PTAB

IPR2025-00493

Samsung Electronics Co Ltd v. Four Batons Wireless LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Methods for improving handoff of a mobile device.
  • Brief Description: The ’348 patent discloses a "Silent Proactive Handoff" method where a mobile device uses "silent periods" of an application (i.e., periods of low or no data traffic) to temporarily connect to a target network and perform handoff actions, such as authentication, before a full handoff is needed.

3. Grounds for Unpatentability

Ground 1: Obviousness over Hsu - Claims 1-8 and 13-15 are obvious over Hsu.

  • Prior Art Relied Upon: Hsu (Application # 2004/0165563).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hsu discloses all limitations of the independent claims. Hsu teaches a mobile device with an active packet data session on a cellular network that waits for the session to become "idle" (the claimed "silent period") before tuning away to scan for a WLAN (a "target network"). Petitioner contended this scanning, along with subsequent authentication and Mobile IP registration described by Hsu, constitutes performing a "handoff action" "proactively" because it is based on factors other than the degradation of the current network connection. This process occurs while the device is still using the current network, which satisfies the mobile device's requirements.
    • Motivation to Combine (for §103 grounds): Not applicable (single reference).
    • Expectation of Success (for §103 grounds): Not applicable (single reference).

Ground 2: Obviousness over Hsu and Hutchison - Claims 10, 11, 20, and 21 are obvious over Hsu in view of Hutchison.

  • Prior Art Relied Upon: Hsu (Application # 2004/0165563) and Hutchison (Application # 2004/0198302).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Hsu teaches the foundational proactive handoff method during idle periods but does not explicitly teach monitoring traffic to predict those periods. Hutchison remedies this by disclosing a technique for timer-based sleep to save battery life, which involves monitoring the "time since last activity" (the claimed "monitoring of time periods") and using a "usage modeling" function (the claimed "prediction model") to estimate the probability of future data traffic and determine an appropriate sleep duration. Petitioner argued this sleep duration is an "actionable silent period."
    • Motivation to Combine (for §103 grounds): A POSITA would combine Hutchison's power-saving techniques with Hsu's handoff system to improve efficiency. Hsu expressed a desire to "maximize a sleep mode," providing a clear reason to incorporate Hutchison's advanced method for predicting idle periods. This combination applies a known technique (predictive sleep) to a known system (proactive handoff) to achieve the predictable result of improved power management.
    • Expectation of Success: A POSITA would have a high expectation of success, as both references operate in the same technical field of managing connectivity and power states for mobile devices in wireless networks.

Ground 3: Obviousness over Hsu and Shoaib - Claims 16 and 17 are obvious over Hsu in view of Shoaib.

  • Prior Art Relied Upon: Hsu (Application # 2004/0165563) and Shoaib (Application # 2003/0193910).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground built upon the teachings of Hsu by adding a specific handoff criterion from Shoaib. Claim 16 requires that after starting a handoff action, the device switches back to the current network if that network continues to satisfy its requirements. While Hsu taught using various criteria to initiate a handoff, Shoaib explicitly disclosed evaluating "local signal criteria" of the current network to determine if its signal strength is satisfactory. Petitioner argued that this teaching from Shoaib directly maps to the limitation of checking the current network's status and switching back if it remains adequate.
    • Motivation to Combine (for §103 grounds): Hsu's disclosure of handoff criteria was open-ended, which Petitioner argued would have prompted a POSITA to consult other references like Shoaib for additional, well-known criteria. Incorporating a check on the current network's quality, as taught by Shoaib, would be an obvious way to improve the robustness of Hsu's handoff logic and avoid unnecessary network switching, a predictable improvement.
    • Expectation of Success: Success would be expected, as combining decision-making criteria from two network handoff systems is a straightforward design choice for a POSITA.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 4) for claims 18 and 19 based on Hsu in view of Ivanov (Patent 5,457,810), which introduced using the mobile station's speed to estimate the time it will be within a candidate network as a criterion for determining whether to perform a proactive handoff.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under Fintiv would be inappropriate. The parallel district court trial date is only five months before the statutory deadline for a Final Written Decision (FWD), a gap Petitioner contended is not determinative.
  • Investment in the parallel proceeding was characterized as low, with the case in its early stages.
  • Petitioner emphasized an incomplete overlap of issues, as the IPR challenges claims (e.g., 18-21) not asserted in the district court litigation, arguing that denial would leave these claims unaddressed.
  • Petitioner also argued that denial under §325(d) is unwarranted because the prior art references asserted in the petition were not previously considered by the USPTO during prosecution.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-8, 10-11, and 13-21 of the ’348 patent as unpatentable under 35 U.S.C. §103.