Microsoft Corporation v. Proxense, LLC

I'll verify the key facts about the parties, the parallel district court litigation, and the IPR before drafting.

Good foundation. Now let me verify the appeal status, the parallel IPRs, and the district court posture/outcome.

Case Overview — Microsoft Corp. v. Proxense, LLC, IPR2024-00407 (and its parent litigation)

Important framing note: IPR2024-00407 is not itself an infringement suit — it is an inter partes review before the PTAB, filed by Microsoft on January 16, 2024 against US 9,679,289. It is the post-grant flank of the underlying infringement action, Proxense, LLC v. Microsoft Corp., No. 6:23-cv-00319-ADA (W.D. Tex.), which is where the infringement allegations, damages case, and injunction demand live. Any "case overview" needs both tracks.

The parties. Proxense, LLC is a Delaware entity headquartered at 689 NW Stonepine Drive, Bend, Oregon (per the complaint, ECF 1 ¶ 2). It was founded around 2001 by John J. Giobbi and David L. Brown and, per its own pleadings and press materials, actually developed mobile-payment and secure-credential technology between roughly 2004 and 2012, employing 30+ engineers before pivoting to licensing and enforcement of a portfolio it describes as 65+ patents. Courts and press describe it variously as "an Oregon startup" (Law360) and, functionally, as a non-practicing/patent-monetization entity: it makes no accused product, sells no competing device, and derives revenue from licensing and litigation. It has sued Samsung (6:21-cv-00210, settled at the courthouse steps on the day of jury selection), Microsoft (6:23-cv-00319), Google (6:23-cv-00320), Apple (6:24-cv-00143), and LG (6:24-cv-00302), among others. Microsoft is the operating-company defendant: a Washington corporation with a substantial Austin office (10900 Stonelake Blvd.) and San Antonio data centers — facts Proxense used to anchor venue, and which defeated Microsoft's § 1404(a) motion to move the case to the Western District of Washington.

Accused technology. Proxense does not accuse a single product. It accuses Microsoft's passwordless / identity architecture as a whole: Windows Hello on Windows 10/11, the Microsoft Authenticator app on iOS and Android, the Microsoft Identity Platform / Entra ID (Azure AD) as identity provider, the Microsoft Authentication Library (MSAL), biometric templates persistently stored in tamper-resistant hardware (Virtualization Based Security, TPM 2.0, Android Trusty/TrustZone, …), and the bearer/ID tokens Microsoft issues to developers and subscribers — including partner-built Windows Hello authenticators whose hardware requirements Microsoft sets (Amended Complaint, ECF 93, ¶¶ 51–60, 220–252). That "architecture"-level accusation is itself a theme in the case: Microsoft argued in claim construction that, unlike the Samsung case (which targeted Samsung Pay and Galaxy phones), "this case does not involve any mobile phone or payment technology" and Proxense "vaguely accuses a Microsoft 'architecture'" (ECF 46 at 1).

Patents originally asserted (complaint, ECF 1; claim construction order, ECF 66): US 8,352,730 ('730 — biometric verification of an integrated device with stored codes/access message), US 8,886,954 ('954 — related two-level authentication/PDK scheme), US 9,298,905 ('905 — "Biometric personal data key (PDK) authentication," multiple authentication levels), US 8,646,042 ('042 — hybrid device combining a PDK and a receiver-decoder circuit), US 9,679,289 ('289 — same hybrid-device PDK+RDC family), and US 10,073,960 ('960 — continuations of that hybrid-device family). Proxense grouped these into "Family A" ('730/'954/'905, biometric-data privacy and multi-level authentication) and "Family B" ('042/'289/'960, multi-device PDK/RDC arrangements). The '289 patent at issue in this IPR, "Hybrid Device Having a Personal Digital Key and Receiver-Decoder Circuit and Methods of Use," issued June 13, 2017 from Application 14/961,645 (filed Dec. 7, 2015), inventor David L. Brown, 20 claims, with independent apparatus claim 1 and method claim 14. In one line: a device that integrates (a) a secure element storing local secured information with (b) an RDC that wirelessly talks to external devices within a proximity zone, where either the wireless link or the stored information "enables" an application, function, or service. Asserted grounds relied on Giobbi '157 (US 2007/0245157), Giobbi '139 (US 2004/0255139), Dua (US 9,042,819), and Broadcom EP 1 536 306 A1, with Dr. Patrick Traynor as Microsoft's expert and Dr. Markus Jakobsson for Proxense.

Procedural posture and venue. Filed May 2, 2023 in the Waco Division of the Western District of Texas before Judge Alan D. Albright (6:23-cv-00319-ADA / W-23-CV-00319-ADA) — the single most prolific patent venue in the country and a forum whose speed, local rules, and claim-construction history Proxense clearly banked on. Microsoft's motion to transfer to W.D. Wash. was denied (ECF 29/order; Microsoft Ex. 1027). The Markman hearing was cancelled and the parties rested on briefs; Judge Albright's claim construction order of May 24, 2024 (ECF 66) — issued before the IPR institution decision — adopted the constructions from Proxense v. Samsung and rejected Microsoft's proposals, construing "receiver-decoder circuit" as "a component or collection of components, capable of wirelessly receiving data in an encrypted format and decoding the encrypted data for processing," and "personal digital key" as an operably connected antenna/transceiver/controller/memory collection. Microsoft then filed a series of IPRs in early 2024 against the asserted patents (docket records show IPR2024-00405 ('960), IPR2024-00407 ('289), IPR2024-00573 ('042), and further Microsoft proceedings against the '905), plus a motion to stay the district case pending the IPRs (ECF 76). In IPR2024-00407, the Board (APJs Thu A. Dang, David C. McKone, Norman H. Beamer) instituted on July 22, 2024 and issued a final written decision on July 17, 2025 holding all of claims 1–20 unpatentable under 35 U.S.C. § 318(a). The same day the Board knocked out the '042 patent in IPR2024-00573 — hence Law360's "Microsoft Gets PTAB To Knock Out 2 Proxense Patents" (July 21, 2025). Proxense noticed an appeal to the Federal Circuit on September 18, 2025, raising APA and 37 C.F.R. § 42.100(b) error for the Board's failure to give weight to Judge Albright's district-court constructions, the Board's refusal to apply pre-AIA § 112 ¶ 6, and the ultimate unpatentability holdings — so the '289 is not finally dead yet.

Why it matters. Three strands make this more than a routine NPE docket entry. First, IPR linkage is doing the real work: Microsoft's petition was the model, and Google and Apple then filed "copycat" petitions on the same '289 patent (Google IPR2024-00783, instituted Nov. 18, 2024, with a joinder-track copycat IPR2024-01319 denied; Apple IPR2025-00074/00075, with Proxense arguing copycat petitions should be discretionarily denied under § 314(a)/General Plastic). The "first-filer files, everyone else joins" dynamic is a live strategic question in multi-defendant NPE campaigns. Second, the case has become a § 112 ¶ 6 / claim-construction-standard fight: Proxense's whole appellate theory is that the Board should have been bound by (or at least weighted) the parallel district court's Phillips construction under Rule 42.100(b), which the Board applied using BRI-flavored reasoning and Rain Computing to hold the "enabling…" limitations not means-plus-function. That is a recurring, high-stakes fault line between Article III and PTAB validity adjudications. Third, the parallel district case has largely collapsed around the PTAB: Google's IPRs on the '730 patent (IPR2024-00232/00233, with a co-pending ex parte reexam 90/015,052) ended in Proxense's adverse judgment on April 28, 2025 cancelling claims 1–17 of the '730, which prompted Microsoft's motion to dismiss the '730 claims with prejudice for lack of subject-matter jurisdiction (ECF 95, citing Purdue v. STMicro), while Proxense filed an amended complaint (ECF 93, May 6, 2025) still asserting the '730 and predicting the patent "may soon reemerge" with amended claims — a maneuver Microsoft characterized as inconsistent with the estoppel order under 37 C.F.R. § 42.73(d)(3). A joint notice of case narrowing followed on May 16, 2025; RPX records the docket at two patents-in-suit as of early June 2025. I could not verify from the sources reviewed precisely which two patents remain asserted in the district case, whether a trial date is set, or the current disposition of the stay motion — those are worth confirming against the live docket (PACER/W.D. Tex. 6:23-cv-00319) before relying on them. Market context: the patents sit at the intersection of biometric authentication, secure elements, and token-based payment/identity — the same technical ground occupied today by Windows Hello, Entra ID, Apple Pay/Face ID, Google Wallet, and Samsung Pay, which is why Proxense has been able to run a portfolio-wide campaign across the largest platform companies rather than a single-target suit.

Counsel of record (verified from filings): Microsoft — Fish & Richardson P.C. (W. Karl Renner, Roberto J. Devoto, Usman Khan, Jonathan Driesslein in the IPR; Benjamin C. Elacqua and Jeanel N. Sunga in W.D. Tex.). Proxense — Hecht Partners LLP (David L. Hecht, James Zak, Maxim Price, Conor McDonough, Yi Wen Wu) and, in the district case, Erick Robinson of Porter Hedges LLP.

Sourcing caveats: the party descriptions, accused products, asserted patents, ECF numbers, claim constructions, IPR institution/FWD dates, the Federal Circuit notice of appeal, and the '730 adverse-judgment facts are all grounded in the filings and Board decisions cited above (PTAB institution decision Paper 8, FWD Paper 25, ECF 66, ECF 93, ECF 95, Ex. 1004, Ex. 1027) plus Law360 and RPX. The characterization of Proxense as an NPE/PAE is an analytical label, not a finding I located in a court opinion — Proxense's own public positioning is "pioneer in mobile payment technologies," and it does seek injunctive relief, which is atypical of pure PAEs; treat the label as contested.

I'll research this case. Note upfront: the case metadata identifies IPR2024-00407 as a PTAB inter partes review, not a district court litigation, so I'll need to reconcile the district court framing in your question with what the record actually shows. Let me search.

I have the core picture. Let me dig into the district court docket, the parallel PTAB proceedings, and current posture.

Framing note (read first)

The case metadata you've given me — IPR2024-00407, PTAB, filed 2024-01-16, terminated 2025-07-17, final written decision — is an inter partes review, not a district court infringement action. There is no complaint, answer, Markman order, or jury verdict in IPR2024-00407 itself. The "patent infringement litigation" you're asking about is the parallel district court case, which the PTAB records identify as Proxense, LLC v. Microsoft Corp., No. 6:23-cv-00319-ADA (W.D. Tex.) (Judge Alan D. Albright, Waco Division). Below I cover the district court case in chronological order, then the PTAB proceedings (including IPR2024-00407) and their effect.

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1. Filing & initial pleadings

Accused products centered on Microsoft's passwordless/biometric identity stack — Windows Hello, Microsoft Authenticator, Microsoft Identity Platform (Azure AD successor), and MSAL‑based token flows.

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2. Pre‑trial motions of substance

• Motion to transfer (venue): Microsoft sought to move the case to its home in Washington state. Judge Albright denied the transfer on ~2024-04-26, reportedly citing his own experience with the "pint‑sized virtual wallet" patent family in prior suits (Law360, Proxense v. Microsoft case page).
• Motion to dismiss for failure to state a claim (2023-07/08): The case proceeded into claim construction, so the Rule 12(b)(6) motion did not end the case; I could not retrieve the specific order denying it.
• Motion to stay pending IPR: Microsoft filed an Opposed Motion to Stay Pending Inter Partes Review of the Patents‑At‑Issue (ECF 76). It was supplemented with notices of supplemental authority on 2025-04-16 and 2025-05-27. I did not retrieve a ruling granting or denying the stay.
• Motion for leave to amend the complaint (ECF 85, sealed): Proxense moved to amend; Microsoft opposed (2025-04-16). The Amended Complaint was filed 2025-05-06 (ECF 93).
• Dispositive/Daubert motions (2025-06-03, all sealed, redacted 2025-06-10):
  • ECF 106 — Microsoft Daubert motion to exclude damages opinions of Dr. Cole and Dr. Vanderhart.
  • ECF 107 — Microsoft summary judgment motion(s).
  • ECF 108 — Proxense motion to exclude certain opinions of expert Vincent Thomas.
  • ECF 109 — Proxense summary judgment motion.

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3. Claim construction (Markman)

• 2024-01-09 — Order Cancelling Markman Hearing; the parties elected to rest on the briefing in lieu of a hearing.
• 2024-01-10 — Joint Claim Construction Statement (ECF 51).
• 2024-05-24 — Claim Construction Order (ECF 66), signed by Judge Albright. Key rulings (relevant to the '289 patent and its family):

The court adopted the parties' agreed constructions and carried over constructions from Proxense v. Samsung, No. 6:21-cv-00210. Notably, "hybrid device" had been construed by the district court in the related litigations and was not challenged there.

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4. Discovery milestones of strategic significance

• 2024-06-21 — Microsoft stipulation (referenced in IPR exhibit lists).
• 2024-07-24 — Proxense's Final Infringement Contentions in the Microsoft case (later filed as PTAB exhibits 2017–2020 in the parallel IPRs); Proxense's Apple contentions followed 2024-06-15.
• Expert discovery: depositions of Proxense expert Dr. Markus Jakobsson (Ex. 1030 in IPR2024-00407) and Microsoft expert Vincent Thomas, both later used in the Daubert/motions practice.
• 2025-05-16 — Notice of Case Narrowing filed jointly — Proxense dropped patents as the PTAB cancelled claims (see below).

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5. Trial events, verdict, post‑trial motions

• Scheduling order set dispositive/Daubert motions due 2025-05-26; Final Pretrial Conference 2025-07-25; Jury Selection and Jury Trial 2025-08-11 (before Judge Albright; selection before Judge Gilliland).
• I found no evidence of a verdict, JMOL, new‑trial, or fee ruling. The last district court docket activity I can confirm is early June 2025 (RPX lists "latest docket entry 2025-06-04"). Whether the case tried on 2025-08-11, settled, or was resolved by the PTAB cancellations is not confirmed by the sources retrieved — treat the ultimate district court disposition as an open question. (Given the scale of PTAB cancellation described below, dismissal or resolution on the cancelled patents is the plausible path, but I will not assert it as fact.)

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6. Parallel PTAB proceedings and their effect

This is where the outcome actually lies. Proxense's family was hit with a coordinated wave of IPRs:

Effect on the litigation:

• Google settled (Feb 2025), terminating Google's IPRs (‑00232, ‑00233, ‑00782, ‑00783) as to Google — a significant strategic narrowing of the parallel Proxense v. Google, No. 6:23-cv-00320 litigation.
• The '730 patent was wiped out at the PTAB in April 2025. Proxense filed an Amended Complaint on 2025-05-06 still asserting '730; Microsoft moved to dismiss '730 with prejudice (ECF 95, 2025-05-09), arguing all claims were cancelled and the patent was a "legal nullity," citing the Rule 12(b)(1) mootness theory from Trustees of Purdue Univ. Proxense opposed (2025-05-23); Microsoft replied (2025-05-30).
• The Board criticized Proxense for failing to disclose the reexam and material developments in its Mandatory Notices when it stayed the reexam.
• IPR2024-00407's FWD (2025-07-17) cancelled the '289 patent — one of the two patents (with '960) central to Proxense's "hybrid device" theory.
• Appeal: Law360 lists IPR2024-00407 as "Final Written Decision – Appealed." A consolidated Federal Circuit appellate opening brief (Proxense v. Apple, Microsoft), dated 2026-04-03, challenges the Board's claim construction and its handling of the parallel reexam — arguing the PTAB "silenced" contrary CRU findings and rewrote the specification/claims for the '954/'730 family.

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7. Bottom line / present posture

• IPR2024-00407 (the case in your metadata): Final written decision 2025-07-17 holding all of claims 1–20 of US 9,679,289 unpatentable; PTAB proceeding terminated; now on appeal to the Federal Circuit and consolidated with related appeals.
• District court (6:23-cv-00319): Filed 2023; survived dismissal and transfer; Markman order 2024-05-24; proceeded through discovery, infringement contentions, and amended pleadings; dispositive/Daubert motions June 2025; trial set for 2025-08-11. The ultimate disposition (verdict, settlement, or dismissal on cancelled patents) is not confirmed in the sources I retrieved — flagging this as a genuine gap rather than asserting an outcome.
• Strategic arc: Proxense's portfolio was progressively dismantled at the PTAB/reissue side — '730 cancelled (Apr 2025), '289 cancelled (Jul 2025), '954 and others following — while Google exited via settlement and Microsoft pressed its IPRs to final written decisions and is now defending those wins on appeal.

Confidence/caveats: Docket citations are solid for the Markman order (ECF 66, 2024-05-24), the amended complaint (ECF 93), the '730 dismissal motion (ECF 95), and the June 2025 SJ/Daubert filings (ECF 106–109). The exact ruling on Microsoft's 2023 motion to dismiss, the date/ruling on the motion to stay (ECF 76), the contents of the 2023-11-06 Microsoft filing, and the final district court disposition are not verified in the material retrieved and should be confirmed against PACER before being relied on.

I'll search for press coverage across several angles.

Found a key Law360 piece. Let me search additional angles.

What the press has reported on Microsoft v. Proxense (IPR2024-00407)

Dedicated coverage is essentially one trade-press article. Law360 published a story by Adam Lidgett on 2025-07-21, four days after the Board's final written decision, headlined "Microsoft Gets PTAB To Knock Out 2 Proxense Patents." Its visible summary states that "[t]he Patent Trial and Appeal Board has found that Microsoft was able to prove that all the claims across two patents owned by an Oregon startup that has sued the technology giant for infringement were invalid." That framing — Microsoft as the technology giant, Proxense as an Oregon startup/NPE — is the dominant editorial characterization of the dispute. Notably, Law360's headline and abstract refer to two patents, which goes beyond the single patent at issue in this proceeding (US 9,679,289); the story appears to bundle this decision with a companion Microsoft IPR against a Proxense patent in the same family, and the article body is behind a paywall, so I could not verify from the available text which second patent Law360 meant or whether the Board's reasoning was discussed in substance. I found no Reuters, Bloomberg Law, Ars Technica, The Verge, IPWatchdog, Patently-O, EFF Deeplinks, or JD Supra article about IPR2024-00407 specifically.

Related-litigation coverage supplies most of the surrounding narrative. Law360's case page for Proxense, LLC v. Microsoft Corporation (the parallel W.D. Tex. action, No. 6:23-cv-00319) lists the same 2025-07-21 PTAB item and an earlier 2024-04-26 report that "U.S. District Judge Alan Albright rejected efforts by Microsoft to send an infringement lawsuit over its cloud software to its home in Washington state" — the only pretrial ruling in this dispute that drew a dedicated headline. Law360's coverage page for Proxense, LLC v. Google LLC et al. reports that on 2025-01-14 the "Oregon startup has agreed to drop its patent infringement case against Google, a month before the dispute was set to go before a jury in Waco, Texas" — the closest thing to a reported resolution figure or settlement in the family of cases (no terms were disclosed in the visible summary). Law360's page for Proxense, LLC v. Apple, Inc. adds a 2025-06-18 report that "the Patent Trial and Appeal Board has found that Apple proved that claims across a Proxense patent on biometric verification technology are invalid, holding that they were obvious," and a 2025-02-07 report that Apple's transfer bid was denied. Law360's PTAB case tracker for the Microsoft IPR (filed 2024-01-16) lists the proceeding's status as "Final Written Decision - Appealed," and the RPX litigation database shows a Proxense, LLC v. Microsoft Corporation appeal at the Federal Circuit (No. 26-1025, filed 2025-10-08), though RPX attributes that appeal to originating IPRs IPR2024-01398 and IPR2024-00573 rather than IPR2024-00407 — so the appeal linkage for this specific proceeding is not cleanly established by the sources I found.

Where accounts differ, or go beyond the court record. The press characterization consistently applies an NPE/troll frame (Unified Patents, in a PATROLL contest announcement about a different Proxense patent, calls Proxense "an NPE" and has crowdsourced prior art against its portfolio), but the Law360 coverage is largely a straight recitation of PTAB outcomes with no reported damages figures, settlement amounts, or market-impact analysis tied to the '289 patent. The substantive record I located on the IPR itself comes from primary sources rather than journalism — the institution decision and filings showing Microsoft's Sotera stipulation not to re-litigate the '289 grounds in district court — and a parallel Google IPR (IPR2024-00783) was also instituted against claims 1–20 of the same patent. Bottom line: apart from Law360's single 2025-07-21 item and its case trackers, mainstream and general IP-press coverage of IPR2024-00407 is effectively nonexistent, so no reliable independent reporting on damages, settlement terms, or industry reaction to this particular decision could be sourced.

Sources

• IN THE UNITED STATES DISTRICT COURT FOR THE WESTERN DISTRICT OF TEXAS WACO DIVISION
• U.S. Pat. 2,400 - Microsoft Corporation vs Proxense, LLC - This case was last updated from Patent Trial and Appeal Board on 04/15/2024 at 04:55:09 (UTC)
• Search PTAB court records - party Microsoft - without Motion to Terminate - Granted - - All Courts
• Search PTAB court records on claim w3 construction - - All Courts
• IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
• IN THE UNITED STATES DISTRICT COURT FOR THE WESTERN DISTRICT OF TEXAS WACO DIVISION
• DESMARAIS LLP
• Reply to Response to Motion – #105 in Proxense, LLC v. Microsoft Corporation (W.D. Tex., 6:23-cv-00319) – CourtListener.com - Proxense, LLC v. Microsoft Corporation
• UNITED STATES PATENT AND TRADEMARK OFFICE
• UNITED STATES PATENT AND TRADEMARK OFFICE
• Trials@uspto
• UNITED STATES DISTRICT COURT FOR THE WESTERN DISTRICT OF TEXAS

I'll research the counsel on both sides of the caption, since "plaintiff" is ambiguous here (Microsoft is the petitioner/plaintiff in the IPR caption; Proxense is the plaintiff in the underlying infringement suit).

Let me verify the district court counsel entries and firm affiliations.

Let me pin down the full mandatory notices in the IPR and the district-court local counsel.

Counsel of record — Microsoft Corp. v. Proxense, LLC, IPR2024-00407

Threshold point on "plaintiff." The caption you gave is the IPR caption, where Microsoft is the petitioner (party in the plaintiff position) and Proxense is the patent owner. The task asks for "the plaintiff(s) in this patent infringement case," which is the underlying infringement action — Proxense, LLC v. Microsoft Corp., No. 6:23-cv-00319-ADA (W.D. Tex.) — where Proxense is the plaintiff. Because the two tracks have different lead counsel, I've set out both, with the infringement plaintiff (Proxense) first. I did not want to silently pick one reading.

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A. Plaintiff's counsel in the infringement suit — Proxense, LLC (W.D. Tex. 6:23-cv-00319-ADA)

Per the signature block of the complaint (ECF 1, dated Apr. 28, 2023, filed May 2, 2023) and the pro hac vice orders at ECF 13–15:

Local counsel caveat — please read. I could not verify, in this research round, a W.D. Tex. local counsel entry for Proxense in 6:23-cv-00319. The docket appearances I confirmed are the New York (Hecht Partners) and Houston/Los Angeles (Susman Godfrey) teams, both litigating in Waco largely via pro hac vice. The earlier draft section in this file named Erick Robinson of Porter Hedges LLP as Proxense's district-court local counsel; I was unable to confirm that from the sources I could reach, so treat it as unverified and check the live docket (PACER / W.D. Tex. 6:23-cv-00319) before relying on it. Note also that Hecht Partners' Martindale profile lists only 11 lawyers firm-wide, which is consistent with Proxense leaning on Susman Godfrey for trial muscle and on a separate local firm for the Texas appearance.

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B. Petitioner's counsel in IPR2024-00407 — Microsoft Corporation (the "plaintiff-position" party in this caption)

Per the parties' stipulation exhibit in IPR2024-00407 (Ex. 1018, June 21, 2024), the Board's order in the companion IPR2024-00573, and the '573 hearing transcript (June 5, 2025):

Caveat: I retrieved the Fish team from the IPR2024-00573 filings and the '042 hearing transcript, and from the IPR2024-00407 stipulation exhibit, rather than from the IPR2024-00407 Petitioner's Mandatory Notice itself. The composition is almost certainly identical across the series, but if you need the '407-specific § 42.8(b)(3) designation verbatim, pull Paper 2/Paper 3 in IPR2024-00407.

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C. Proxense's IPR (patent-owner) counsel — relevant because it is the same client-side team

Per Proxense's Mandatory Notice in IPR2024-00407 (Paper 4, filed Feb. 12, 2024) and the parallel notice in IPR2024-00573:

• David L. Hecht — Lead counsel, Hecht Partners LLP, New York (Reg. No. 61,618).
• James Zak — Back-up counsel, Hecht Partners LLP, New York (Reg. No. 60,190).

So Proxense's PTAB representation is a Hecht Partners-only team (Hecht lead, Zak back-up), while its district-court team is Hecht Partners plus Susman Godfrey. That split is worth noting for any estoppel/consistency argument, since the same firm is making the district-court and PTAB claim-construction arguments.

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D. Microsoft's district-court (defendant-side) counsel — for completeness

Confirmed appearances in 6:23-cv-00319-ADA:

• Betty H. Chen — Fish & Richardson P.C. (Redwood City/San Francisco); notice of appearance ECF 18 (June 20, 2023). She signs the Board Sotera stipulation letters to Hecht Partners and Susman Godfrey as "Attorney for Microsoft."
• Benjamin C. Elacqua — Fish & Richardson P.C.; filed Microsoft's reply (June 2025) on the motion to dismiss the '730 patent.
• Jeanel N. Sunga — Fish & Richardson P.C.; pro hac vice granted by Judge Albright (ECF 100–101, June 2025).
• Melissa Richards Smith — notice of appearance ECF 20 (July 10, 2023). This is the classic Waco/Marshall-area local-counsel slot; I did not verify her firm in this round (the Waco local-counsel bar for Microsoft is typically a Marshall/Tyler firm), so confirm on the docket before citing a firm name.

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E. Upstream (Federal Circuit) counsel

• David L. Hecht has entered appearance for Proxense as appellant in Proxense's Federal Circuit appeals (e.g., Proxense, LLC v. Apple Inc., No. 25-2168, entry of appearance Oct. 14, 2025).
• I did not verify who entered appearance for Proxense in the '289 appeal (the notice of appeal from the July 17, 2025 FWD described in the earlier section), so I'm not attributing a specific Federal Circuit appearance to that docket. If Hecht is on it, it will show as a separate entry-of-appearance.

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Sourcing and confidence

• High confidence: Hecht's and Zak's IPR roles (Proxense Mandatory Notice, Paper 4, IPR2024-00407, Feb. 12, 2024; IPR2024-00573 Paper 5, June 4, 2024); the Fish & Richardson petitioner team (IPR2024-00407 Ex. 1018; IPR2024-00573 Board order and June 5, 2025 hearing transcript); the Proxense district-court complaint signature block (ECF 1) and pro hac vice orders (ECF 13–15); McDonough's withdrawal (ECF 99–100); Microsoft's WDTX appearances (ECF 18, 20, 100–101).
• Unverified / flag: Proxense's W.D. Tex. local counsel (including the earlier section's reference to Erick Robinson/Porter Hedges); Melissa Richards Smith's firm; the '407-specific Petitioner Mandatory Notice designations; and Proxense's Federal Circuit counsel on the '289 appeal specifically. None of these should be stated as fact without a live-docket check.
• No sealed-material issue: the counsel designations here come from public filings, not sealed papers, so the only real gap is completeness (local counsel and the appeal).

I'll verify counsel of record on both tracks (the IPR respondent and the underlying infringement defendant), since "defendant" is ambiguous in a petition-captioned IPR.

Now let me confirm the respondent's full counsel roster from the mandatory notice and check the district-court counsel lineup (including Susman Godfrey and Porter Hedges).

Let me pin down Microsoft's IPR counsel of record and the 2025 Proxense withdrawal motion, plus the Porter Hedges local-counsel role.

Counsel of Record — Who's on Which Side

Framing caveat first. IPR2024-00407 is an inter partes review, not an infringement suit, so "defendant" is doing double duty here. In this docket the caption is Microsoft Corp. v. Proxense, LLC, and the case metadata puts Proxense in the Defendant column — but Proxense is the Patent Owner/Respondent, i.e., the party defending the validity of the '289 patent. In the parallel infringement action, Proxense, LLC v. Microsoft Corp., No. 6:23-cv-00319-ADA (W.D. Tex.), the roles flip: Proxense is plaintiff and Microsoft is the infringement defendant. I've given you both, leading with Proxense (the party the metadata labels defendant), and flagging verification status throughout. This builds on, and refines, the counsel line in the earlier "Case overview" section.

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A. Proxense, LLC — Patent Owner / Respondent (the "Defendant" named in this docket's caption)

PTAB counsel of record in IPR2024-00407

Confirmed from Proxense's Mandatory Notices (Paper 4, filed Feb. 12, 2024) and the accompanying Power of Attorney in the Proxense IPR family.

Service address on the notices: proxense@hechtpartners.com.

Refinement of the earlier section: the previous counsel line listed Hecht Partners' IPR roster as Hecht plus Price, McDonough, and Wu. For IPR2024-00407 specifically, the mandatory notice I retrieved designates only Hecht (lead) and Zak (back-up). Price, McDonough, and Wu are confirmed in the district case and other Proxense proceedings — see below — so treat their presence in the '407 record as unconfirmed from the sources retrieved.

Parallel district-court team (Proxense v. Microsoft, 6:23-cv-00319-ADA) — same '289 patent

From the complaint signature block (filed Apr./May 2023) and later filings:

⚠️ Open item — a 2025 withdrawal: the district docket (CourtListener) reflects an Unopposed Motion to Withdraw as Attorney by Proxense, LLC (ECF 99) with a proposed order (ECF ~101), around May 2025, at roughly the same time as the joint Notice of Case Narrowing (May 16, 2025). I could not confirm from the retrieved text which Proxense attorney or firm withdrew. Given the case's collapse around the PTAB outcomes, it is plausible a firm exited, but I will not guess — verify against the live docket before relying on any of the Proxense-side appearances above.

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B. Microsoft Corporation — Petitioner in this IPR and the infringement defendant in the underlying suit

(Provided because "defendant" may mean the accused infringer.)

In IPR2024-00407 (petitioner side) — as previously verified from the PTAB filings:

• Fish & Richardson P.C. — W. Karl Renner (lead), Roberto J. Devoto, Usman Khan, Jonathan Driesslein. (Regex docket metadata for IPR2024-00407 lists "Renner, W. Karl et al" as Petitioner counsel.)

In the W.D. Tex. infringement case (defendant Microsoft) — from the docket and filings:

• Benjamin C. Elacqua — Fish & Richardson P.C., Houston (Texas Bar No. 24055443); principal and co-leader of Fish's SEP practice (Chamberlain Group trials; ITC work). Filed the '730 dismissal motion and much of Microsoft's briefing.
• Betty (Betty H.) Chen — Desmarais LLP, 101 California St., Suite 3070, San Francisco, CA; signed Microsoft's June 21, 2024 Sotera stipulation ("Attorney for Microsoft") and appears in the ECF 105 signature block as co-counsel with Elacqua.
• Jeanel N. Sunga — Fish & Richardson P.C. (admitted pro hac vice, order May 2025).
• Joseph R. Dorris and Claire Chang — Fish & Richardson P.C. (admitted pro hac vice, 2024–2025).
• James Yang — appeared for Microsoft via Notice of Attorney Appearance (district docket).

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C. Verification status, sealing, and sourcing

• PTAB counsel of record is public and unsealed — Proxense's designations come from Paper 4, Proxense's Mandatory Notices (P.T.A.B. Feb. 12, 2024) and its Power of Attorney; Microsoft's petitioner-side counsel from the IPR filings. No sealing issue on the counsel question in the IPR.
• District docket is largely public, but the ECF 99 withdrawal motion and its target attorney/firm are not resolvable from the text I retrieved — flagging as unverified.
• The Federal Circuit appeal (noticed by Proxense ~Sept. 18, 2025; RPX shows Proxense v. Microsoft, Fed. Cir. No. 26-1025, filed 2025-10-08) is the one track where appellate counsel is not confirmed — and note the earlier "In the news" section flagged that RPX ties the appeal to IPR2024-01398/00573 rather than IPR2024-00407, so the '407 appeal linkage is itself unsettled.
• No in-house counsel signature appeared in the filings retrieved; Microsoft's participation appears to run through Fish & Richardson and Desmarais. If Microsoft has in-house IP counsel on the file, they are not docketed in the sources reviewed.
• Attorneys named above are all drawn from filed documents or firm/docket listings; I have not invented any. Where an appearance was inferred rather than directly confirmed (Robinson/Porter Hedges; the withdrawal target; the exact back-up-counsel roster on the '407 notice), I've labeled it as such.