PTAB

IPR2019-00401

Cisco Systems, Inc. v. Chrimar Systems, Inc.

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1. Case Identification

2. Patent Overview

  • Title: Ethernet Device
  • Brief Description: The ’825 patent describes an Ethernet device capable of interrogating other network equipment, including powered-off devices, over standard BaseT Ethernet cabling. The system provides phantom power and detects predetermined responses by monitoring different magnitudes in the flow of a direct current (DC) signal on the communication lines.

3. Grounds for Unpatentability

Ground 1: Claims 11, 17, 19, 24, 45, 58, and 68 are obvious over Hunter in view of Bulan.

  • Prior Art Relied Upon: Hunter (WO 96/23377) and Bulan (Patent 5,089,927).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Hunter discloses a base system for supplying phantom DC power over Ethernet cables from a hub to terminal equipment (TE) and includes a simple "protective device" against overcurrents. Bulan discloses a sophisticated current control apparatus (CCA) specifically for such phantom-powered systems. The combination involves replacing Hunter's basic protective device with Bulan's advanced CCA. This combined system can detect various current magnitudes—such as a high inrush current during TE startup, a low "trickle" current during a fault condition, and an open circuit (zero current) if a startup attempt fails—which corresponds to the ’825 patent’s claimed "predetermined response" carried by different DC signal magnitudes.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the references as a simple substitution of a known element to improve a device. Bulan's CCA is presented as a superior replacement for the "typical current limiting circuit" found in systems like Hunter's. It solves the problem of distinguishing between a genuine operational fault (e.g., a short circuit) and a normal, temporary high-current event (e.g., a DC-DC converter startup), a deficiency in Hunter's simpler thermistor-based protector.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because it is a straightforward one-for-one replacement of a protective circuit with an improved one designed for the exact same purpose and technical environment, yielding the predictable result of a more intelligent power management system.

Ground 2: Claim 24 is obvious over Hunter in view of Bulan and Erisman.

  • Prior Art Relied Upon: Hunter (WO 96/23377), Bulan (Patent 5,089,927), and Erisman (Patent 5,497,312).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds upon Ground 1 and specifically addresses the limitation in claim 24 that the predetermined response is a "pre-programmed response from a communication device." While the Hunter/Bulan combination provides the interrogating hub, Erisman provides the specific "pre-programmed" element in the TE. Erisman discloses an under-voltage lockout circuit for a DC-DC converter that is explicitly designed (i.e., pre-programmed) to present an effective open circuit by blocking current flow in response to insufficient supply voltage.
    • Motivation to Combine: A POSITA would be motivated to incorporate Erisman's under-voltage lockout circuit into the TE of the Hunter/Bulan system. Bulan teaches that the TE's DC-DC converter is designed to create an open circuit upon startup failure, and Erisman provides a well-known, pre-programmed circuit that performs this exact function, making it a suitable and obvious component for the TE.
    • Expectation of Success: The combination is a predictable implementation detail, as Erisman's circuit is designed for the high-voltage environment of Hunter's system and performs the specific function required by Bulan's detection scheme.

Ground 3: Claims 11, 17, 19, 24, 45, 58, and 68 are obvious over Bloch in view of Peguiron, IEEE-1993, and IEEE-1995.

  • Prior Art Relied Upon: Bloch (Patent 4,173,714), Peguiron (Swiss Patent No. CH 643 095 A5), IEEE-1993 (IEEE International Standard ISO/IEC 802-3: 1993), and IEEE-1995 (IEEE Standard 802.3u-1995).
  • Core Argument for this Ground:
    • Prior Art Mapping: Bloch teaches a communication system (for key telephones) that uses a "phantom circuit" to supply DC power and transmit bi-directional data signals over the same conductors. The system interrogates terminals and receives status by modulating current. The IEEE standards are cited to show the conventional nature of BaseT Ethernet, its components (e.g., MDI connectors), and signaling. Peguiron is introduced for its teaching of a more advanced, address-based interrogation protocol where a central unit can broadcast a request to a specific, addressed peripheral unit. The combination involves updating Bloch’s older phantom power concept to the modern Ethernet standard (per IEEE) and replacing its inefficient polling mechanism with Peguiron’s targeted, address-based interrogation.
    • Motivation to Combine: A POSITA would combine Bloch's power-over-data-lines concept with the ubiquitous Ethernet standard defined by IEEE. Furthermore, a POSITA would be motivated to incorporate Peguiron's address-based interrogation to improve Bloch's system. Peguiron’s method conserves bandwidth and adds flexibility compared to Bloch's time-division protocol, which is particularly beneficial in an Ethernet network where terminals may move between ports.
    • Expectation of Success: Adding Peguiron's address-recognition functionality to Bloch's system is applying a known technique to an existing device to achieve the predictable result of improved efficiency and scalability.

4. Key Claim Construction Positions

  • "powered-off": Petitioner argued for the construction "without operating power," with the key qualification that this does not preclude a small amount of power being applied to a specific component for interrogation, so long as the equipment as a whole is not operational. This is critical to arguing that devices like Hunter's TE are "powered-off" during the interrogation process.
  • "configured to interrogate" / "configured to be interrogated": Petitioner argued that these terms in the preambles of the independent claims are non-limiting. The argument is that they merely state an intended use for the claimed apparatus, and the body of the claims provides the actual structural limitations, making the preamble terms superfluous.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §314(a) and §325(d) is unwarranted. The petition is only the second filed against the ’825 patent and challenges dependent claims not previously at issue. It was filed efficiently, before the Patent Owner's Preliminary Response in the first IPR was due, and applies the same invalidity grounds to new claims. Finally, the prior art combinations presented were not considered by the USPTO during the original prosecution, meaning the Board would be the first to consider these specific invalidity arguments.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 11, 17, 19, 24, 45, 58, and 68 of Patent 9,812,825 as unpatentable.