PTAB

IPR2025-00496

Samsung Electronics Co Ltd v. Four Batons Wireless LLC

Log In
Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Substantially Real-Time Comparison of Quality of Interfaces by Mobile Devices
  • Brief Description: The ’006 patent discloses methods for a mobile device with multiple network interfaces (e.g., cellular and Wi-Fi) to compare the quality of these heterogeneous networks in substantially real-time. The device uses statistical tests on path quality metrics to determine whether to switch from a current interface to an alternative one to improve communication performance.

3. Grounds for Unpatentability

Ground 1: Obviousness over Guo and Neave - Claims 1-13 and 16 are obvious over Guo in view of Neave.

  • Prior Art Relied Upon: Guo (Application # 2004/0170191) and Neave (H.R. Neave, P.L. Worthington, DISTRIBUTION-FREE TESTS, a 1989 statistics text).
  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Guo taught the foundational framework of the challenged claims. Guo disclosed a method for a mobile device to perform a "vertical handoff" between heterogeneous wireless networks, such as a Wireless Wide Area Network (WWAN, e.g., cellular) and a Wireless Local Area Network (WLAN, e.g., Wi-Fi). This involved a mobile device with multiple interfaces continuously monitoring and comparing Quality of Service (QoS) metrics like residual bandwidth between an active network and an available alternative network in real-time to decide whether to switch. Petitioner asserted this mapped to the core limitations of independent claims 1-3, including the mobile device, multiple heterogeneous interfaces, real-time comparison, and selecting an interface based on the comparison.

      Petitioner contended that while Guo taught the need for a QoS comparison, it did not explicitly detail the statistical algorithm for performing it. This is where Neave was introduced. Neave, a general-purpose statistics textbook, disclosed various non-parametric statistical tests for comparing two data samples to determine if one is superior on average. Specifically, Neave taught the "one-sided version of Rosenbaum's test," which is described as a "quick-and-easy" and effective method for this purpose, particularly when the underlying data distributions are unknown or vary in spread and location. Petitioner argued that applying Rosenbaum's test from Neave to the QoS data comparison in Guo supplied the missing claim limitations, such as performing "sequential two sample tests" (claims 1 and 3) or a "non-parametric and on-line two-sample method" (claim 2). Dependent claims were allegedly met by the combination, as Rosenbaum's test is non-parametric, works for unequal sample sizes, is performed on-line, and is based on the "length of a high-end extreme run" of samples, as recited in claims 8-12.

    • Motivation to Combine: Petitioner argued a person of ordinary skill in the art (POSITA) implementing Guo's system would have been motivated to find an efficient and reliable statistical method to compare the QoS data from the two networks. Given that network performance data in a wireless environment is unpredictable and its statistical distribution is unlikely to be known in advance, a POSITA would naturally look to well-known non-parametric tests. Neave provided a finite and predictable set of such solutions, including Rosenbaum's test, which it lauded as particularly effective and "quick" for situations where detecting differences in location rapidly is essential. Therefore, a POSITA would combine Neave's statistical method with Guo's network handoff framework to achieve a functional and improved system for making handoff decisions.

    • Expectation of Success: Petitioner asserted a POSITA would have had a reasonable expectation of success because applying a standard, well-documented statistical test (from Neave) to a known data comparison problem (in Guo) was a straightforward application of known principles. Neave's tests were designed for general applicability, including in engineering, and their implementation was predictable.

4. Arguments Regarding Discretionary Denial

  • Fintiv Factors (§314(a)): Petitioner argued that discretionary denial under Fintiv would be inappropriate. The parallel district court trial date was characterized as speculative and scheduled for approximately 13 months after the petition filing, with a Final Written Decision (FWD) expected only five months after that date. Petitioner also asserted that investment in the parallel litigation was low at the time of filing, as no substantive orders had been issued and significant discovery remained. Finally, Petitioner noted an incomplete overlap, as it challenged claims 1-13 and 16 in the inter partes review (IPR), whereas the Patent Owner had only asserted infringement of claims 1-8 and 16 in the district court, meaning several challenged claims would not be addressed in that forum.

  • §325(d) Factors: Petitioner argued against denial under §325(d), contending that the petition raised new issues not considered during prosecution. The primary prior art reference, Guo, was never before the examiner. The asserted combination of Guo and Neave was therefore also never considered. Petitioner further argued that the examiner only allowed the claims after amendments were made to overcome a different reference (Bye), but that Guo taught the very limitations added by those amendments, representing a material difference from the prosecution record.

5. Relief Requested

  • Petitioner requested institution of an IPR and cancellation of claims 1-13 and 16 of Patent 8,798,006 as unpatentable.