DCT

5:25-cv-00109

Velocity Communication Tech LLC v. TP Link Corp Pte Ltd

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Key Events
Amended Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 5:25-cv-00109, E.D. Tex., 11/12/2025
  • Venue Allegations: Plaintiff alleges venue is proper because Defendants are foreign corporations, making venue appropriate in any judicial district. Alternatively, Plaintiff alleges venue is proper based on Defendants’ commission of infringing acts within the district and the presence of a regular and established place of business through their distribution partner and agent, Anixter, which has multiple locations within the Eastern District of Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s Wi-Fi 6-compliant wireless networking products infringe eleven patents related to foundational technologies for wireless communications, including Orthogonal Frequency Division Multiple Access (OFDMA), beamforming, and power control.
  • Technical Context: The lawsuit concerns technologies integral to the IEEE 802.11ax (Wi-Fi 6) standard, which is a cornerstone of modern high-efficiency wireless local area networking used in a vast range of consumer and enterprise products.
  • Key Procedural History: The complaint alleges Defendant had knowledge of patents essential to the 802.11ax standard through Letters of Assurance submitted to the IEEE standards body by the original patent assignees (NXP and ZTE). Plaintiff also alleges providing pre-suit notice to Defendant of the patents-in-suit and its infringement allegations via a letter.

Case Timeline

Date Event
2004-12-20 U.S. Patent No. 8,270,343 Priority Date
2005-12-07 U.S. Patent No. 8,265,573 Priority Date
2006-03-09 U.S. Patent No. 8,238,859 Priority Date
2007-03-23 U.S. Patent No. 8,675,570 Priority Date
2007-08-28 U.S. Patent No. 8,238,832 Priority Date
2007-10-15 U.S. Patent Nos. 8,213,870; 8,644,765; 9,083,401; 10,200,096 Priority Date
2008-09-15 U.S. Patent No. 8,260,213 Priority Date
2012-06-29 U.S. Patent No. 9,596,648 Priority Date
2012-07-03 U.S. Patent No. 8,213,870 Issued
2012-08-07 U.S. Patent Nos. 8,238,832 and 8,238,859 Issued
2012-09-04 U.S. Patent No. 8,260,213 Issued
2012-09-11 U.S. Patent No. 8,265,573 Issued
2012-09-18 U.S. Patent No. 8,270,343 Issued
2014-02-04 U.S. Patent No. 8,644,765 Issued
2014-03-18 U.S. Patent No. 8,675,570 Issued
2015-07-14 U.S. Patent No. 9,083,401 Issued
2017-03-14 U.S. Patent No. 9,596,648 Issued
2019-02-05 U.S. Patent No. 10,200,096 Issued
2020-09-29 NXP submits Letter of Assurance to IEEE for 802.11ax-essential patents
2023-05-19 Bill of Lading shows TP-Link shipment arrival in the U.S.
2023-09-15 TP-Link Hong Kong submits FCC Attestation Letter for AX3000 Router
2024-03-04 ZTE submits Letter of Assurance to IEEE for 802.11ax-essential patents
2024-07-29 TP-Link Singapore seeks FCC authorization for BE11000 Access Point
2024-11-22 TP-Link Hong Kong seeks FCC approval for AX3000 Router
2025-04-12 Bill of Lading shows TP-Link shipment arrival in the U.S.
2025-04-15 Velocity sends notice letter to TP-Link
2025-07-09 Original Complaint filed
2025-11-12 First Amended Complaint filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,675,570 - Scalable OFDM and OFDMA Bandwidth Allocation in Communication Systems

The Invention Explained

  • Problem Addressed: The patent addresses spectral inefficiency in wireless communication systems using Orthogonal Frequency Division Multiplexing (OFDM) (Compl. ¶70). This inefficiency arose because conventional systems used fixed subcarrier spacings that could not evenly divide nominal channel bandwidths (e.g., 1.25 MHz, 5 MHz, 20 MHz), forcing the use of non-data-bearing "guard bands" to prevent interference, which wasted spectrum (’570 Patent, col. 6:27-34; Compl. ¶72).
  • The Patented Solution: The invention proposes a method for allocating bandwidth that uses a common, precisely chosen subcarrier spacing that is mathematically aligned with both the channel grid ("raster") and all nominal channel bandwidths (Compl. ¶73). This precise alignment allows for the aggregation of multiple carriers with reduced or eliminated guard bands, which minimizes inter-carrier interference and maximizes the use of available spectrum (’570 Patent, col. 7:4-10; Compl. ¶73).
  • Technical Importance: This approach provided a scalable and spectrally efficient method for allocating bandwidth, improving throughput and the flexible aggregation of different channel widths for multiple simultaneous users (Compl. ¶74).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶196).
  • Claim 1 of the ’570 Patent recites:
    • A method for allocating spectral bandwidth for an OFDM or OFDMA system, comprising:
    • choosing a common subcarrier spacing of orthogonal subcarriers to evenly divide a given nominal carrier bandwidth; and
    • using one or more edge subchannels at a spectral end of a channel as guard subchannels without transmitting signals.
  • The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 8,260,213 - Method and Apparatus to Adjust a Tunable Reactive Element

The Invention Explained

  • Problem Addressed: The patent addresses impedance mismatch and reactance drift in radio frequency (RF) transmission systems (Compl. ¶81). Components like Voltage Variable Capacitors can experience a drift in their reactance due to changes in temperature or residual polarization, leading to reduced antenna performance and degraded signal quality (’213 Patent, col. 1:19-26; Compl. ¶83).
  • The Patented Solution: The invention provides an adaptive tuning architecture that dynamically adjusts antenna system components in real time (Compl. ¶84). It employs a reactance detection circuit to monitor the signal and an error correction circuit to detect any drift from a desired reactance, which then generates a correction signal to keep the antenna system optimally tuned (’213 Patent, col. 4:5-15; Compl. ¶85).
  • Technical Importance: This method improves wireless transmitter performance by ensuring efficient and high-fidelity signal transmission, which is particularly beneficial for devices that communicate over multiple frequencies and bandwidths (Compl. ¶86).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶214).
  • Claim 1 of the ’213 Patent recites:
    • A method, comprising:
    • receiving a first signal from a signal source coupled to a first tunable reactive element;
    • producing according to the first signal a second signal representing a measure of reactance of the first tunable reactive element;
    • receiving a control signal representing a desired reactance of the first tunable reactive element;
    • comparing the second signal to the control signal to produce a difference signal;
    • integrating the difference signal to produce a third signal; and
    • applying the third signal to the first tunable reactive element to reduce a difference between the measured reactance and the desired reactance.
  • The complaint does not explicitly reserve the right to assert dependent claims.

Multi-Patent Capsule: U.S. Patent No. 8,238,832

  • Patent Identification: U.S. Patent No. 8,238,832, Antenna Optimum Beam Forming for Multiple Protocol Coexistence on a Wireless Device, issued August 7, 2012 (the "’832 Patent").
  • Technology Synopsis: The patent is directed to solving signal interference when a single wireless device must simultaneously communicate with multiple remote devices using different wireless protocols (Compl. ¶90). The invention teaches generating and shaping multiple antenna beam patterns so that each beam directs its signal to the intended recipient while actively suppressing its signal strength in the direction of other simultaneous communications to reduce crosstalk (Compl. ¶93).
  • Asserted Claims: At least claim 18 (Compl. ¶232).
  • Accused Features: The complaint alleges that Access Points practicing the IEEE 802.11ax standard, which includes mandatory capabilities for Downlink Multi-User MIMO, infringe the patent (Compl. ¶¶229, 232).

Multi-Patent Capsule: U.S. Patent No. 8,270,343

  • Patent Identification: U.S. Patent No. 8,270,343, Broadcasting of Textual and Multimedia Information, issued September 18, 2012 (the "’343 Patent").
  • Technology Synopsis: The patent addresses the inefficient broadcasting of files containing both textual and multimedia data formats (Compl. ¶100). The invention teaches a method where a single block of text and multiple sub-blocks of related multimedia data are packaged together into time-sliced packets, enabling efficient, simultaneous transmission of different data types (Compl. ¶102).
  • Asserted Claims: At least claims 1, 3, 7, 10, 11, 13, and 15 (Compl. ¶250).
  • Accused Features: The complaint alleges that devices practicing the 802.11ax standard, which must handle mixed-media content for multiple users, infringe the patent (Compl. ¶¶247, 250, 107).

Multi-Patent Capsule: U.S. Patent No. 8,213,870

  • Patent Identification: U.S. Patent No. 8,213,870, Beamforming Using Predefined Spatial Mapping Matrices, issued July 3, 2012 (the "’870 Patent").
  • Technology Synopsis: The patent claims improvements to wireless MIMO systems by using a codebook of predefined spatial mapping matrices (Compl. ¶112). The invention involves sequentially transmitting packets using different matrices, measuring reception quality, selecting an optimal matrix for subsequent transmissions, and re-selecting if quality thresholds are not met, thereby improving range and throughput (’870 Patent, col. 1:62-2:7; Compl. ¶112).
  • Asserted Claims: At least claims 1, 2, 3, 5, 6, 7, 8, 9, 10, 12, 13, 14, 16, 17, 18, 19, and 20 (Compl. ¶268).
  • Accused Features: The complaint alleges that Access Points practicing the 802.11ax standard, which utilizes beamforming, infringe the patent (Compl. ¶¶265, 268).

Multi-Patent Capsule: U.S. Patent No. 8,644,765

  • Patent Identification: U.S. Patent No. 8,644,765, Beamforming Using Predefined Spatial Mapping Matrices, issued February 4, 2014 (the "’765 Patent").
  • Technology Synopsis: This patent, a continuation of the ’870 Patent, addresses shortcomings in traditional beamforming, which consumed overhead and was range-limited (Compl. ¶¶123, 127). The invention discloses iteratively transmitting data packets using different predefined matrices, receiving channel estimates from the receiver, and selecting a matrix based on those estimates, while also re-selecting if a packet error rate threshold is exceeded (Compl. ¶128).
  • Asserted Claims: At least claims 1, 2, 3, 4, 7, 8, 9, 10, 12, 14, 15, 16, and 17 (Compl. ¶286).
  • Accused Features: The complaint alleges that Access Points practicing the 802.11ax standard infringe the patent (Compl. ¶¶283, 286).

Multi-Patent Capsule: U.S. Patent No. 9,083,401

  • Patent Identification: U.S. Patent No. 9,083,401, Beamforming Using Predefined Spatial Mapping Matrices, issued July 14, 2015 (the "’401 Patent").
  • Technology Synopsis: This patent, also in the same family as the ’870 and ’765 Patents, improves MIMO communications by using predefined spatial mapping matrices with both channel estimate-driven selection and reception quality metric-based re-selection (Compl. ¶¶134, 136). The solution involves iteratively transmitting packets with different matrices, receiving channel estimates, selecting the best matrix based on those estimates, and re-selecting if a quality metric falls below a threshold (Compl. ¶139).
  • Asserted Claims: At least claims 1, 2, 4, 7, 8, 9, 15, 16, 17, and 18 (Compl. ¶304).
  • Accused Features: The complaint alleges that Access Points practicing the 802.11ax standard infringe the patent (Compl. ¶¶301, 304).

Multi-Patent Capsule: U.S. Patent No. 10,200,096

  • Patent Identification: U.S. Patent No. 10,200,096, Beamforming Using Predefined Spatial Mapping Matrices, issued February 5, 2019 (the "’096 Patent").
  • Technology Synopsis: Also in the same family, this patent addresses the problem of sounding packets having a shorter effective range than beamformed data packets (Compl. ¶¶146, 149). The invention discloses using a codebook of predefined matrices, measuring a reception quality metric for each, and then selecting the matrix with the highest quality for subsequent transmissions, moving channel selection into the data path to improve range and reduce overhead (Compl. ¶151).
  • Asserted Claims: At least claims 1, 2, 3, 5, 6, and 7 (Compl. ¶322).
  • Accused Features: The complaint alleges that Access Points practicing the 802.11ax standard infringe the patent (Compl. ¶¶319, 322).

Multi-Patent Capsule: U.S. Patent No. 8,238,859

  • Patent Identification: U.S. Patent No. 8,238,859, Radio Receiver, issued August 7, 2012 (the "’859 Patent").
  • Technology Synopsis: The patent addresses performance degradation in radio receivers operating in dynamic wireless environments, particularly due to manufacturing variations in components (Compl. ¶¶161, 163). The invention teaches an iterative process of setting an adjustable component to different values, measuring the resulting signal quality for each setting, and repeating the cycle to determine the optimal configuration for robust data reception (Compl. ¶167).
  • Asserted Claims: At least claims 1-5, 7-16, and 18-22 (Compl. ¶340).
  • Accused Features: The complaint alleges that devices practicing the 802.11ax standard, which must adapt to changing RF conditions, infringe the patent (Compl. ¶¶337, 340).

Multi-Patent Capsule: U.S. Patent No. 8,265,573

  • Patent Identification: U.S. Patent No. 8,265,573, Wireless Subscriber Communication Unit and Method of Power Control with Back-Off Therefore, issued September 11, 2012 (the "’573 Patent").
  • Technology Synopsis: The patent is directed to solving interference and inefficient spectrum use in crowded wireless environments by implementing advanced power control (Compl. ¶172). The invention teaches adjusting and "backing off" transmitter output power in response to network conditions, such as interference, to prevent spectral degradation and improve data transmission speed and efficiency (’573 Patent, col. 2:18-22; Compl. ¶173, 176).
  • Asserted Claims: At least claim 12 (Compl. ¶358).
  • Accused Features: The complaint alleges that devices practicing the 802.11ax standard with the 6E extension, which operate in dense environments, infringe the patent (Compl. ¶¶355, 358).

Multi-Patent Capsule: U.S. Patent No. 9,596,648

  • Patent Identification: U.S. Patent No. 9,596,648, Unified Beacon Format, issued March 14, 2017 (the "’648 Patent").
  • Technology Synopsis: The patent addresses the inefficiency of broadcasting network information via lengthy, periodic beacon frames, which consumes airtime and power (Compl. ¶¶183-184). The invention discloses a unified beacon format that allows for dynamically generating either a concise "short" beacon or a comprehensive "full" beacon, including an indicator of which type is being sent, to improve efficiency (’648 Patent, col. 1:57-2:1; Compl. ¶187).
  • Asserted Claims: At least claim 1 (Compl. ¶376).
  • Accused Features: The complaint alleges that Access Points practicing the 802.11ax standard infringe the patent (Compl. ¶¶373, 376).

III. The Accused Instrumentality

Product Identification

  • The complaint names a broad range of TP-Link wireless networking infrastructure products, including those in the Archer, Deco, and EAP product lines, that are compliant with the IEEE 802.11ax (Wi-Fi 6 and Wi-Fi 6E) standard (Compl. ¶¶193, 211).

Functionality and Market Context

  • The accused products are alleged to be wireless routers, access points, and mesh Wi-Fi systems that implement the 802.11ax standard to provide high-efficiency wireless networking (Compl. ¶¶3, 13). Plaintiff alleges that by complying with this standard, the products necessarily practice the technologies claimed in the patents-in-suit (Compl. ¶3). For example, the complaint provides a screenshot of a Walmart webpage showing the "TP-Link Tri-Band 6-Stream Wi-Fi 6E Router" available for purchase in Marshall, Texas, highlighting its availability within the judicial district (Compl. ¶41, p. 20).
  • TP-Link is alleged to market its Wi-Fi 6 products as designed to "improve speed, increase efficiency and reduce congestion in heavy bandwidth usage scenarios" (Compl. ¶14). The complaint alleges that TP-Link specifically configures its products for the U.S. market, for example, by certifying to the FCC that its routers only operate on Wi-Fi channels 1-11, which are permitted in the United States (Compl. ¶30). An FCC attestation letter for the accused AX3000 router is provided as evidence of this configuration (Compl. p. 13).
  • The complaint alleges a global manufacturing and distribution chain where products are made outside the U.S., imported, and sold to end-users through an established channel of distributors and retailers, including in Texas (Compl. ¶13). A bill of lading showing a shipment from China to the U.S. for delivery to a customer in El Paso, Texas, is provided as an example of this activity (Compl. ¶17, p. 10).

IV. Analysis of Infringement Allegations

The complaint incorporates infringement allegations by reference to claim chart exhibits that were not attached to the publicly filed document. The following summarizes the narrative infringement theory for the two lead patents.

U.S. Patent No. 8,675,570 Infringement Allegations

The complaint alleges that the Accused Products, by practicing the IEEE 802.11ax standard, necessarily infringe at least claim 1 of the ’570 Patent (Compl. ¶196). The core of the infringement theory is that the 802.11ax standard mandates the use of OFDMA technology in a way that practices the patented method of using a common subcarrier spacing to enable scalable bandwidth allocation without wasteful guard bands (Compl. ¶¶69-74, 196). The specific mapping of claim 1 elements to the 802.11ax standard and the functionality of the Accused Products is detailed in Exhibit 12, which was not publicly available for review (Compl. ¶199).

  • Identified Points of Contention:
    • Scope Questions: A central issue may be whether compliance with the 802.11ax standard requires the use of a "common subcarrier spacing" that "evenly divide[s] a given nominal carrier bandwidth" as recited in claim 1. The analysis will question whether the standard allows for alternative, non-infringing implementations of OFDMA.
    • Technical Questions: The dispute may turn on what evidence shows that the specific subcarrier spacing and channel allocation methods implemented in the Accused Products meet all limitations of claim 1. The question is whether the operation of the products aligns with the patent's specific method for eliminating guard bands, or if they use different techniques to manage inter-carrier interference.

U.S. Patent No. 8,260,213 Infringement Allegations

The complaint alleges that the Accused Products directly infringe at least claim 1 of the ’213 Patent because their functionality incorporates the invention recited therein, as driven by the demands of the 802.11ax standard (Compl. ¶214). The theory suggests that for a device to operate effectively across the multiple frequencies and bandwidths specified by the 802.11ax standard, it must employ an adaptive tuning architecture to correct for reactance drift, which is what the patent claims (Compl. ¶86). The complaint references Exhibit 13 for a detailed element-by-element analysis, which was not publicly available (Compl. ¶214).

  • Identified Points of Contention:
    • Scope Questions: The analysis will question whether the term "reactance detection circuit" as used in the patent reads on the specific circuitry within the Accused Products. The construction of this term and "error correction circuit" will be critical to determining if the products' internal RF management systems fall within the claim scope.
    • Technical Questions: A key question will be what evidence demonstrates that the Accused Products perform the specific sequence of steps in claim 1: measuring a reactance drift from a desired state and generating an integrated correction signal to compensate. The defense may argue that their products achieve impedance matching through a fundamentally different technical process that does not map onto the claim's elements.

V. Key Claim Terms for Construction

For U.S. Patent No. 8,675,570:

  • The Term: "a common subcarrier spacing...to evenly divide a given nominal carrier bandwidth" (from claim 1).
  • Context and Importance: This term is the core of the inventive concept. Its construction will determine whether the specific OFDMA numerology used in the 802.11ax standard, and implemented by Defendant, falls within the scope of the claim. Practitioners may focus on whether "evenly divide" requires a perfect integer division with zero remainder or allows for practical implementations with negligible residual bands.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the goal of providing a "scalable and spectrally efficient method" and allowing for "flexible aggregation of different channel widths" (Compl. ¶74). This purpose-driven language may support an interpretation that covers any subcarrier spacing scheme that achieves this goal, even if not mathematically perfect in all cases.
    • Evidence for a Narrower Interpretation: The background criticizes prior art where subcarrier spacing "cannot be divided evenly by nominal carrier bandwidths" (’570 Patent, col. 6:27-34). This language, contrasting with the invention, may support a stricter, more literal requirement for the "evenly divide" limitation.

For U.S. Patent No. 8,260,213:

  • The Term: "reactance detection circuit" (from claim 1).
  • Context and Importance: This term is critical because infringement depends on whether the Accused Products contain a structure that performs this specific function. The infringement analysis hinges on whether general-purpose signal monitoring or impedance matching circuits in a modern RF front-end can be characterized as the specific "reactance detection circuit" taught by the patent.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent's abstract describes the invention broadly as "a method involving a step to tune a plurality of tunable reactive elements by measuring a drift in reactance." This may support construing "reactance detection circuit" as any circuit capable of performing this measurement function.
    • Evidence for a Narrower Interpretation: The specification discloses specific embodiments of the circuit, such as one using an AM/Peak Detector (Figure 5) or a Frequency Discriminator (Figure 6) (’213 Patent, col. 4:50-65). These specific examples may be used to argue for a narrower construction limited to the disclosed structures or their equivalents.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement for all asserted patents. Inducement is based on allegations that TP-Link advertises and provides user manuals, product support, and marketing materials that encourage and instruct customers to use the Accused Products in their normal, infringing manner (i.e., in compliance with the 802.11ax standard) (Compl. ¶¶ 200, 203, 218). Contributory infringement is alleged on the basis that the accused components are material to the inventions, are not staple articles of commerce, have no substantial non-infringing uses, and are known by TP-Link to be especially adapted for infringement (Compl. ¶¶ 204, 222).
  • Willful Infringement: Willfulness is alleged based on pre-suit and post-suit knowledge. Pre-suit knowledge is alleged from at least three sources: (1) industry-wide knowledge from Letters of Assurance submitted by original assignees (NXP and ZTE) to the IEEE regarding patents essential to the 802.11ax standard, dating back to September 2020 (Compl. ¶¶ 64, 201); (2) a direct notice letter sent from Plaintiff to TP-Link on April 15, 2025 (Compl. ¶65); and (3) service of the original complaint on or after July 9, 2025 (Compl. ¶66). The complaint asserts that despite this knowledge, TP-Link continued to infringe, describing the conduct as "willful, wanton, malicious, in bad faith, deliberate, consciously wrongful, flagrant, or characteristic of a pirate" (Compl. ¶207).

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of technical necessity and proof: does the IEEE 802.11ax standard, as a technical matter, require the implementation of every limitation of the asserted claims? Plaintiff’s case appears to rest heavily on this premise of standard-essentiality, and a key evidentiary question will be whether a device can be fully compliant with the standard while employing alternative, non-infringing technical methods.
  • A second central question will be one of corporate attribution: can Plaintiff successfully prove that the four named TP-Link entities, organized in four different countries, operated as a single enterprise or under such direction and control that the manufacturing, importation, marketing, and sales activities can be attributed across all entities for infringement liability and damages in the United States?
  • A third key question will be one of claim scope and technological evolution: can patent claims directed at solving specific technical problems from the mid-2000s, with specific circuit implementations disclosed, be construed to cover the highly integrated and complex RF management systems in modern Wi-Fi 6 products? This will raise fundamental questions of whether the accused technology represents a mere implementation of the patented concepts or a technologically distinct solution.