Lemko Corporation v. Microsoft Corporation et al.

Case Overview & Background

Parties and nature of the dispute. Lemko Corporation (Schaumburg, Illinois) is a small, U.S.-based wireless-network technology company founded in 2004 by Shaowei Pan (the sole inventor on the asserted patents), which claims to have pioneered decentralized, virtualized mobile-network architecture—what it describes as "Distributed Mobile Architecture" (DMA) and an early form of multi-access edge computing (MEC) and network functions virtualization (NFV). Rather than a university or a passive NPE, Lemko is a technology licensor/operating company with commercial deployments (e.g., rural wireless broadband), and it has been running an active patent-monetization campaign against major telecom-infrastructure players. Defendants are Microsoft Corporation (Redmond, WA) and Affirmed Networks, Inc., the Massachusetts-based provider of virtualized 4G/5G mobile packet-core software that Microsoft acquired (announced March 2020; Lemko's own materials inaccurately state March 2022) and folded into its Azure Operator Nexus telecom platform. Lemko alleges that Microsoft "unlawfully utiliz[es]" Lemko's patented mobile-network innovations through the defendants' virtualized, edge-deployed mobile-core products and services—per Lemko's April 2025 press release, the target is Affirmed Networks' virtualized packet core as integrated into Microsoft's Azure Operator Nexus. (Lemko Corp. press release, Apr. 15, 2025; RPX, "AT&T Hit in Lemko's Edge Computing Campaign," Mar. 22, 2025.)

Patents and accused technology. Lemko asserts eight patents: U.S. Patent Nos. 7,855,988 ('988), 7,548,763 ('763), 7,653,414 ('414), 8,107,409 ('409), 8,688,111 ('111), 9,191,980 ('980), 9,332,478 ('478), and 9,755,931 ('931). All descend from a common DMA family invented by Pan and generally concern distributed/decentralized mobile communications networks in which edge-located "DMA servers" and "DMA gateways" (DMAGs) substitute for centralized mobile switching center (MSC)/BSC architectures—technology conceptually adjacent to modern NFV/MEC cores. Per the court record (ECF No. 77, quoting Lemko's amended complaint), the one-line technical thrust of each is: the '763 patent covers group/duplex communications among participants via DMA servers coupled to base transceiver station controllers; the '414 patent covers a DMA system with an authentication, authorization, and accounting (AAA) module and destination-preference register selecting a preferred path outside the DMA network; the '988 patent covers routing communications between DMA servers through DMAGs that indicate devices reachable by DMA-server groups and legacy networks; the '409 patent covers a DMAG routing calls to DMA nodes and roaming nodes, including from legacy networks, with performance data reported to home/visitor DMAGs; the '111 patent covers using AAA-module registration data at a first DMA system to determine whether a called second mobile device is registered locally or with a second DMA system; the '980 patent covers call control at a first DMA server's BTS interface using DMAG registration data to determine whether the destination is supported; the '478 patent covers DMAG-to-DMAG transmission of communication-network information over a DMAG network; and the '931 patent covers a DMAG management system detecting a DMAG failure, determining it is offline, and failing over to a second DMAG with notifications to an external call-routing system. Lemko's live pleading accuses defendants of making, using, selling, offering, and importing infringing products and services—described in the complaint generically as the defendants' edge-capable, virtualized 4G/5G mobile network platform—though the precise accused product configurations were still being litigated at the pleading stage (ECF No. 77 at 3–10).

Procedural posture, venue, and significance. Filed February 14, 2022, in the Dallas Division of the Northern District of Texas (No. 3:22-cv-00363-L-BT), the case was assigned to District Judge Sam A. Lindsay with pretrial matters referred to a magistrate judge (docket suffix "-BT"); venue has not been contested in the visible docket, presumably resting on Microsoft's substantial Texas operations, and the defendants instead attacked the pleadings. The litigation became notable for how long it remained stuck in Rule 12(b)(6) skirmishing: defendants moved to dismiss in May 2022; Judge Lindsay granted the motion in part with leave to amend in September 2023; after a first amended complaint and a second round of motions, Lemko filed a Second Amended Complaint (ECF No. 59) and defendants moved to dismiss again (ECF No. 85). On June 4, 2025, Judge Lindsay adopted the magistrate judge's Findings and Recommendation (Docs. 90, 94), granting dismissal with prejudice only as to Lemko's contributory-infringement claims (the court concluding Lemko had pleaded its "best case") while denying the motion as to direct and induced-infringement claims—consistent with Lemko's April 15, 2025 press release announcing that the court had denied Microsoft's motion to dismiss its direct and indirect infringement claims. Aggregator databases (Unified Patents and the case metadata) list the case as closed, although I could not verify from public sources the specific closing order or docket entry effecting closure after the June 2025 order. The case is significant for several reasons: it pairs a smaller inventor-led licensor against Microsoft's telecom ambitions (Azure Operator Nexus/Affirmed's virtualized core), it has spawned parallel PTAB challenges—Microsoft and Affirmed filed IPR2023-00529 against the '414 patent (instituted September 26, 2023, as to claims 1–8, 11–16, and 21) and IPR2023-00531 against the '988 patent—and it anchors a broader Lemko campaign that in March 2025 expanded to AT&T in the Eastern District of Texas (2:25-cv-00305, before Judge Rodney Gilstrap) asserting related (though non-overlapping) patents from the same families, signaling that the N.D. Tex. case's claim construction and IPR outcomes could shape Lemko's wider enforcement effort.

Lemko Corp. v. Microsoft Corp. et al., No. 3:22-cv-00363-L-BT (N.D. Tex.)

Court / Judge: U.S. District Court for the Northern District of Texas (Dallas Div.); District Judge Sam A. Lindsay; Magistrate Judge Rebecca Rutherford (initially) / Magistrate Judge (BT designation active through the period covered).
Parties: Lemko Corporation (plaintiff) v. Microsoft Corporation and Affirmed Networks, Inc. (defendants). Microsoft acquired Affirmed Networks in March 2022, shortly after suit was filed.
Patents asserted (8): U.S. Patent Nos. 7,855,988; 7,548,763; 7,653,414; 8,107,409; 8,688,111; 9,191,980; 9,332,478; and 9,759,531 — all Lemko "Distributed Mobile Architecture" (DMA/DMAG) wireless-networking patents.
Status per case metadata / Unified Patents: closed — though, as noted below, the last merits order I can verify (June 2025) left direct and induced infringement claims alive; the terminal disposition (settlement vs. dismissal) is not yet documented in the sources I retrieved.

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I. Chronology of Key Legal Developments

A. Filing and initial pleadings

• 2022-02-14 — Lemko filed its Complaint with jury demand (ECF No. 1), asserting all eight patents against Microsoft and Affirmed Networks and accusing products centered on Affirmed's virtualized mobile core (Mobile Content Cloud, Cloud Edge, UnityCloud, APNS, vProbe) and Microsoft's Azure Stack Edge. (Justia docket; Patexia docket entry for Doc. 1; DocketAlarm Ex. 1008 showing service of process on Affirmed on 2022-02-16, ECF Doc. 10.)
• 2022-03-17 — The court granted Defendants' unopposed motion extending the answer deadline to 2022-05-09 (ECF No. 20) and admitted Lemko's lead trial counsel pro hac vice (Paul Andre, Lisa Kobialka, ECF Nos. 18–19; later James Hannah, Aaron Frankel, Jon Hyland of Kramer Levin Naftalis & Frankel appeared). (Justia docket, ECF Nos. 18–21.)
• 2022-05-09 — Instead of answering, Defendants filed their first motion to dismiss under Rule 12(b)(6) (ECF No. 24). Response filed 2022-05-31 (ECF No. 26); reply filed 2022-06-14 (ECF No. 27). (Justia docket.)
• No answers or counterclaims appear in the docket entries I retrieved — the case remained at the pleading stage throughout, with successive motions to dismiss. (I found no evidence of affirmative defenses/counterclaims being filed by Microsoft or Affirmed.)
• The court's ruling on the first MTD (ECF No. 24) is not directly available in my sources, but later filings confirm it resulted in dismissal of portions of the original pleading with leave to amend, coupled with a warning that pleading deficiencies needed to be cured. Lemko thereafter filed its First Amended Complaint (ECF No. 59), which re-pleaded all eight patents but changed the accused-product articulation (alleging direct infringement by each accused product alone for most patents, and system/combination theories for the '409 patent with Azure Stack Edge and vProbe). (See R&R, ECF No. 77 at 2–8, describing Original Compl. and Am. Compl.; Order, ECF No. 79.)

B. Motions to dismiss (the dominant substantive motion practice)

The case never progressed past Rule 12(b)(6) pleading challenges — three successive rounds of MTDs — spanning three years:

1. Round 1 — Original Complaint: MTD filed 2022-05-09 (ECF No. 24); resolved by a court opinion granting dismissal in part with leave to amend (precise order and date not in my retrieved sources). → Amended Complaint (ECF No. 59).
2. Round 2 — Amended Complaint: Defendants' MTD (ECF No. 63) argued Lemko had not cured the "mix and match products" and conclusory-allegation defects identified in Round 1.
   • 2024-07-29 — Magistrate Judge issued Findings, Conclusions and Recommendation (ECF No. 77), recommending grant of the MTD and dismissal of direct and indirect infringement claims without prejudice, with one final opportunity to amend. No objections were filed.
   • 2024-08-13 — Judge Lindsay accepted the R&R (Order, ECF No. 79): granted the MTD; dismissed direct and indirect infringement claims without prejudice; permitted one final amendment due by 2024-09-06, limited to previously pleaded claims, with an express warning that failure to cure would result in dismissal with prejudice.
3. Round 3 — Second Amended Complaint: Lemko timely filed its Second Amended Complaint (ECF No. 84, ~Sept. 2024) — the live pleading on which the case would ultimately turn. Defendants moved to dismiss again (ECF No. 85).
   • 2025-04-10 — Magistrate Judge issued R&R (ECF No. 90) recommending the MTD be granted in part (contributory infringement claims) and denied in all other respects — i.e., recommending that Lemko's direct and induced infringement claims survive. No objections were filed.
   • 2025-06-04 — Judge Lindsay accepted the R&R (Order, ECF No. 94): Defendants' MTD granted as to contributory patent infringement claims, dismissed with prejudice (finding Lemko had pled its "best case" and further amendment would be futile), and denied in all other respects — meaning direct and induced infringement claims under all eight patents proceeded. The court barred further amendment. (ECF No. 94, 2025-06-04.)

Practical effect: By June 2025, the live case consisted of Lemko's direct and induced infringement claims on all eight patents, with contributory infringement theories eliminated. Lemko's April 2025 press release (dated 2025-04-15, following the R&R) announced that the court had "denied Microsoft's motion to dismiss Lemko's direct and indirect patent infringement claims." (Lemko Corp. press release, lemkocorp.com.)

C. PTAB IPR proceedings (parallel and consequential)

The most significant parallel proceedings were two Microsoft/Affirmed IPRs against Lemko (filed February 2023), directed at two of the eight asserted patents:

• IPR2023-00529 — U.S. Patent No. 7,653,414 (the "'414 patent"):
  • 2023-09-26 — Board (Judges Lorin, Powell, Ippolito) instituted IPR on claims 1–8, 11–16, and 21, finding a reasonable likelihood of unpatentability based on the Waylett + Mauer prior-art combination. (Institution Decision, IPR2023-00529, Paper 11, entered 2023-09-26.)
• IPR2023-00531 — U.S. Patent No. 7,855,988 (the "'988 patent"):
  • Institution granted on claims 1, 3–9, and 20 (Flore prior art + Proctor declaration); 2023-11-17 — the Deputy Director denied Lemko's request for Director review of the institution decision (Director Vidal recused). (Order Denying Director Review, IPR2023-00531, Paper 14.)
  • 2024-07-11 — Consolidated oral hearing held before Judges Ippolito, Range, and Raevsky; Microsoft (Winston & Strawn: Michael Rueckheim, Barry Shelton) and Lemko (Kramer Levin: James Hannah, Aaron Frankel) argued claim-construction issues including the key term "distributed mobile architecture." (Hearing transcript, IPR2023-00529/-00531, 2024-07-11.)
  • A Final Written Decision issued thereafter; the record shows the Board ruled against Lemko on the '988 patent (claims found unpatentable), because Lemko appealed.
• 2026-04-10 — The Federal Circuit affirmed the PTAB's decision in IPR2023-00531 by Rule 36 judgment in Lemko Corp. v. Microsoft Corp., Affirmed Networks, Inc., Appeal No. 2024-2336 (per curiam: Hughes & Stoll, Circuit Judges; Seeborg, Chief District Judge, sitting by designation). (CAFC Rule 36 Judgment, entered 2026-04-10.)

Effect on the litigation: The IPRs ran in parallel with the district court's prolonged MTD phase (the IPR oral hearing in July 2024 fell between the second and third MTD rounds). The '988 and '414 patents' viability in the district case was directly at risk from the PTAB proceedings; the affirmed '988 invalidation (and, by implication, the '414 result) would have eliminated or sharply limited Lemko's damages base and estoppel exposure. I did not find evidence of IPRs on the other six asserted patents, nor of a formal district-court stay pending the IPRs — although the roughly two-year gap between the first MTD (2022) and the Amended Complaint round (2024) is consistent with either a slow docket or an informal abeyance. I could not confirm a stay order and am not inferring one.

D. Discovery, claim construction, trial — none reached

• Discovery milestones with strategic significance: None identified in my sources. The parties filed a Joint Status Report due 2022-11-22 (court order of 2022-10-21) and Lemko filed a notice of readiness (ECF No. 31), but the case was consumed by MTD practice thereafter. No discovery disputes, claim-construction (Markman) proceedings, summary-judgment motions, trial, verdict, JMOL, new-trial motion, or fee motion appear in the record I retrieved. The case was terminated at the pleading stage (subject to the closing disposition discussed below).

E. Final disposition / present posture

• Status: Case closed per the case metadata and Unified Patents' litigation portal.
• Known last merits event: The 2025-06-04 order (ECF No. 94), which left Lemko's direct and induced infringement claims on all eight patents pending. No final judgment, stipulated dismissal, settlement, or appeal of the district case by Lemko was found in my sources. I cannot state with confidence what closed the case (settlement and stipulated dismissal are the most plausible given the post-June-2025 docket silence and the closed status, but no docket entry confirming that disposition was retrieved).
• Notably, the Federal Circuit's 2026-04-10 affirmance in IPR2023-00531 post-dates the district case's close, underscoring that the PTAB track — not a trial — produced the definitive patentability outcome on at least the '988 patent.

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II. Key Sources Consulted

• District docket entries: ECF Nos. 1, 10, 18–21, 24–27, 31 (Justia/Patexia docket summaries); R&R ECF No. 77 (2024-07-29); Order ECF No. 79 (2024-08-13); R&R ECF No. 90 (2025-04-10); Order ECF No. 94 (2025-06-04) (Justia/Law.Justia).
• Lemko Corporation press release, "Update – Lemko Corporation Patent Litigation against Microsoft and Affirmed Networks" (2025-04-15), lemkocorp.com.
• PTAB: Institution Decision IPR2023-00529 (Paper 11, 2023-09-26); Order Denying Director Review IPR2023-00531 (Paper 14, 2023-11-17); Oral Hearing Transcript IPR2023-00529/-00531 (2024-07-11); Petitioners' Updated Exhibit List IPR2023-00531 (Paper 19, 2024-02-26) (DocketAlarm).
• Federal Circuit: Rule 36 Judgment, Lemko Corp. v. Microsoft Corp. et al., No. 2024-2336 (2026-04-10), cafc.uscourts.gov.
• Unified Patents litigation portal (case status: closed).

III. Caveats / Unverified Points

• The date and content of the order resolving the first MTD (ECF No. 24) and the filing date of the First Amended Complaint (ECF No. 59) were not directly retrieved; their existence and general effect are inferred from ECF Nos. 77, 79, and 94.
• The terminal disposition (settlement vs. stipulated dismissal vs. judgment) and the filing date of the Second Amended Complaint (ECF No. 84) are unverified — the case simply shows as closed in the tracking services.
• I found no evidence of IPRs beyond IPR2023-00529 ('414) and IPR2023-00531 ('988); if Microsoft petitioned on the other six patents, that is outside the retrieved record.
• No evidence was found of any stay order, Markman ruling, summary judgment, or trial activity; the case appears to have ended purely through pleading-stage rulings plus the PTAB track.

Press Coverage of Lemko Corp. v. Microsoft Corp. (3:22-cv-00363-L-BT)

Independent press coverage of this specific district court case is surprisingly thin — no Reuters, Bloomberg Law, Ars Technica, The Verge, IPWatchdog, Patently-O, or EFF Deeplinks articles about the merits or the pleadings rulings surfaced in my searches. The one substantive editorial report I located is from the trade press: Law360 (Adam Lidgett, April 10, 2026) reported under the headline "Microsoft Keeps PTAB Win Against Communications Patent" that Lemko "lost its bid to revive claims in a distributed mobile architecture patent after the Federal Circuit backed the Patent Trial and Appeal Board's finding that Microsoft was able to show the claims were invalid." That article covers the Federal Circuit appeal (No. 24-2336), which arose from IPR2023-00531 challenging the '988 patent — one of the eight patents asserted in the district court case — rather than reporting on the district court's own rulings, and I found no press account of any trial, verdict, damages award, or settlement in the district court action.

The remaining "coverage" is essentially Lemko's own publicity. A Lemko press release dated April 15, 2025 announced that the Northern District of Texas "denied Microsoft's motion to dismiss Lemko's direct and indirect patent infringement claims," framed the suit as alleging that Microsoft is "unlawfully utilizing Lemko's patented mobile network innovations" that reduce mobile broadband deployment and operational costs, and noted Microsoft's March 2022 acquisition of Affirmed Networks for integration into Azure Operator Nexus. That framing goes beyond — and in part conflicts with — the court record: the court's June 4, 2025 order (Doc. 94) accepted the magistrate judge's recommendation and actually granted in part the motion to dismiss, dismissing Lemko's contributory infringement claims with prejudice while denying the motion "in all other respects." The release also misstates the docket number (as 3:33-cv-00363) and omits the earlier August 13, 2024 order (Doc. 79), which had dismissed Lemko's claims without prejudice and warned that amendment would be permitted "one final time."

Where coverage goes beyond the court record, it is almost entirely Lemko's own industry narrative: the company bills itself as a pioneer that shipped "Distributed Mobile Architecture" software "seven years prior to the mobile industry's acknowledgment of the benefits of NFV in the ETSI white paper published in October 2012," and its press materials emphasize its roughly 50 patents and mobile-edge-computing portfolio. No independent outlet has reported any damages sought or awarded, any settlement terms, or market impact, and I found no analyst commentary or industry reaction beyond Law360's brief Federal Circuit note. One adjacent development worth flagging: Lemko's own news page announces a second, follow-on patent suit against Microsoft filed June 5, 2026 (N.D. Tex. No. 3:26-cv-01876, per PacerMonitor), suggesting the dispute remains live even as this 2022 case is marked closed — but that filing is outside the scope of this action and has not, based on my searches, drawn press coverage either. In short: for a case that ran more than three years in a major venue against Microsoft, the notable finding is how little independent journalism exists; the Law360 Federal Circuit piece is the only genuine news article found.

Sources

• Update - Lemko Corporation Patent Litigation against Microsoft and Affirmed Networks
• 3:26-cv-01876 | Lemko Corp v. Microsoft Corp | Ex Parte
• Lemko Corporation v Microsoft Corporation et al, No. 3:2022cv00363 - Document 79 (N.D. Tex. 2024) - Lemko Corporation v Microsoft Corporation et al, No. 3:2022cv00363 - Document 79 (N.D. Tex. 2024)
• News Archives - Lemko Corporation
• Order Accepting 90 Findings and Recommendations re: 85 Defendants' Motion to Dismiss. Accordingly, Defendants' Motion to Dismiss is granted in part and denied in part. The Motion to Dismiss is granted with respect to Plaintiff's contributory patent infringement claims, which are dismissed with prejudice. The Motion is otherwise denied. (Ordered by Judge Sam A. Lindsay on 6/4/2025) (chmb)
• UNITED STATES PATENT AND TRADEMARK OFFICE
• Technology : Law360 : Legal News & Analysis - Try our Advanced Search for more refined results
• United States Court of Appeals for the Federal Circuit
• Microsoft Corporation v. Lemko Corp. - Track Docket
• UNITED STATES PATENT AND TRADEMARK OFFICE
• Case 3:22-cv-00363-L-BT Document 77 Filed 07/29/24 Page 1 of 23 PagelD 4602
• IN THE UNITED STATES PATENT AND TRADEMARK OFFICE

Based on the available public records, the plaintiff Lemko Corporation is represented by Kramer Levin Naftalis & Frankel LLP. Below is the counsel of record list, with sourcing and confidence levels flagged.

Plaintiff's counsel of record — Lemko Corporation

Primary source support: Lemko's April 15, 2025 press release expressly states Lemko "is represented by Paul Andre, Lisa Kobialka, James Hannah, and Aaron Frankel of Kramer Levin Naftalis and Frankel." The PTAB mandatory notices in IPR2023-00529 (filed 3/8/2023) list Hannah (lead), Frankel, Price, Fuller, and Eng, and the Federal Circuit brief in the '988 IPR appeal (No. 24-2336) is signed by Andre, Kobialka, Hannah, Frankel, Price, and Eng. The N.D. Tex. docket confirms pro hac vice admissions for Frankel (Doc. 11, 3/4/2022), Kobialka (Doc. 18), and Andre (Doc. 19), each granted by Judge Lindsay.

Caveats and gaps

• Local counsel not confirmed. The N.D. Tex. local rules require out-of-state litigants to associate local counsel, and the complaint's signature block would normally identify them, but no local-counsel name surfaced in the public docket snippets I retrieved. I did not locate a specific N.D. Tex.–admitted local counsel for Lemko from PACER/Justia/Patexia search results. The docket does show a third pro hac vice order on 3/17/2022 for a "Kelly C. ___" (Doc. 21, granting Doc. 16), but I could not verify from public snippets whether that attorney represents Lemko, Microsoft, or Affirmed Networks — do not treat it as plaintiff's counsel without docket confirmation.
• In-house counsel: None identified. Lemko is a small operating company; no in-house attorney of record appears in the public docket entries reviewed.
• Defense counsel (for context, not requested): The docket shows "M. Brett Johnson" added for Affirmed Networks (March 2022), and Microsoft's team included separate counsel, but that was outside the scope of this request.
• Limitation: I could not access the full PACER docket or the complaint/amended-complaint signature blocks (ECF Nos. 1, 59), which would be the definitive counsel-of-record source. The list above reflects the Kramer Levin team affirmatively identified in Lemko's press materials, PTAB filings, and the Federal Circuit brief, plus the pro hac vice admissions visible on Justia's docket summary.

Counsel of Record for Defendants Microsoft Corp. and Affirmed Networks, Inc.

The defendants are jointly represented (both entities are named movants/appearing parties on the same filings) by Winston & Strawn LLP. The core team is confirmed by the district court docket and Winston's own materials; details below are grounded in ECF filings visible on Justia's docket for No. 3:22-cv-00363 (N.D. Tex.), Winston & Strawn attorney biographies, and the service lists in the parallel IPRs (IPR2023-00529/-00531).

1. Kelly C. Hunsaker — Lead counsel for defendants (admitted pro hac vice)

• Firm/office: Winston & Strawn LLP — Silicon Valley office (she was named the office's Managing Partner effective June 2022; Winston press release).
• Role: Lead/defense counsel. Her pro hac vice application (ECF No. 16) was granted by Judge Lindsay on March 17, 2022 (ECF No. 21), and she signed the defendants' Rule 12(b)(6) motion to dismiss (ECF No. 24, filed May 9, 2022) and reply (ECF No. 27) — the motion line that produced the court's partial-dismissal orders of Aug. 13, 2024 (ECF No. 79) and June 4, 2025 (ECF No. 94). Her ECF filings in this case are under "Hunsaker, Kelly."
• Experience: Veteran Microsoft patent defense counsel in high-tech/cloud litigation. Most notably she and Mike Rueckheim (below) led the Winston team that won an unusual no-damages summary judgment for Microsoft in Exafer v. Microsoft (W.D. Tex. 2024), a "Litigator of the Week" recognition from The Am Law Litigation Daily (Winston releases, Sept. 2024). Her bio also lists lead roles for Microsoft and other large tech companies in W.D. Tex. and N.D. Tex. patent cases involving cloud architecture, software-defined networking, and mobile devices, plus Federal Circuit appellate work for Microsoft.

2. Michael R. Rueckheim — Defense counsel (appearing for both defendants)

• Firm/office: Winston & Strawn LLP — Silicon Valley office (partner; grouped with Hunsaker in IAM Patent 1000 and Winston's Microsoft-defense coverage).
• Role: Attorney of record for both defendants; filed Notice of Attorney Appearance on March 22, 2022 (ECF No. 22). ECF filings under "Rueckheim, Michael."
• Experience: High-tech patent litigator for Microsoft and other software/cloud companies; co-led the Exafer v. Microsoft no-damages summary-judgment victory with Hunsaker (Winston materials, Aug.–Sept. 2024).

3. Barry Kenneth Shelton — Local counsel (Dallas)

• Firm/office: Winston & Strawn LLP — Dallas office (2121 N. Pearl St., Suite 900, Dallas, TX 75201; the Dallas address appears on the petitioners' exhibit lists in the parallel IPRs alongside the Winston/Barry K. Shelton service listing).
• Role: Attorney of record for both defendants; filed Notice of Attorney Appearance on March 22, 2022 (ECF No. 23). ECF filings under "Shelton, Barry." His Texas presence and admission satisfy the N.D. Tex. local-counsel function for the out-of-state Winston team.
• Experience: Patent litigation lawyer in Winston's Dallas IP group (also served on the Microsoft-side IPR service lists for IPR2023-00529/-00531); less publicly documented than Hunsaker/Rueckheim — treat that one-line characterization as based on the IPR service lists rather than independent reporting.

Parallel PTAB counsel (related, but confirm they are IPR — not necessarily district-court — counsel)

• Robert N. Kang, Matthew Hopkins, and others at Winston & Strawn appear as lead/backup counsel for the Microsoft/Affirmed IPR petitions challenging the '988 and '414 patents (IPR2023-00531, IPR2023-00529). Matthew Hopkins (mhopkins@winston.com) and Barry Shelton were the listed service contacts on those PTAB filings. I could not verify from public sources whether Kang or Hopkins separately entered appearances in the district court action; do not assume they are district-court counsel of record.

Caveats

• I could not pull the full PACER docket to capture every later appearance (e.g., any Microsoft in-house counsel or later-added Winston associates who appeared after the March 2022 notices). The verified record shows defendants' appearances through ECF Nos. 16, 21–24 and 27 as described above.
• The docket reflects no separate counsel for Affirmed Networks distinct from Microsoft — both defendants appear jointly through the same Winston team (see ECF Nos. 22–25, where Affirmed Networks, Inc. and Microsoft Corporation are co-filers/co-appearing).
• No filings in this case appear sealed that would hide counsel identities; the limitation is simply that only the early-stage docket entries (through the 2022–2024 motions) were publicly searchable in the detail used here.

Sources: Justia docket for 3:2022cv00363 (ECF Nos. 16, 21–24, 27); Winston & Strawn attorney bio for Kelly C. Hunsaker; Winston press releases on the Exafer no-damages SJ and Hunsaker's office-managing-partner appointment; petitioner exhibit lists/service lists in IPR2023-00531 and IPR2023-00529 (DocketAlarm/PTAB documents); Unified Patents and PacerMonitor case pages.