PTAB

IPR2025-01165

Samsung Electronics Co Ltd v. Wilus Institute Of Standards Technology Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: AGGREGATED-MPDU, METHOD FOR TRANSMITTING RESPONSE FRAME THERETO, AND WIRELESS COMMUNICATION TERMINAL USING SAME
  • Brief Description: The ’926 patent relates to a method and wireless terminal for managing communications in a wireless local area network (WLAN). The technology focuses on defining various formats for an Aggregated MAC Protocol Data Unit (A-MPDU) and specifying the logic for determining and transmitting the appropriate response frame.

3. Grounds for Unpatentability

Ground 1: Obviousness over Chu in view of IEEE-D1 or IEEE-D2 - Claims 1-14 are obvious over Chu in view of IEEE-D1 or, alternatively, IEEE-D2.

  • Prior Art Relied Upon: Chu (Application # 2017/0111951), IEEE-D1 (an IEEE 802.11ax draft standard, Dec. 1, 2016), and IEEE-D2 (an IEEE 802.11 standards contribution, Sep. 14, 2016).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Chu taught a system for generating A-MPDUs and determining a corresponding response frame—such as an Ack, BlockAck, or Multi-STA BlockAck—based on MAC Protocol Data Unit (MPDU) delimiter information (e.g., End of Frame (EOF) and length fields) and separate Ack policy bits. However, Petitioner contended Chu did not explicitly teach how to handle A-MPDUs containing a mix of MPDUs requiring different acknowledgment types. IEEE-D1 and IEEE-D2, which describe enhancements for the 802.11ax standard, allegedly cured this by disclosing an enhanced multi-Traffic Identifier (TID) A-MPDU format that expressly allows for mixed EOF values (0 and 1) and mixed policies (Ack and BlockAck) within a single A-MPDU. The combination allegedly teaches the claimed feature of determining a response frame type (including an Ack, compressed BlockAck, or Multi-STA BlockAck) based on the combination of MPDU type (derived from EOF/length fields) and Ack policy information, particularly triggering a Multi-STA BlockAck when mixed MPDU types are present.
    • Motivation to Combine: A POSITA would combine these references for several reasons. First, Chu explicitly incorporated the 802.11ax standard by reference, making it obvious to look to drafts like IEEE-D1 and IEEE-D2 to ensure system alignment and interoperability. Second, the combination provided a more flexible and efficient A-MPDU aggregation format by allowing diverse traffic types (those requiring a simple Ack and those requiring a BlockAck) to coexist in a single frame, which reduces transmission overhead. The IEEE drafts provided clear, predictable rules for implementing this enhanced functionality.
    • Expectation of Success: A POSITA would have had a high expectation of success because the IEEE drafts provided specific, compatible enhancements to the 802.11ax framework that Chu’s system was already designed to operate within. The combination involved applying known wireless communication techniques to a compatible system to achieve predictable improvements in efficiency.

Ground 2: Obviousness over IEEE-D3 - Claims 1 and 8 are obvious over IEEE-D3.

  • Prior Art Relied Upon: IEEE-D3 (the published IEEE 802.11-2016 standard, Dec. 14, 2016).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that the IEEE-D3 standard, as a single comprehensive reference, disclosed all elements of independent claims 1 and 8. The standard described wireless communication terminals (e.g., access points and stations) comprising the necessary processors and communication units. Petitioner argued IEEE-D3 explicitly detailed the structure of A-MPDUs, which are carried in a physical layer protocol data unit (PPDU) and consist of one or more subframes. Each subframe includes an MPDU and an MPDU delimiter containing both an EOF field and a length field. Crucially, the standard also specified an "Ack Policy subfield" within the Quality of Service (QoS) control field. The value of this policy subfield, in combination with the EOF and length fields, dictates the acknowledgment type. IEEE-D3 taught that this logic is used to determine and transmit the appropriate response frame, such as an Ack frame for a VHT single MPDU or a compressed BlockAck frame for multiple MPDUs under the same TID, thus rendering the claimed invention obvious.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-14 of Patent 11,664,926 as unpatentable under 35 U.S.C. §103.