PTAB

IPR2018-01773

Sprint Spectrum LP v. Intellectual Ventures II LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Combined Open and Closed Loop Power Control
  • Brief Description: The ’828 patent discloses a method and system for power control in wireless networks that strategically combines aspects of both open-loop and closed-loop power control schemes to overcome the respective disadvantages of each. The invention purports to enable a User Equipment (UE) to switch between a combined power control mode and a solely open-loop mode.

3. Grounds for Unpatentability

Ground 1: Obviousness over Zeira, Krishnan, and Khan

Claims 1-2, 5-6, 8-9, 12-13, 15-16, 19-20, 22-23, 26-27, 29-30, 33-34, 36-37, and 40-41 are obvious over Zeira in view of Krishnan and Khan.

  • Prior Art Relied Upon: Zeira (Patent 6,600,772), Krishnan (Patent 7,493,133), and Khan (Application # 2004/0190485).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the primary reference, Zeira, discloses the core invention: a combined open/closed loop power control system where a UE calculates transmit power based on both a path loss estimate (open-loop) and accumulated Transmit Power Control (TPC) commands (closed-loop). Petitioner contended that Krishnan teaches sending a feedback signal, such as an "enable/disable bit," to indicate whether closed-loop power control should be active, directly corresponding to the ’828 patent’s claimed "indication of whether accumulation of...TPC commands is enabled." Finally, Petitioner asserted that Khan explicitly teaches transmitting both TPC commands and scheduling grants (an "allocation of a scheduled uplink resource") on a "single physical channel" to improve efficiency, mapping to the remaining key limitation of the independent claims.
    • Motivation to Combine: A POSITA starting with Zeira’s combined power control system, which already contemplated using either solely open-loop or a combined mode, would be motivated to implement Krishnan’s explicit enable/disable signal as a predictable way to manage these modes. Zeira’s disclosure of "assigned resource units" without specifying the assignment mechanism would have motivated a POSITA to consult a reference like Khan, which addresses the same technical environment (CDMA systems) and teaches an efficient method for transmitting scheduling grants and TPC commands together on a single physical channel.
    • Expectation of Success: Petitioner argued that combining these known elements would have been straightforward. Implementing Krishnan's enable/disable bit in Zeira's system was a simple control mechanism, and applying Khan's channel multiplexing technique to Zeira's control signals was a predictable use of established functions to achieve improved efficiency.

Ground 2: Obviousness over Zeira, Krishnan, Khan, and Andersson

Claims 2, 9, 16, 23, 30, and 37 are obvious over Zeira in view of Krishnan, Khan, and Andersson.

  • Prior Art Relied Upon: Zeira (Patent 6,600,772), Krishnan (Patent 7,493,133), Khan (Application # 2004/0190485), and Andersson (Patent 6,334,047).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground adds Andersson to the combination of Ground 1 to address the dependent claims requiring a "multilevel TPC command." Petitioner argued that Andersson explicitly discloses an adaptive power control technique using variable step sizes for TPC commands, such as a typical 1 dB adjustment or a larger 8 dB adjustment to respond to changing channel conditions. This variable-size command directly teaches the claimed "multilevel TPC command."
    • Motivation to Combine: Zeira expressly contemplates that the change in power level for a TPC command, while typically 1 dB, could have "other values." Petitioner argued this disclosure would have directly motivated a POSITA to look for prior art teaching specific techniques for implementing variable TPC step sizes to gain known advantages, such as rapidly addressing fast fading. Andersson provides just such a technique, including using a flag bit to signal which step size to use, making its teachings highly compatible with and a predictable improvement upon Zeira's system.
    • Expectation of Success: Integrating Andersson’s variable step-size TPC commands into Zeira's system would be a simple and predictable modification, as it involved applying a known technique to a known system to achieve an expected benefit.

4. Key Claim Construction Positions

  • "multilevel TPC command": Petitioner proposed that this term should be construed as "a TPC command of a variable size." This construction is based on the ’828 patent’s specification, which juxtaposes a TPC command indicating a change "by a fixed amount" with the alternative use of a "multi-level TPC command." This distinction, Petitioner argued, implies that "multilevel" means the command is of a variable, rather than fixed, size.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that the Board should decline to exercise its discretion to deny institution under §325(d). Although a PCT application corresponding to Zeira and the published application for Krishnan were considered during prosecution, Petitioner contended that the Examiner never considered them in the specific combination presented in the petition. Crucially, Khan, which teaches the key "single physical channel" limitation, was cited in an IDS but never substantively applied or discussed by the Examiner in combination with Zeira and Krishnan.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-2, 5-6, 8-9, 12-13, 15-16, 19-20, 22-23, 26-27, 29-30, 33-34, 36-37, and 40-41 of the ’828 patent as unpatentable.