US 7539158

I'll search for the specific patent number and any 2026 litigation docket activity.

Let me run more targeted searches for litigation/docket activity and the patent's current ownership.

Let me pin down whether patent 7,539,158 specifically was at issue in the 2026 Federal Circuit decision.

US 7,539,158 — Verification and Summary

Important caveat on the docket search: I searched for 7,539,158 / "7539158" against USPTO and Federal Circuit material. I found no 2026 CAFC docket, appeal, or decision in which U.S. Patent No. 7,539,158 is the patent on appeal. The only Lemko-related Federal Circuit matter in 2026 that surfaced is Lemko Corp. v. [Microsoft Corp.](/litigations/by-plaintiff/Microsoft%20Corp.), No. 2024‑2336 (Fed. Cir. Apr. 10, 2026) (Rule 36 judgment, per curiam, affirming PTAB), which is an appeal from IPR2023‑00531 and concerns U.S. Patent No. 7,855,988 (the "'988 Patent"), not the '158 patent. (CAFC Rule 36 judgment; Justia docket 24-2336; Law360, Apr. 10, 2026.)

The '158 patent appears only as one of a portfolio list in Lemko marketing/prosecution exhibits (e.g., "7,539,158; 7,486,967; 7,548,763; …"). Two Lemko infringement suits exist against Microsoft/AT&T and a second Microsoft suit was reported in 2026 (Case No. 3:26‑cv‑01876, N.D. Tex.), but I could not confirm from the results retrieved which patents are asserted there. Do not assume '158 is in those cases without checking the complaints. (Lemko news; Exparte docket 3:26-cv-01876)

Date note: You gave the current date as April 26, 2026, but several retrieved items are dated after that (e.g., the Apr. 10, 2026 CAFC judgment is before it, but the June 5, 2026 Lemko/Microsoft filing and August 2026 CAFC items are after it). I am reporting them as found rather than reconciling the discrepancy.

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Bibliographic data (from the patent record)

Source: Google Patents US7539158B2.

Abstract (as issued)

"A communications system includes one or more distributed mobile architecture servers. Each distributed mobile architecture servers includes a compute readable medium [sic]. Moreover, a mobile switching center module and a base station controller module are embedded in the computer readable medium. Each distributed mobile architecture server is in direction physical connection [sic] with a wireless transceiver. Telephony traffic received from the wireless transceiver can be switched by one or more distributed mobile architecture servers. Also, the telephony traffic can be transmitted between the distributed mobile architecture servers via a peer-to-peer connection."

(Note the typographical errors "compute readable medium" and "direction physical connection" are in the issued text; I am quoting literally, not correcting.)

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Independent claims — plain language

The patent has 15 claims, only one of which is independent: claim 1. Claims 2–15 all depend, directly or indirectly, from claim 1. There is therefore a single independent claim to summarize.

Claim 1 — a two-node distributed-mobile-architecture (DMA) communications system. In plain terms, the claim requires:

1. A first DMA server built as: (a) a computer-readable medium; (b) an MSC (mobile switching center) module embedded in that medium, where the MSC module includes an AAA (authentication, authorization, accounting) module that is configured to support generation of call detail records (CDRs) at that first DMA server; and (c) a BSC (base station controller) module embedded in the same medium. The first DMA server is in direct physical connection with a first wireless transceiver.
2. A second DMA server with the same structure: its own computer-readable medium, its own MSC module embedding its own AAA module configured to support CDR generation at the second server, its own BSC module, and a direct physical connection to a second wireless transceiver.
3. The peer-to-peer limitation: telephony traffic received at the first wireless transceiver is transmitted from the first DMA server to the second DMA server via a peer-to-peer connection.

In other words, the independent claim is not merely "a box that combines MSC + BSC." It requires (i) two such servers, (ii) each server having its own embedded AAA module supporting locally generated CDRs, and (iii) traffic flowing between them over a peer-to-peer link. That AAA/CDR-per-server and peer-to-peer combination is the distinguishing core of the granted claim as opposed to the broader language in the abstract ("one or more" servers).

Selected dependent claims (for context, all depend from claim 1):

• Cl. 2 — the peer-to-peer traffic flow continues while the first DMA server moves from a first location to a second (i.e., mobility of the server itself, echoing the in-field/vehicle deployments).
• Cl. 3 — same, where the second DMA server is also moving.
• Cl. 4 — the first DMA server stores subscriber administrative information on its computer-readable medium.
• Cls. 5–10 — additional gateways inside the first DMA server: PSTN gateway (5), media gateway (6), PDSN gateway or GGSN (7), simple Internet phone gateway (8), SS7 gateway (9), and a gatekeeper module coupled to the PSTN gateway, media gateway, PDSN/GGSN, SIP gateway, and the AAA module (10).
• Cls. 11–15 — structure of the first BSC module: cellular radio network controller (11), cellular selection/distribution unit (12), call protocol controller (13), the CPC communicates with the first wireless transceiver (14), and an operations, maintenance, and provisioning (OMP) module (15).

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Practical takeaway

• The patent is a Lemko Corporation asset (Lemko Corp is the listed assignee; Motorola Solutions holds a covenant not to sue; Piccadilly Patent Funding is a security holder). Adjusted expiration is stated as March 4, 2027.
• Its independent claim is narrowly built around two DMA servers, each with an AAA module generating CDRs locally, interconnected peer-to-peer — a more specific combination than the generic "MSC + BSC in one box" description in the abstract.
• No authoritative 2026 CAFC docket tying 7,539,158 to an appeal was found. The 2026 Lemko Federal Circuit activity concerns a different Lemko patent (the '988 patent). If you need certainty on whether '158 is asserted in the pending Lemko v. Microsoft / Lemko v. AT&T district cases, that would require pulling the complaints and infringement contentions directly — I did not obtain documents confirming that, and I will not infer it.

I'll research litigation involving US patent 7539158 across patent litigation databases and court records.

Let me search more targeted litigation databases and for the patent owner (Lemko Corp).

I have good context on Lemko's campaigns. Now let me search specifically for whether the '158 patent itself is named in any suit, and check the Motorola ownership dispute.

Summary Answer

I found no litigation — district court, Federal Circuit, ITC, PTAB, or foreign — in which U.S. Patent No. 7,539,158 is identified as an asserted or challenged patent. I cannot state this with absolute certainty (patent dockets, sealed complaints, and non-U.S. actions are not fully indexable from public search), but nothing in the sources I was able to reach names the '158 patent as a patent-in-suit.

Per your explicit instruction, I limited the search to the literal number 7539158 / 7,539,158 and did not substitute look-alike numbers. Note that many results for "539" or "753" patents (e.g., the '539 patents in the Collegium/DD Karma/Valtrus matters) are unrelated and were excluded.

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What the '158 patent is and who owns it (for identification)

Source: Google Patents, US7539158B2 (assignment, family, and status data).

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Litigation involving the '158 patent

Plaintiff(s): none identified
Defendant(s): none identified
Jurisdiction: —
Case number: —
Filing date: —
Outcome/status: —

No case number, plaintiff, or defendant could be tied to the '158 patent in the sources searched (Google Patents, PTAB/PTACTS filings, Justia Dockets, Unified Patents/PTAB materials, Law360 headlines, and Lemko's own corporate newsroom).

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Related litigation and proceedings that do NOT name the '158 patent (offered for context, explicitly not responsive to your request)

To avoid any implication that these involve the '158 patent, I list them separately. Each asserts or challenges different Lemko/other patents.

1. Motorola, Inc. v. Lemko Corp., et al. — N.D. Ill., Case No. 1:08-cv-05427 (filed 2008).

• Nature: Motorola sued Lemko and 14 individuals for, inter alia, declaratory judgment that Motorola owned "eight patents and ten pending patent applications" (the "Lemko patents") filed/granted 2004–2009, plus trade-secret/misappropriation claims.
• Status/outcome: Summary judgment denied Jan. 10, 2012 (Kennelly, J.) (Motorola's ownership/trade-secret claims survived). The record reflects Motorola Solutions later obtained a covenant not to sue from Lemko (recorded 2012), and Lemko's CEO/CTO (Nicholas Labun / ShaoWei Pan) were defendants.
• Relevance to '158: I could not confirm whether the '158 patent was among the patents Motorola sought. Its 2004 filing date falls within the described window, so it could have been within the ownership dispute, but the opinion does not enumerate it and I will not assert it was.

1. Lemko Corp. v. [Microsoft Corp.](/litigations/by-plaintiff/Microsoft%20Corp.) and Affirmed Networks, Inc. — N.D. Tex., Case No. 3:22-cv-00363-L-BT (filed Feb. 14, 2022; complaint describes a Feb. 2022 filing).

• Patents asserted: 7,548,763; 7,653,414; 7,855,988; 8,107,409; 8,688,111; 9,191,980; 9,332,478; 9,755,931 (per Mondaq/Law360 coverage). '158 is not among them.
• Status: Motion to dismiss granted in part (contributory infringement dismissed with prejudice), otherwise denied — Order filed June 4, 2025 (Lindsay, J.), Docket 94.

1. Lemko Corp. v. AT&T Inc., et al. — E.D. Tex., Case No. 2:25-cv-00305-JRG (filed Mar. 17, 2025; Judge Rodney Gilstrap).

• Patents asserted: 7,840,230; 7,979,066; 8,224,322; 8,310,990; 8,340,667; 8,359,029; 9,198,020. '158 is not among them.
• Status: Pending; IPRs filed by Microsoft/AT&T against some of these (e.g., IPR2025-01142 on the '990 patent), with Lemko seeking discretionary denial.

1. PTAB IPRs on Lemko patents (not '158): e.g., Microsoft Corp. v. Lemko Corp., IPR2023-00529 ('414 patent), IPR2023-00531 ('988 patent), IPR2023-00530 (denied institution); Microsoft Corp. and AT&T Services, Inc. v. Lemko Corp., IPR2025-01142 ('990 patent). Related Federal Circuit appeal: Lemko Corp. v. Microsoft Corp., No. 24-2336 (Fed. Cir.), decided against Lemko around April 2026 (Law360, Apr. 10, 2026).

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Caveats on completeness

• Google Patents has no litigation section populated for this patent, and no litigation database result tied a case to the literal number 7,539,158.
• I could not confirm whether '158 was among the patents Motorola asserted ownership over in No. 1:08-cv-05427; the opinion names no such patent, and the parties' complaint exhibit list was not available to me.
• Sealed complaints, ITC Section 337 investigations, state-court actions, or non-U.S. proceedings (e.g., the '158 family's Chinese/UK counterparts) may exist but were not surfaced.
• The Feb. 2012 Motorola Solutions "covenant not to sue" and the Mar. 2025 Piccadilly "patent security agreement" are recorded assignments/agreements, not litigation, though they bear on enforceability and enforcement funding.

If you want, I can attempt a follow-up focused on the Motorola v. Lemko complaint exhibits to determine definitively whether the '158 patent was part of the ownership dispute.

PTAB proceedings on file — US 7,539,158 ("System, method and device for providing communications using a distributed mobile architecture," Pan, Lemko Corp.)

Sourcing note. The structured "PTAB proceedings on file" block in this prompt — the canonical USPTO Open Data Portal list — returns zero AIA trial proceedings for US 7,539,158 as of the most recent ingest. I ran independent web checks (PTAB petition/decision PDFs indexed by Docket Alarm and PTAB CTS, the Unified Patents PTAB case-list portal, Federal Circuit appeal materials, and the N.D. Tex. docket in Lemko Corp. v. [Microsoft Corp.](/litigations/by-plaintiff/Microsoft%20Corp.)). Nothing surfaced an IPR, PGR, or CBM naming U.S. Patent No. 7,539,158 as the challenged patent. Where I report findings below, I mark every item that concerns a different Lemko patent and say so explicitly. I did not find any proceeding whose number I could not verify, and I have not invented any.

Proceedings overview

Total AIA trial proceedings on US 7,539,158: 0 (zero) — no active proceedings, no claims invalidated, no claims sustained, no settlements, and no institution denials, because no petition has ever been filed against this patent on the public record. The defensive posture this creates is not "the patent is hardened by surviving IPRs" — it is the more ambiguous signal that the '158 has simply never been worth attacking: although it is the earliest patent in the Lemko distributed-mobile-architecture family (filed 2004-11-08, priority date 2004-11-08, issued 2009-05-26, 15 claims, all asserted-claim text directed to a first and second DMA server each embedding an MSC module with an AAA module that generates CDRs, connected over a peer-to-peer link), it was not among the eight Lemko patents asserted against Microsoft and Affirmed Networks, and it is therefore the one family member that has never been stress-tested at the Board. A defendant facing an assertion of the '158 gets no § 315(e)(2) estoppel benefit from the Microsoft/Affirmed campaign and no invalidation roadmap stamped by the Board — but also faces a patent that expires soon (see below) and whose core claim term, "distributed," the Board has already construed adversely to Lemko in a sibling case.

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No proceedings on US 7,539,158

There is no proceeding to report at claim level. To be precise about the negative finding:

• No petition has been filed under 35 U.S.C. §§ 311–319 (IPR) directed to the '158.
• No petition under §§ 321–329 (PGR) — and in any event the '158 (filed 2004-11-08) is a pre-AIA patent outside the PGR window.
• No CBM review. The '158 is a § 101-eligible-looking telecommunications infrastructure patent, but CBM availability (SAP America v. Versata transitional authority) is now moot for pre-AIA patents after Unwired Planet v. Google (Fed. Cir. 2020) — not a path a defendant can use today regardless.
• Federal Circuit: no appeal involving the '158. The only Lemko PTAB appeal I could verify concerns a different patent (see below).

Defensive value: 1–2 sentences. The absence of any PTAB challenge means a defendant cannot piggyback on an existing estoppel or an existing cancellation. Conversely, nothing in the record suggests the '158 has ever been asserted — not in Lemko Corp. v. Microsoft Corp. / Affirmed Networks, No. 3:22-cv-00363-L-BT (N.D. Tex.) (asserted patents: '763, '414, '988, '409, '111, '980, '478, '931 — the '158 is not listed in the operative complaint as described by the court), and I found no evidence of it in the AT&T dispute either. Treat the '158 as an untested, un-asserted family member rather than a hardened one.

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Related family proceedings (NOT on the '158 patent — reported only as pattern evidence)

These are real proceedings I verified; none of them names the '158, and none of them creates estoppel against a defendant accused of infringing the '158. They matter only as a roadmap.

IPR2023-00531 — Microsoft Corporation and Affirmed Networks, Inc. v. Lemko Corporation

• Type: Inter Partes Review
• Patent: U.S. Patent No. 7,855,988 (the '988, a different Lemko patent)
• Filed: 2023-02-14
• Status: Final Written Decision — appealed by Patent Owner; Board record shows termination 2024-09-10
• Judge panel: Judges Brian Range, Frances Ippolito, Scott Raevsky, Hubert Lorin, and Neil Powell (panel change orders entered 2024-05-28 and 2024-06-17)
• Petition grounds: claims 1, 3–9, and 20 unpatentable under 35 U.S.C. § 102, anticipated by U.S. Patent Application Publication 2007/0021120 (Flore), with the Declaration of James Proctor (Ex. 1003) and 3GPP TS 23.002 v7.1.0 (Ex. 1006)
• Institution decision: instituted 2023-09-25; Patent Owner's Request for Director Review of institution was denied 2023-11-17
• Final Written Decision: issued 2024-09-10. The Board found the challenged claims unpatentable over Flore. Lemko's Federal Circuit appeal brief (dated 2025-01-29) confirms the FWD rejected Lemko's "distributed" argument: Lemko states the Board "repeated Lemko's proposed construction … mentioned, without endorsing, Microsoft's proposed 'plain meaning' of distributed … and determined that it 'need not assign further meaning to the term DMA.'" The Board construed "communications information" and declined to further construe "distributed." Law360 reported on 2026-04-10 that the Federal Circuit affirmed, backing the Board's invalidity finding on this distributed-mobile-architecture patent. I could not verify the CAFC docket number from the sources retrieved, so I am not supplying one.
• Settlement / termination: none reported; tried to FWD and appealed.
• Appeal: Fed. Cir. appeal by Lemko, notice of appeal 2024-09-16; oral-argument/briefing record confirms appeal of the FWD; affirmed per Law360 (2026-04-10). Confirm the docket on CourtListener before citing.
• Defensive value for the '158: this is the most useful sibling, because the Board's treatment of the "distributed" limitation and its willingness to accept a hardware-based prior-art system (Flore) as anticipating a Lemko DMA claim shows how the claim term "distributed mobile architecture" has been read against Lemko. But the FWD expressly declined to construe "distributed," so its claim-construction value is limited and non-precedential. Sources: PTAB CTS petition document store (https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1558047](/patent/1558047)) and Docket Alarm docket (https://www.docketalarm.com/cases/PTAB/IPR2023-00531/Microsoft_Corporation_v._Lemko_Corp/).

IPR2023-00529 — Microsoft Corporation and Affirmed Networks, Inc. v. Lemko Corporation

• Type: Inter Partes Review — U.S. Patent No. 7,653,414 (not the '158)
• Filed: 2023-02-15 (per Unified Patents case list); institution 2023-09-26; terminated 2024-08-30 (FWD)
• Grounds: claims of the '414 challenged as obvious over Waylett in view of Mauer (per Petitioner's Reply and Patent Owner's Response)
• Notes: Lemko's Request for Director Review of the institution decision (2023-10-10) was denied; joint oral hearing with IPR2023-00531 held 2024-07-11. I did not verify the claim-level outcome of the '414 FWD and will not guess at it.
• Source: https://portal.unifiedpatents.com/ptab/caselist?petitioners=Affirmed+Networks+Inc

IPR2023-00530 — Microsoft / Affirmed v. Lemko (U.S. Patent No. 7,548,763)

• Filed 2023-02-14; not instituted on the merits (institution date 2023-09-25, terminated 2023-09-25). Per Lemko's later briefing, the Board found "Waylett does not necessarily teach a computer readable medium" because Waylett's functions "are implemented in hardware."

IPR2023-00570 — Affirmed Networks v. Lemko (U.S. Patent No. 9,191,980)

• Filed 2023-02-15; not instituted on the merits (2023-09-26).

IPR2025-01142 — Petitioner (AT&T) v. Lemko (U.S. Patent No. 8,310,990)

• Petition challenging independent claim 1 and claims 3–9 of the '990 patent; parallel E.D. Tex. litigation; Lemko filed a Request for Discretionary Denial under Fintiv / § 325(d). Decision on Institution deadline stated as 2026-01-08. Not the '158.

Pattern read-across: Microsoft/Affirmed filed a coordinated four-petition campaign (IPR2023-00529, -00530, -00531, -00570) tied to the N.D. Tex. complaint, winning institution on two of four and an affirmance on the '988. AT&T later filed IPR2025-01142 against the '990. No defensive aggregator (e.g., Unified Patents) appears in the chain — Unified's portal indexes Lemko patents for analytics only; the petitioners here are operating-company defendants. Separate from PTAB, note the ownership/encumbrance chain: Motorola Solutions obtained a covenant not to sue (recorded 2012-02-08) and Piccadilly Patent Funding LLC is recorded as security holder on Lemko's patents (2025-03-25) — worth checking before negotiating a license, since those documents can affect who can release what.

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Strategic summary

Claim status of the '158. All 15 claims of US 7,539,158 stand UNTESTED at the PTAB — none canceled, none sustained through an AIA trial, none subject to a certificate of cancellation or a written FWD. The claims remain presumptively valid under § 282, and there is no Board record to cite for or against them. Claim 1 (the only independent claim; claims 2–15 all depend, directly or through intervening claims, on claim 1) requires two DMA servers, each with its own embedded MSC module containing an AAA module "configured to support generation of" call detail records, each in direct physical connection with a wireless transceiver, with traffic carried between them over a peer-to-peer connection. Any invalidity attack has to take out that whole combination — including the CDR-generation AAA limitation, which was added/emphasized in this family and is not present in the sibling patents that the Board has invalidated. That said, the family's core architecture limitation — "distributed mobile architecture" — is the same term the Board has repeatedly struggled with, and the Federal Circuit has now affirmed at least one Lemko invalidation without resolving its construction.

Estoppel landscape. Because there are no IPRs on the '158, § 315(e)(2) estoppel is irrelevant here: Microsoft, Affirmed, and AT&T are estopped only as to the patents they actually petitioned on (the '988, '414, '763, '980, '990), and estoppel is patent-specific — it does not spill over to the '158. Practically, that means a defendant accused of the '158 can raise any § 102/§ 103 ground, including the very Flore, Waylett, and Mauer references the Board already accepted against sibling claims, plus any art Lemko's prosecution never saw. It also means the defendant must build that record itself; there is no ready-made FWD to hand the district court. Note the § 315(b) one-year bar runs from service of a complaint asserting the '158 — if Lemko amends or refiles to add the '158 to a pending case, calendar that date immediately.

Timing / exposure. Per the Google Patents structured data for US 7,539,158, the patent is Active with an adjusted expiration of 2027-03-04 (statutory 20-year term ran from 2004-11-08; the extra time is PTA). That is a short runway — roughly 18 months from today (2026-09-20). A defendant's realistic exposure is past damages over a limited window, which materially weakens Lemko's leverage and makes a defensive IPR a poor investment: the FWD (statutory 12-month trial deadline under § 316(a)(11), so roughly 18 months from petition to FWD) would not arrive before the patent expires. Also flag, but do not treat as legal advice: the priority date is rendered inconsistently across public databases (the ODP/Google record says 2004-11-08; Unified Patents' page shows 2004-11-07). Confirm the actual § 102(b) critical date against the file wrapper before relying on any pre-2004 art.

Recommended next steps

• If you are a defendant facing an assertion of the '158: there is no FWD to quote and no canceled claim to point at. Your validity case is DIY — pull the Flore, Waylett, and Mauer references and the Board's institution decisions in IPR2023-00529/-00531 (links above) as a starting framework, and concentrate on the AAA/CDR-generation and peer-to-peer limitations, which are the '158's distinguishing claim language. Consider a favorable claim construction of "distributed mobile architecture" (Lemko argued for a narrow reading requiring distributed call-routing functionality; the Board never adopted one, and the Fed. Cir. affirmed without construing it) as a non-infringement lever.
• IPR is likely the wrong tool here. With expiration at 2027-03-04 and the § 316(a)(11) one-year FWD deadline from institution, a petition filed now would be decided around the patent's expiry. Weigh that against the cost, and against the ~18-month exposure window.
• Do the encumbrance diligence before settling. The 2012 Motorola Solutions covenant-not-to-sue and the 2025-03-25 Piccadilly Patent Funding security agreement are recorded against Lemko's portfolio; confirm who actually has standing to grant a release.
• Watch for a new petition. The absence of PTAB activity is a signal, not a warranty: if Lemko begins asserting the '158 (e.g., by amending the N.D. Tex. or E.D. Tex. complaints), expect § 315(b) clocks to start and a defensive petition to follow within days. Re-check the ODP "PTAB proceedings on file" block and PTAB CTS before any filing.
• Verify before citing: I could not confirm (a) the claim-level disposition of the IPR2023-00529 FWD on the '414, or (b) the Federal Circuit docket number and opinion text for the '988 appeal. Pull both from PTAB E2E (https://ptacts.uspto.gov/ptacts/) and CourtListener (https://www.courtlistener.com/) rather than citing this summary as authority.

I'll gather evidence from the search tools before reconstructing the chain. Let me run several targeted searches.

Let me dig for the specific reel/frame records and the entities involved.

US 7,539,158 — Ownership & Assignment Reconstruction

Scope note / data limitation up front. The authoritative Google Patents legal-events record for this patent (fetched 2026-09-17) lists four post-filing recorded events, but it does not expose reel/frame numbers, and it does not expose the correspondent of record. I was unable to retrieve the USPTO Patent Assignment Center record (assignmentcenter.uspto.gov) with reel/frame and correspondent fields before my tool budget was exhausted. I am therefore not able to supply reel/frame numbers or correspondent names, and I will not fabricate them. Everything below is grounded in the legal-events text in the patent record; where a field is unknown I say so. To complete the reel/frame + correspondent columns, pull the patent number at https://assignmentcenter.uspto.gov/patent/index.html and https://patents.google.com/patent/[US7539158B2](/patent/US7539158B2)/en (Legal Events tab).

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Inventors

• ShaoWei Pan — sole named inventor.
• Employer at time of filing (2004-11-08): Lemko Corporation (Schaumburg/Itasca, IL), where Pan served as Chief Technology Officer and director.
• Prior employer: Motorola, Inc. — Pan was Director of Advanced Technology & Development and a prolific inventor (>60 patents/applications assigned to Motorola). He left Motorola in late March 2004 and filed this application ~7 months later.

Unusual pattern (note it). This is not the classic "inventors leave the original assignee within 12 months" fire-sale tell — it is the inverse: the sole inventor had joined Lemko roughly seven months before filing, and Motorola later sued Lemko and Pan asserting it was the rightful owner of the Lemko patents (including this family), on the theory that the inventions were conceived during Motorola employment and that Motorola's employee agreement carried a six-month post-termination presumption of conception during employment (see Motorola v. Lemko, N.D. Ill. 1:08-cv-05427, op. filed 2012-01-10). That ownership cloud, not a fire-sale, is the defining early biography of this patent. Pan remains associated with Lemko (CTO) — no departure-from-assignee pattern.

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Original assignee

• Lemko Corporation (Illinois), assignee of record from the 2004-11-08 filing onward.
• Shipped a product embodying the claims? Yes — Lemko commercialized its Distributed Mobile Architecture (DMA) / Node1 product line (3G, later 4G/private LTE/5G), and the patent record and litigation filings state that Lemko marked its products with its patent numbers and presented the DMA/Node1 solution to AT&T as patent-practicing. See Lemko's AT&T complaint and the Microsoft v. Lemko IPR papers (Lemko's Node1 "practices the challenged claims"; '990 patent marking on Lemko products).
• Primary line of business: telecom infrastructure — distributed/edge mobile core (DMA servers combining MSC + BSC functionality), private LTE/5G networks, rural broadband, public-safety/military deployments.
• Current status: Operating, but small and financially stressed. CB Insights reports ~$13.18M total raised, last round ~$250K (a PPP-type loan), investors including the Paycheck Protection Program and Mayfair Partners. No Chapter 7/11 bankruptcy for Lemko was surfaced. Separately, Lemko is an active patent litigant (portfolio campaign vs. Microsoft/Affirmed Networks in N.D. Texas, 2022; vs. AT&T, 2025).

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Assignment timeline

Reel/frame and correspondent fields below are not available from the sources I could reach and are marked not retrieved. The dates, conveyance types and parties are taken from the patent's Google Patents legal-events record.

• 2004-11-08 (executed) / recorded 2004-11-08 — Reel not retrieved/NNNN

  • Conveyance: Assignment of Assignors' Interest
  • Assignor: PAN, SHAOWEI
  • Assignee: LEMKO CORPORATION
  • Correspondent: not retrieved
  • Context: Original assignment — sole inventor assigns to his employer at filing.

• 2006-08-16 (recorded) — Reel not retrieved/NNNN

  • Conveyance: Change of Assignee's Address
  • Assignor: LEMKO CORPORATION
  • Assignee: LEMKO CORPORATION
  • Correspondent: not retrieved
  • Context: Change of address only — administrative, no transfer of title.

• 2012-02-08 (recorded) — Reel not retrieved/NNNN

  • Conveyance: Covenant Not to Sue (recorded as an assignment-record event)
  • Assignor: LEMKO CORPORATION
  • Assignee: MOTOROLA SOLUTIONS, INC.
  • Correspondent: not retrieved
  • Context: Litigation settlement — resolves the Motorola v. Lemko ownership/trade-secret dispute; it is a covenant/license-type instrument, not a title transfer, so title remained with Lemko.

• 2025-03-25 (recorded) — Reel not retrieved/NNNN

  • Conveyance: Patent Security Agreement
  • Assignor: LEMKO CORPORATION
  • Assignee: PICCADILLY PATENT FUNDING LLC, AS SECURITY HOLDER
  • Correspondent: not retrieved
  • Context: Securitization / collateral — a security interest over the patent granted to a funding counterparty; again not an ownership transfer. Title stays with Lemko.

Bottom line of the chain: the patent has been encumbered (2012 covenant; 2025 security interest) but has never left Lemko Corporation's ownership. The last recorded event is a security interest, so Lemko is the current owner of record.

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Timeline diagram

timeline
    title Ownership of US 7539158
    2002 : Lemko Corporation incorporated
    2004 : Pan files app assigned to Lemko
    2006 : Lemko address change recorded
    2009 : Patent issues as US 7539158
    2012 : Covenant not to sue to Motorola Solutions
    2025 : Patent security interest to Piccadilly

(Event text kept short and punctuation-free for parser safety. Note per the operating rules this is illustrative only; the authoritative dates are in the timeline above.)

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NPE / troll-pattern signals

1. Shell-entity transfer — not present. Title never moved to a licensing-only LLC. The only non-Lemko assignee entries are (a) a 2012 covenant not to sue to Motorola Solutions and (b) a 2025 security interest to Piccadilly Patent Funding LLC "as security holder." Neither conveys ownership. There is no "IP Holdings/Patents/Ventures" LLC in the ownership chain. (Cite: Google Patents legal events 2012-02-08 and 2025-03-25.)

2. Known asserter in the chain — not present. The owner, Lemko Corporation, does not appear on the standard public NPE lists supplied (Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, etc.). It is a telecom equipment vendor that ships DMA/Node1 hardware-software. I could not independently verify Piccadilly Patent Funding LLC against Unified Patents / RPX high-frequency-plaintiff lists, so its role is best described as financier/security holder, not retrieved as to NPE-list status.

3. Repeat correspondent across the chain — unclear / insufficient data. The correspondent of record is not exposed in the sources I reached. Signal cannot be scored. This is the one column most worth completing on Assignment Center — if all four recordings share one prosecuting attorney/firm, that is a genuine finding; a single appearance would not be. not retrieved for all four events.

4. Cascading transfers — not present. Only one true transfer (2004). No chain of LLC-to-LLC assignments in <24 months; the 2006, 2012 and 2025 entries are an address change, a covenant, and a lien respectively.

5. Pre-litigation transfer — not present (closest thing is the 2025 lien). There is no ownership assignment within 6 months of an infringement suit naming this patent. The 2025-03-25 patent security agreement to Piccadilly does precede Lemko's 2025 AT&T assertion activity by ~4 months, which is a financing-before-assertion tell — but it is a lien, not a title transfer, and I have not confirmed that US 7,539,158 itself is one of the asserted patents (Lemko's AT&T/Microsoft suits assert '230, '322, '667, '029, '990, and the '988/'763 family members). Mark unclear.

6. Bankruptcy fire-sale — not present. No Lemko Chapter 7/11 found; the patent was not sold out of an estate. (Distinguish from the Motorola litigations, which are civil IP disputes, not bankruptcies.)

7. Privateering — not present. No evidence of a parent/operating company transferring to an NPE to assert on its behalf. Lemko asserts its own patents in its own name.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT, Unified, or OIN. The patent remains on offense.

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Verdict

Operating-company assertion.

Justification. Title never leaves Lemko Corporation — the 2004-11-08 assignment is the only true transfer, the 2006-08-16 entry is an address change, the 2012-02-08 Motorola Solutions entry is a covenant not to sue (settlement, no title transfer), and the 2025-03-25 Piccadilly entry is a security interest, not a conveyance. Lemko ships products embodying the DMA/Node1 claims (it patent-marks and demonstrated them to AT&T) and asserts the family against named competitors — AT&T (2025) and Microsoft/Affirmed Networks (N.D. Tex. 2022) — which is classic operating-company assertion, not NPE behavior. The residual caution for a prosecution analyst: Lemko is small and financially stressed (≈$13M lifetime raise; last round ≈$250K) and has now pledged the portfolio as collateral to a funding entity (Piccadilly Patent Funding LLC, 2025-03-25), an assertion-financing tell that could foreshadow a shift toward monetization if the operating business falters — worth monitoring but not, on the present record, a basis to call it an NPE.

Verification link: https://assignmentcenter.uspto.gov/patent/index.html (search patent number 7539158) and https://patents.google.com/patent/US7539158B2/en — the reel/frame and correspondent fields I flagged as not retrieved should be filled from there before this reconstruction is treated as complete.

Caveats: (i) reel/frame numbers and correspondents of record were not retrievable in this session and are not guessed; (ii) Piccadilly Patent Funding LLC's business I could not independently document — only its recorded capacity as "security holder"; (iii) whether US 7,539,158 specifically is asserted in the 2022–2025 Lemko suits is unconfirmed, so the pre-litigation-transfer signal is scored unclear rather than present.

I'll search for the patent and its cited prior art.

Let me pull the full citation list and verify key references.

Prior-Art Analysis — U.S. Patent No. 7,539,158

0. Record verification (no auto-correction applied)

Sources: https://patents.google.com/patent/[US7539158B2](/patent/US7539158B2)/en · https://www.sumobrain.com/patents/us/System-method-device-providing-communications/7539158.html

Search note (honesty statement): A literal search of the USPTO patent number returns this patent and only this patent (no near-number substitution was performed). Google Patents reproduces the USPTO front page, including the "References Cited" section, and that reproduction — the longest and most complete list I could obtain — is the basis for §2–§4 below. I could not open the USPTO PatentCenter file wrapper itself in this session; therefore I cannot confirm (i) whether any reference below was cited by the examiner versus merely listed on an IDS, or (ii) whether the granted claim 1 (which recites an AAA module "configured to support generation of … call detail records") reflects a pre- or post-grant amendment. Where my analysis depends on those unknowns, I say so.

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1. The reference list is a mixed bag — triage is mandatory

The Google Patents "Citations (61)" list is not a clean §102 prior-art set. It contains:

1. Genuine pre-2004-11-08 prior art (patents/published applications with publication or filing dates before the '158 critical date) → could support §102(a)/(b) or §102(e).
2. Post-filing U.S. patents whose applications were filed before 2004-11-08 → potential §102(e)(2) art only (date of invention shifts matter).
3. Post-2004-11-08 published applications → not §102(a)/(b) prior art on their face.
4. The applicant's own later Lemko/Pan applications (US 2006/0234747, US 2006/0234774, US 2007/0202847, US 2007/0232267, US 2007/0287452, US 2008/0039144, US 2008/0146158) — these are family members/later filings, not prior art at all. Likewise the "Other References" (Pan U.S. App. Nos. 12/146,618; 12/108,209; 12/163,601; 12/171,840; 12/172,639; 12/238,269) are 2008 co-pending applications — they post-date the '158 and are not prior art.

Only categories 1–2 can carry a §102 challenge. I analyze those below.

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2. Tier 1 — The most relevant references (serious §102 candidates)

Claim 1 is a two-node system claim. Its elements are: (a) a first DMA server with a computer-readable medium; (b) an MSC module embedded in that medium including an AAA module configured to support generation of CDRs at the server; (c) a BSC module embedded in that medium; (d) direct physical connection to a first wireless transceiver; (e) a second, identically-configured DMA server; and (f) telephony traffic transmitted from the first to the second server via a peer-to-peer connection.

2.1 US 2004/0014466 A1 — Jesse et al. — "Radio system having distributed real-time processing"

• Publication date: 2004-01-22. Applicant/assignee: Radioframe Networks.
• Description: Base-station/base-station-controller functionality decomposed into distributed processing modules with real-time scheduling among them — i.e., the BSC/MSC control plane implemented as distributed software rather than a monolithic hardware appliance.
• §102 exposure: The closest concept-level match to the "embedded in a computer readable medium" software-implementation limitation (the very limitation the PTAB later relied on to distinguish Waylett-type hardware appliances in the sibling Lemko IPRs — see §5). Potentially relevant to claims 1, 11–13. It does not appear to disclose the two-server peer-to-peer telephony transport of (f), so it reads more naturally as §103 fodder than as §102 anticipation.

2.2 US 2004/0204097 A1 — Scheinert et al. — "Internet base station"

• Publication date: 2004-10-14 (pre-critical-date).
• Description: A base station that incorporates local switching/control and connects to a core network over the Internet (IP backhaul).
• §102 exposure: Relevant to the "base station + embedded core-function" and IP-backhaul concepts in claims 1, 5, 14. Single-site focus; does not disclose two cooperating servers with a peer-to-peer trunk. §103 candidate.

2.3 US 6,539,237 B1 / US 6,807,431 B2 — Sayers et al. (interWAVE/Cellcom-heritage family)

• "Method and apparatus for integrated wireless communications in private and public network environments" — US 6,539,237 B1 granted 2003-03-25 (filed 1998-11-09); US 6,807,431 B2 granted 2004-10-19; related US 6,807,432 B2 ("Wireless transmission network card") granted 2004-10-19.
• Description: A single platform integrating private (enterprise) and public (cellular/PSTN) wireless communications — i.e., an MSC-like switching function co-located with radio/base-station control and PSTN gateway functions.
• §102 exposure: This is the most structurally on-point reference for the "MSC module + BSC module in one unit" + PSTN gateway combination of claims 1, 5, 10. What it does not appear to show is the peer-to-peer connection between two such units (element (f)) or the AAA/CDR-at-the-server limitation (element (b)). Could be argued against claims 5–10 (dependency chain) but not full claim 1.

2.4 US 6,839,903 B2 — Kang — "Method of providing public network service when call management device is in a down state in private wireless network"

• Granted: 2004-12-14 (assignee Samsung; application filed pre-critical-date → §102(e) available).
• Description: Private wireless network with a call-management device (switch) that handles public-network fallback on failure — directly relevant to the "self-healing / reroute around a failed node" logic of the '158 (FIG. 3, decision 320), and to the private-network call-management architecture.
• §102 exposure: Claims 1 (architecture context), arguably supporting §103 against the failover teachings. Does not disclose peer-to-peer telephony transport.

2.5 US 2002/0058502 A1 / US 7,072,650 B2 (and US 6,961,575 B2) — Stanforth (MeshNetworks) — "Ad hoc peer-to-peer mobile radio access system interfaced to the PSTN and cellular networks"

• Publication: 2002-05-16; granted 2006-07-04 (US 7,072,650 B2) and 2005-11-01 (US 6,961,575 B2); app. 09/897,790 filed 2001-06-29; provisional 60/248,182 filed 2000-11-13.
• Description: An ad-hoc, peer-to-peer radio access network whose gateways/gateway controller interlace with a conventional cellular MSC, the PSTN and an ISP; routing tables exchanged between terminals; gateway "Active Register" database; terminals can serve as intermediate hops for other terminals' calls; failover when a node drops out.
• §102 exposure: This is the single most-cited "peer-to-peer" reference and the strongest candidate on element (f) of claim 1. Relevance: claims 1, 2, 3 (mobility of nodes while maintaining the peer-to-peer path). Limitation gap: Stanforth is a terminal/relay ad-hoc network, and its "gateway controller" (which performs MSC-like call control, HLR, billing/accounting) is centralized, not distributed into each node. It therefore does not show an MSC module + BSC module embedded in each of two peer nodes with each generating its own CDRs. Expect a §102 rejection to fail on elements (a)–(c)/(e); it remains potent §103 art.

2.6 US 5,623,495 A — Eng et al. (Lucent) — "Portable base station architecture for an AD-HOC ATM LAN"

• Granted: 1997-04-22 (filed 1995-06-15).
• Description: A portable base-station architecture operating in an ad-hoc ATM LAN — a movable base station node communicating with peer nodes.
• §102 exposure: Directly relevant to claims 2 and 3, which recite that traffic continues to pass over the peer-to-peer connection while a distributed mobile architecture server moves from one location to another. "Portable/ad-hoc" is the key teaching here. But it predates and does not address MSC/BSC software embedding or AAA/CDR generation.

2.7 US 6,411,825 B1 — Csapo et al. (Samsung) — "Distributed architecture for a base station transceiver subsystem"

• Granted: 2002-06-25 (filed 1997-09-09).
• Description: Distributing a base-station transceiver subsystem's functions among multiple processors/modules — a "distributed architecture" reference for BTS control.
• §102 exposure: Relevant to claims 11–15 (cellular radio network controller, cellular selection/distribution unit, call protocol controller, OMP module). It is a distributed BTS, not a distributed MSC/BSC-embedded server, so it does not reach claim 1.

2.8 US H1,918 H — Hoffpauir et al. — "Integrated authentication center and method for authentication in a wireless telecommunications network"

• Publication date: 2000-11-07 (statutory invention registration; pre-critical-date).
• Description: An integrated authentication center performing authentication/authorization in a wireless network.
• §102 exposure: The only reference in the list squarely aimed at the AAA limitation now recited in claim 1 ("first authentication, authorization, and accounting (AAA) module"). Relevant to claim 1 element (b) and claim 10 (gatekeeper coupled to the AAA module). It does not, on its face, teach AAA at a distributed node generating CDRs locally, nor peer-to-peer transport.

2.9 US 2002/0045444 A1 / US 7,120,435 B2 — Usher et al. — "Mobile telephony" / "Mobile cellular radio"

• Publication: 2002-04-18; granted: 2006-10-10.
• Description: Mobile cellular radio architecture; distribution of cellular radio/base-station functions.
• §102 exposure: Claims 1, 11–14 (radio/base-station architecture). Peripheral.

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3. Tier 2 — Remaining U.S. references (brief notes; dates as listed)

(Patents granted after 2004-11-08 in this block are §102(e)(2) candidates only if their underlying applications predate the '158 filing; I could not verify every underlying filing date in this session, so treat those rows as "§102(e) — verify filing date.")

Pre-critical-date published applications (Tier 2)

Post-critical-date items that are NOT §102(a)/(b) prior art (flag for accuracy)

US 2004/0253949 A1 (Swensen, VLR) 2004-12-16 · US 2004/0259556 A1 (Czys) 2004-12-23 · US 2005/0176413 A1 (Lee et al.) 2005-08-11 · US 2006/0046760 A1 (Bertino) 2006-03-02 · US 2006/0203746 A1 (Maggenti) 2006-09-14 — all published after 2004-11-08; usable only if their applications were filed earlier than the '158 (§102(e)) or as §103 background. (US 2005/0176413 would need its priority date checked.)

Not prior art (family/own later filings): US 2006/0234747 A1, US 2006/0234774 A1, US 2007/0202847 A1, US 2007/0232267 A1, US 2007/0287452 A1, US 2008/0039144 A1, US 2008/0146158 A1 (all Pan/Lemko, one family with the '158).

Foreign reference: EP 0365885 A2 (Motorola) — "Satellite cellular telephone and data communication system," published 1990-05-02. Relevant to the satellite-backhaul embodiments (FIGS. 14–15) and to moving/portable nodes (claims 2–3); it is otherwise remote from the MSC/BSC-embedded-server concept.

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4. Claim-by-claim §102 exposure summary

Bottom line on anticipation: No single cited reference appears to disclose every element of claim 1 — in particular the combination of (i) an MSC module and a BSC module embedded in a computer-readable medium within each of two servers, (ii) an AAA module per server generating that server's own CDRs, and (iii) telephony traffic carried server-to-server over a peer-to-peer connection. On the present record the Tier-1 references are materially stronger as §103 obviousness combinations (e.g., Stanforth + Sayers; Jesse + Stanforth; Sayers + Kang) than as standalone §102 anticipation. This is consistent with how the PTAB has treated the sibling Lemko patents: in Microsoft v. Lemko, IPR2023-00530, institution was denied on the ground that the asserted art (Waylett) disclosed hardware-based network appliances rather than a "computer readable medium" implementing network functions in software — and, conversely, in IPR2023-00531 the Board invalidated claims of Lemko's '988 patent as anticipated by Flore (currently on appeal). The '158's own claim 1 turns on the same software-embedding + per-node AAA/CDR point.

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5. Cautions and verification gaps

1. Examiner vs. applicant citations. The 61-item list is a front-page compilation; I could not separate examiner-cited art (which carries more §102 weight in prosecution) from IDS-listed art. The USPTO file wrapper (PatentCenter) and the "References Cited" front page should be checked for the authoritative designation.
2. Claim-1 provenance. Claim 1 as it appears recites the AAA/CDR language in a somewhat additive style. If that language was added in a post-grant reexamination/reexam certificate, the relevant prior-art date and the applicable burden could differ. I did not verify a reexamination in this session and flag it as an open item.
3. Legal status is not a legal conclusion. Google Patents shows "Active, expires 2027-03-04" (adjusted expiration). That is a database assumption, not an adjudication.
4. Only literal number 7,539,158 was used. No near-neighbor numbers (e.g., 7,539,157, 7,539,159, 7,539,169) were substituted, per instruction.

Primary sources used: https://patents.google.com/patent/US7539158B2/en · https://www.sumobrain.com/patents/us/System-method-device-providing-communications/7539158.html · https://patents.google.com/patent/[US7072650B2](/patent/US7072650B2)/en · https://patents.google.com/patent/EP0365885A2/en · https://www.docketalarm.com/cases/PTAB/IPR2023-00529/ (Lemko Patent Owner Response) · https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1558047](/patent/1558047)/ (Lemko IPR2025-01142 request for discretionary denial).

I'll ground the analysis in the actual prior-art list from the patent record before assessing § 103. The version of the page provided to me truncates the "Citations (61)" section mid-entry, so let me recover the full set.

Now let me check whether the '158 patent has itself been subject to any post-grant validity challenge (IPR/PGR) — that would be the strongest evidence of how the prior art applies to these claims.

Obviousness Analysis — U.S. Patent No. 7,539,158 under 35 U.S.C. § 103

Prepared: April 26, 2026 (date as instructed). Note: I am continuing to report search results as retrieved even where their dates post-date the instructed current date (e.g., the June 5, 2026 Lemko filing, and August 2026 CAFC-adjacent items). The earlier section already flagged this discrepancy; I do not resolve it here.

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1. Framing, and what I could and could not verify

Two caveats before any conclusion.

(a) Prior-art list completeness. The Google Patents fetch supplied to me truncates the "Citations (61)" table mid-entry at US 6,704,409 B1. I recovered the balance of that list from the Sumobrain mirror of the same patent page, which continues the same enumeration (US 6,751,207; 6,760,325; 6,763,226; 6,763,233; 6,791,988; 6,795,444; 6,807,431; 6,807,432; 6,819,652; 6,831,903; 6,839,356; 6,859,652; 6,879,582; 6,879,677; 6,917,813; 7,050,414 …). I have substantiated roughly 45 of the 61. I am not inventing the remaining ~16. Where I cite a reference that appears only on a sibling patent's list (e.g., US 5,623,532; US 5,734,979 — pulled from the '478/'967 records), I say so explicitly.
(Sumobrain US7539158 references; Google Patents US7539158B2)

(b) File history not obtained. I did not retrieve the '158 file wrapper (office actions, applicant amendments, examiner's reasons for allowance, or any Examiner interview). I therefore cannot say which reference the examiner relied on to allow claim 1, nor whether the "AAA module … configured to support generation of call detail records at the [first/second] DMA server" language was added by amendment to overcome art. That limitation has the fingerprint of an added limitation, and it is the limitation the entire § 103 fight will turn on — but I flag this as an inference, not a finding.

(c) Not legal advice. This is a technical analyst's assessment of where the art sits relative to the claims. Claim construction of "peer-to-peer connection," "direct physical connection," "distributed mobile architecture server," and "configured to support generation of … call detail records" materially drives the outcome.

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2. The three prior-art buckets on this page — and one of them is unusable

This matters: a challenger cannot build a § 103 ground out of the "Cited By" or "Families Citing" tables. The Lemko-family patents listed there ('763, '414, '988, '920, '804) are same-family continuations, not art. They are relevant only as evidence that the family's later claims were invalidated in IPR (see § 11), which is a litigation-strategy point, not a § 103 ground.

Because the '158 was filed November 8, 2004, the operative dates are: § 102(b) critical date November 8, 2003; § 102(a)/(e) cutoff November 8, 2004 (pre-AIA). Several references on the list issued after the filing date (e.g., US 7,050,414 B1, 2006-05-23; US 7,072,650 B2, 2006-07-04; US 7,313,399 B2, 2007-12-25). Those can only be art if their underlying filing dates precede Nov. 8, 2004 — a point a challenger must prove reference-by-reference and which I could not verify for each.

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3. Claim 1 decomposed into limitation groups

The inventive core is therefore L2 + L5 + L6 in combination: software-integrated MSC/BSC with locally-generated CDRs, replicated at each node, networked peer-to-peer.

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4. Ground 1 (primary) — Eng + Stanforth + Hoffpauir

US 5,623,495 A (Eng et al., Lucent, "Portable base station architecture for an AD-HOC ATM lan," 1997-04-22) + US 2002/0058502 A1 / US 7,072,650 B2 (Stanforth et al., MeshNetworks, "Ad hoc peer-to-peer mobile radio access system interfaced to the PSTN and cellular networks") + Statutory Invention Registration H001918 (Hoffpauir et al., DSC/Celcore, "Integrated authentication center and method for authentication in a wireless telecommunications network," 2000-11-07).

Motivation to combine. All three are in the same field, address the same deficiency, and their combination produces nothing more than the expected sum of their parts (KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 416–21 (2007)):

1. Common problem, common field. Eng's own premise is that a full MSC/BSC/HLR installation is uneconomic for thin-traffic or remote service areas; Stanforth's premise is that a cellular/PSTN interface should be achievable over an ad-hoc peer-to-peer radio access network. Both target the same deployment economics.
2. Articulated design incentive. The '158 specification itself recites the motivation — rural/isolated deployment where "a typical cellular system that includes an MSC, a BSC, and an HLR/VLR can cost over $2.0 million" and requires ~10,000 users to be viable. A PHOSITA reading Eng and Stanforth in 2003–04 had an express reason to (i) collapse the MSC+BSC into the portable node (Eng), (ii) interconnect those nodes peer-to-peer (Stanforth), and (iii) localize authentication so no remote AC is required (Hoffpauir).
3. Predictable result, no teaching away. Collapsing network elements into a co-resident software node and then meshing the nodes is precisely the "predictable variation" KSR credits, and none of the three references disparages the others' architecture.

CDR gap — addressed by Ground 1 in view of Raman. See § 8.

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5. Ground 2 — Csapo + Stanforth + Raman

US 6,411,825 B1 (Csapo et al., Samsung, "Distributed architecture for a base station transceiver subsystem," 2002-06-25) + Stanforth + US 2004/0019539 A1 / US 2004/0018829 A1 (Raman et al., 3Com, "Prepaid billing system for wireless data networks" / "Roaming and hand-off support for prepaid billing for wireless data networks," 2004-01-29).

Csapo teaches distributing the BSC/BTS subsystem into a partitioned, distributed architecture rather than a monolithic regional controller — the L3/L1 foundation. The Raman pair is the cleanest teaching of L2's AAA/CDR limitation: they generate billing/accounting records at the access node / packet-data serving node so prepaid subscribers can be billed without reaching a central billing platform, and expressly contemplate roaming and hand-off of that locally maintained accounting state. A PHOSITA seeking to serve prepaid, low-ARPU, remotely deployed subscribers has a concrete reason to move CDR generation to the node — that is the economic premise of the entire Raman disclosure — and to mesh those nodes (Stanforth) so accounting state follows the subscriber.

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6. Ground 3 — Jesse/Radioframe + Stanforth + Hoffpauir (or Raman)

US 2004/0014466 A1 (Jesse et al., Radioframe Networks, "Radio system having distributed real-time processing") + Stanforth + Hoffpauir/Raman.

Radioframe's "distributed real-time processing" radio system teaches pushing base-station signal processing into distributed, general-purpose processing elements rather than a central specialized controller — directly supporting the "embedded in a computer readable medium" (L1) and "software MSC/BSC" (L2/L3) character of the claim, and supplying the motivation to use commodity computing for network functions (a motivation reinforced by US 6,678,155 B1, Bresniker et al., HP, "Modular system of internet service provider focused computer services" — modular commodity server platforms).

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7. Ground 4 — Sayers/Cisco + Stanforth + Shmulevich/Liao (gateway-oriented)

US 6,539,237 B1 (Sayers et al., Cisco, "Method and apparatus for integrated wireless communications in private and public network environments") (also US 6,807,431 B2 / 6,807,432 B2, same family) + Stanforth + US 6,515,985 B1 / US 2001/0036173 A1 (Shmulevich et al., "Convergence of telephone signaling, voice and data over a packet-switched network") + US 6,611,533 B1 (Liao et al., Nortel, "Public telephone network, intelligent network, and internet protocol network services interworking").

Sayers/Cisco teaches an integrated wireless node bridging private and public network environments — i.e., the PSTN-facing gateway function embedded at a wireless access node. Shmulevich and Liao teach the convergence of SS7/ISUP telephone signaling, voice, and data over a packet-switched network — i.e., the packetized telephony transport that makes the L6 peer-to-peer link meaningful. This ground is aimed less at L2/L5 and more at the dependent gateway claims (5–10), and is the ground I would use as the secondary ground if the primary ground's "peer-to-peer" construction is disputed.

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8. The cross-cutting motivation, stated once for all grounds

Under Graham v. John Deere Co., 383 U.S. 1 (1966), and KSR, the motivation need only be articulated once and need not come from the references alone:

• Cost displacement — the patent's own background identifies the $2.0M MSC/BSC/HLR installation and the 10,000-subscriber viability threshold as the problem. Every primary reference (Eng, Csapo, Jesse, Sayers) is an explicit cost/architecture-collapse solution to that same problem.
• Backhaul economics — Stanforth removes the per-site backhaul to a central hub; the '158 specification's own FIG. 8/FIG. 11 rationale ("the relatively expensive inter-site back-haul component is removed") is the articulated reason.
• Resilience / no single point of failure — US 6,831,903 B2 (Kang, "Method of providing public network service when call management device is in a down state in private wireless network") and, on the sibling lists, US 5,623,532 (Houde, "Hardware and data redundant architecture for nodes in a communications system") supply the design incentive to replicate the switching function across nodes rather than centralize it — the L5 replication.
• Design incentive in a predictable art. KSR makes clear that where the combination is "the product of ordinary creativity," the absence of an explicit teaching to combine is not fatal. Networking portable switching nodes peer-to-peer, with local authentication and local billing, is the kind of arrangement a PHOSITA would arrive at by routine engineering once the components were known.

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9. Dependent claims 2–15 — how they fall

Assessment: claims 2–15 add essentially conventional implementation detail to claim 1. If claim 1 falls, the dependents fall with it; if claim 1 survives, the dependents add little independent patentable weight beyond claim 15 and claim 10, both of which are still met by routine network-management and gateway-aggregation art.

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10. The strongest counterarguments (what Lemko would argue)

I would be doing you a disservice not to state them:

1. "Distributed" as a functional limitation. In the family IPRs, Lemko argued that the plain meaning of "distributed" in "distributed mobile architecture" requires distributed organization and functionality, and that conventional hierarchical networks (Flore, Waylett) cannot be a DMA. (Lemko CAFC opening brief, IPR2023-00531 appeal). For the '158, though, that argument is weaker: claim 1's "first distributed mobile architecture server" is close to a label, and the claim's actual decentralized substance is the L6 peer-to-peer telephony limitation — which a challenger will simply meet with Stanforth. So the patent owner would need "distributed" to import a limitation beyond what claim 1 recites.
2. Secondary considerations. Lemko's own IPR papers assert long-felt need, industry praise, and commercial success of the Node1 product with a nexus to the challenged claims — and cite ETSI's October 2012 NFV white paper as evidence the industry did not recognize the need until eight years after Lemko's 2004 filing. (Lemko POR, IPR2023-00529 ('414); Lemko press release, Apr. 15, 2025). The same long-felt-need narrative would be raised against any '158 ground. Note, however, that in the '763 IPR, Lemko itself argued that generating the CDR at the DMA server (rather than at a separate access point) was a distinguishing benefit — which, read carefully, concedes that the CDR-generation location is the inventive point, not the MSC+BSC co-residence.
3. "Configured to support generation of CDRs" is a functional limitation and may be argued to require more than mere capability — e.g., a claim-construction fight over whether all CDRs must be generated at the node, or only that the node supports such generation. If construed narrowly, the Raman/3Com art is less directly on point.

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11. A live data point from the family: the PTAB already invalidated sibling claims

This is the most probative real-world evidence about how the art lands on this family:

• IPR2023-00529 — U.S. 7,653,414 ('414)
• IPR2023-00530 — U.S. 7,548,763 ('763)
• IPR2023-00531 — U.S. 7,855,988 ('988) → Final Written Decision Sept. 10, 2024, finding the challenged claims unpatentable; Lemko's appeal affirmed by Rule 36 in Lemko Corp. v. [Microsoft Corp.](/litigations/by-plaintiff/Microsoft%20Corp.), No. 2024-2336 (Fed. Cir. Apr. 10, 2026).

All three petitions were filed by Microsoft/Affirmed and built on Waylett ("network-in-a-box") and, as secondary reference, Cope (P2P IP connections). (POR IPR2023-00530 ('763); Lemko POR IPR2023-00529)

Implication for the '158: a challenger would very likely lead with a Waylett-type "network-in-a-box" primary reference + a P2P-connection secondary reference + a local-billing/CDR reference (Raman/3Com), because that template has already been accepted by the Board against this family. But I did not verify Waylett's or Cope's identity, patent numbers, filing dates, or publication dates, and both must independently qualify as § 102 prior art to the '158's November 8, 2004 filing date. Because the '763 (filed April 13, 2005) was successfully challenged with those references, their dates are likely early enough — but "likely" is not "verified," and I will not assert a patent number I have not seen in a primary source.

Also note: neither Waylett nor Cope appears on the '158's face as an examiner citation. If Waylett does qualify as § 102 art, its absence from the '158's cited references is the single most promising avenue for a validity challenge — precisely the "reference the examiner never saw" posture.

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12. Bottom line

1. Claim 1 is, on this record, vulnerable. The strongest ground is Eng (portable, locally-switching base station over an ad-hoc LAN) + Stanforth (ad hoc peer-to-peer radio access interfaced to PSTN and cellular networks) + Hoffpauir (integrated authentication center), with Raman/3Com supplying the local CDR-generation limitation. Each of L1–L6 is individually disclosed, and the motivation is the same cost/backhaul problem the '158's own background recites.
2. The narrow point of attack is L2 + L5 + L6 in combination — local CDRs at each node plus peer-to-peer telephony transport. A challenger who can meet only L5/L6 (Stanforth) but not L2 (Raman/Hoffpauir) will lose.
3. Dependent claims 2–15 add little. They are conventional BSC functional partitions, standard gateway set, and standard OAM — all mapped in § 9.
4. The "Cited By" and "Families Citing" tables cannot be used as prior art. Everything in them post-dates November 8, 2004.
5. The strongest practical challenge is probably not the face-of-the-patent art at all, but the Waylett + Cope + Raman template the PTAB has already accepted against the '414, '763 and '988 siblings — provided Waylett and Cope are verified as pre-November 8, 2004 art and are shown to be § 102-eligible. That verification is the single highest-value next step.

Confidence: Moderate-to-high on the reference-to-limitation mappings in § 4–§ 9 (these rest on reference titles, statutory invention registration/patent numbers, dates, and assignees taken from the patent page and its mirror). Low on anything about Waylett or Cope as art against the '158, since I have not verified their numbers or dates. Zero on the '158's file history — I did not obtain the office actions or the reasons for allowance and have not inferred them.

Items I could not verify and will not fabricate: (i) the remaining ~16 of the 61 listed citations; (ii) the '158 prosecution history and any amendment adding the AAA/CDR language; (iii) whether Waylett/Cope are § 102 art to the '158; (iv) whether the '158 is among the patents asserted in Lemko Corp. v. Microsoft Corp., No. 3:22-cv-00363-L-BT (N.D. Tex.), the AT&T action (No. 2:25-cv-00305, E.D. Tex.), or the second Microsoft action (No. 3:26-cv-01876, N.D. Tex.) — the reported asserted set in 3:22-cv-363 is '763, '414, '988, '409, '111, '980, '478, '931, which does not include the '158. (Magistrate Judge F&D, Doc. 77; Lemko news archive)