PTAB

IPR2024-00823

Valeo SE v. Foras Technologies Limited

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1. Case Identification

2. Patent Overview

  • Title: System and Method for Loss of Lockstep Detection and Recovery
  • Brief Description: The ’958 patent discloses a system and method for improving fault tolerance in computer systems that use paired, lockstep processors. The technology focuses on detecting a "loss of lockstep" (LOL) between the processors, determining if the LOL is recoverable, and using firmware to manage recovery, including interaction with an Advanced Configuration and Power Interface (ACPI)-compatible operating system.

3. Grounds for Unpatentability

Ground 1: Claims 1-8 and 13-22 are obvious over Bigbee in view of Nguyen.

  • Prior Art Relied Upon: Bigbee (Application # US 2003/0126498A1) and Nguyen (Application # US 2004/0123201 A1).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Bigbee discloses a fault-tolerant data processing system with nearly all the core components of the challenged claims, including lockstep processor cores operating in functional redundancy check (FRC) mode, an ACPI-compatible operating system, and firmware for detecting a loss of lockstep and performing a recovery routine. However, Petitioner contended Bigbee fails to explicitly disclose the key step of first "determining if the lockstep is recoverable." Petitioner asserted that Nguyen remedies this deficiency by disclosing a high-reliability processor that explicitly determines whether a detected error (e.g., a soft error or mismatch error) is recoverable. Nguyen teaches different handling mechanisms based on this determination: a system reset for a non-recoverable error versus a specific recovery routine to restore lockstep for a recoverable error. The combination of Bigbee’s system with Nguyen’s recoverability determination logic allegedly renders the challenged claims obvious.
    • Motivation to Combine (for §103 grounds): A person of ordinary skill in the art (POSITA) would combine Nguyen’s teachings with Bigbee’s system to enhance system reliability and availability. Petitioner argued it was critical in fault-tolerant systems to distinguish between recoverable and non-recoverable errors to avoid unnecessary system downtime (by not resetting for a recoverable error) and prevent data corruption (by not attempting to recover from a non-recoverable error). Adding Nguyen’s logic for determining recoverability would have been a natural and predictable solution to fill a gap in Bigbee’s disclosure and improve its function.
    • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success in this combination. Petitioner argued that implementing logic in firmware was a well-known technique. Bigbee’s system is described as ACPI-compliant and includes firmware layers (like PAL and SAL) suitable for implementing error diagnosis and recovery routines. Therefore, incorporating Nguyen's determination logic into Bigbee’s existing firmware architecture would have involved only ordinary programming skill and known industry standards.

4. Key Claim Construction Positions

  • "Detection of Loss of Lockstep" / "Detecting Loss of Lockstep": Petitioner argued this term should be construed to include both (1) detecting an actual lockstep mismatch error and (2) detecting a "precursor to lockstep mismatch," meaning an error in an individual processor that could eventually propagate and cause a mismatch. This broad construction, supported by the specification and dependent claims, is crucial because the prior art (Bigbee) teaches detecting errors within individual processor cores that serve as such precursors.
  • "Lockstep is Recoverable" / "Loss of Lockstep is Recoverable": Petitioner proposed construing this term to mean "lockstep is recoverable from the detected loss of lockstep." This construction ties the recoverability assessment directly to the specific error that was detected, which aligns with the logic taught by the asserted prior art, particularly Nguyen.

5. Arguments Regarding Discretionary Denial

  • Discretionary Denial under Fintiv: Petitioner argued that discretionary denial under 35 U.S.C. §314(a) is inappropriate. The petition was filed with a motion to join an already-instituted IPR (IPR2023-01373, the "BMW IPR"), which conserves judicial resources. Petitioner contended that the co-pending district court litigation is in its infancy, with discovery having just begun and a trial date set for August 2025, well after the March 2025 statutory deadline for a Final Written Decision in the BMW IPR. Finally, Petitioner asserted the merits are strong, as the Board already instituted the BMW IPR on the same ground.
  • Discretionary Denial under §325(d): Petitioner argued denial is improper because the petition presents a new ground and arguments not previously considered by the USPTO. The core combination of Bigbee and Nguyen was never before the examiner. While Bigbee was listed in an Information Disclosure Statement (IDS), it was never substantively analyzed or relied upon in a rejection. Nguyen was never presented to the examiner at all. Petitioner contended this combination is not cumulative because it addresses the very feature—determining if a lockstep mismatch has occurred as part of determining recoverability—that was the basis for allowance, a feature Bigbee alone does not teach.

6. Relief Requested

  • Petitioner requests the institution of an inter partes review and the cancellation of claims 1-8 and 13-22 of the ’958 patent as unpatentable.