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

1. Case Identification

• Case #: IPR2025-01110
• Patent #: 11,716,171
• Filed: June 9, 2025
• Petitioner(s): Samsung Electronics Co., Ltd. and Samsung Electronics America, Inc.
• Patent Owner(s): Wilus Institute of Standards and Technology Inc.
• Challenged Claims: 1-16

2. Patent Overview

• Title: WIRELESS COMMUNICATION TERMINAL AND WIRELESS COMMUNICATION METHOD FOR MULTI-USER CONCURRENT TRANSMISSION
• Brief Description: The ’171 patent discloses a wireless communication terminal and method for enabling simultaneous uplink multi-user (MU) transmissions. The technology centers on using a "trigger frame" that can include a padding field to provide receiving terminals with additional time to process the frame before transmitting a response.

3. Grounds for Unpatentability

Ground 1: Obviousness over Kim - Claims 1-16 are obvious over Kim.

• Prior Art Relied Upon: Kim (Application # 2019/0357256).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Kim discloses all limitations of the challenged claims. Kim teaches a trigger frame for uplink MU transmission that includes a User Information field, a Padding field, and a Frame Check Sequence (FCS) field. Critically, Kim’s User Information field contains an Association Identifier (AID) subfield (AID 12) which, when set to a specific reserved value (4095), explicitly indicates the start of the Padding field. This directly maps to the key limitation of independent claims 1 and 9—that the AID field is set to a value related to the padding field—which was added during prosecution to secure allowance of the ’171 patent. Kim further taught that the padding field extends the trigger frame's length to allow a recipient station sufficient time to prepare for its response, satisfying other key limitations. For dependent claims, Kim was argued to disclose setting all padding bits to '1', placing the padding before the FCS, and using a second padding field in the response frames to ensure simultaneous transmission termination among multiple users.
  • Motivation to Combine (for §103 grounds): As a single-reference ground, Petitioner contended that Kim's disclosure is so comprehensive that any minor differences between it and the claimed invention would have been obvious modifications to a person of ordinary skill in the art (POSITA).
  • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success in implementing the claimed features based on Kim’s detailed disclosure of a functionally identical system.

Ground 2: Obviousness over Chu and Choi - Claims 1-16 are obvious over Chu in view of Choi.

• Prior Art Relied Upon: Chu (Application # 2015/0131517) and Choi (Application # 2015/0230244).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Chu describes a system using an uplink scheduling frame for MU OFDMA transmissions and discloses including padding bits at the end of the frame to provide stations with sufficient time to prepare for their response. However, Chu does not specify a mechanism for signaling the presence or start of these padding bits. Choi was argued to remedy this deficiency by teaching a method to signal padding using a specific, reserved value within an AID-related field (a ∆AID field) to mark the boundary between meaningful data and subsequent padding bits. The combination of Chu’s general framework for padded trigger frames with Choi’s specific signaling mechanism was argued to render the key limitations of claims 1 and 9 obvious.
  • Motivation to Combine (for §103 grounds): A POSITA, recognizing the implementation gap in Chu regarding how to identify padding, would combine its teachings with Choi’s explicit solution. Choi addresses the precise problem of reliably parsing frames with variable-length fields and padding, a known issue in the same technical domain. Applying Choi's established, modular technique (using a reserved AID value) to Chu's system would have been an obvious design choice to improve parsing efficiency and reliability.
  • Expectation of Success (for §103 grounds): Success would have been expected because both references operate in similar multi-user wireless environments and address related frame-timing and coordination problems. Choi’s signaling mechanism is self-contained and would not require fundamental changes to Chu’s frame structure, making the integration predictable.

4. Key Technical Contentions (Beyond Claim Construction)

• Priority Date Challenge: A central argument of the petition was that the ’171 patent is not entitled to a priority date earlier than its filing date of January 11, 2021. Petitioner contended that the key limitation recited in independent claims 1 and 9—"the AID field is set to a value related to a first padding field"—lacks written description support in any of the parent or foreign priority applications. Because this feature was allegedly first introduced in the application that became the ’171 patent, Petitioner argued the claims are not entitled to an earlier date. This contention is critical as it establishes that Kim, with a 2018 filing date, qualifies as prior art under §102(a)(2).

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial is unwarranted. The petition noted the existence of co-pending district court litigation but stated its intent to utilize the PTAB’s bifurcated briefing process to rebut any discretionary denial contentions raised by the Patent Owner, referencing a Fintiv Stipulation filed as an exhibit.

6. Relief Requested

• Petitioner requests institution of an IPR and cancellation of claims 1-16 of the ’171 patent as unpatentable.