Apple Inc v. Invt SPE Inc

1. Case Identification

• Case #: IPR2018-01473
• Patent #: 6,611,676
• Filed: August 21, 2018
• Petitioner(s): Apple Inc., HTC Corporation and HTC America, Inc., ZTE(USA) Inc.
• Patent Owner(s): Invt SPE LLC
• Challenged Claims: 1-11

2. Patent Overview

• Title: Communication Terminal Apparatus and Transmission Rate Control Method
• Brief Description: The ’676 patent describes a communication terminal apparatus for a Code Division Multiple Access (CDMA) system. The invention focuses on controlling transmission power and switching the transmission rate based on reception quality information to improve communication quality without causing excessive interference to other users.

3. Grounds for Unpatentability

Ground 1: Obviousness over Keskitalo and Lindell - Claims 1-3, 5-9, and 11 are obvious over Keskitalo in view of Lindell.

• Prior Art Relied Upon: Keskitalo (International Publication No. WO 95/10145) and Lindell (Patent 5,524,275).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Keskitalo taught a CDMA system where a mobile station adjusts transmission power based on control signals and can also alter its transmission rate by changing the "spreading ratio" when signal quality deteriorates, particularly when transmit power is already at its maximum. This was alleged to disclose most limitations of independent claims 1, 6, and 7, including a means for changing the transmission rate to improve connection quality without increasing interference. However, Keskitalo did not explicitly teach calculating an average transmission power and comparing it to a predetermined allowable value. Petitioner asserted that Lindell supplied these missing elements. Lindell described a radio transmitter power controller that uses an "average power determining circuit," such as an integrator, to calculate the average power over a period and compares this average to a predetermined threshold to automatically reduce power. The combination of Keskitalo's rate-switching system with Lindell's average power monitoring allegedly rendered the claims obvious.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine these references to improve upon Keskitalo's power control mechanism. While Keskitalo recognized the need for a maximum power limit, Lindell provided a known and superior method for implementing such a limit by using average power. This approach was not only useful for managing interference, as in Keskitalo, but also for complying with regulatory guidelines on RF exposure and conserving battery power, which are based on power levels over time. A POSITA would thus have been motivated to incorporate Lindell's well-understood average power monitoring and control into Keskitalo's system to gain these known benefits.
  • Expectation of Success: The proposed modification was described as straightforward, requiring only a slight circuit or software modification to implement Lindell’s integrator circuit and comparator into the Keskitalo system. The result—a system that adjusts transmission rate when a maximum average power threshold is reached—was argued to be entirely predictable.

Ground 2: Obviousness over Keskitalo, Lindell, and Tiedemann - Claims 4 and 10 are obvious over Keskitalo in view of Lindell and further in view of Tiedemann.

• Prior Art Relied Upon: Keskitalo (WO 95/10145), Lindell (Patent 5,524,275), and Tiedemann (Patent 5,822,318).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addressed the additional limitations of claims 4 and 10, which require the system to not only decrease the transmission rate when average power reaches the allowable maximum but also to increase the transmission rate when the channel recovers and the average power is sufficiently below the maximum. The Keskitalo/Lindell combination taught the rate decrease. Petitioner contended that Tiedemann taught the inverse, rate-increasing functionality. Tiedemann explicitly disclosed a variable-rate CDMA system that decreases the data rate when the mobile station's power is at maximum but also "increases" the data rate when the power is detected to be "lower than a threshold."
  • Motivation to Combine: Petitioner argued it would be a matter of common sense for a POSITA to implement a bidirectional rate adjustment mechanism. A system that could only decrease its transmission rate in response to poor channel conditions but could never restore the higher rate when conditions improved would operate inefficiently and be commercially impractical. Tiedemann provided a clear, express teaching for implementing this necessary, symmetrical functionality. A POSITA, seeking to build a robust and functional version of the Keskitalo/Lindell system, would have naturally included the rate-increase feature taught by Tiedemann to allow the system to adapt dynamically to changing channel conditions.
  • Expectation of Success: Adding the rate-increase capability was presented as a predictable and necessary improvement to create a properly functioning communication system. The combination was straightforward and would not have required undue experimentation.

4. Key Claim Construction Positions

• Petitioner argued that several terms in claim 1 should be construed as means-plus-function limitations under 35 U.S.C. §112, ¶ 6, and identified corresponding structures from the ’676 patent’s specification. These constructions were central to mapping the prior art.
  • "means for increasing or decreasing transmission power...": The corresponding structure was identified as a "Transmission RF circuit 109" programmed or designed to control power based on a control signal.
  • "means for calculating an average value of the transmission power...": The corresponding structure was identified as a "processor or other circuitry" programmed to monitor and calculate the average transmission power (Pave).
  • "means for comparing the average value with the allowable transmission power value": The corresponding structure was identified as a "processor or other circuitry" programmed to perform the comparison and determine if the average power exceeds the allowable power.
  • "means for changing a transmission rate...": The corresponding structure was identified as a "processor or other circuitry" in the medium access control layer (layer 2) programmed to lower or increase the transmission rate based on the comparison result.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-11 of Patent 6,611,676 as unpatentable.