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

1. Case Identification

• Patent #: 8,902,760
• Filed: August 3, 2018
• Petitioner(s): Cisco Systems, Inc.
• Patent Owner(s): ChriMar Systems, Inc.
• Challenged Claims: 73, 106, 112, 134, 142, 145, and 146

2. Patent Overview

• Title: Network System and Optional Tethers
• Brief Description: The ’760 patent is directed to systems for equipment networked over pre-existing wiring, such as Ethernet cables. The technology focuses on using the same wire pairs for both data communication and for supplying DC power (a technique known as "phantom powering") to detect and identify network-connected devices.

3. Grounds for Unpatentability

Ground 1: Claims 73, 106, 112, 134, 142, and 145 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 argued that Hunter disclosed a BaseT Ethernet system that supplied DC "phantom power" from a central hub to remote terminal equipment (TE) over twisted-pair conductors. Hunter’s system used a simple protective device (e.g., a thermistor) to prevent overcurrents. The combination replaced Hunter’s simple device with the more sophisticated "current control apparatus" (CCA) from Bulan. Bulan’s CCA was designed to detect and distinguish between different current magnitudes, such as a normal startup inrush from a DC-DC converter versus a fault condition like a short circuit, and to respond accordingly. The petition asserted that this combination taught every limitation of independent claim 73, including the "BaseT Ethernet hub" element added during re-examination, which was explicitly disclosed by Hunter. Dependent claims were met because the combined system inherently included a controller in the TE (claim 106), used current magnitudes to represent information (claim 112), employed a detection protocol (claim 134), could distinguish TE states (claim 142), and operated while the TE was "powered-off" (claim 145), as the detection occurs before the TE's DC-DC converter fully starts.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine these references because Bulan explicitly criticized simple protective circuits used in phantom power systems (like Hunter's) and taught its CCA as a superior, direct replacement. The motivation was to improve a known device (Hunter's system) with a known technique (Bulan's intelligent current limiting) to achieve a predictable result: a more robust phantom power system that could safely manage power-up sequences and faults.
  • Expectation of Success: Petitioner contended a POSITA would have had a high expectation of success because Bulan’s CCA was intended to be a one-for-one substitute for existing current-limiting circuits, making the integration into Hunter’s system straightforward.

Ground 2: Claim 146 is obvious over Hunter in view of Bulan, further in combination with Nelson.

• Prior Art Relied Upon: Hunter (WO 96/23377), Bulan (Patent 5,089,927), and Nelson (Patent 4,823,070).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built on the Hunter/Bulan combination to challenge claim 146. The key limitation in claim 146[e] required the TE to have a path to "change impedance" in response to a DC condition. While the Hunter/Bulan combination implied a DC-DC converter in the TE, Nelson was added to explicitly disclose the standard operation of such a converter. Nelson taught that a switching voltage regulator (a necessary component of a DC-DC converter) inherently changes its impedance by switching elements in and out of a circuit to regulate an unregulated input voltage (the "DC condition" from the phantom power) into a constant output voltage.
  • Motivation to Combine: The motivation to combine Hunter/Bulan with Nelson was strong, as a POSITA implementing the phantom-powered TE would necessarily require a DC-DC converter to create usable operating voltages. Nelson disclosed a conventional, well-known switching voltage regulator circuit that was a suitable and obvious choice for this purpose.
  • Expectation of Success: Success was expected because combining a standard voltage regulator (Nelson) into a phantom-powered device (Hunter/Bulan) was a routine design task for a POSITA.

Ground 3: Claim 146 is obvious over Bloch in view of IEEE 802.3 and Peguiron.

• Prior Art Relied Upon: Bloch (Patent 4,173,714), IEEE 802.3 (1993 and 1995 standards), and Peguiron (CH 643 095 A5).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground presented an alternative invalidity theory. Petitioner argued Bloch taught a general communication system (e.g., a telephone system) using a "phantom circuit" to supply power and send data signals over the same four conductors. The IEEE 802.3 standard was cited to provide the specific context of a BaseT Ethernet network, including hubs, DTEs (Data Terminal Equipment), and standard cabling, which a POSITA would use to implement Bloch's teachings. Peguiron was added to teach an interrogation protocol where a central unit sends an addressed signal to a specific peripheral, which then responds. This combination allegedly met claim 146 because Bloch’s terminal changes impedance to send signals, and in the combined system, this would occur in response to a DC condition (either the phantom power itself or an interrogation signal from the central unit as taught by Peguiron).
  • Motivation to Combine: A POSITA would be motivated to combine Bloch with IEEE 802.3 to apply the known benefits of phantom powering to a standard Ethernet network, eliminating the need for separate power supplies. Peguiron would be added to improve Bloch's signaling protocol by making it addressable and more bandwidth-efficient—a known design goal—allowing a central hub to query specific devices without requiring all devices to transmit periodically.
  • Expectation of Success: The combination was presented as an application of known techniques to a known system to achieve predictable results. Integrating Peguiron’s address-recognition functionality into Bloch’s system was framed as a simple substitution of one signaling method for an improved one.

4. Key Claim Construction Positions

• "BaseT": Petitioner proposed this term be construed as "twisted pair Ethernet in accordance with the 10Base-T or 100Base-T standards." This construction grounded the claims in well-known industry standards disclosed by the prior art.
• "wherein at least one of the different magnitudes of current flow through the loop is part of a detection protocol": Petitioner proposed this phrase means "an intended use of the different magnitudes of current flow...for detecting current/impedance or a change in current/impedance." This construction was argued to be consistent with the Board's prior interpretations and was broad enough to encompass the fault/startup detection functionality of the Bulan reference.
• "powered off": Petitioner proposed this term means "without operating power," but clarified this does not preclude applying power to a component of the network equipment (e.g., a remote module for asset tracking) even if the main equipment is not operating. This construction was crucial for mapping prior art to claim 145, as detection occurs before the TE's DC-DC converter has started and can supply operating power.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §314(a) and §325(d) was inappropriate. The core argument was that this IPR presented the Board with its first opportunity to review the challenged claims, which were amended during an ex parte re-examination. A prior IPR (the "Juniper IPR") found related original claims unpatentable over similar art, but the Board was unable to rule on the amended claims because they did not exist at the time that petition was filed. Petitioner asserted that this IPR would be an efficient use of Board resources, as it asks the Board to apply its prior analysis from the Juniper IPR to the new, but highly similar, amended claims.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 73, 106, 112, 134, 142, 145, and 146 of the ’760 patent as unpatentable.