PTAB

IPR2024-00510

AT&T Mobility LLC v. Daingean Technologies Ltd

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Key Events
Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: Communication Method and Base Station
  • Brief Description: The ’976 patent is directed to wireless communication networks, specifically relating to signaling and procedures for uplink ultra-reliable low-latency communication (URLLC). The challenged claims concern a method and apparatus for managing periodic uplink resource grants, which are configured by Radio Resource Control (RRC) signaling and activated or deactivated using Downlink Control Information (DCI) formats scrambled with a specific type of Radio Network Temporary Identifier (RNTI).

3. Grounds for Unpatentability

Ground 1: Obviousness over Babaei and Fwu - Claims 2 and 4 are obvious over Babaei in view of Fwu.

  • Prior Art Relied Upon: Babaei (Patent 10,959,218) and Fwu (International Publication No. WO 2016/130175).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Babaei taught the core framework of the challenged claims, including using RRC signaling to configure periodic uplink grants with specific periodicities and using DCI formats scrambled with a Semi-Persistent Scheduling (SPS) RNTI to activate and deactivate those grants. Babaei also disclosed receiving confirmation via a Medium Access Control Control Element (MAC CE) identified by a Logical Channel Identifier (LCID). Petitioner asserted that Fwu supplemented Babaei by teaching the configuration of different "numerologies" (e.g., subcarrier spacing and symbol duration) via RRC signaling to support a wider variety of services, including low-latency applications.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) aiming to provide a broad range of periodic services on a 3GPP network would combine Babaei’s system for managing multiple periodic grants with Fwu’s system for configuring multiple numerologies. Because changes in numerology directly impact symbol time and available transmission intervals, combining the two would be a logical step to create a more flexible and efficient network.
    • Expectation of Success: The combination would predictably result in a base station capable of configuring a user equipment (UE) to transmit using both a periodicity (from Babaei) and a numerology (from Fwu) suitable for the demands of a specific application, which was a known goal in the art.

Ground 2: Obviousness over Babaei, Fwu, and Lee - Claims 2 and 4 are obvious over Babaei and Fwu in further view of Lee.

  • Prior Art Relied Upon: Babaei (Patent 10,959,218), Fwu (WO 2016/130175), and Lee (Patent 10,869,331).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the combination of Babaei and Fwu. Petitioner contended that Lee provided explicit teachings for claim limitations that were only suggested in the primary combination. Specifically, Lee taught using distinct RNTIs for different service types: an SPS-C-RNTI for conventional VoIP traffic and a different V2X-SPS-RNTI for Vehicle-to-Everything (V2X) traffic. This V2X-SPS-RNTI is explicitly "differentiated from the... first RNTI" and is also different from the standard C-RNTI used for dynamic scheduling, thereby meeting the claim requirement for a "first RNTI being different from a Cell-RNTI... and a semi-persistent scheduling C-RNTI." Lee also expressly disclosed transmitting these DCI messages in the common search space.
    • Motivation to Combine: A POSITA, having combined Babaei and Fwu, would be motivated to incorporate Lee’s teachings to solve a problem identified in Babaei: the increased UE processing load from managing a large number of SPS RNTIs. Lee’s solution of using distinct, service-specific RNTIs provided a more structured and efficient approach to managing different periodic uplink services than Babaei's proposals.

Ground 3: Obviousness over Babaei, Fwu, and Agiwal - Claims 2 and 4 are obvious over Babaei and Fwu in further view of Agiwal.

  • Prior Art Relied Upon: Babaei (Patent 10,959,218), Fwu (WO 2016/130175), and Agiwal (Application # 2018/0035332).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground again built upon the Babaei and Fwu combination, adding Agiwal to address collision avoidance between different service types. Petitioner argued that Agiwal taught a "skip indication"—a DCI format scrambled by a special "skip-RNTI"—broadcast in the common search space. This signal instructs a UE with a scheduled eMBB transmission to temporarily halt (deactivate) its transmission to allow a higher-priority URLLC transmission to proceed, and then resume (reactivate) its scheduled transmission. This skip-RNTI is different from a C-RNTI or standard SPS-RNTI. Petitioner asserted it would be obvious to add the MAC CE confirmation taught by Babaei to this system.
    • Motivation to Combine: A POSITA would be motivated to integrate Agiwal's skip-RNTI collision avoidance scheme into the flexible network of Babaei and Fwu. This would allow the network to reliably multiplex scheduled, periodic traffic with high-priority, low-latency traffic in an overlapping frequency space, thereby maximizing bandwidth utilization while preventing data loss.

4. Key Technical Contentions (Beyond Claim Construction)

  • Priority Date Challenge: A central contention of the petition was that the challenged claims were not entitled to their asserted priority date of January 6, 2017. Petitioner argued the priority application failed to provide written description support for two key limitations: (1) a DCI format scrambled by an RNTI that is "different from a Cell-RNTI," and (2) the transmission of this DCI format in a "common search space." This argument, if successful, establishes that the Babaei, Lee, and Agiwal references, which have effective filing dates after the asserted priority date but before the patent’s actual filing date, qualify as prior art under 35 U.S.C. §102.

5. Arguments Regarding Discretionary Denial

  • §325(d) Inapplicable: Petitioner argued that discretionary denial under 35 U.S.C. §325(d) was inappropriate. The grounds were based on prior art references (Babaei, Fwu, Lee, and Agiwal) that were not cited during the original prosecution of the ’976 patent. Therefore, the Examiner never considered the specific combinations or arguments presented in the petition, making the challenges substantially different from those previously evaluated by the USPTO.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 2 and 4 of the ’976 patent as unpatentable.