PTAB

IPR2025-00960

Sony Interactive Entertainment LLC v. Ax Wireless LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Non-Transitory Computer-Readable Information Storage Media for Variable Header Repetition in a Wireless OFDM Network
  • Brief Description: The ’272 patent relates to methods for improving the reliability of header information in Orthogonal Frequency Division Multiplexing (OFDM) wireless networks. The technology involves generating and transmitting different packet types with distinct header structures, including a "first packet type" with a two-part header and a "second packet type" with a four-part header created by repeating header information.

3. Grounds for Unpatentability

Ground 1: Obviousness over Hansen and July 2005 WWiSE - Claims 1-3, 5, 7-9, 11-13, 15, and 17-19 are obvious over Hansen in view of July 2005 WWiSE.

  • Prior Art Relied Upon: Hansen (Application # 2006/0182017) and July 2005 WWiSE (IEEE 802.11-05/0149r5, “WWiSE Proposal: High Throughput Extension to the 802.11 Standard”).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination of Hansen and July 2005 WWiSE disclosed all limitations of the challenged claims. Hansen disclosed a "compromise" greenfield Physical Layer Protocol Data Unit (PPDU) for 802.11n systems, which serves as the claimed "first packet type" with a two-part header field (HT-SIG1 and HT-SIG2). July 2005 WWiSE, an IEEE proposal for the same 802.11n standard, taught an extended range (ER) capability achieved by duplicating the header symbol to enhance reliability. Petitioner contended that applying WWiSE’s header repetition technique to Hansen’s two-part header would result in the claimed "second packet type" comprising a four-part header field (HT-SIG1, repeated HT-SIG1, HT-SIG2, repeated HT-SIG2).
    • Motivation to Combine: A POSITA would combine these references to incorporate the known benefits of extended range communication into Hansen’s greenfield system. Hansen itself was presented as a compromise between competing 802.11n proposals, encouraging a POSITA to integrate beneficial features from other proposals like WWiSE. The primary motivation was to extend the reliable communication range by using the temporal and frequency diversity provided by WWiSE's header repetition.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because both references addressed the same 802.11n standard development and built upon well-known 802.11 protocols. The proposed modification—repeating a header and using a reserved bit to signal the mode—was a common and predictable technique in evolving communication standards.

Ground 2: Obviousness over Hansen, July 2005 WWiSE, and Choi - Claims 1-3, 5, 7-9, 11-13, 15, and 17-19 are obvious over Hansen and July 2005 WWiSE in view of Choi.

  • Prior Art Relied Upon: Hansen (Application # 2006/0182017), July 2005 WWiSE (IEEE 802.11 Proposal), and Choi (Application # 2005/0243774).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented as an alternative, arguing that if the Hansen/WWiSE combination was deemed insufficient to teach the specific symbol ordering of the four-part header, Choi supplied the missing element. Choi taught a repetition coding scheme for wireless OFDM systems where a coded block of data is duplicated immediately after the original block (post-coding, pre-modulation). Petitioner asserted that Choi’s method provided the explicit mechanism for generating the four OFDM symbols for the second packet type’s header in the specific sequence required by the claims (e.g., Symbol 1, Repeated Symbol 1, Symbol 2, Repeated Symbol 2).
    • Motivation to Combine: A POSITA, seeking to implement the header repetition concept from WWiSE, would have been motivated to look for known repetition coding techniques and would have found Choi. Choi was in the same field of wireless OFDM communication, was applicable to 802.11 standards, and explicitly taught using its repetition coding to achieve extended range capabilities. The motivation was to use Choi’s established method to implement the high-level concept proposed in WWiSE efficiently.
    • Expectation of Success: Success would be expected because the integration of a known repetition encoder (from Choi) into a transceiver architecture (from Hansen) was a straightforward application of known design principles. Such post-coding repetition schemes were known in other standards (e.g., G.9960), making the outcome predictable.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-3, 5, 7-9, 11-13, 15, and 17-19 of the ’272 patent as unpatentable.