Comarco Wireless Systems LLC v. AT&T Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Comarco Wireless Systems LLC (Texas)
  • Defendant: AT&T Inc. (Delaware)
  • Plaintiff’s Counsel: Direction IP Law
• Case Identification: 2:25-cv-00173, E.D. Tex., 02/13/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant maintains regular and established places of business within the Eastern District of Texas.
• Core Dispute: Plaintiff alleges that Defendant’s USB chargers, power hubs, and portable batteries infringe three patents related to power supply systems that communicate with portable electronic devices to determine appropriate power levels and control battery charging.
• Technical Context: The technology addresses the need for intelligent power adapters that can safely charge a variety of portable devices from different power sources, such as wall outlets, car chargers, and airplane power ports.
• Key Procedural History: The complaint alleges that Plaintiff sent notice letters, including claim charts, to Defendant on August 1, 2023, and April 13, 2024, putting Defendant on notice of the alleged infringement prior to the lawsuit's filing, which forms the basis for willfulness allegations.

Case Timeline

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

U.S. Patent No. 9,413,187 - "Power Supply System Providing Power and Analog Data Signal for Use by Portable Electronic Device to Control Battery Charging"

• Patent Identification: U.S. Patent No. 9,413,187, “Power Supply System Providing Power and Analog Data Signal for Use by Portable Electronic Device to Control Battery Charging,” issued August 9, 2016 (Compl. ¶13).

The Invention Explained

• Problem Addressed: The patent describes the problem of portable electronic devices being damaged by receiving an incorrect power level when connected to various DC power sources, such as those in automobiles versus airplanes, which can cause batteries to overheat or catch fire (Compl. ¶10; ’187 Patent, col. 1:19-27).
• The Patented Solution: The invention is a power supply system with data circuitry that engages in a "handshake" with the portable electronic device. The power supply receives a "first signal" from the device and, in response, provides a "second signal" back to the device. This second signal is specifically an analog signal whose "parameter level" (e.g., its voltage) indicates the potential power output level of the supply system, allowing the portable device to intelligently control its own battery charging ('187 Patent, Abstract; col. 4:1-25).
• Technical Importance: This approach enables a universal charger to communicate its capabilities to a device, allowing the device to make an informed decision on how to safely draw power, thereby enhancing safety and interoperability (Compl. ¶11).

Key Claims at a Glance

• The complaint asserts independent claim 8 and dependent claim 9 (Compl. ¶17).
• Essential elements of independent claim 8 include:
  • A power supply system external to a portable electronic device, comprising power circuitry to provide DC power.
  • Data circuitry configured to receive a first signal from the portable device and provide a second signal to the portable device.
  • A connector on a cable end with four conductors for transferring DC power, ground, the first signal from the device, and the second signal to the device.
  • Wherein the data circuitry provides the second signal in response to the first, with the second signal being an analog signal having a parameter level that indicates the potential power output level of the power supply system.

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U.S. Patent No. 10,855,087 - "Power Supply Systems"

• Patent Identification: U.S. Patent No. 10,855,087, “Power Supply Systems,” issued December 1, 2020 (Compl. ¶14).

The Invention Explained

• Problem Addressed: The patent background describes the risk that arises when a user connects a single DC/DC adapter to different power environments, such as an automobile outlet versus an airplane's EMPOWER system. A user might forget to change the connector type, leading to the device improperly attempting to charge its battery from a source not intended for charging, which could cause damage or fire (’087 Patent, col. 1:56-2:10).
• The Patented Solution: The patented system includes a power supply with comparison circuitry that automatically determines the nature of the connected DC power source (e.g., by comparing its voltage to a predefined reference value). Based on this determination, the power supply sends a signal to the portable electronic device, which can then enable or disable its own battery charging functions accordingly, removing the potential for user error (’087 Patent, Abstract; col. 3:37-48).
• Technical Importance: This invention automates the safety decision-making process within the power adapter itself, making charging systems more robust and less reliant on user action to prevent damage (Compl. ¶11).

Key Claims at a Glance

• The complaint asserts independent claim 1, as well as claims 5-7, 11, and 15-17 (Compl. ¶37).
• Essential elements of independent claim 1 include:
  • A power supply system with power circuitry to provide direct current power.
  • Data circuitry configured to receive a first signal from a portable electronic device and to provide a second signal to be sent to the device.
  • The circuitry is coupled to the device via a connector with first, second, third, and fourth conductors for transferring power, ground, the first signal, and the second signal, respectively.
  • Wherein the data circuitry, in coordination with the first signal, provides the second signal, which has a parameter level that is usable by the portable device to control the charging of its battery.

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U.S. Patent No. 10,951,042 - "Power Supply Systems"

• Patent Identification: U.S. Patent No. 10,951,042, “Power Supply Systems,” issued March 16, 2021 (Compl. ¶15).
• Technology Synopsis: This patent claims the invention from the perspective of the portable electronic device itself. It describes a portable device containing a rechargeable battery and circuitry configured to engage in a four-conductor communication handshake: it provides a first signal to an external power supply and receives a second signal back, using the parameter level of that second signal to control its own battery charging based on the power it receives (’042 Patent, Abstract; col. 11:2-25).
• Asserted Claims: Independent claims 1 and 11, as well as claims 5-6 and 15-16 (Compl. ¶52).
• Accused Features: The complaint accuses the "AT&T 10K Power Delivery Portable Battery with USB-C In/Out + USB-A Out" of infringing this patent (Compl. ¶52).

III. The Accused Instrumentality

Product Identification

• The accused instrumentalities are a range of AT&T-branded power accessories, including the AT&T Multi Port 72W Power Delivery Power Hub, various Dual Port Power Delivery Car and Wall Chargers, and the AT&T 10K Power Delivery Portable Battery (Compl. ¶17, ¶37, ¶52).

Functionality and Market Context

• The complaint alleges these products function as external power supplies that provide DC power to portable electronic devices (Compl. ¶19, ¶40). Their accused functionality is grounded in their alleged compliance with industry standards such as USB Battery Charging (BC) 1.2 and USB Power Delivery (PD) (Compl. ¶19, ¶39). These standards allegedly implement a communication protocol where the charger and the device exchange signals over data lines (e.g., D+/D- or CC pins in a USB connector) to negotiate and control the delivery of power (Compl. ¶21, ¶28, ¶41). The complaint includes a screenshot of the AT&T USB Power Hub 72W product page, which lists "3 USB-C ports and 1 USB-A port" as features (Compl. p. 59). These are consumer electronics products marketed for charging devices like laptops, phones, and tablets (Compl. p. 7, p. 59).

IV. Analysis of Infringement Allegations

The complaint alleges infringement based on the accused products' compliance with USB standards. The diagram from the USB specification included in the complaint shows different power levels associated with standards like USB BC 1.2 and USB Power Delivery (Compl. p. 13).

U.S. Patent No. 9,413,187 Infringement Allegations

U.S. Patent No. 10,855,087 Infringement Allegations

Identified Points of Contention

• Scope Questions: A central question for the '187 patent may be whether the signaling described in the USB BC 1.2 standard, as depicted in the complaint's diagram (Compl. p. 14), constitutes an "analog signal having a parameter level to indicate...the potential power output level." An analysis may focus on whether this signaling conveys multiple potential power levels, as the patent language suggests, or if it functions as a more binary enable/disable signal. For the '087 patent, a scope question arises from mapping the "third" and "fourth" conductors to the CC1 and Vconn pins of the USB-C standard; the inquiry may be whether the Vconn signal's primary function (powering cable electronics) can be construed as the claimed "second signal" for controlling charging in the device.
• Technical Questions: The complaint frequently invokes the doctrine of equivalents for the '187 patent, arguing that the D- signal, even if a modified version of a signal originating in the portable device, performs the same function (Compl. ¶21, ¶23). This raises the question of whether the accused data circuitry "provides" a signal in the manner required by the claim or merely modifies and passes through a signal. For the '087 patent, the complaint's theory is that the Vconn signal "enables the SOP* communication that controls" charging (Compl. ¶46, ¶67). This presents an evidentiary question: does the Vconn signal itself contain a "parameter level" usable for control, or does it merely power the circuitry that conducts a separate control communication?

V. Key Claim Terms for Construction

Claim Term: "an analog signal having a parameter level" ('187 Patent, Claim 8)

• Context and Importance: This term is critical to the infringement theory against products compliant with the USB BC 1.2 standard. The case may turn on whether the voltage detection on the D- line, as described in the complaint, meets this definition. Practitioners may focus on this term because the accused functionality involves comparing a voltage to a threshold, which could be argued as a binary-like decision rather than the communication of a variable "parameter level" indicating a range of potential power outputs.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification states that the data signal may be used to "set the magnitude of V.sub.out and limit the amount of current which may be drawn" (’187 Patent, col. 3:12-14), which could support interpreting any voltage level used for control as a "parameter level."
  • Evidence for a Narrower Interpretation: The claim requires the parameter level "to indicate...the potential power output level." This language may support a narrower construction requiring the signal to communicate specific information about what power levels (e.g., 5W, 7.5W, 10W) are available, not just whether charging is permitted.

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Claim Term: "second signal having a parameter level that is usable by the portable electronic device in connection with control of charging" (’087 Patent, Claim 1)

• Context and Importance: Plaintiff maps this term to the Vconn signal in the USB-PD standard. The viability of this infringement theory depends on whether a signal that enables a separate communication protocol (SOP*) can itself be considered "usable...in connection with control of charging." Practitioners may focus on this term to dispute the causal link between the Vconn signal and the ultimate control of charging.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim requires the data circuitry to act "in coordination with the first signal" to provide the second signal (’087 Patent, col. 11:18-19). The phrase "in connection with" could be argued to be broad enough to cover a signal that is an essential prerequisite for the control communications to occur.
  • Evidence for a Narrower Interpretation: The specification describes a "V.sub.data signal" being "received by control circuitry of an electronic device" to disable or enable charging (’087 Patent, col. 3:45-48). This could support a narrower reading where the "second signal" itself must directly convey the control-related information, rather than merely enabling a different communication channel.

VI. Other Allegations

Indirect Infringement

• The complaint alleges both induced and contributory infringement for all three patents. The allegations are based on Defendant providing the accused chargers to its customers with instructions and advertisements for their infringing use (i.e., charging portable electronics) after allegedly gaining knowledge of the patents from pre-suit notice letters (Compl. ¶32-34, ¶47-49, ¶60-62).

Willful Infringement

• The complaint alleges willful infringement for all three patents. The basis for this claim is Defendant's alleged continued infringement after receiving notice of the patents and infringement contentions, including claim charts, in letters dated August 1, 2023, and April 13, 2024 (Compl. ¶35, ¶50, ¶63).

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

• A core issue will be one of technical mapping: can the claimed elements of a four-conductor communication system—specifically a "first signal" from a device and a responsive "second signal" from a power supply—be mapped onto the complex, multi-stage signaling protocols of industry standards like USB BC 1.2 and USB Power Delivery, or is there a fundamental mismatch between the patent's disclosure and the operation of the accused standards?
• A second key issue will be one of definitional scope: can the term "analog signal having a parameter level to indicate...power output" be construed to cover a voltage comparison against a single threshold as in BC 1.2? Similarly, can a signal that powers cable electronics (Vconn) be construed as a "signal...usable...in connection with control of charging" a device under the USB-PD standard?
• Finally, a central question will be one of objective recklessness: assuming infringement is found, did Defendant's alleged continuation of selling the accused products after receiving two detailed notice letters with claim charts constitute behavior rising to the level of willful infringement, warranting enhanced damages?