Mercedes-Benz USA, LLC v. Carucel Investments, LP

1. Case Identification

• Case #: IPR2019-01442
• Patent #: Patent 7,848,701
• Filed: July 31, 2019
• Petitioner(s): Mercedes-Benz USA, LLC
• Patent Owner(s): Carucel Investments, L.P.
• Challenged Claims: 10, 15-18, 31, 33-35

2. Patent Overview

• Title: Mobile Communication System With Moving Base Station
• Brief Description: The ’701 patent describes a system to address the cellular "handoff problem" by using movable base stations that act as intermediaries between a mobile unit (e.g., a phone in a vehicle) and the fixed cellular network. By moving along with traffic, these base stations remain in range of the mobile unit for longer periods, reducing the number of handoffs required and purportedly improving connection stability.

3. Grounds for Unpatentability

Ground 1: Obviousness over Gilhousen761, Gilhousen501, and Adachi - Claims 10 and 17 are obvious over Gilhousen761 in view of Gilhousen501 and Adachi.

• Prior Art Relied Upon: Gilhousen761 (Patent 5,519,761), Gilhousen501 (Patent 5,101,501), and Adachi (Patent 5,652,765).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Gilhousen761 discloses an airborne mobile base station (an aircraft) that uses CDMA technology to communicate with ground stations, satisfying the "movable base station" limitation of claim 10. The combination with Gilhousen501, by the same inventor, introduces the concept of "soft handoff" and a controller that compares signal strengths to select the strongest signal, which maps to the controller functions of aligning and combining signals. Adachi was argued to supply the claimed "plurality of spatially separated antennas" to mitigate multipath fading. Claim 17, which requires the base station be conveyed by a vehicle, was asserted to be met by Gilhousen761's aircraft.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Gilhousen761 and Gilhousen501 because they address the same field of CDMA communications in mobile environments and are from the same inventor, with Gilhousen501 offering a known improvement (soft handoff) to the base technology used in Gilhousen761. A POSITA would further incorporate Adachi's well-understood use of spatially separated antennas as a standard solution to mitigate the known problem of multipath fading in any mobile wireless system, including the airborne system of Gilhousen761.
  • Expectation of Success: Petitioner asserted a POSITA would have had a high expectation of success, as the combination involved applying known improvements (soft handoff, antenna diversity) to solve well-understood problems (handoff reliability, signal fading) within the same technological field (CDMA).

Ground 2: Obviousness over Ito, Gilhousen501, and Adachi - Claims 10, 16-18, 31, and 34-35 are obvious over Ito in view of Gilhousen501 and Adachi.

• Prior Art Relied Upon: Ito (Patent 5,276,686), Gilhousen501 (Patent 5,101,501), and Adachi (Patent 5,652,765).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Ito discloses a "mobile base device" installed in a car that serves as an intermediary between a user's handset and a fixed cellular network, meeting the core limitations of a movable base station. However, Ito uses an FDMA/TDMA protocol. The combination replaces Ito's protocol with the superior CDMA "soft-handoff" techniques from Gilhousen501, which provides the controller for aligning, combining, and selecting signals. Adachi again provides the spatially separated antennas. This combination was argued to render claims 10, 17, and 18 obvious. Ito's disclosure of using time slots in its TDMA system was argued to teach the limitation of claim 16.
  • Motivation to Combine: A POSITA would have been motivated to replace the older FDMA technology in Ito with the superior CDMA technology from Gilhousen501 to improve call quality, reduce dropped calls, and increase system capacity, consistent with industry trends at the time. The motivation to add Adachi's antennas was to gain the known benefits of antenna diversity to combat signal fading, which would enhance the performance of the improved Ito-Gilhousen501 system.
  • Expectation of Success: Success would be expected and the result predictable, as it involved substituting a known, superior technology (CDMA) for an older one (FDMA) and adding a standard component (diversity antennas) to achieve their well-known benefits.

Ground 3: Obviousness over Ito and Jakes - Claims 10, 15-18, 31, and 33-35 are obvious over Ito in view of Jakes.

• Prior Art Relied Upon: Ito (Patent 5,276,686) and Jakes (a 1971 IEEE publication on space diversity).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground argued for modifying Ito's mobile base device by incorporating the teachings of Jakes. Jakes explicitly teaches using a plurality of spatially separated antennas on a mobile unit to improve performance and combat multipath fading by either selecting the best signal or combining signals. Petitioner asserted this combination directly teaches a movable base station (from Ito) with a plurality of antennas and a controller that can align, combine, and/or select the best signal (from Jakes).
  • Motivation to Combine: Jakes provides an explicit motivation, teaching that mobile communication systems like Ito's can achieve significant performance improvements and combat signal fading by employing space diversity with multiple antennas. A POSITA would have been directly motivated to apply the fundamental techniques from Jakes to improve the reliability of the system disclosed in Ito.
  • Expectation of Success: Petitioner argued for a high expectation of success because implementing antenna diversity as taught by Jakes was a well-known, routine design choice for improving mobile communication systems at the time of the invention.

4. Key Claim Construction Positions

• Petitioner asserted that for the purposes of the IPR, it adopted the claim constructions used by the Patent Owner in related district court litigation. Key constructions included:
  • "fixed port": "a stationary device at which signals can enter or exit a communication network."
  • "base station": "a fixed device a mobile radio transceiver... talks to... to get to the landline phone network."
• Petitioner argued that based on these constructions, a standard cellular base station in the prior art satisfies the limitations for both a "fixed port" and a "base station."
• For the term "configured to move relative to Earth," Petitioner adopted the Patent Owner's litigation position that this is met when a movable base station is installed in a vehicle, and applied this broad interpretation to the prior art vehicles disclosed in Gilhousen761 and Ito.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §325(d) or §314(a) would be inappropriate.
• It contended that this petition was not a "serial" petition because Mercedes-Benz USA, LLC had not previously filed against the ’701 patent.
• Petitioner further argued it did not have a "significant relationship" with other petitioners (like Volkswagen Group of America) who had filed separate IPRs against the patent family. It noted that the Patent Owner filed separate district court actions against each automaker for different accused products and that the grounds asserted in this petition were substantively different from those in the other IPRs.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 10, 15-18, 31, and 33-35 of Patent 7,848,701 as unpatentable.