Stormborn Tech LLC v. Fortinet Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Stormborn Technologies LLC (Texas)
  • Defendant: Fortinet, Inc. (Delaware)
  • Plaintiff’s Counsel: Sand, Sebolt & Wernow Co., LPA
• Case Identification: 4:22-cv-00919, E.D. Tex., 10/27/2022
• Venue Allegations: Plaintiff alleges venue is proper because Defendant operates a sales office and maintains a regular and established place of business within the Eastern District of Texas.
• Core Dispute: Plaintiff alleges that Defendant’s wireless networking products infringe a patent related to dynamically adjusting data transmission rates in response to measured channel error rates.
• Technical Context: The technology concerns adaptive data rate control in spread-spectrum communication systems, a foundational technique for maintaining reliable connections in environments with variable signal quality, such as Wi-Fi and cellular networks.
• Key Procedural History: The complaint notes a prior ruling in Stormborn Tech LLC v. Topcon Positioning Systems Inc, where a court allegedly held that claim 11 of the patent-in-suit is not impermissibly abstract and provides a specific technological solution tied to a concrete structure.

Case Timeline

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

U.S. Reissue Patent No. RE44,199 - "Variable throughput reduction communications system and method"

• Patent Identification: RE44,199, "Variable throughput reduction communications system and method," issued May 7, 2013 (the "’199 Patent").
• The Invention Explained:
  • Problem Addressed: The patent identifies a problem in multi-cell wireless systems where a device at the edge of its cell experiences significant interference from adjacent cells, which degrades the signal and increases the error rate (’199 Patent, col. 1:50-57). Prior methods to combat this, such as increasing the processing gain, were inflexible as they required fundamental changes to the receiver's architecture (’199 Patent, col. 1:63-66).
  • The Patented Solution: The invention describes a closed-loop feedback system. A receiver decodes received data, calculates the "error rate" of the decoded channels, and then uses a "command processor" to generate a "data-rate control signal" based on that error rate (’199 Patent, col. 2:63-65; Fig. 5). This control signal is transmitted back to the original transmitter, instructing it to adjust the data rate—for example, by changing the number of data channels or the encoding scheme—to maintain a reliable connection without altering the receiver's hardware (’199 Patent, col. 4:6-15).
  • Technical Importance: This approach allows a communication system to dynamically trade speed for reliability, adapting to changing network conditions in real-time to maintain a target quality of service.
• Key Claims at a Glance:
  • Independent Claim 11 (Receiver):
    • demodulator circuitry for detecting transmitted signals
    • decoder circuitry for FEC decoding and de-interleaving to produce decoded channels, each having an error rate
    • command processor circuitry responsive to the error rate for generating a data-rate control signal to produce a desired data rate
    • transmitting circuitry for conveying the control signal back to the transmitter
    • multiplexer circuitry for combining the decoded channels into a stream of received data
  • Independent Claim 13 (Method):
    • detecting the transmitted signals
    • FEC decoding and de-interleaving to produce decoded channels, each having an error rate
    • using command processor circuitry responsive to the error rate to generate a data-rate control signal
    • transmitting the error rate dependent control signal back to the transmitter
    • multiplexing the decoded channels into a single stream of received data
  • The complaint also asserts dependent claims 12 and 14 and reserves the right to assert others (Compl. ¶¶ 20, 22, 56, 75).

III. The Accused Instrumentality

Product Identification

• The complaint identifies the "Fortinet FortiGate/FortiWiFi 60D-3G4G-VZW" as a representative accused product (the "Accused Product") (Compl. ¶57). Plaintiff reserves the right to add other products (Compl. ¶57, n.1).

Functionality and Market Context

• The complaint alleges the Accused Product is a wireless networking device that practices a method for recovering wireless data transmitted over sub-channels (Compl. ¶57). The infringement allegations suggest the Accused Product contains functionality to detect transmitted wireless signals, perform Forward Error Correction (FEC) decoding, and use a processor to generate and transmit a data-rate control signal back to a transmitter to manage data throughput (Compl. ¶¶ 59-62). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint references a non-included "Exhibit C" claim chart but provides a narrative infringement theory for method claim 13, which is summarized below.

’199 Patent Infringement Allegations

• Identified Points of Contention:
  • Technical Questions: A central question will be what specific technical mechanism the Accused Product uses to adapt its data rate. The complaint alleges it is "responsive to the error rate of the decoded channels," but provides no evidence to distinguish this from other common rate-adaptation triggers, such as Signal-to-Noise Ratio (SNR), Received Signal Strength Indication (RSSI), or pilot signal quality. The case may turn on whether the accused system's rate control is in fact driven by a post-decoding error rate metric.
  • Scope Questions: The complaint's allegations are conclusory, stating that the Accused Product "practices" each step without detailing how. Discovery will be needed to determine if the functions performed by the Accused Product's components map onto the specific structures and steps required by the claims.

V. Key Claim Terms for Construction

• The Term: "command processor circuitry responsive to the error rate of the decoded channels"
• Context and Importance: This phrase is the inventive core of the asserted claims. The outcome of the infringement analysis will likely depend on whether this term is construed narrowly to require direct use of a calculated bit-error or frame-error rate, or more broadly to cover systems that respond to any metric correlated with channel quality. Practitioners may focus on this term because it distinguishes the claimed invention from prior art systems that might adjust rates based on pre-decoding signal characteristics.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: Plaintiff may point to general language in the specification, such as the command processor "determines a desired-data rate" in response to a "syndrome signal," arguing "syndrome" should be read broadly to encompass any indication of channel quality that informs the desired data rate (’199 Patent, col. 2:63-65).
  • Evidence for a Narrower Interpretation: Defendant may argue that the specification consistently and specifically links this functionality to the output of an "FEC decoder." The patent states the processor "reads or is fed the syndrome from the plurality of FEC decoders" and that this syndrome is generated "from an error rate of the multiplicity of added channels" (’199 Patent, col. 8:6-9; col. 7:46-48). This suggests the "error rate" is a specific, post-decoding metric, not a general signal quality indicator.

VI. Other Allegations

• Indirect Infringement: The complaint alleges inducement by "encouraging infringement" and contributory infringement by selling the Accused Products for an infringing use, asserting they are not staple articles of commerce (Compl. ¶¶ 70-71). The factual support for these allegations is not detailed beyond the act of selling the products.
• Willful Infringement: Willfulness is alleged based on knowledge of infringement obtained "at least as of the service of the present Complaint" (Compl. ¶68). This appears to be a claim for post-filing willfulness only.

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

1. A core issue will be one of claim construction: can the phrase "responsive to the error rate of the decoded channels" be interpreted to cover modern rate adaptation algorithms that rely on general signal quality metrics like SNR, or is it limited to the specific mechanism of using a syndrome generated by an FEC decoder, as detailed in the patent’s preferred embodiment?
2. A key evidentiary question will be one of technical proof: what factual evidence can Plaintiff produce to demonstrate that the Accused Product’s rate control mechanism operates based on the specific post-decoding "error rate" required by the claims, rather than other, more common techniques for wireless rate adaptation?