XR Communications, LLC d/b/a Vivato Technologies v. D-Link Systems, Inc.

I'll research this case across dockets, opinions, and PTAB records.

Now let me dig into the parties' background, the accused products, and the parallel PTAB proceedings.

Let me verify the C.D. Cal. docket details, the accused D-Link products, and the IPR outcomes.

Case Overview and Background

The parties. Plaintiff-appellant XR Communications, LLC, doing business as Vivato Technologies, is a Delaware LLC with its principal place of business in Venice, California, and the record owner by assignment of the patent portfolio of Vivato, Inc. — the venture-backed smart-antenna Wi-Fi startup founded in 2000 (its complaints name Siavash Alamouti, Ken Biba, Vahid Tarokh and others as early innovators; defendants' claim-construction brief dismissively calls it "a failed wireless technology company"). XR does not appear to make or sell anything; RPX and Ex Parte both classify it as an NPE/patent-assertion entity, and it litigates through Russ August & Kabat (Marc A. Fenster, Reza Mirzaie, Brian Ledahl, Minna Chan, James Pickens), a firm known for contingency-fee patent enforcement. The nominal appellee is D-Link Systems, Inc., but the district case was a consolidated, ten-defendant campaign against essentially the entire Wi-Fi equipment industry: D-Link, Belkin, Newo (Amped Wireless), Aruba Networks, Netgear, Ruckus Wireless, Ubiquiti, ASUS/ASUSTeK, Cisco and Extreme Networks. Of those, only ASUS, Cisco and Extreme appeared and defended the appeal — the Federal Circuit revised the caption on July 8, 2022 to reflect the "non-participation" of D-Link, Belkin, Aruba, Netgear, Ruckus, Ubiquiti and Newo (Fed. Cir. Dkt. 20). ASUS was represented by Kasowitz Benson Torres, Cisco by Perkins Coie, and Extreme by Ropes & Gray.

The accused technology. XR targeted the industry's 802.11ac "Wave 2" / MU-MIMO access points and routers (and, in later waves, Wi-Fi 6/802.11ax gear) — the generation of Wi-Fi equipment that uses explicit sounding and beamforming feedback to steer multiple simultaneous data streams to different clients. The complaints map standard-compliant behavior to claim language: an access point transmits a null-data-packet sounding announcement, the client(s) return channel-state/compressed-beamforming feedback (a VHT Compressed Beamforming frame), the AP computes a steering matrix, and Group ID Management frames are used to reassign a client to a different beam. XR's theory was that implementing the standard is infringement — the classic "standard-as-infringer" approach for legacy antenna patents. RPX records 36 accused products in the district court case and 75 across the appeal; the complaints describe the accused products generically by standard compliance rather than by an exhaustive model list. (I did not independently verify the specific D-Link model numbers accused in the 2017 complaint; the public docket excerpts available describe the category, not a full product list.)

The three asserted patents (29 claims asserted across the ten defendants, per defendants' opening claim-construction brief):

• U.S. Patent No. 6,611,231 — "Wireless packet switched communication systems and networks using adaptively steered antenna arrays" (priority April 27, 2001). Claims a wireless routing device with an adaptive antenna array and "control logic" that places transmission peaks and nulls in the far field based on routing information, plus "search receiver logic" that updates that routing information from cross-correlated signal information. This is the patent that ultimately killed the campaign — on § 112 indefiniteness of "search receiver logic," not on the prior art.
• U.S. Patent No. 7,062,296 — "Forced beam switching in wireless communication systems having smart antennas." An access point with a smart antenna transmits multiple narrow directed beams, determines from an uplink transmission whether an associated client should be moved to a different beam, and forces re-association to that beam (the accused mapping: Group ID reassignment under 802.11ac). '296 is the parent of the '728 patent; they share a specification.
• U.S. Patent No. 7,729,728 — same title and disclosure as '296, issued June 1, 2010 from Application No. 11/420,860; claims the forced-beam-switching system in apparatus/system form.

Procedural posture. The lead case was XR Communications, LLC v. D-Link Systems, Inc., No. 8:17-cv-00596 in the Central District of California, Southern Division (Santa Ana), consolidated with the Los Angeles-numbered cases (2:17-cv-02945, -02948, -02951, -02953, -02959, -02961, -02968, 8:17-cv-00674, 5:17-cv-00744). The case was originally assigned to Judge Andrew J. Guilford (Magistrate Judge Jay C. Gandhi), and by the time of the dispositive rulings it was before Judge David O. Carter (Magistrate Judge John D. Early) — the caption on appeal lists Judge Carter. Venue mattered in two ways: the C.D. Cal. was already the consolidated forum for the

I'll research this case thoroughly across the dockets, PTAB, and Federal Circuit records.

XR Communications (Vivato) v. D-Link Systems — Litigation Timeline & Outcome

Scope note: The Federal Circuit appeal you asked about (No. 22-1785) is only the last chapter of a seven-year, multi-front campaign. The C.D. Cal. case was consolidated under lead case No. 8:17-cv-00596-DOC-JDE (Judge David O. Carter), with companion C.D. Cal. cases 2:17-cv-02948-AG-JCG, 2:17-cv-02951-AG-JCG (Cisco), and 2:17-cv-02953-AG-JCG (Extreme). A parallel N.D. Cal. track—XR Communications v. Ruckus Wireless, No. 3:18-cv-01992-WHO (Judge William H. Orrick)—produced the indefiniteness judgment that disposed of the C.D. Cal. case. I flag below where sourcing is thin.

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I. Filing and Initial Pleadings (2017–2018)

Answers/counterclaims. Defendants answered with denials, invalidity and non-infringement defenses, and declaratory-judgment counterclaims of invalidity. Two points are well documented: (i) every defendant pleaded collateral estoppel as an affirmative defense and attached the IPR filings as exhibits—a fact the district court relied on in finding XR on notice (Order of 2022-04-18, No. 8:17-cv-00596, ECF 313, at 4); and (ii) the April 2022 final judgments in the Cisco and Extreme cases expressly dismissed those defendants' counterclaims on the '296, '728, and '231 patents (ECF 42 in No. 2:17-cv-02951; ECF 48 in No. 2:17-cv-02953, both 2022-04-15). I was unable to verify the precise filing dates of each defendant's answer; treat that detail as unsourced.

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II. Parallel PTAB Proceedings (2018–2020) — the decisive front

This is where the case was actually won and lost.

'296 and '728 patents — claims cancelled.

• Six IPRs—IPR2018-00725, -00726, -00763, -00764, -01017, and -01018—resulted in final written decisions cancelling all asserted claims of the '296 and '728 patents. Per secondary reporting, the cancellations included claims 1–2, 4–7, 17–18, 20–23, 33, 35–38 of the '296 patent and claim 16 of the '728 patent. The C.D. Cal. final judgments recite the cancellation of all asserted '296/'728 claims as the basis for dismissal of those patents. (Cisco ECF 42; Extreme ECF 48, 2022-04-15.)

'231 patent — XR survives the PTAB.

• IPR2018-00701 — institution denied 2018-08-27.
• IPR2018-00762 (Cisco, petitioner) — instituted 2018-09-19 on claims 1–9 and 12. The Board construed "cross-correlated signal information that is received by said receiver" as requiring cross-correlation at the time of receipt and held Cisco had not proven the claims obvious.
• IPR2018-01016 (Ruckus, petitioner) — also challenged the '231 patent (institution decision not verified).
• 2020-11-25 — Federal Circuit affirms the Board in Cisco Systems, Inc. v. XR Communications, LLC, No. 2020-1105 (nonprecedential; Moore, Reyna, Taranto). Effect: the '231 patent emerged from the PTAB intact, which is why the case turned on § 112 indefiniteness in district court rather than § 103.

Strategic effect. The IPR wipeout of two of the three patents collapsed most of the damages exposure. But the PTAB's handling of the '231 patent also seeded the collateral-estoppel arguments later run against XR in C.D. Cal.

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III. Stays, Lifted Stays, and the Markman Phase (2018–2022)

Stays pending IPR. The C.D. Cal. cases were stayed pending the IPR wave (and Cisco's ensuing Federal Circuit appeal). Following the November 2020 affirmance and the February 2021 joint status reports, the stays were lifted and the campaign "roared to life" again in 2021—including new suits against Ruckus (N.D. Cal. No. 3:21-cv-04679-WHO) and ARRIS (W.D. Tex. No. 6:21-cv-00621). Source: Mondaq/PTAB Litigation Blog, "Stays Lifted, Wireless Networking Campaign Roars To Life Against Both Existing And New Defendants" (2021). I could not verify the exact stay-entry and stay-lift dates from the docket; the precise orders should be pulled from PACER.

Claim construction — C.D. Cal. (Special Master). On 2021-12-03 the court appointed a Special Master (Dkt. 260). The parties filed opening claim-construction briefs 2021-11-30 (Dkts. 256–257) and responsive briefs 2021-12-23 (Dkts. 272–273), with a Second Amended Joint Claim Construction Statement filed 2021-11-30 (Dkt. 255). The Special Master conducted a claim construction hearing on 2022-01-18 and issued a Report and Recommendation construing terms in the '728, '939, and '376 patents. The court also treated XR's late claim-construction positions as waived where not raised in this process (ECF 313 at 3–4, citing Cent. Admixture and Spigen Korea).

Claim construction — N.D. Cal. (the dispositive ruling). 2021-09-01: Judge Orrick issues the Claim Construction Order in No. 3:18-cv-01992-WHO (Dkt. 191

I'll research the counsel of record for XR Communications in this Federal Circuit appeal and the underlying district court litigation.

Counsel of Record for Plaintiff-Appellant XR Communications, LLC d/b/a Vivato Technologies

Bottom line: XR Communications was represented throughout by a single firm — Russ August & Kabat LLP (RAK), Los Angeles — with no local counsel, no in-house counsel of record, and no co-counsel from another firm appearing in either the C.D. Cal. actions or the Federal Circuit appeal. The Federal Circuit opinion names the appellate team on its face: "MARC A. FENSTER, Russ August & Kabat, Los Angeles, CA, for plaintiff-appellant. Also represented by MINNA CHAN, BRIAN DAVID LEDAHL, REZA MIRZAIE, JAMES PICKENS." XR Commc'ns, LLC v. D-Link Sys., Inc., Nos. 2022-1785 et al., slip op. at 2 (Fed. Cir. May 18, 2023) (nonprecedential).

Appellate counsel (Fed. Cir. Nos. 22-1785, -1787, -1789 to -1792)

District court (C.D. Cal. Nos. 2:17-cv-02948/02951/02953-AG-JCG; 8:17-cv-00596-DOC-JDE)

RAK filed and litigated these cases in its own name as lead counsel — RAK is Los Angeles-based, so no local counsel was required or retained. Caption blocks identify Marc A. Fenster (CA SBN 181067) as "Lead Attorney," with Reza Mirzaie (SBN 246953) and Brian D. Ledahl (SBN 186579) as the core team; James N. Pickens appears on later filings. Mirzaie handled fact-witness depositions in the case. (Complaint/caption signature blocks, e.g., C.D. Cal. No. 8:17-cv-00596; deposition transcripts at ECF Nos. 182-4 and 182-8 in the related W.D. Tex. proceeding.)

Caveats and sourcing notes

• No in-house counsel for XR Communications appears on the Federal Circuit or C.D. Cal. dockets; XR is a patent-licensing entity (formerly Vivato) and litigated entirely through outside counsel.
• The PTAB team is not identical to the appellate team: in IPR2019-00209 (Netflix v. Realtime Adaptive Streaming, XR as patent owner), XR designated Philip Wang (Reg. No. 74,621) as lead counsel with Mirzaie and Christian Conkle as back-up — all RAK. Wang is not listed on the Federal Circuit opinion.
• The Federal Circuit docket (Justia/PACER Monitor/Patexia mirrors) shows the RAK team as the only appellant-side appearances; co-defendants were represented by Kasowitz Benson Torres (ASUS), Perkins Coie (Cisco), Ropes & Gray (Extreme), Covington (Aruba), DLA Piper (Netgear/Newo), Duane Morris (Ruckus), Simpson Thacher (Ubiquiti), Polsinelli, and the Law Offices of S.J. Christine Yang (D-Link).
• I did not locate any sealed appearance or confidential designation affecting counsel identity; the appearances are public docket entries.

I'll research the counsel of record for this appeal and the underlying district court case.

Good initial data. Let me drill into the actual docket appearances for D-Link specifically, both in the district court and on appeal.

Let me pull the actual Federal Circuit docket entry lists and the PacerMonitor party/counsel table.

Bottom line

Counsel of record on the Federal Circuit side is unusually thin in this appeal: the May 18, 2023 per curiam opinion lists appellee counsel for only three defendant groups — ASUS/Asustek, Cisco, and Extreme Networks. D-Link — the named appellee in No. 22‑1785 — appears in the caption as a "Defendant" but not as a "Defendant‑Appellee," and no D‑Link attorney is identified in the opinion's counsel block. D‑Link's district‑court counsel of record was solo practitioner Christine H. Yang (Law Offices of S.J. Christine Yang), per the PacerMonitor party table.

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1. Counsel identified in the Federal Circuit's disposition (No. 22‑1785, May 18, 2023)

Source: XR Commc'ns, LLC v. D-Link Sys., Inc., Nos. 2022‑1785 et al. (Fed. Cir. May 18, 2023) (nonprecedential), counsel block — https://cases.justia.com/federal/appellate-courts/cafc/22-1785/22-1785-2023-05-18.pdf and https://www.courtlistener.com/opinion/[9400192](/patent/9400192)/xr-communications-llc-v-d-link-systems-inc/

Note: the opinion does not use the "argued" designation (it is a short per curiam affirmance), so "lead" above reflects first-listed counsel in each appellee block rather than a confirmed arguing attorney.

2. D-Link Systems, Inc. — the named defendant in 22‑1785

• Christine H. Yang — lead (and apparently sole) counsel of record for D-Link Systems, Inc., Law Offices of S.J. Christine Yang, Fountain Valley, CA (Orange County). PacerMonitor's party table for the consolidated Federal Circuit proceeding lists D‑Link as "Defendant‑Appellee — Represented By Christine H. Yang, Law Offices of S.J. Christine Yang" (https://www.pacermonitor.com/public/case/44552613/XR_Communications,_LLC_v_DLink_Systems,_Inc).
  • Experience note: a small-firm/solo IP practice in Orange County that regularly defends technology companies in patent suits. I was not able to verify a fuller patent-litigation track record from a firm website or reported decision within this research pass — treat that characterization as unconfirmed.
• Important caveat on D-Link's appellate participation: in the Federal Circuit's caption, D‑Link (with Belkin, Newo, Aruba, Netgear, Ruckus, Ubiquiti, and Aruba Networks LLC) is listed only as "Defendants," while ASUS/Asustek, Cisco, and Extreme are the only "Defendants‑Appellees." That strongly suggests D‑Link did not file an appellee brief or otherwise appear in the merits briefing of the consolidated appeal. I could not pull the 22‑1785 docket entries directly to confirm whether an appearance was filed and later withdrawn — so the precise posture is not fully verified. The Federal Circuit docket would resolve it (docket available at https://dockets.justia.com/docket/circuit-courts/cafc/22-1785).

3. Other consolidated appellees (Nos. 22‑1787/1789/1790/1791/1792), per PacerMonitor party table

These appear in the consolidated party table; only some are corroborated by the opinion itself.

Caveat: the PacerMonitor party table aggregates counsel across the consolidated appeal and may include attorneys whose appearances were district-court-only or later withdrawn. The Belkin line in particular is a genuine gap — I could not confirm Belkin's appellate counsel, and Belkin's representation may have been handled by the Kasowitz team (which represented the ASUS entities) or by separate counsel; I am not asserting either.

4. District court (C.D. Cal. No. 8:17‑cv‑00596‑DOC‑JDE) defense-side counsel

The underlying case was consolidated with 2:17‑cv‑02948, ‑02951, and ‑02953 before Judge David O. Carter. The C.D. Cal. docket shows a large defense-side appearance list, including (among others) Adam Robert Alper, Amadou A. Diaw, Don F. Livornese, Ronald R. Wielkopolski, Aaron Gabriel Fountain, Jeffrey R. Cole, Michael A. Piazza, Jack Shaw, John W. Downing, Margaux Azurin Savee, Bo Jin, Jonathan C. Sanders, David A. Garr, Mark Y. Chen, Abirami Gnanadesigan, Allan Gabriel, Matthew J. Rizzolo, and Jacob Buczko (per https://unicourt.com/case/pc-db1-xr-communications-llc-v-d-link-systems-inc-[432630](/patent/432630) and the Patexia document list for 8:17‑cv‑00596).

I am deliberately not assigning firms or roles to those names, because the aggregator does not attribute each attorney to a specific defendant. Confirming which of them represented D‑Link (as opposed to Aruba, Belkin, Netgear, etc.) requires the actual C.D. Cal. docket report, which I could not open.

5. For contrast — plaintiff-appellant's counsel

Marc A. Fenster (lead), with Minna Chan, Brian D. Ledahl, Reza Mirzaie, and James N. Pickens, all of Russ August & Kabat, Los Angeles, CA (per the opinion; entry of appearance at Fed. Cir. ECF No. 18, June 17, 2022; Robert Gajarsa withdrew as non-principal counsel at ECF No. 25, Oct. 7, 2022 — https://services.patexia.com/lawsuits/XR-Communications-LLC-v-D-Link-Systems-Inc-id-[163857](/patent/163857)/documents).

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Sourcing and gaps — read before relying

• Well sourced: the appellee counsel block in the Federal Circuit opinion (justia PDF / CourtListener opinion 9400192); D‑Link's identification with Christine H. Yang (PacerMonitor party table); the plaintiff-side appearances (opinion + Fed. Cir. ECF 18, 25).
• Moderately sourced: the other appellees' counsel from PacerMonitor's aggregate table — reliable as to who appeared somewhere in the consolidated proceeding, but not necessarily as to who briefed the appeal.
• Not sourced / do not rely on: Belkin's counsel; D‑Link's exact appellate posture (whether an appearance was filed and withdrawn vs. never filed); any firm-level "experience" descriptions beyond general practice-group characterizations; and the specific mapping of appeal numbers 22‑1787/1789/1790/1791/1792 to individual defendants (uncertain — the source I saw showed a 22‑1789 docket page captioned "XR Communications v. D-Link Systems, Inc.," which appears to be a lead-caption artifact).
• No indication in anything I reviewed that any of these counsel appearances were sealed; the underlying summary-judgment and expert-related filings in C.D. Cal. were filed under seal, but the appearances themselves are public.