PTAB

IPR2022-00697

CommScope Inc v. TQ Delta LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Packet Retransmission
  • Brief Description: The ’411 patent relates to methods and systems for error correction in a communication transceiver, specifically within the context of Digital Subscriber Line (DSL) technology. The invention combines interleaving and retransmission techniques by using a shared memory and employs a message during initialization to indicate how this memory should be allocated between the two functions.

3. Grounds for Unpatentability

Ground 1: Claims 1-2, 9-11, 17-19, and 25 are obvious over G.993.2 in view of BI-089.

  • Prior Art Relied Upon: G.993.2 (ITU-T Recommendation (2006)) and BI-089 (ITU-T SG15/Q4 Contribution (Oct. 2000)).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that G.993.2, a VDSL2 standard, disclosed all elements of the challenged claims except for the retransmission function and its integration with a shared memory. G.993.2 taught VDSL transceivers using interleaving, a shared interleaver memory, and an initialization phase with messages (e.g., O-PMS) to configure operational parameters. Petitioner asserted that BI-089 supplied the missing elements by teaching the use of an Automatic Repeat Request (ARQ) protocol for retransmitting packets to combat impulse noise in DSL systems. BI-089 explicitly taught that when ARQ is applied, "the memory and delay associated with interleaving can be reapplied to ARQ." A POSITA would have therefore understood how to modify G.993.2’s initialization messages to indicate whether a portion of the shared memory should be allocated to the retransmission function (taught by BI-089) or the interleaving function (taught by G.993.2).
    • Motivation to Combine: A POSITA would combine G.993.2 and BI-089 to improve the performance of VDSL2 systems in the presence of burst errors, a well-known problem. BI-089 proposed ARQ as a superior alternative to interleaving for impulse noise and suggested reallocating memory resources from interleaving to ARQ, providing a clear reason to add this known technique to the G.993.2 standard to create a more robust and flexible system.
    • Expectation of Success: A POSITA would have had a high expectation of success because G.993.2 already included a retransmission protocol ("RQ protocol") for its initialization phase, making its extension to normal operation straightforward. The combination involved applying a known error-correction technique (ARQ) to a known system (VDSL) to solve a known problem (impulse noise), yielding predictable results.

Ground 2: Claims 1-2, 9-11, 17-19, and 25 are obvious over Mazzoni in view of G.993.1 in view of BI-089.

  • Prior Art Relied Upon: Mazzoni (Application # 2003/0021338), G.993.1 (ITU-T Recommendation (June 2004)), and BI-089 (ITU-T SG15/Q4 Contribution (Oct. 2000)).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that this combination also rendered the challenged claims obvious. Mazzoni disclosed VDSL transceivers using a shared memory allocated between interleaving and deinterleaving functions. However, Mazzoni lacked a specific initialization procedure. G.993.1, an earlier VDSL standard, provided a detailed initialization protocol where transceivers exchange messages (e.g., O-CONTRACTn) to negotiate capabilities and parameters, including memory usage for interleaving. BI-089 again supplied the teaching of an ARQ retransmission function and the rationale for reallocating memory from interleaving to ARQ.
    • Motivation to Combine: A POSITA implementing Mazzoni’s VDSL transceiver would need an initialization procedure and would have naturally looked to the G.993.1 standard, which provided a compatible protocol for the same technology. To improve the resulting system’s known susceptibility to impulse noise, the POSITA would have then been motivated to incorporate the ARQ techniques from BI-089. This would involve modifying the G.993.1 initialization messages to allow the transceiver to choose between interleaving and ARQ and to allocate Mazzoni’s shared memory accordingly.
    • Expectation of Success: The expectation of success was high, as this ground involved combining compatible VDSL technologies (Mazzoni and G.993.1) and adding a well-understood error-correction technique (BI-089’s ARQ) to enhance performance against a known problem, which would produce predictable improvements in noise immunity at the cost of some latency jitter.

4. Key Claim Construction Positions

  • Petitioner accepted the constructions for "transceiver" and "packet" from a prior district court litigation involving the ’411 patent.
  • "transceiver": "communications device capable of transmitting and receiving data wherein the transmitter portion and receiver portion share at least some common circuitry"
  • "packet": "a grouping of bytes"
  • Petitioner stated that no other claim terms required construction for the purposes of the petition.

5. Arguments Regarding Discretionary Denial

  • §325(d) Arguments: Petitioner argued against discretionary denial under §325(d), stating that the primary references asserted in the petition (G.993.2, BI-089, Mazzoni, G.993.1) were not the same or substantially the same as the art considered by the examiner during prosecution. Although G.993.2 was cited in an IDS, there was no evidence it was substantively considered, and the examiner’s rejections relied solely on a different reference (Moon).
  • Fintiv Arguments: Petitioner argued that discretionary denial under Fintiv was inappropriate. The scheduled trial date in the parallel district court litigation was close to the statutory deadline for a Final Written Decision (FWD), and COVID-19 related delays made the trial date uncertain. Furthermore, the district court case was in its early stages, with significant investment of resources yet to occur, and Petitioner noted its diligence in filing the petition well before the statutory deadline.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 2, 9, 10, 11, 17, 18, 19, and 25 of the ’411 patent as unpatentable.