PTAB

IPR2025-01044

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 Using Enhanced Distributed Channel Access
  • Brief Description: The ’879 patent is directed to methods for improving the efficiency of wireless communication, particularly in systems using contention-based channel access and multi-user uplink (UL-MU) transmissions. The technology involves a wireless terminal that dynamically adapts its channel access parameters based on whether it is scheduled to participate in a UL-MU transmission, switching between a "legacy" parameter set and a "multi-user" (MU) parameter set to reduce collisions.

3. Grounds for Unpatentability

Ground 1: Obviousness over Zhou, Cherian, and Kim - Claims 1-3 and 8-10 are obvious over Zhou in view of Cherian and Kim.

  • Prior Art Relied Upon: Zhou (Application # 2017/0202023), Cherian (Application # 2017/0325264), and Kim (Application # 2018/0034595).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination of Zhou, Cherian, and Kim taught all limitations of the independent claims. Zhou allegedly disclosed a base system for selecting different Enhanced Distributed Channel Access (EDCA) parameter sets for stations (STAs) based on their capability for UL-MU transmissions. Cherian was argued to build on this by teaching the transition between a single-user (SU) mode (first parameter set) and an MU mode (second parameter set) upon receiving a trigger frame, and using a timer to control the duration of the MU mode. Kim was asserted to provide the final elements by disclosing different acknowledgment (ACK) policies, including options for an immediate response or no response, which informs when a transmission is complete. Petitioner specifically mapped Kim’s teachings to the mutually exclusive "when" clauses of claim 1 ([1.5] and [1.6]), arguing Kim taught setting a timer either after the transmission ends (if no ACK is requested) or after the ACK is received (if an ACK is requested).
    • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA) would combine these references to solve the known problem of optimizing wireless network performance in environments supporting both SU and MU operation. A POSITA would logically integrate Zhou's parameter selection, Cherian's mode-transition management, and Kim's ACK policies to create a more robust and efficient system. The combination addressed the known needs for efficient mode transitions, reduced overhead, and reliable data delivery, representing predictable solutions to a known design need.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because combining these teachings involved applying known techniques (parameter switching, timers, ACK protocols) to improve a known device (a wireless terminal) in a predictable way.

Ground 2: Obviousness over Zhou, Cherian, Kim, and Ho - Claims 4-5 are obvious over the combination for Ground 1 in further view of Ho.

  • Prior Art Relied Upon: Zhou (Application # 2017/0202023), Cherian (Application # 2017/0325264), Kim (Application # 2018/0034595), and Ho (Application # 2010/0195664).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground asserted that the additional teachings of Ho rendered claims 4 and 5 obvious. These claims recite specific details of a backoff procedure, including calculating a random integer within a contention window (CW), where the parameter set includes a minimum (CWmin) and maximum (CWmax) value for the CW. Petitioner argued that Ho explicitly taught these features, describing a backoff counter set to a random integer within a CW and disclosing a parameter table with CWmin and CWmax values for different user priorities. Claim 5’s limitation—setting the CW to CWmax if doubling it would exceed the maximum—was also allegedly taught by Ho as a standard part of a bounded exponential backoff mechanism.
    • Motivation to Combine: A POSITA would combine Ho with the primary combination of Zhou, Cherian, and Kim to incorporate a well-defined and standardized approach for managing contention and retransmissions. Adding Ho’s teachings for a bounded backoff mechanism was presented as a logical step to improve the stability and reliability of the system, addressing potential collisions in a predictable manner. This integration leveraged a known technique to enhance the robustness of the overall system.
    • Expectation of Success: The integration would have a high expectation of success as it involved applying a common and fundamental practice in wireless networking (bounded exponential backoff) to the system established by the other references.

Ground 3: Obviousness over Zhou, Cherian, Kim, and Bharghavan - Claims 6-7 are obvious over the combination for Ground 1 in further view of Bharghavan.

  • Prior Art Relied Upon: Zhou (Application # 2017/0202023), Cherian (Application # 2017/0325264), Kim (Application # 2018/0034595), and Bharghavan (Patent 9,197,482).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground focused on claims 6 and 7, which recite operating a plurality of queues classified by access category and performing backoff procedures for each queue. Petitioner contended that Bharghavan taught these very features, describing a system that uses multiple queues for different Quality of Service (QoS) access categories (e.g., voice, video). Bharghavan was also argued to teach pausing contention for a queue when there is no data stored in it (by setting its backoff timer to zero), directly corresponding to the limitations of claims 6 and 7.
    • Motivation to Combine: Petitioner argued that a POSITA would be motivated to combine Bharghavan with the primary references to achieve enhanced QoS management. By dynamically adapting channel access parameters based on real-time traffic conditions (i.e., queue status), the resulting system would be more efficient. Integrating Bharghavan's queue-aware contention mechanism would prevent unnecessary contention from inactive traffic types, addressing a known design need for efficient resource utilization.
    • Expectation of Success: A POSITA would expect this combination to succeed because it involved integrating a known method for QoS management into the comprehensive wireless communication system taught by the primary references, leading to a predictable improvement in network performance.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-10 of Patent 11,516,879 as unpatentable.