PTAB

IPR2016-00428

ARRIS Group Inc v. TQ Delta LLC

Log In
Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Multicarrier modulation system with downstream power back off
  • Brief Description: The ’430 patent discloses a multicarrier communication system, such as a high-speed modem, that transmits data over numerous orthogonal frequency carriers. The technology relates to methods for modulating data onto these carriers and for exchanging performance information, such as channel noise measurements, between transceivers to optimize communication.

3. Grounds for Unpatentability

Ground 1: Obviousness over Hughes-Hartogs, Baran, and Frenkel - Claims 1-6 are obvious over Hughes-Hartogs in view of Baran and Frenkel.

  • Prior Art Relied Upon: Hughes-Hartogs (Patent 4,679,227), Baran (Patent 4,438,511), and Frenkel (Patent 5,838,268).
  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that the combination of Hughes-Hartogs, Baran, and Frenkel teaches all limitations of the challenged claims. Independent claim 1 recites a multicarrier system with specific methods for data modulation and reporting channel characteristics. Petitioner asserted that Hughes-Hartogs teaches the foundational multicarrier system using Discrete Multi-tone (DMT) modulation.

      • For the claim limitation requiring modulation of bits onto DMT symbols using Quadrature Amplitude Modulation (QAM), Petitioner contended that while Hughes-Hartogs discloses DMT, Frenkel clarifies this teaching. Frenkel explicitly references the Hughes-Hartogs patent family as disclosing a prior art DMT system and explains that such systems use QAM (also referred to as QASK) for modulation. A person of ordinary skill in the art (POSITA) would therefore understand the DMT system of Hughes-Hartogs to inherently use QAM as taught by Frenkel.
      • For the limitation requiring that data variables in a received message represent "frequency domain received idle channel noise information," Petitioner asserted that Baran provides this teaching. Hughes-Hartogs expressly states it is a continuation of the work initiated in Baran. Baran teaches the utility of exchanging performance information between modems, including noise measurements for each frequency carrier, to optimize data transmission. A POSITA would have found it obvious to apply Baran's established technique for reporting channel noise to the improved modem system of Hughes-Hartogs. Petitioner further argued this reasoning extends to dependent claims 2-6, which add further well-known modem features.

    • Motivation to Combine: Petitioner’s core argument rested on the explicit and direct cross-citations between the prior art references, which it argued provided a clear roadmap for a POSITA to combine their teachings.

      • First, Hughes-Hartogs expressly states that its application "reflects a continuation of the effort initiated by Baran." Furthermore, Hughes-Hartogs incorporates Baran by reference for its disclosure of modulation techniques. This direct link would have strongly motivated a POSITA to consult Baran to understand the background and foundational techniques upon which Hughes-Hartogs was built, including its methods for exchanging channel performance information.
      • Second, Frenkel explicitly references a patent from the Hughes-Hartogs family (Patent 4,833,706, which shares the same specification) when describing prior art DMT systems. This would have motivated a POSITA to look to Frenkel to understand the specific implementation details, such as the modulation scheme (QAM), used in the system described by Hughes-Hartogs.
      • Petitioner asserted that a POSITA, exercising ordinary curiosity, would naturally "connect the dots" between these interrelated documents to arrive at the claimed invention. The motivation was not based on hindsight but on express directions provided within the references themselves.

    • Expectation of Success: Petitioner argued that a POSITA would have had a high expectation of success in making this combination. The references are not from disparate fields of art; they all relate to high-speed multicarrier modem technology. The combination involved applying a known modulation technique (QAM, as clarified by Frenkel) to a DMT system (Hughes-Hartogs) and incorporating a standard performance reporting feature (noise information, as taught by Baran) into that same system. Because Hughes-Hartogs explicitly builds upon Baran’s work, integrating Baran's features would have been a predictable and straightforward improvement.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-6 of the ’430 patent as unpatentable.