PTAB

IPR2020-01071

Cradlepoint Inc v. Sisvel Intl SA

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Cell Reselection Signalling Method
  • Brief Description: The ’196 patent discloses a method for managing cellular network connection attempts, particularly during congestion. The core concept is sending a connection rejection message from the network to a mobile device that includes frequency-related parameters, which directs the device to attempt a new connection on a different frequency or channel to alleviate congestion.

3. Grounds for Unpatentability

Ground 1: Anticipation by Kallin - Claims 1, 4, 14, and 18 are anticipated by Kallin under 35 U.S.C. §102.

  • Prior Art Relied Upon: Kallin (Patent 5,287,545).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Kallin, which relates to 1G cellular systems, discloses all limitations of the independent claims. Kallin teaches a "directed retry message" sent during network congestion that includes multiple frequency parameters ("CHANPOS") for neighboring cells. The mobile station receives this message, which functionally rejects its initial connection attempt, and uses the included frequency parameters to select the strongest channel and reattempt connection. This process was asserted to map directly to the claimed apparatus receiving a rejection message with a parameter and using it to set a new reception frequency and select a new channel.
    • Key Aspects: The petition asserted that Kallin's "directed retry message" is analogous to the claimed "connection rejection message," and its explicit inclusion of frequency parameters for redirection anticipates the core inventive concept.

Ground 2: Obviousness over Ericsson Alone - Claims 1, 2, 4, 13, 14, and 18 are obvious over Ericsson under 35 U.S.C. §103.

  • Prior Art Relied Upon: Ericsson (3GPP document TSGR2#6(99)813).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Ericsson, a 3GPP standards contribution document, describes the Radio Resource Control (RRC) protocol, including an RRC CONNECTION REJECT message. Crucially, Ericsson explicitly teaches that any RRC message received by the User Equipment (UE) can include various Information Elements (IEs), one of which is "Frequency info." Ericsson further specifies that when a UE receives this IE, it "shall perform" the action of storing and tuning to that frequency.
    • Motivation to Combine (within a single reference): A POSITA would be motivated to include the optional "Frequency info" IE within the existing RRC CONNECTION REJECT message. This would be a simple modification to improve network efficiency by quickly redirecting a UE during connection failure, thus reducing bandwidth consumption and the time required to establish a connection, thereby improving the user experience.
    • Expectation of Success: Success would be highly expected, as it involved implementing a disclosed optional feature (the "Frequency info" IE) in a specified message type (RRC CONNECTION REJECT) to achieve its intended and predictable result (tuning to a new frequency).
    • Key Aspects: Petitioner contended that the patent examiner erred during prosecution by concluding Ericsson was "silent on sending a frequency parameter," thereby overlooking the express teaching that "Frequency info" could be included in any RRC message.

Ground 3: Obviousness over TS 25.331 in view of Kallin or Kissee - Claims 1, 2, 4, 13, 14, and 18 are obvious over TS 25.331v.3.1.0 in view of Kallin or Kissee.

  • Prior Art Relied Upon: TS 25.331v.3.1.0 (3GPP Technical Specification), Kallin (Patent 5,287,545), and Kissee (Patent 6,567,665).
  • Core Argument for this Ground:
    • Prior Art Mapping: TS 25.331, the foundational 3GPP standard for the RRC protocol, discloses an RRC CONNECTION REJECT message but does not require it to contain frequency redirection information. Kallin (1G systems) and Kissee (2G systems) both teach sending frequency or channel information in their analogous "directed retry" messages to redirect a mobile station when a connection is rejected due to congestion.
    • Motivation to Combine: A POSITA developing the 3G system defined in TS 25.331 would look to established practices in prior 1G and 2G systems for handling network congestion. Seeing the well-known and effective technique of using rejection messages to efficiently redirect mobile stations (as taught by Kallin/Kissee), a POSITA would be motivated to add similar frequency information to the RRC CONNECTION REJECT message in TS 25.331 to improve connection speed and reduce network signaling.
    • Expectation of Success: A POSITA would have a high expectation of success, as the combination involved applying a known technique (redirecting with frequency info in a rejection message) from older cellular systems to the then-current 3G standard to achieve the same predictable benefits of faster and more efficient connection reattempts.
  • Additional Grounds: Petitioner asserted numerous additional challenges, including anticipation by C.S0005 (a cdma2000 standard) and various obviousness combinations adding Birgerson (for a SIM card) and Applicant's Admitted Prior Art (for dual/multimode capabilities) to the primary references.

4. Key Claim Construction Positions

  • "apparatus": Petitioner argued this term, found in the preamble of all challenged claims, should be given its plain and ordinary meaning and is not a means-plus-function term. In the alternative, if construed as means-plus-function, the corresponding structure is a "mobile station."
  • "RRC CONNECTION REJECT message": Petitioner proposed construing this term as defined in the 3GPP standard TS 25.331v.3.1.0, which was the version available at the patent's earliest priority date and describes the relevant RRC protocol.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued against discretionary denial under §325(d) by asserting that its grounds were not cumulative to those considered during prosecution. It contended that the examiner never considered the primary prior art references of Kallin (1G system), Kissee (2G system), or C.S0005 (a competing 3G cdma2000 standard).
  • For the Ericsson reference, which was considered during prosecution, Petitioner argued that the examiner made a clear error by failing to appreciate its teaching that "Frequency info" could be included in any RRC message. Petitioner asserted that this alleged error, combined with new expert testimony, presents the reference in a new light, warranting institution.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1, 2, 4, and 13-18 of Patent 8,364,196 as unpatentable.