PTAB

IPR2025-00936

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

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Wireless Communication Method and Wireless Communication Terminal in Basic Service Set Overlapping with Another Basic Service Set
  • Brief Description: The ’597 patent discloses a wireless communication terminal that classifies received data frames as either Intra-Basic Service Set (BSS) or Inter-BSS based on a BSS color identifier. The terminal is configured to not perform operations based on the BSS color when it receives separate signaling information indicating that such operations are disallowed.

3. Grounds for Unpatentability

Ground 1: Claims 1, 7, 9, and 15 are obvious over Lee

  • Prior Art Relied Upon: Lee (Application # 2017/0223731).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Lee discloses all limitations of the independent claims. Lee teaches a wireless station (STA) that performs Clear Channel Assessment (CCA), a spatial reuse operation, based on a "coloring bit" (the claimed BSS color) in a received frame (PPDU) to determine if the frame is from its own BSS. Critically, Lee also discloses a "coloring disable bit" which, when set, signals that the STA "may not perform the change of the CCA level irrespective of information indicated by the coloring bit." Petitioner contended this directly teaches the core claimed feature of not using the BSS color when signaling indicates the operation is not allowed. For dependent claims 7 and 15, Petitioner pointed to Lee's disclosure that a system may use a "reserved field of a legacy BSS coloring bit" set to a predetermined value to achieve the same disabling function without a separate disable bit.

Ground 2: Claims 2-3, 6, 10-11, and 14 are obvious over Lee in view of Stacey

  • Prior Art Relied Upon: Lee (Application # 2017/0223731) and Stacey (Proposed TGax Draft Specification, IEEE 802.11-16/0024r1).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Lee provides the base system of a wireless terminal that can disable BSS color-based operations via a signaling bit, as detailed in Ground 1. Stacey was argued to supply the specific BSS color-based operations recited in the dependent claims. Specifically, Stacey teaches a STA that maintains two distinct Network Allocation Vectors (NAVs)—an "Intra-BSS NAV" and a "regular NAV" (claimed as the Basic NAV)—and sets them based on whether a received frame is an intra-BSS or inter-BSS frame, as determined by the BSS color. Stacey also discloses a power-saving operation where a STA enters a "doze state" only when a received PPDU is identified as an intra-BSS frame using the BSS color.
    • Motivation to Combine: Petitioner argued a person of ordinary skill in the art (POSITA) would have been motivated to combine the references. Because both Lee and Stacey describe enhancements for the same IEEE 802.11ax standard, a POSITA would naturally look to a reference like Stacey for details on specific BSS color-based operations (like NAV setting and power saving) to implement with Lee’s broader concept of disabling such operations. The combination would yield a more robust system that can manage channel access and power consumption efficiently, especially in scenarios like BSS color collisions where BSS color information is unreliable.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success because both documents relate to the same IEEE 802.11 standards development. Combining Lee's disabling mechanism with Stacey's BSS color-based operations was presented as a predictable integration of known elements to improve network performance.

Ground 3: Claims 1, 7-9, and 15-16 are obvious over Choudhury

  • Prior Art Relied Upon: Choudhury (European Application # 2930997).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner contended that Choudhury, by itself, renders the independent claims and several dependent claims obvious. Choudhury discloses a wireless networking station that uses a "COLOR field" (BSS color) to determine whether a transmission is from its own BSS and to decide whether to perform a spatial reuse operation. Crucially, Choudhury teaches that a reserved value of '0000' in the COLOR field can be used to signal a high-interference state. When a STA decodes this '0000' value, it is "required to defer channel access," meaning it does not perform the BSS color-based spatial reuse operation. Petitioner argued this directly teaches the limitations of claims 1 and 9. Because the '0000' value is equivalent to the predetermined value of 0, Petitioner asserted that Choudhury also renders claims 7, 8, 15, and 16 obvious.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of Lee-Zhou (to add BSS color collision detection), Lee-Choudhury, Choudhury-Stacey, and Choudhury-Zhou, which relied on similar motivations to combine elements for improved network management in dense wireless environments.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-16 of Patent 11,700,597 as unpatentable.