no modification of service content is required, and the standardized WML vocabulary bounds the terminal-side recognition problem.
• An explicit distributed "wildcard" recognition example: the RAP ASR looks for "CALL" and returns only the recognized command word to the TAP, which then re-prompts for the name.
• WAP/WML are used by way of example only; the specification expressly says the concepts apply to other markup/script languages and small-vocabulary application protocols.

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5. Litigation / CAFC 2026 docket findings

I found no evidence that US 6,185,535 is or was the subject of a CAFC appeal docketed in 2026, or of any active litigation. Specifically:

• A search for "6185535 CAFC 2026 docket" returned only unrelated 2026 Federal Circuit / PTAB material (e.g., ironSource v. Digital Turbine, a Director-level IPR non-institution discussion, and a Headwater Research appeal docket in E.D. Tex.).
• A search for "6185535 lawsuit litigation 2026" returned no case naming this patent.
• The digit string "6185535" did appear in two unrelated contexts, which I flag so they are not mistaken for this patent:
  • A patent-number search string in a PTAB exhibit list (IPR2019-00916, Apple v. Omni MedSci), where "6185535" is merely one number among hundreds in a database query.
  • A page discussing U.S. Patent 6,535,815 B2 in TCL v. Telefonaktiebolaget LM Ericsson (IPR2015-01772 / IPR2015-01878). That is a different patent number (6,535,815), a different technology, and a different dispute. Do not conflate it with 6,185,535.
• Erisson's public FRAND/licensing litigation (Apple, TCL, Samsung, Adaptix, WiLAN) concerns cellular SEPs; nothing I found asserts the '535 patent.

Practical explanation: the patent's listed legal status is Expired – Lifetime with an anticipated expiration of 2018-10-16 (20 years from the 1998-10-16 US filing date, with no term extension identified on the record). A 2026 appeal would be chronologically implausible absent extraordinary circumstances.

Uncertainty statement: My search was limited to public web sources and I did not query PACER or the CAFC's own docket system directly, nor did I run a full USPTO Patent Center / Global Dossier transaction history. I therefore cannot certify that no post-expiration proceeding (e.g., a late-filed appeal, a reexamination, or an IPR filed against an expired patent) exists. If a definitive negative is required, the authoritative check is the CAFC's CM/ECF docket and the USPTO Patent Center "Global Dossier" record for application 09/173,748 — neither of which I was able to retrieve here. Additionally, I have no authoritative information on any assignments, licenses, or later transfers of this patent beyond the original Ericsson assignment recorded 1998-10-16.

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6. Bottom line

US 6,185,535 is a Telefonaktiebolaget LM Ericsson patent (Hedin & Meier), filed and issued in 1998 and 2001 respectively, covering a distributed client/server speech-recognition architecture for WAP/WML service applications: a small in-terminal ASR handles markup-syntax and terminal-control words, while unrecognized audio is wrapped in markup-language data units (MIME types) and shipped over a digital data link to a remote application part with a more powerful ASR that can also return synthesized audio to the terminal. It has two independent claims (1 and 18), both expired, and I found no CAFC 2026 activity — with the caveat that I could not query the court's docket system or Patent Center directly, so that negative is based on public web searching only.

I'll search for litigation involving US patent 6185535.

Let me search more targeted litigation databases.

Let me check specialized litigation databases directly.

Litigation Search Results for US Patent No. 6,185,535

Short answer: I found no known litigation asserting US Patent No. 6,185,535 (B1).

Patent Identified (confirming the literal number)

• Patent: US 6,185,535 B1 — "Voice control of a user interface to service applications"
• Inventors: Jan Hedin; Bernhard Meier
• Assignee: Telefonaktiebolaget LM Ericsson (AB/Publ)
• Application: US 09/173,748, filed 1998-10-16; granted 2001-02-06
• Status: Expired – Lifetime (anticipated expiration 2018-10-16)
• Source: https://patents.google.com/patent/US6185535/en

Litigation Findings

Searching patent-litigation oriented sources for the specific number returned no case in which this patent was asserted as an infringement cause of action — no district court, ITC, PTAB, or CAFC proceeding involving US 6,185,535 as an asserted or challenged patent. The requested fields (plaintiff, defendant, jurisdiction, case number, filing date, outcome/status) therefore cannot be populated, because no such case was located.

All hits matching the string "6185535" were either:

• Prior-art citations in other parties' patents/prosecution histories (the patent appears as a cited reference in Information Disclosure Statements — e.g., a USPTO PTAB petition document with an IDS listing "6185535" among cited references, at https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1558282](/patent/1558282)/download-documents).
• A misleading co-occurrence in a different patent's file history (e.g., the Apple v. Omni MedSci, IPR2019-00916 Exhibit 1002 search-string listing), which merely lists "6185535" inside a prior-art search query string — not an assertion of this patent.
• An unrelated SEC filing accession identifier ("6185535" as an SEC EDGAR accession number) — not patent litigation.

I also found no evidence the patent was part of Ericsson's later patent-enforcement campaigns (e.g., Ericsson v. Lenovo, Ericsson v. TCL, Ericsson v. HTC, or the Ericsson UPC actions), whose asserted patents are different numbers (e.g., US 10,708,618; 9,641,841; 10,142,659; and various SEPs).

Confidence and Limitations

• Confidence: moderate. This is a negative finding, and negative findings are inherently limited by database coverage.
• I was unable to directly query PACER or run a docket-level lookup on the Unified Patents litigation portal for this specific number within the available search steps. My conclusion rests on searches across general web, Google Patents, the Unified Patents portal, CourtListener, Docket Alarm results, and Federal Circuit blog coverage, none of which surfaced an assertion of US 6,185,535.
• Given the patent expired on 2018-10-16, and that WAP-era voice-control technology (WML/ASR) is a period-specific field, it is plausible the patent was never enforced. However, I cannot state with certainty that no litigation ever existed.

If no litigation is known: yes — no litigation involving US 6,185,535 is known from the sources searched. I recommend confirming with a paid docket search (PACER/LEXIS CourtLink/Docket Navigator/RPX Insight) keyed to the exact number "6,185,535" before relying on this as complete.

Note on the instruction: I interpreted the identifier literally as 6185535 and excluded results for similar/related numbers (e.g., 6,185,536; 10,708,618; 6,185,535-adjacent IDs), which accounted for several of the near-miss search hits.

PTAB / AIA Trial Report — U.S. Patent No. 6,185,535 B1

Patent: Voice control of a user interface to service applications
Patent Owner: Telefonaktiebolaget LM Ericsson (AB) — original assignee and current assignee
Inventors: Jan Hedin; Bernhard Meier
Filing / priority date: 1998-10-16 (no earlier priority claim — US-only priority)
Grant date: 2001-02-06 · Claims: 34 (independent claims 1 and 18)
Anticipated expiration: 2018-10-16 · Legal status: Expired – Lifetime
Source of record: USPTO Open Data Portal structured "PTAB proceedings on file" block, which returns zero AIA trial proceedings, corroborated by Google Patents (https://patents.google.com/patent/[US6185535](/patent/US6185535)/en) and public PTAB docket searches.

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Proceedings overview

Total AIA trial proceedings on file: 0. Breakdown: 0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denials — there is nothing to break down, and no petition has ever been filed against this patent. The bottom line for a defendant is unusual and stronger than a "hardened patent" scenario: no IPR/CBM/PGR has ever touched 6,185,535, and the patent has been expired since 2018-10-16, so a demand letter asserting it today is asserting a dead patent. The relevant defensive work is not PTAB estoppel strategy — it is confirming the expiration date and the § 286 damages window. There is no PTAB FWD to point to, because none exists.

Confidence note: the ODP block is canonical for AIA trials and reports none. My independent web searches surfaced only citation hits to the 6,185,535 number in other parties' prosecution histories and IPR exhibits (e.g., IDS listings and prior-art citation tables in unrelated matters such as IPR2019-00916 (Apple v. Omni MedSci) and IPR2024-00750 (Google)), plus foreign-search-report citations of the patent. Those are cites to the patent, not proceedings on it. I found no IPR, PGR, CBM, or Federal Circuit appeal involving this patent. I did not exhaustively search PACER/Docket Navigator for district court assertions, so I cannot state with high confidence whether the patent was ever asserted in litigation; the absence of any resulting IPR is itself weak evidence that it never drew a serious validity challenge.

Proceedings

None on file

• Type: n/a
• Filed: n/a
• Status: n/a — the structured ODP data returns no proceedings; no proceeding number exists to report, and per the operating rules I will not invent one.
• Judge panel: n/a
• Petition grounds: n/a
• Institution decision: n/a (never petitioned — not "denied"; there is no § 314(a) or § 325(d) denial on record)
• Final Written Decision: n/a
• Settlement / termination: n/a
• Appeal: n/a — no PTAB decision exists to appeal, and I found no Federal Circuit docket entry (CourtListener or otherwise) referencing 6,185,535.
• Defensive value: Because no petitioner ever challenged this patent, there is no § 315(e)(2) estoppel, no claim-cancellation record, and no FWD language to lean on. The entire defensive posture rests on the patent's own status: it expired 2018-10-16, which means every claim 1–34 is unenforceable as to post-expiration conduct and the recoverable-damages window under 35 U.S.C. § 286 (six years pre-suit) has now closed entirely.

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Strategic summary

Claim status: all 34 claims UNTESTED — and all 34 are expired. No claim of 6,185,535 has been canceled, narrowed, or confirmed in an AIA trial, because no trial happened. That is not the same as "all claims sustained" (which would imply the Board upheld them against a challenge); it simply means the patent was never contested at the PTAB. The claims as granted remain: independent method claim 1 and its dependents 2–17; independent apparatus claim 18 and its dependents 19–34. Sets of dependent claims of potential interest to an accused infringer, e.g. claim 5 (re-mapping a current menu item from a first selection to a different second selection), claim 14 (the first vocabulary exclusively WML-syntax words / second vocabulary exclusively server-associated words), and claims 15–17 (keyboard-emulation response; RAP state change; text-to-audio return path), were never construed or tested by any panel.

Estoppel landscape: there is none. § 315(e)(2) estoppel only attaches to a petitioner that obtained an FWD, and § 325(e)(2) does the same for PGR. With zero petitioners there is zero estoppel, so every prior-art ground an IPR petitioner could have raised — including § 102 and § 103 combinations over 1990s WAP/HDML and distributed-speech-recognition art — remains fully available in any forum to any party, subject to whatever a district court does with invalidity contentions. Practically, however, the estoppel question is academic: for a defendant sued today on an expired patent, the cheaper and more certain route is a § 286 / expiration argument rather than an invalidity case.

Pattern signals: no petitioner history, no patent-owner PTAB activity, no aggregator. There is no repeat petitioner (there is no first petitioner), no Unified Patents or other defensive aggregator in the chain, and no pattern of Ericsson pursuing PTAB appeals on this number. Ericsson is an operating company and a large SEP licensor rather than a troll; 6,185,535 belongs to its WAP-era portfolio and has foreign siblings (WO 200023985 A1, EP 1129449 A1, JP 2002-528804 A, CN 1158645 C, AU 1422000 A, BR 9914583 A, MY 117070 A) — but I found no evidence in my searches of enforcement activity on this particular U.S. patent, and importantly no evidence it ever attracted an IPR, which well-asserted patents almost invariably do.

Timing / procedural note for completeness: even if a party wanted to file a new AIA petition now, PGR is unavailable (it requires filing within nine months of grant, long past), CBM review is unavailable (the transitional program sunset on 2020-09-16, and the claims are not obviously directed to a "financial product or service"), and IPR on an expired patent is of little practical value absent a live past-damages dispute. Any IPR would also be subject to the § 315(b) one-year bar if the petitioner has been served with a complaint.

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Recommended next steps

• Do not build a defense around a PTAB record that does not exist. There is no FWD to quote and no canceled claim to cite. If you are corresponding with opposing counsel, the argument is statutory, not adjudicative: the patent's 20-year term ran from 1998-10-16 and it expired 2018-10-16 (Google Patents lists "Anticipated expiration 2018-10-16" and status "Expired – Lifetime"; https://patents.google.com/patent/US6185535/en).
• Run the § 286 math before anything else. 35 U.S.C. § 286 bars recovery for infringement committed more than six years before the complaint is filed. For any complaint filed on or after 2024-10-16, the entire six-year lookback window post-dates expiration, i.e., there is no period of enforceable patent term inside the recoverable window. Confirm the maintenance-fee history to rule out any reinstatement/petition-based extension of the term, and confirm there is no reissue or continuation in the family being asserted instead (a common pivot when a parent has expired).
• Verify there is no live district court case. Because I could not exhaustively check PACER/CourtListener for this patent, treat any demand letter as the first data point: request the case number and asserted claims, then confirm via PACER that no co-pending case exists. If a case is pending, note that no IPR petitioner exists to blame and that any IPR you file would be yours alone, with § 315(b) timing driven by the service date.
• If a demand letter cites claims 1–34, the strongest response is not "invalidity" but "expired, and § 286 leaves nothing recoverable." Any invalidity theory you do preserve (the 1990s WAP/WML and distributed-ASR prior art cited in the specification's own background and in the foreign search reports) should be pled defensively alongside the expiration argument, not instead of it.
• Flag the absence itself. No AIA trial has ever been filed against 6,185,535 despite two decades of WAP-era licensing activity by a sophisticated owner. That is a meaningful signal that this number was not Ericsson's enforcement vehicle — consistent with, though not proof of, the conclusion that a letter citing it should be scrutinized closely.

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Sources: USPTO ODP structured PTAB data (canonical, zero proceedings — as supplied in this task); Google Patents, US6185535B1, https://patents.google.com/patent/US6185535/en (bibliographic data, claims, expiration status); USPTO PTAB TPACTS petition/document search results (no proceeding on 6,185,535; only citations to it inside unrelated IPR exhibits, e.g., IPR2019-00916 and IPR2024-00750 prosecution-history exhibits); European search report for EP 3 040 985 A1 (cites US 6,185,535 B1 as prior art with its full family listing). No PTAB FWD, no CAFC docket entry, and no CourtListener record for this patent was found. Where a fact could not be verified, I have said so rather than assuming it.

I'll verify the assignment record and any litigation involving this patent before producing the report.

Let me check the uspto.report record and look for any litigation or post-issuance transfers.

Let me check for any litigation asserting this specific patent and any NPE transfers.

US 6,185,535 B1 — Assignment / Ownership Reconstruction

Patent: US 6,185,535 B1 — "Voice control of a user interface to service applications"
Filed: 1998-10-16 · Granted: 2001-02-06 · Anticipated expiration: 2018-10-16 (Expired – Lifetime)
Family: WO2000023985A1, EP1129449A1, JP2002528804A, CN1158645C, AU1422000A, BR9914583A, MY117070A — all filed 1999-10-05/12, all naming Telefonaktiebolaget LM Ericsson as applicant.

Sourcing caveat up front: I was able to retrieve the Google Patents legal-events record (live fetch, 2026-09-25) and run corroborating web searches, but the live USPTO Assignment Center / assignment.uspto.gov record (reel/frame, execution date, correspondent of record) did not surface in any retrievable result. Google Patents' legal-events panel for the 1998 assignment deliberately abbreviates to "SEE DOCUMENT FOR DETAILS" and does not expose the reel/frame in its indexed text. I am therefore not reporting a reel/frame number — I have no verified value for it and will not invent one. Everything below that is not reel/frame-grounded is flagged as such.

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Inventors

Pattern observations:

• Both inventors assigned to Ericsson on the filing date itself (1998-10-16), the classic employee-invention assignment executed at filing. This is the opposite of the "inventors depart / retain rights" pattern that precedes a fire-sale — there is no evidence either inventor held back rights.
• Both inventors appear only on this single patent in the retrieved data; I could not confirm a broader co-inventor portfolio or their subsequent employment from the sources available. No evidence of inventor departure within 12 months of filing was found, but this was not positively verified against employment records. Do not read absence of evidence as evidence of absence.
• Technical subject matter (WAP/WML voice-controlled terminal interface, 1998) is consistent with Ericsson's mobile-terminal/mobile-data R&D of that era.

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Original assignee

On the issued patent: Telefonaktiebolaget LM Ericsson — rendered variously as "Telefonaktiebolaget LM Ericsson AB" (Google Patents assignee field) and "Telefonaktiebolaget Lm Ericsson (Publ)" (family-document headers). Treated here literally as recorded; the two forms denote the same Swedish parent.

• Primary line of business: multinational telecommunications equipment vendor — radio access networks, mobile core, and (in the relevant era) mobile handsets and WAP-capable terminals.
• Did they ship a product embodying the claims? The patent describes a distributed voice-controlled service application for WAP terminals (terminal-side small-vocabulary ASR + remote more-powerful ASR, with audio carried as MIME types over the WAP data channel). Ericsson was a first-tier WAP handset and infrastructure vendor at the time (e.g., the R380 and MC218 class of WAP devices). Direct product-mapping of these claims to a specific shipping SKU is not established by the sources retrieved — treat as "operating company in the relevant field," not "verified product-practicing."
• Current status: Operating. Telefonaktiebolaget LM Ericsson remains an active, publicly listed company. Google Patents lists the current assignee as Telefonaktiebolaget LM Ericsson AB — i.e., the patent never left its original owner.
• Context: Ericsson did not divest this patent. This is notable because Ericsson has systematically monetized other patent families (the 2013–2014 Ericsson–Samsung license, the later Ericsson v. Apple and Ericsson v. Acer campaigns), and '535 sits squarely in the voice/WAP interface space that later became a dense NPE target zone.

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Assignment timeline

The record contains one recorded assignment — the original inventor-to-company assignment. There are no post-issuance transfers on record.

• 1998-10-16 (executed) / recorded 1998-10-16 (Google Patents legal-event date; exact recording date and reel/frame not retrievable — flagged, not fabricated) — Reel not available in retrieved sources
  • Conveyance: Assignment of Assignors' Interest (employee invention assignment at filing)
  • Assignor: Jan Hedin; Bernhard Meier (jointly)
  • Assignee: Telefonaktiebolaget LM Ericsson
  • Correspondent: Not determinable from the sources I could access. Google Patents renders this event only as "SEE DOCUMENT FOR DETAILS"; the Assignment Center record carries the attorney/agent of record. I have no verified correspondent name and will not supply one. (If the reviewer can pull the Assignment Center entry, the correspondent is the single most useful field to capture — see signal 3 below.)
  • Context: Original employee-invention assignment — not an acquisition, fire-sale, reorg, securitization, or asserter transfer.

No further recorded assignments. Google Patents legal events show, after filing: 2001-02-06 publication and grant, and 2018-10-16 anticipated expiration. No assignment, security agreement, merger, change of name, license, release, or correction events appear post-issuance, and "Current Assignee" remains the Ericsson parent.

Litigation cross-check (no hits on this patent): Ericsson's active US patent campaign — Ericsson Inc. v. Acer Inc., D. Del. 1:26-cv-00176, consolidated with 1:25-cv-01106 — asserts 8,737,333; 9,526,048; 9,999,097; 10,237,791; 11,044,053. US 6,185,535 is not among the asserted patents. No other suit asserting '535 surfaced. '535 shows up widely only as cited prior art in later voice-recognition patents (the Google Patents "Cited By" list runs to 227 entries), which reflects technical relevance, not ownership activity.

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Timeline diagram

timeline
    title Ownership of US 6185535
    1998 : Filed by Telefonaktiebolaget LM Ericsson
         : Inventors assign rights to Ericsson
    2001 : Patent granted
    2018 : Patent expires

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NPE / troll-pattern signals

1. Shell-entity transfer — not present. No assignment to any "IP / Patents / Licensing / Holdings / Ventures" entity appears anywhere in the chain. The only recorded assignee is Telefonaktiebolaget LM Ericsson, the operating parent. (Compare the textbook pattern — SAIC → VirnetX — which this patent does not exhibit.)
2. Known asserter in the chain — not present. No current or prior assignee matches Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg entity. Cross-checked against the Google Patents current-assignee field (Ericsson) and the family-document assignee of record (Ericsson).
3. Repeat correspondent across the chain — unclear / not determinable. There is only one link in the chain, so "recurrence" cannot exist by definition. More importantly, the correspondent of record for that single 1998 recording was not retrievable from the sources I accessed. This is the one field that would let a reviewer confirm the absence of an NPE-recording attorney, and it should be pulled directly from the Assignment Center.
4. Cascading transfers — not present. Zero post-issuance assignments; therefore zero chained-LLC hops in any time window, let alone <24 months.
5. Pre-litigation transfer — not present. No assignment within 6 months (or any period) before any infringement suit naming '535. No suit naming '535 was found at all.
6. Bankruptcy fire-sale — not present. Ericsson has not filed Chapter 7/11; no proceeding sold this asset; no transfer of record exists.
7. Privateering — not present. No transfer to a third-party assertion vehicle, and no SEC-filing or Patent Progress/EFF coverage tying '535 to a privateering arrangement was found.
8. Defensive aggregator (anti-NPE) — not present. The chain terminates at an operating telecom vendor, not at RPX, AST, LOT, Unified Patents, or OIN. The patent was not neutralized by aggregation — it simply remained with Ericsson and expired.

Additional structural fact: the patent reached its anticipated expiration on 2018-10-16 with Ericsson still as assignee of record. It is outside any assertion window.

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Verdict

Insufficient data (no records beyond the original assignment)

Justification: The only recorded conveyance is the 1998-10-16 inventor-to-Telefonaktiebolaget-LM-Ericsson assignment of assignors' interest; no post-issuance assignment, security interest, merger, or change-of-name appears in the Google Patents legal-events record, and the current assignee field still reads Telefonaktiebolaget LM Ericsson. The "insufficient data" call here reflects the rubric's literal definition — only the original assignment exists — not any ambiguity about who owns the patent: the chain is a single-owner chain terminating at an operating telecommunications company that never divested it, and the patent expired 2018-10-16. Every NPE/troll signal above is not present on the available evidence, with the sole exception of signal 3 (correspondent recurrence), which is unverifiable because the single record's correspondent field and reel/frame could not be retrieved — that gap, not any affirmative adverse finding, is what caps the confidence at "insufficient data" rather than an affirmative non-NPE clearance.

Verification link: https://assignmentcenter.uspto.gov/ (search by patent number 6185535; the same records are indexed at https://assignment.uspto.gov/patent/index.html). Also: https://patents.google.com/patent/[US6185535B1](/patent/US6185535B1)/en (legal events panel).

What a follow-up pull should capture (I could not, and did not substitute guesses): the reel/frame, the execution-vs-recording date pair, and the correspondent of record for the 1998-10-16 assignment. If that correspondent turns out to be an attorney who recurs across other Ericsson filings, that is routine prosecution-side recording, not an NPE tell — but it should be checked rather than assumed.

I'll research this systematically. Let me start by searching for the patent and its cited prior art references.

Let me search more specifically for the front-page "References Cited" (patent citations) of US6185535, which wasn't in the provided text.

Let me look for the front-page references cited on FreePatentsOnline and Justia for this patent.

Summary

I located the patent and verified its identifying data, but I must flag an important limitation up front: I was not able to retrieve the actual prior-art references cited on the face of US 6,185,535 (its "References Cited" / Form PTO‑892 list), and I will not fabricate them. Below I explain exactly what I could verify, what the sources did and did not contain, and how a proper § 102 analysis should be structured.

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1. Patent verification (literal identifiers)

From the authoritative text and corroborating sources (Google Patents US6185535B1, uspto.report/patent/grant/6185535):

Note: one secondary source renders the inventor name as "Fedrin et al." (a garbled "Hedin et al."). Per the operating rule, I am not auto‑correcting the identifier — the operative citation is US 6,185,535 B1, Hedin et al. — but I note the discrepancy in the source.

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2. Critical terminology problem: "citations" runs in two directions

This matters for a § 102 question:

• Backward citations ("References Cited" / "cited by examiner") = prior art the examiner applied against 6,185,535. This is what you asked for.
• Forward citations ("Cited By (227)") = later patents/publications that cite 6,185,535. These are post‑date the 1998‑10‑16 priority date and are therefore not prior art to 6,185,535 under § 102.

The full text you supplied contains only the forward list ("Cited By (227)"). The face-of-patent "References Cited" block was truncated out of the fetch. I attempted several retrieval paths (Google Patents, FreePatentsOnline, Justia, USPTO.report, PTAB/file-history exhibits) and the searches returned the forward-citation table and generic patent-number lists, not the examiner's cited-art list for this specific patent.

Therefore I cannot give you the enumerated prior-art citations with dates and § 102 mappings without fabricating them. Stating them from memory would violate the "do not fabricate" rule, since I do not have high-confidence recall of the specific nine or so references on this patent's face.

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3. What I can report (clearly labeled)

Forward citations (NOT prior art — provided only for context)

Representative entries from the "Cited By (227)" table in the supplied text:

• US 6,249,808 B1 — "Wireless delivery of message using combination of text and voice," AT&T Corp., priority 1998‑12‑15.
• US 6,385,583 B1 — "Markup language for interactive services and methods thereof," Motorola, Inc., priority 1998‑10‑02 (note: 14 days before 6,185,535's priority date, but published 2002‑05‑07 — so it is not § 102(a)/(b) art against 6,185,535; at most a potential § 102(e)/interference-type consideration, which requires file-wrapper analysis).
• US 2002/0072918 A1 — "Distributed voice user interface," G. M. White, priority 1999‑04‑12.
• US 6,633,846 B1 — "Distributed realtime speech recognition system," Phoenix Solutions, priority 1999‑11‑12.

Every other "Cited By" entry likewise post-dates the 1998‑10‑16 priority date and is not available as § 102 art.

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4. What the § 102 analysis for 6,185,535 must look like

Because pre‑AIA § 102 governs (application filed 1998), qualifying art must be:

• § 102(a): known/used by others in the U.S., or patented/published anywhere, before the invention date;
• § 102(b): patented or described in a printed publication, or in public use/on sale, more than one year before 1998‑10‑16 (i.e., before 1997‑10‑16);
• § 102(e): a U.S. patent or published application filed before the invention date (printed‑publication date rules apply from 2000‑11‑29);
• § 102(g): prior invention by another.

For a reference to anticipate (not merely render obvious), it must disclose every element of the claim. Mapping the claim set:

The strongest § 102 candidates for this field would be pre‑1997‑10‑16 art in: (a) client/server or distributed speech recognition; (b) voice browsers / voice‑enabled markup systems; and (c) transmission of compressed/encoded speech over a data channel as an attachment/multipart (MIME) type. I did not verify which specific references the examiner actually applied, so I am not naming them.

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5. Recommendation to close the gap

To get the definitive cited-art list (and thus a verifiable § 102 chart):

1. USPTO PatentCenter / Global Dossier for application 09/173,748 → open the file wrapper and retrieve the Form PTO‑892 "List of References Cited by Examiner" and the examiner's Office Actions. This is the authoritative source.
2. Google Patents → the "Patent Citations" (backward) table on the US6185535B1 page (distinct from "Cited By"). My fetches returned the forward table only.
3. The WO counterpart WO2000023985A1 (PCT/SE1999/001769) International Search Report, which lists the "Documents Considered to Be Relevant."
4. USPTO.report and FreePatentsOnline front pages, which reproduce the "References Cited / Foreign References / Other References" blocks.

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6. Honest uncertainty statement

• Verified: the patent's identity, dates, assignee, claims, family, and the forward citation set (227).
• Not verified: the specific examiner‑cited prior‑art references (the backward citations) for US 6,185,535. Web results contradicted my expectation that these would surface readily, and per the operating rules I am treating those results as ground truth — which means the list is not available to me, and I am not supplying a fabricated one.
• If you can paste the patent's "References Cited" block (or grant me another retrieval pass on the file wrapper), I will produce exactly what you asked for: full citation, publication/filing date, brief description, and claim‑by‑claim § 102 anticipation mapping for each reference.

I'll pull whatever the page's reference material supports before writing the § 103 analysis.

Obviousness Analysis — US 6,185,535 B1 under 35 U.S.C. § 103

Patent under analysis: US 6,185,535 B1, "Voice control of a user interface to service applications" (Hedin & Meier; Telefonaktiebolaget LM Ericsson). App. 09/173,748; filed 1998-10-16; granted 2001-02-06; expired 2018-10-16.

Cross-reference note (no contradiction found): the identifier is rendered "6185535" throughout the source page and "6,185,535" in the prior sections. Per the no-auto-correction rule I use the identifiers exactly as they appear in each source. Nothing in the prior sections' claim summary or bibliographic data conflicts with what follows; the prior sections correctly identified the two independent claims (1 and 18) and the dependent-claim groupings, which I map to prior art below.

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1. Scope of the "Prior Art" record — what this page actually contains

The fetched page's Prior Art section consists of two things, and they are not the same kind of evidence:

(a) "Prior art keywords": vocabulary, input signal, application part, audio input, terminal. This is a machine-generated relevance signature, useful only as evidence of what the classification/search algorithm treated as the inventive core (i.e., the vocabulary-split and the audio-input signal path).

(b) "Cited By (227)": a forward-citation table. Forward citations are presumptively not prior art to the patent that they cite. I checked every visible entry's listed priority date against the '535 priority date of 1998-10-16. Exactly one visible entry predates it:

Record limitation (stated explicitly): the fetched page omits the '535's own backward citation list (its front-page "References Cited" / the "Citations" block that Google Patents normally renders between the Claims and "Cited By"). I could not recover the references the Examiner actually applied or the applicants disclosed. All patent citations I quote below therefore come from search results (third-party front pages and family-citation tables), not from this page's prior-art section, and I label them as such. Anyone relying on this for a real validity challenge must pull the file wrapper (App. 09/173,748) and the WO 2000/023985 international search report.

Date inconsistency to flag: the task states "Current Date: April 26, 2026"; the system context states 2026-09-28. Nothing in the § 103 analysis turns on the difference, but recency-dependent statements (e.g., any § 282/§ 286 posture) should pin one date.

Also note: the '535 expired 2018-10-16, so § 103 matters only for pre-expiration conduct within the § 286 six-year lookback (i.e., roughly 2012–2018), not prospectively.

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2. Governing law and the PHOSITA

• Pre-AIA § 103(a) governs (application filed 1998-10-16, well before the AIA's 2013 change). KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), nonetheless supplies the operative obviousness test for a pre-AIA case tried today: a combination of familiar elements according to known methods is obvious when it does no more than yield predictable results, and a "finite number of identified, predictable solutions" supports a finding of obviousness.
• Motivation must be articulated with a rational underpinning — In re Kahn, 441 F.3d 977 (Fed. Cir. 2006), and may come from the references themselves, from the applicant's own admissions, or from the ordinary creativity of the skilled artisan.
• Graham v. John Deere, 383 U.S. 1 (1966), factors are applied below.
• PHOSITA (1998): a B.S. in EE/CS (or equivalent) with ~2–3 years' experience in telephony IVR / speech recognition, plus working familiarity with the then-new WAP 1.0 / WML 1.0 specifications. This is a mature, crowded, incremental art; the '535 is an integration patent, not a science patent.
• Means-plus-function: claim 18's "means for…" limitations invoke § 112(f); corresponding structures are the disclosed TAP 201 / RAP 205 components (TAP control logic 235, ASR 227, MIME formatting unit 247, RAP ASR 307, RAP control logic 305). This affects claim construction, not the § 103 analysis, which proceeds claim-element by claim-element.

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3. The prior-art record assembled

Table A — The one page-supplied reference that can qualify, and its family

Because the page supplies only US 6,385,583 B1 on date, the analysis must lean heavily on the Motorola "VoxML" family, which search results confirm:

(Search sources: https://patents.google.com/patent/[US6385583B1](/patent/US6385583B1)/en ; https://portal.unifiedpatents.com/patents/patent/US-[6493671](/patent/6493671)-B1 ; https://patents.searchlight.law/doc/US6493673 — the US 6,493,673 backward citation list is where the Motorola family references are visible.)

Table B — Supplementary references surfaced by search (pre-1998-10-16 effective dates)

These are not on the '535 page; I list them because they materially strengthen or weaken specific grounds. Priority dates are as listed by third-party databases and should be independently verified.

Table C — Admitted prior art inside the '535 itself (the strongest evidence)

Under § 103 the applicant's own Background is admissible as an admission of what was known. The '535 Background concedes all of the following as existing before October 1998:

1. "[T]he most common type of terminal for Internet access is a conventional PC… with a large, high resolution display" and keyboard entry of commands (§ Background).
2. WAP/WML standardization enabling "terminals with small displays, limited processing power and a low data transmission bandwidth … to access and control services and content"; "the simple syntax and limited vocabulary in WML makes WAP suitable for controlling the service."
3. "An ASR for supporting a voice-controlled application may be a user shared resource in a central server or a resource in the client terminal." — i.e., both topologies were known.
4. "[T]he processing power of today's mobile terminals … is sufficient for implementing an isolated word ASR with a small vocabulary (e.g., for dialing and for accessing a personal telephone book)."
5. "A problem that exists in present day centralized server ASRs is that a voice channel (voice call) has to be established between the terminal and a gateway or server that performs voice recognition[,] … [and] may introduce distortion, echoes and noise that will degrade the recognition performance."
6. "A centralized ASR is also an expensive and limited network resource…"

Point 3 alone is close to dispositive of the "two ASRs, one local and one remote" concept; points 4–6 supply the articulated motivation to move the easy words into the terminal and the rest to a cheaper, better-fed remote recognizer. This is a textbook KSR "design incentive" scenario — but note it cuts both ways on claim 1's packaging limitation (see § 8).

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4. Claim 1 — element-by-element

Result: every element of claim 1 has a pre-1998-10-16 counterpart; the only genuinely "new" feature is the architectural allocation — using residue audio (rather than a whole utterance or a voice channel) as the markup payload.

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5. Proposed § 103 grounds

Ground 1 (primary): US 6,269,336 + US 6,385,583 + US 6,327,568.
Motorola '336/'583 teach a markup-language voice browser whose dialog elements (INPUT, GRAMMAR, OPTIONLIST) invoke ASR and whose RECORD element already ships recorded audio to a remote machine inside the same markup/HTTP conversation. Philips '568 teaches splitting speech processing between a device and a network resource. Motivation: (i) the '535's own admission that central ASR is "an expensive and limited network resource"; (ii) the recognition that WML's vocabulary is small and thus recognisable on-device; (iii) the RECORD element's existing teaching that audio may be POSTed onward. Ground 1 reaches claim 1, and via the same disclosure claims 2, 3, 4, 6–12, 15, 16.

Ground 2: Ground 1 + US 6,418,199 (Perrone, "Voice control of a server").
Perrone supplies the express client/server voice-control-of-an-application-server frame, including the notion of a limited command vocabulary at the client and the server acting on recognized commands. This closes any gap on "remote application part service logic."

Ground 3 (for the reverse-direction claims 17/34): Ground 1 + US 5,899,975 (Nielsen, speech presentation of web pages) + US 5,915,001 (Uppaluru).
Text-to-speech rendering of network content to a caller was decades old in IVR and expressly taught for web content by Nielsen. Motorola '583's TTS unit 252 (and the VoxML <AUDIO SRC> element) teaches formatting synthesized audio into markup for playback at the client. Motivation: the '535's own stated advantage — "eliminating the need for any text-to-speech conversion module in the terminal."

Ground 4 (for claims 13–14/30–31, the two-vocabulary split): Ground 1 + the WAP/WML specification evidence cited in CBM2014-00145 Ex. 1008 + the '535's own admission.
The '535 concedes WML's "simple syntax and limited vocabulary" and that "limited vocabular[ies] … keep the failure rate low." Motorola '583 dynamically selects/loads grammars per step and separates the markup-syntax layer (voice browser 250) from the application layer. Combining those teaches allocating markup-syntax words to one recognizer and application words to another — the very thing claim 14 recites.

Ground 5 (for claims 5 and 15/32): Ground 1 + the '535's admitted gateway/proxy art.
The '535's own Background describes a gateway/proxy that converts HTML to WML, filters content, and substitutes voice for text, and the spec states the preferred approach is for the RAP to "generate … the necessary keyboard emulation response." Keyboard/keypad emulation by an intermediary is thus admitted prior art, and re-associating a displayed menu item with a different key/selection value is a routine programming choice with no new technical effect.

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6. Dependent claims — where the case is strong and where it is not

• Strong (near-certain obviousness): claims 2/19 (compressed digitally encoded speech — GSM codecs were ubiquitous and the '535 itself uses a "GSM voice encoder"); 17/34 (TTS + markup carriage of audio — Nielsen, VoxML AUDIO, IVR history); 15/32 (keyboard emulation — admitted in the '535's own gateway discussion); 7/24, 8/25, 9/26 (message contains state info / text / binary data — express design choices, no unexpected result); 4/21, 5/22 (menu-item selection and re-association — ordinary user-interface programming).
• Moderate: claims 3/20 (recognized words select terminal functions) and 6/23 (generate a corresponding message to the remote part) — well supported by Motorola '583's state-machine/GO/<OPTION NEXT> architecture.
• Narrower, requires the two-vocabulary argument: claims 13/30 and especially 14/31 ("the first vocabulary exclusively includes words defined by a syntax of the first predefined markup language; and the second vocabulary exclusively includes words associated with the remote server"). The word "exclusively" is the hardest limitation in the patent. A challenger needs the Ground-4 grammar-allocation showing; a patent owner would argue that prior-art systems mixed the vocabularies, making the partition the point of novelty. This is the claim set most likely to survive a § 103 challenge.
• Claims 10–12/27–29 (forwarding to the remote server; second data link; first protocol may equal second) are expressly rendered obvious by the '535's own statement that the first protocol "may, but need not be the same as the second."

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7. Claim 18 (apparatus)

Claim 18 is the means-plus-function mirror of claim 1 and adds nothing in substance. Under WMS Gaming v. IGT, 184 F.3d 1339 (Fed. Cir. 1999), each "means" is limited to the corresponding structure in the specification and equivalents. The § 103 analysis is identical to § 4 above, element for element: means for receiving audio (mic 215), first ASR (ASR 227 database 233), TAP service logic (245/235), means for formatting (MIME formatting unit 247), means for communicating (RAP interface 243 / WAP stack 213), the remote part's means for extracting plus RAP service logic (321). No separate ground is needed.

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8. Counterarguments, weaknesses, and the Graham factors

Where this invalidity theory is vulnerable:

1. The "residue" formulation. Every reference I found ships whole audio (VoxML RECORD) or whole utterances to a server, or splits features, not vocabulary membership. A rigorous patent owner will argue that the '535's claimed step of using a first ASR to separate a recognized part from an unrecognized part, and forwarding only the unrecognized part as markup content, is not disclosed or suggested by art that forwards all audio. Ground 1 needs the Philips '568 "distributed hardware sharing" teaching to be read as vocabulary-partitioning, which may be a stretch and must be verified against the reference's actual text — I have not read US 6,327,568's specification directly; treat that reading as unverified.
2. Date fragility of the page-supplied reference. US 6,385,583's only claim to prior-art status is its 1998-10-02 date — a 14-day margin over the '535's filing, and valid only as pre-AIA § 102(e) art for subject matter actually supported by App. 09/165,487 as filed (and possibly its two 1998-07-24 provisionals). If any part of the relied-upon disclosure was added later, that part is not prior art. US 6,269,336 (1998-07-24) is the safer anchor of the family, but it is not on this page's list and its date comes from a third-party database.
3. Teaching away (weak argument available to the owner). The '535 Background disparages centralized ASR ("expensive and limited," voice-channel degradation). A patent owner could frame this as teaching away from remote recognition. Counter: the reference criticizes the voice-channel transport and cost, not remote recognition over a data channel — which is precisely what the claim requires. This argument should fail, but it will be raised.
4. Secondary considerations — none of record. I found no evidence of commercial success, licit copying, industry praise, unexpected results, or a nexus to any product. The patent expired in 2018 (its full 20-year term) with, per the prior sections, no known litigation. The absence of any enforcement or licensing activity is not itself a Graham factor, but it removes the usual objective indicia that would rebut an obviousness case.
5. Scope/content of the prior art and level of skill. The field was mature and incremental; the artisan had strong incentives to trade central ASR cost against terminal processing, and the '535 admits the terminals of the day could already do small-vocabulary isolated-word recognition. KSR thus weighs toward obviousness.

Graham balance: differences from the art are narrow and architectural; motivation is documented in the patent's own Background; results are predictable (fewer network resources, no voice channel, bounded terminal vocabulary). Absent rebuttal evidence, claims 1 and 18 and most dependents are, on this record, more likely than not obvious; claims 14 and 31 ("exclusively …") present the closest question.

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9. Bottom line

• The page's own prior-art material is thin: only US 6,385,583 B1 (Motorola, priority 1998-10-02) predates the '535's 1998-10-16 date, and only as potential § 102(e) art. The 226 other "Cited By" entries are all later filings and cannot be prior art. The page also omits the '535's backward citations, which I could not recover.
• The decisive evidence is the patent's own admitted prior art: WAP/WML, in-terminal small-vocabulary isolated-word ASR, centralized server ASR, and the express problems with voice-channel ASR. Those admissions supply the motivation for the claimed split.
• The strongest articulated grounds are Ground 1 (Motorola US 6,269,336 / US 6,385,583 + Philips US 6,327,568) and Ground 2 (adding Perrone US 6,418,199), with the Motorola RECORD/FORM elements supplying the markup-and-MIME carriage of audio and the Philips reference supplying the distribution of recognition. Ground 3 (Nielsen US 5,899,975 + Uppaluru US 5,915,001) disposes of the reverse-direction claims 17/34; Ground 4 disposes of the two-vocabulary claims 13–14/30–31; Ground 5 disposes of the keyboard-emulation and menu re-association claims.
• Claims 1, 18, 2/19, 3–5/20–22, 6–12/23–29, 15/32, 16/33, 17/34 are, on this record, strong obviousness candidates. Claims 14/31 are the narrowest and would require the most careful showing.
• Caveats: I did not read the full specifications of US 6,327,568, US 6,269,336, US 6,418,199, or US 5,899,975; their priority dates come from third-party databases; and a real challenge must be grounded in the App. 09/173,748 file wrapper plus the WO 2000/023985 international search report, neither of which I was able to retrieve.