DCT

2:23-cv-00013

Winterspring Digital LLC v. Microchip Technology Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:23-cv-00013, E.D. Tex., 01/13/2023
  • Venue Allegations: Venue is asserted based on Defendant maintaining a regular and established place of business within the Eastern District of Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s networking microchips, including Ethernet switches and transceivers, infringe three patents related to high-speed signal transmission, packet tagging, and network traffic admission control.
  • Technical Context: The technology at issue addresses the management of data traffic in high-speed Ethernet networks, a function critical to the performance and scalability of modern data centers, enterprise networks, and telecommunications infrastructure.
  • Key Procedural History: The complaint does not mention any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the patents-in-suit.

Case Timeline

Date Event
2000-07-28 U.S. Patent No. 7,774,468 Priority Date
2002-04-08 U.S. Patent No. 7,164,692 Priority Date
2002-12-20 U.S. Patent No. 7,420,975 Priority Date
2007-01-16 U.S. Patent No. 7,164,692 Issued
2008-09-02 U.S. Patent No. 7,420,975 Issued
2010-08-10 U.S. Patent No. 7,774,468 Issued
2023-01-13 Complaint Filing Date

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

U.S. Patent No. 7,164,692 - Apparatus and Method for Transmitting 10 Gigabit Ethernet LAN Signals Over a Transport System

The Invention Explained

  • Problem Addressed: The patent describes the challenge of transmitting high-speed (10 Gigabit) Ethernet LAN signals over long-distance transport systems, which traditionally required encapsulating the native Ethernet frames into a different, more complex protocol like SONET, adding cost and inefficiency (Compl. ¶12; ’692 Patent, col. 3:1-10).
  • The Patented Solution: The invention proposes a transceiver that can directly receive a native 10GE LAN signal, convert it into an internal electrical format for processing (such as re-clocking and performance monitoring), and then re-transmit it over a transport system without requiring conversion to a SONET-based standard ('692 Patent, Abstract; col. 5:18-34). This allows for a more direct and efficient extension of LAN technology over a wide area.
  • Technical Importance: This approach aimed to simplify network architectures and lower costs by eliminating the need for protocol conversion hardware, thereby making high-speed Ethernet more viable for metropolitan and long-haul networks ('692 Patent, col. 6:10-17).

Key Claims at a Glance

  • The complaint asserts independent claim 10 (Compl. ¶19).
  • Essential elements of claim 10 include:
    • Receiving a 10GE LAN client signal transmitted over a transport system.
    • Converting the signal to an intermediate form.
    • Recovering clock data and a data stream from the intermediate signal.
    • Reconverting the intermediate signal back to a 10GE LAN client signal.
    • Transferring the signal to a client system.
    • Monitoring the intermediate form with a "10GE LAN media access controller."

U.S. Patent No. 7,420,975 - Method and Apparatus For High-Speed Frame Tagger

The Invention Explained

  • Problem Addressed: The patent identifies that general-purpose network processors can become a performance bottleneck because they are tasked with processing all incoming data bytes at line speed to determine packet types, a heavy workload that can slow down the network (’975 Patent, col. 1:30-41).
  • The Patented Solution: The invention describes a dedicated, high-speed hardware apparatus—a "frame tagger"—that offloads the packet classification task. This apparatus performs a multi-pass comparison of data within a packet against predetermined values to determine its protocol type, and then steers the packet to the appropriate interface (e.g., a central processor or a network processor) based on the classification ('975 Patent, Abstract; col. 4:39-55).
  • Technical Importance: By using dedicated hardware for high-speed packet classification, this solution enables network equipment to handle traffic at line speed more efficiently, improving overall throughput and performance ('975 Patent, col. 1:35-41).

Key Claims at a Glance

  • The complaint asserts independent claim 5 (Compl. ¶29).
  • Essential elements of claim 5 include:
    • A network processor interface and a central processor interface.
    • A "protocol determination logic block" that performs a first-pass comparison and, if the result is positive, a second-pass comparison to produce a set of results.
    • A "tag select logic block" that applies a tag and steers the packet to one of the interfaces based on the set of results.

U.S. Patent No. 7,774,468 - Network Traffic Admission Control

Technology Synopsis

  • The patent addresses the problem that network edge devices often lack visibility into the available bandwidth across the entire network path, making it difficult to guarantee quality of service for new communication sessions (’468 Patent, col. 1:51-62). The patented solution involves a central "director node" that allocates a "real-time bandwidth pool" to an edge node for a given path; the edge node then performs local admission control for individual sessions using this pre-allocated pool ('468 Patent, Abstract).

Asserted Claims

  • Independent claim 1 (Compl. ¶37).

Accused Features

  • The complaint accuses products like the VSC7558 enterprise switch of infringement, alleging they perform a method of requesting bandwidth from a director node, receiving a real-time bandwidth pool, and allocating portions of that pool to new communication sessions (Compl. ¶¶37-38).

III. The Accused Instrumentality

  • Product Identification: The complaint accuses a wide range of Microchip networking components, including the VSC8491 transceiver, the SparX-IV and SparX-5 families of Ethernet switches (e.g., VSC7546, VSC7558), and various Ethernet PHYs and controllers (Compl. ¶18, ¶28, ¶36).
  • Functionality and Market Context:
    • The accused products are semiconductor components that provide core functionality for networking equipment like enterprise switches and routers (Compl. ¶15).
    • The complaint alleges the VSC8491 transceiver performs a method of receiving, converting, recovering clock and data from, reconverting, and monitoring 10GE LAN signals (Compl. ¶20).
    • The VSC7546 ethernet switch is alleged to contain logic for determining a packet's protocol type via a multi-pass comparison and then tagging and routing the packet accordingly (Compl. ¶30).
    • The VSC7558 enterprise switch is alleged to implement a traffic admission control method where it requests bandwidth from a director node, receives a bandwidth pool, and allocates portions of that pool to establish real-time communication sessions (Compl. ¶38). A datasheet excerpt included in the complaint describes the VSC7558 as a "200G Enterprise Switch" that provides a "rich set of enterprise Ethernet switching features" (Compl. p. 16).

IV. Analysis of Infringement Allegations

'692 Patent Infringement Allegations

Claim Element (from Independent Claim 10) Alleged Infringing Functionality Complaint Citation Patent Citation
receiving the 10GE LAN client signal transmitted over the transport system; The Microchip VSC8491 transceiver receives 10GE LAN client signals. ¶20 col. 14:10-12
converting the 10GE LAN client signal to an intermediate signal; The VSC8491 converts the received signal to an intermediate signal. ¶20 col. 14:12-13
recovering clock data from the intermediate signal; The VSC8491 recovers clock data from the intermediate signal. ¶20 col. 14:14-15
recovering a data stream from the intermediate signal; The VSC8491 recovers a data stream from the intermediate signal. ¶20 col. 14:16-17
reconverting the intermediate signal to the 10GE LAN client signal; The VSC8491 reconverts the intermediate signal to a 10GE LAN client signal. ¶20 col. 14:18-19
transferring the 10GE LAN client signal to a client system; and The VSC8491 transfers the 10GE LAN client signal to a client system. ¶20 col. 14:20-21
monitoring the intermediate form with a monitoring device, wherein the monitoring device is a 10GE LAN media access controller. The VSC8491 monitors the intermediate form with a device alleged to be a 10GE LAN media access controller. ¶20 col. 14:22-24
  • Identified Points of Contention:
    • Scope Questions: A question may arise as to whether the accused VSC8491, a single transceiver component, can practice a method claim that begins with "receiving the 10GE LAN client signal transmitted over the transport system." The defense may argue this claim language implies a system-level context that a single chip cannot satisfy.
    • Technical Questions: The complaint alleges the product's monitoring device is a "10GE LAN media access controller" (Compl. ¶20). A block diagram of the accused VSC8491 transceiver shows it interfacing with a "Dual 10 GbE MAC/NIC" (Compl. p. 6, Fig. 2). A key question will be whether the monitoring function is performed by the VSC8491 itself or by the external MAC/NIC, and whether the product's internal monitoring circuitry (e.g., the "VScope™" feature mentioned on p. 7) meets the specific definition of a "10GE LAN media access controller" as required by the claim.

'975 Patent Infringement Allegations

Claim Element (from Independent Claim 5) Alleged Infringing Functionality Complaint Citation Patent Citation
a network processor interface suitable for coupling to a network processor; The Microchip VSC7546 ethernet switch is alleged to include a network processor interface. ¶30 col. 9:51-53
a central processor interface suitable for coupling to a central processor; The VSC7546 switch is alleged to include a central processor interface. ¶30 col. 9:54-56
a protocol determination logic block to determine a protocol type of data in a packet, wherein the protocol determination logic compares the protocol information in a first pass to predetermined values to procedure a first result and, if the first result is positive, compares the protocol information in a second pass... The VSC7546 switch is alleged to include a protocol determination logic block that performs a multi-pass comparison to determine a packet's protocol type. A datasheet excerpt describes the accused product's "analyzer" performing Layer 2 and Layer 3 forwarding based on header information (Compl. p. 11). ¶30 col. 9:57-64
a tag select logic block to apply a tag to the packet...and if the first result is positive the packet should be sent to either the central processor interface or the network processor interface based on the set of results. The VSC7546 switch is alleged to include a tag select logic block to apply a tag and route the packet based on the results of the protocol determination. ¶30 col. 10:1-8
  • Identified Points of Contention:
    • Technical Questions: A primary technical question will be whether the functionality of the accused switch's "analyzer" and "Layer 2/3 forwarding" blocks, as described in its datasheet (Compl. p. 11), actually performs the specific two-pass comparison required by the claim. The defense may argue that standard routing and forwarding logic operates differently from the claimed multi-pass protocol determination method.
    • Scope Questions: The claim requires steering a packet to either a "central processor interface" or a "network processor interface." The complaint's evidence describes the accused product determining a "destination port set" (Compl. p. 11). The court may be asked to decide if determining a destination port is equivalent to the claimed function of steering between two distinct types of processor interfaces.

V. Key Claim Terms for Construction

  • Patent: '692 Patent

    • The Term: "monitoring device is a 10GE LAN media access controller"
    • Context and Importance: This term is critical because infringement of claim 10 hinges on whether the accused product's internal monitoring circuit meets this specific structural and functional definition. Practitioners may focus on this term because the accused product's datasheet refers to a "VScope™ input signal monitoring integrated circuit" (Compl. p. 7), which Defendant may argue is functionally and structurally distinct from a full Media Access Controller (MAC).
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification describes the MAC 312 as a "performance-monitoring device for the intermediate 10GE LAN signals" ('692 Patent, col. 10:1-3), which could support an interpretation where any device performing this function meets the limitation.
      • Evidence for a Narrower Interpretation: The term "media access controller" has a well-established meaning in network engineering. Defendant may argue the patent uses the term to imply a complete MAC layer component, as depicted as a distinct block in Figure 3, not merely any circuit that monitors a signal ('692 Patent, Fig. 3).

  • Patent: '975 Patent

    • The Term: "protocol determination logic block"
    • Context and Importance: This term defines the core inventive concept of the patent. The dispute will likely center on whether the accused switches' architecture contains a structure that meets this definition, particularly the requirement for a multi-pass comparison.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The abstract broadly describes the invention as a logic block "to determine a protocol type of data in a packet and steer the packet" ('975 Patent, Abstract), which could be argued to cover any hardware that classifies and directs packets.
      • Evidence for a Narrower Interpretation: The specification discloses a specific embodiment comprising a "Protocol Extractor," a "Data Register," and a "Comparator" ('975 Patent, Fig. 3). A defendant may argue that the claim should be limited to this disclosed structure and that the accused product's more general "analyzer" (Compl. p. 11) does not conform to it.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that Defendant induces infringement by providing the accused products to customers and end-users (Compl. ¶¶21, 31, 39). The allegations are supported by references to Defendant's product datasheets, which describe the infringing functionalities (Compl. pp. 6-7, 10-11), and an application note that allegedly instructs users on how to configure features like VLAN tagging (Compl. p. 12, Fig. 13). This screenshot of a "Quick VLAN Setup" guide may be presented as evidence of intent to encourage infringing use of the packet tagging features.
  • Willful Infringement: For each patent, the complaint alleges that Defendant had knowledge of infringement "at least as of the date of this Complaint" (Compl. ¶¶22, 32, 40). This phrasing suggests the willfulness claim is based on alleged post-filing conduct, as no specific facts supporting pre-suit knowledge are pleaded.

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

  • A central issue will be one of technical mapping: do the functional blocks described in the accused products' marketing and technical documents (e.g., the VSC8491's "VScope" circuit, the SparX-5's "analyzer") actually perform the specific, multi-step operations and possess the specific structures required by the patent claims, or is there a fundamental mismatch in their technical operation?
  • The case will also turn on questions of claim construction and scope: can terms rooted in a specific patent disclosure, such as the '692 patent's "10GE LAN media access controller" or the '468 patent's "director node," be construed broadly enough to read on the corresponding features of the accused components as alleged in the complaint?
  • Finally, a key evidentiary question for the indirect infringement claims will be one of intent: do the product datasheets and configuration guides cited in the complaint constitute sufficient evidence that Defendant actively intended to instruct or encourage its customers to use the accused products in a manner that directly infringes the asserted method claims?