PTAB

IPR2014-01134

Amazon.com Inc v. Cellular Communications Equipment LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Multicode Transmission by a Subscriber Station
  • Brief Description: The ’174 patent describes a power control method for a subscriber station in a UMTS radio communication system. The method involves determining and maintaining a "transmit power difference" (i.e., power headroom) at the start of a transmission to prevent the station from exceeding its maximum transmit power, which could otherwise lead to aborted transmissions, especially when using multiple codes simultaneously.

3. Grounds for Unpatentability

Ground 1: Anticipation by Baker - Claims 1, 6, 9, 14, 18, and 19 are anticipated by Baker.

  • Prior Art Relied Upon: Baker (Application # 2008/0151840).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Baker, which was not considered during prosecution, discloses every element of the challenged claims. Baker teaches a power control method in a UMTS system where a mobile station transmits on multiple channels (DPDCH, DPCCH, and HS-DPCCH for ACK/NACK signals) using different codes. To avoid exceeding the maximum power limit when transmitting an ACK/NACK signal, Baker’s mobile station determines the power required for the ACK/NACK transmission and reduces the power of the other channels accordingly before the ACK/NACK transmission begins. This reserved power, corresponding to the higher power requirement of either an ACK or a NACK, is the claimed "transmit power difference." Baker’s method maintains this difference between the total maximum power and the total transmit power at the start of the ACK/NACK message transmission. Petitioner contended this directly maps to the limitations of independent claims 1, 9, and 18, and that Baker’s disclosure of a microprocessor-controlled mobile station meets the limitations of dependent claims 6, 14, and 19.

Ground 2: Obviousness over Reed and Baker - Claims 1, 6, 9, 14, 18, and 19 are obvious over Reed in view of Baker.

  • Prior Art Relied Upon: Reed (Patent 7,689,239) and Baker (’840 application).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Reed teaches the core concept of determining and maintaining power headroom in a CDMA system. Reed discloses a mobile station that determines its maximum transmission power, subtracts a headroom value, and uses the remaining power to set a maximum data rate, thereby preserving the headroom. Reed also discloses that a mobile station can transmit two or more data streams simultaneously. While Reed did not explicitly state that these streams use a plurality of codes, Petitioner argued that Baker's explicit disclosure of assigning individual codes to simultaneous signals in a spread spectrum system would have been a known and obvious implementation detail to a person of ordinary skill in the art (POSITA).
    • Motivation to Combine: A POSITA would combine Reed and Baker because both address the same fundamental problem of power control and headroom management in CDMA wireless systems. Combining Reed's dynamic headroom adjustment with Baker's explicit multi-code transmission method was presented as a simple substitution of one known element (multi-code signaling from Baker) for another (multi-stream signaling in Reed) to achieve predictable results.
    • Expectation of Success: A POSITA would have had a high expectation of success because implementing Reed's headroom management on a multi-code system as taught by Baker was a well-understood design choice within the field of wireless communications.

Ground 3: Anticipation by Love - Claims 1, 6, 9, 14, 18, and 19 are anticipated by Love.

  • Prior Art Relied Upon: Love (Patent 7,321,780).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Love, also not considered during prosecution, discloses all claimed elements. Love describes a method for a mobile station in a UMTS system to determine its transmission rate for an enhanced uplink channel (EUDCH) while transmitting on multiple other channels (DPCCH, HS-DPCCH, etc.), each with its own code. Love teaches calculating the available power margin for the EUDCH by subtracting the power used by other channels from a maximum allowed power level (Pmax), which is set by the base station. This difference between the absolute physical maximum power of the mobile station and the network-defined Pmax is the claimed "transmit power difference." By selecting a data rate for the EUDCH based on this calculated power margin, the mobile station ensures the total power of all codes does not exceed Pmax, thereby maintaining the headroom at the start of the EUDCH transmission. Petitioner argued this anticipates all limitations, including those in the dependent claims, as Love discloses the mobile station performing these determinations using a processor.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge against claims 1, 6, 9, 14, 18, and 19 over Reed in view of Love, which relied on similar combination rationales as Ground 2.

4. Key Claim Construction Positions

  • "maintained": Petitioner proposed this term should be construed according to its definition in the ’174 patent's specification: "A difference between two values is maintained if the distance between the two values is greater than or equal to the difference." This construction was important to show that prior art methods reserving a minimum amount of headroom met the claim limitation.
  • "the codes": Petitioner argued this term refers to the "plurality of codes for transmitting messages" from the preamble, making the preamble limiting. This construction was central to asserting that the patent requires power calculations to account for a plurality of codes, a feature Petitioner argued was disclosed in the prior art. Petitioner noted that Patent Owner had previously asserted the claims against systems measuring power for only a single code, a position Petitioner contended was inconsistent with the claim language.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1, 6, 9, 14, 18, and 19 of the ’174 patent as unpatentable under 35 U.S.C. §§ 102 and 103.