PTAB

IPR2025-01189

Samsung Electronics Co Ltd v. Hannibal IP LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method of Physical Downlink Control Channel Monitoring and Related Device
  • Brief Description: The ’911 patent discloses a power-saving method for a user equipment (UE) in a wireless communication system. The method involves configuring two distinct search spaces on a physical downlink control channel (PDCCH): a first for scheduling signals and a second for power-saving wake-up signals (WUS) associated with discontinuous reception (DRX) functionality. The purported invention is to not monitor the second (WUS) search space when the UE is already in a DRX "active time."

3. Grounds for Unpatentability

Ground 1: Claims 1-3, 5-6, 10-12, and 14-15 are Anticipated or Rendered Obvious by Nimbalker

  • Prior Art Relied Upon: Nimbalker (International Publication No. WO 2020/130930).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Nimbalker discloses every element of the independent claims. Nimbalker describes a DRX system for LTE and NR networks that uses a WUS to reduce power consumption. It teaches configuring a UE with a first search space for regular PDCCH monitoring (for scheduling information) during an "ON Duration" and a second, WUS-PDCCH search space for monitoring a WUS. Critically, Petitioner asserted Nimbalker explicitly teaches the core concept of the ’911 patent: that the UE "skip[s] monitoring of the WUS" or "need not monitor for the WUS" during occasions that overlap with the DRX "active time," such as when an inactivity timer is running. Nimbalker also discloses that if a WUS is missed, the UE may still monitor the PDCCH during the ON duration to avoid latency, which Petitioner mapped to the limitation of starting a DRX on-duration timer in response to not receiving the power-saving signal.
    • Key Aspects: Petitioner contended that the Examiner for the ’911 patent did not have Nimbalker during prosecution and that its disclosure directly corresponds to the allegedly novel features of the challenged claims.

Ground 2: Claims 2, 4, 11, and 13 are Obvious over Nimbalker in view of R1-1905031

  • Prior Art Relied Upon: Nimbalker (WO 2020/130930) and R1-1905031 (a 3GPP contribution titled "PDCCH-based power saving channel design").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Nimbalker provides the foundational DRX system with WUS functionality. R1-1905031 was presented to supplement Nimbalker by explicitly teaching the advantages of using distinct physical resources for the different search spaces and using the WUS to trigger a bandwidth part (BWP) switch. For claims 2 and 11, which require separate time and frequency resources for the first and second search spaces, R1-1905031 teaches it is "advantageous" for the WUS CORESET to have a configuration that is "distinct" from the scheduling PDCCH CORESET. For claims 4 and 13, which add using the power-saving signal for indicating a BWP switch, R1-1905031 teaches including a "BWP id" in the wake-up DCI so the UE can switch to the appropriate BWP before the on-duration starts.
    • Motivation to Combine: A POSITA would combine Nimbalker's power-saving framework with the specific, advantageous techniques described in the 3GPP standards document R1-1905031. The motivation was to improve system efficiency and power savings, as R1-1905031 explicitly details the benefits of using distinct resources and BWP switching within a WUS-based DRX context.
    • Expectation of Success: Petitioner asserted a POSITA would have a high expectation of success, as the combination involved implementing well-understood, documented 3GPP techniques into a compatible system (Nimbalker) to achieve predictable improvements in resource management and power efficiency.

Ground 3: Claims 7-9 and 16-18 are Obvious over Nimbalker in view of Anil

  • Prior Art Relied Upon: Nimbalker (WO 2020/130930) and Anil (International Publication No. WO 2019/135654).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground addresses claim limitations related to UE behavior during specific procedures like random access and beam failure recovery. Petitioner combined Nimbalker's primary teaching—to not monitor the WUS search space during DRX "active time"—with Anil's disclosure that a UE enters an "active time" while performing a random access procedure (e.g., after transmitting a PRACH preamble for beam failure recovery). The combination directly results in not monitoring the WUS space during a random access procedure, as recited in claims 7 and 16. For claims 9 and 18, which require the power-saving signal to be received only from a "special cell (SpCell)," Anil provides a definition for SpCell and describes multi-cell operations where a primary cell (SpCell) and secondary cell exist.
    • Motivation to Combine: A POSITA would be motivated to integrate Anil's robust beam failure recovery and random access procedures into Nimbalker's power-saving system. Applying Nimbalker's rule (skip WUS monitoring when active) to the active time defined by Anil's procedures was argued to be a straightforward step to conserve power. Restricting WUS signals to the SpCell, as taught by combining the references, was presented as an obvious design choice to simplify UE operation and reserve secondary cells for other functions.
    • Expectation of Success: Success would be expected because the combination merges two complementary aspects of wireless communication—power saving and connection robustness—to achieve the predictable result of a power-efficient device that can also handle events like beam failure.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge against claims 2, 4, 11, and 13 based on Nimbalker in view of R1-1903016, which provided similar teachings to R1-1905031 regarding BWP switching and dedicated WUS configurations.

4. Relief Requested

  • Petitioner requests institution of inter partes review and cancellation of claims 1-18 of Patent 11,368,911 as unpatentable.