PTAB

IPR2016-01007

Cisco Systems Inc v. TQ Delta LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Multicarrier Modulation Messaging for Power Level Per Subchannel Information
  • Brief Description: The ’956 patent discloses a system for exchanging diagnostic and test information, such as power level per subchannel, between transceivers over a digital subscriber line (DSL). The system uses multicarrier modulation, specifically a Quadrature Amplitude Modulation (QAM) scheme with more than one bit per carrier, to transmit this information.

3. Grounds for Unpatentability

Ground 1: Obviousness over Milbrandt, Hwang, and ANSI T1.413 - Claims 1-10 are obvious over Milbrandt in view of Hwang and the ANSI T1.413 standard.

  • Prior Art Relied Upon: Milbrandt (Patent 6,636,603), Hwang (Patent 6,590,893), and ANSI T1.413 (the 1995 ADSL Standard).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that the combination of references taught every element of the challenged claims. Milbrandt disclosed a DSL communication system with transceivers (modems) that measure diagnostic information, such as received signal power spectrum density, and communicate it using multicarrier Discrete Multi-tone (DMT) modulation. Milbrandt also explicitly stated its system used ADSL techniques that comply with the ANSI T1.413 standard.

    Petitioner contended that Hwang supplemented Milbrandt by providing additional detail on the standard ADSL technology used by Milbrandt. Specifically, Hwang taught that DMT signals are modulated using QAM and can carry up to 15 bits of data per subchannel, thus disclosing the claimed limitation of using QAM with "more than 1 bit per subchannel."

    Finally, Petitioner asserted that the ANSI T1.413 standard, which Milbrandt explicitly sought to comply with, taught transmitting diagnostic data variables (like bits and gains) for each sub-carrier as an ordered sequence or "array." Milbrandt taught storing its diagnostic data (attenuation information, which represents power level) in a grid, which Petitioner argued was functionally an array. A person of ordinary skill in the art (POSITA) would have found it obvious to transmit the diagnostic data from Milbrandt's system in the array format specified by the ANSI standard to ensure compliance and efficient data handling. For claims reciting information "during Showtime," Petitioner argued that Milbrandt’s measurements "during operation" in its ANSI-compliant system met this limitation, and the ANSI standard itself taught making Signal-to-Noise Ratio (SNR) data available per subchannel.

    • Motivation to Combine: Petitioner asserted multiple motivations for a POSITA to combine the references. First, a POSITA implementing Milbrandt's DSL system would combine it with Hwang because Hwang provided more specific, known details about the same standard ADSL technology Milbrandt employed, such as the use of high-bit-rate QAM. This combination would be a straightforward application of a known technique to a known system to achieve predictable results, such as higher data throughput. Second, because both Milbrandt and Hwang explicitly referenced using ADSL techniques compliant with the ANSI T1.413 standard, a POSITA would have been directly motivated to consult the ANSI standard for implementation details, such as data formatting (arrays) and required diagnostic parameters (SNR), to ensure system compliance, interoperability, and robustness.

    • Expectation of Success: Petitioner argued a POSITA would have had a high expectation of success. The combination involved applying known modulation techniques (Hwang) and standard-based data formats (ANSI T1.413) to a standard-compliant DSL diagnostic system (Milbrandt). This was merely the implementation of a communications system according to its governing standard, which would predictably yield an operational and commercially desirable system.

4. Key Claim Construction Positions

  • "during Showtime" (claims 9-10): Petitioner argued this term, used in DSL communication standards, should be construed as "during normal communications of an ANSI T1.413-compliant device." This construction was important for mapping Milbrandt’s disclosure of measuring noise "during operation" in its ANSI-compliant system to the claim limitation.
  • "array" (claims 1-10): Petitioner proposed that "array" should be interpreted as "an ordered collection of multiple data items of the same type." This construction was central to arguing that the ANSI T1.413 standard’s teaching of transmitting an ordered sequence of per-subchannel data met the claim limitation, and that it would have been obvious to transmit Milbrandt's grid-stored data in this format.
  • "transceiver" (claims 1-10): Petitioner proposed construing this term as a "device, such as a modem, with a transmitter and receiver." This construction allowed Petitioner to map the modems disclosed in Milbrandt directly to the claimed "transceiver."

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-10 of the ’956 patent as unpatentable under 35 U.S.C. §103.