PTAB

IPR2017-01324

Dali Wireless Inc v. CommScope Technologies LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Digital RF Transport System
  • Brief Description: The ’747 patent discloses a digital radio frequency (RF) transport system designed to extend the coverage of a wireless base station. The system addresses issues with transporting RF channels having different bandwidth requirements by adjusting the analog-to-digital (A/D) sampling rate for each analog input based on its specific bandwidth, thereby improving transport efficiency.

3. Grounds for Unpatentability

Ground 1: Obviousness over Bellers and Farhan - Claims 1-17 are obvious over Bellers in view of Farhan.

  • Prior Art Relied Upon: Bellers (Patent 8,446,530) and Farhan (International Publication No. WO 01/56197).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Bellers and Farhan together teach all limitations of the challenged claims. Bellers discloses a system for processing video signals that uses adaptive sampling, where analog-to-digital converters (ADCs) employ different sampling rates based on the spatial frequency (i.e., bandwidth) of the content being sampled. Bellers further teaches combining these differently sampled signals into a single digital output. Farhan discloses a broadband communications system that digitizes different portions of an analog RF spectrum using separate ADCs, multiplexes the outputs into a serial bit stream, and transmits it over an optical medium. Petitioner contended that Bellers teaches the core inventive concept of selecting sample rates based on the bandwidth of the input (claim 1(b)), while Farhan provides the context of a digital RF transport system with multiple ADCs, multiplexing, serialization, and transmission (claims 1(a), 1(c)-(e)). For the system claims (e.g., claim 7), Petitioner asserted that Farhan discloses the host unit ("headend") and multiplexer circuit, while Bellers provides the teaching of ADCs operating at sample rates related to signal bandwidth.
    • Motivation to Combine: Petitioner argued a person of ordinary skill in the art (POSITA) would combine these references to improve the bandwidth efficiency of Farhan’s system. A POSITA would have recognized the benefit of implementing Bellers' adaptive sampling technique within Farhan’s digital RF transport framework to optimize the sampling rate for each RF channel, thereby avoiding the inefficiency of using a fixed, high sampling rate for all channels regardless of their actual bandwidth.
    • Expectation of Success: Petitioner asserted a POSITA would have had a reasonable expectation of success because both references operate in the known field of sampling analog signals for digital transport. The common technology and predictable nature of combining adaptive sampling with a broadband communication system would make the integration straightforward.

Ground 2: Obviousness over Bellers and Grace - Claims 7-11 and 13-17 are obvious over Bellers in view of Grace.

  • Prior Art Relied Upon: Bellers (Patent 8,446,530) and Grace (IEEE Journal on Selected Areas in Communications, Vol. 8, No. 7 (Sept. 1990)).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued this combination also renders the system claims obvious. Grace discloses a broadband communications system that uses synchronous quantized subcarrier multiplexing to transport video, voice, and data. It teaches assigning different ADCs to parallel analog input channels and tailoring the parameters of each ADC to the specific requirements of each channel to maximize bandwidth efficiency. Bellers, as in Ground 1, provides the explicit teaching of ADCs with flexible sampling rates adapted to the bandwidth of the input signals.
    • Motivation to Combine: The motivation was again to improve bandwidth efficiency. A POSITA looking to optimize Grace’s multi-channel transport system would have been motivated to incorporate the adaptive sampling rates taught by Bellers. This would allow for a more dynamic and efficient allocation of digital bandwidth than simply tailoring static ADC parameters, as suggested by Grace.
    • Expectation of Success: Petitioner contended success would be expected because both references describe well-understood techniques for sampling and multiplexing analog signals. Combining Bellers' adaptive sampling with Grace's multi-channel system was presented as a predictable design choice for improving system performance.

Ground 3: Obviousness over Ichiyoshi and Farhan - Claims 1, 7, 8, 10, 11, and 14 are obvious over Ichiyoshi in view of Farhan.

  • Prior Art Relied Upon: Ichiyoshi (Patent 6,014,366) and Farhan (International Publication No. WO 01/56197).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Ichiyoshi, like Bellers, teaches the key concept of variable bandwidth allocation. Ichiyoshi discloses a variable-bandwidth communication network where bandwidth is assigned in integer multiples of a base frequency interval. It describes sampling independent information signals with a sampling frequency set based on the channel frequency interval. This, combined with Farhan’s disclosure of a digital RF transport system using multiple ADCs and multiplexing (as in Ground 1), allegedly renders the claims obvious.
    • Motivation to Combine: Petitioner argued a POSITA would be motivated to combine Ichiyoshi’s variable-bandwidth sampling system with Farhan’s broadband communication architecture. The goal would be to leverage Ichiyoshi’s more efficient bandwidth allocation method within the practical transport system context provided by Farhan, thereby optimizing the sampling of different RF signals.
    • Expectation of Success: Success was asserted to be predictable, as the combination involves applying known principles of variable-rate sampling (Ichiyoshi) to a standard digital transport system (Farhan), both of which use common components and signal processing techniques.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-17 of the ’747 patent as unpatentable under 35 U.S.C. §103.