PTAB

IPR2021-00696

ZTE Corp v. WSOU Investments LLC

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1. Case Identification

2. Patent Overview

  • Title: Video Coding and Decoding Using Virtual Reference Data
  • Brief Description: The ’960 patent relates to methods and apparatuses for encoding and decoding video signals. The invention uses "virtual reference data," which is generated from portions of an original video signal but does not represent any portion of an actual video frame intended for display, to improve video compression efficiency.

3. Grounds for Unpatentability

Ground 1: Obviousness over Caglar and Duvivier - Claims 1, 2, 6-16, and 20-28 are obvious over Caglar alone or in view of Duvivier.

  • Prior Art Relied Upon: Caglar (Application # 2006/0146934) and Duvivier (Application # 2005/0286634).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Caglar taught the core limitations of independent claims 1 and 9. Specifically, Caglar disclosed a video encoding system that generates a "virtual reference frame" from a complete frame of an original video signal for use in INTER-frame coding. Critically, Petitioner asserted that Caglar’s virtual frame is not intended for display, meeting the key negative limitation of the claims. Caglar was also argued to teach incorporating this virtual reference data into a bit-stream for transmission. For dependent claims requiring block-based encoding and incorporation into structures like a "dual block," Petitioner contended that any potential gap in Caglar’s disclosure was addressed by Duvivier, which taught efficiently storing video data by forming macroblocks containing partition data, header data, and reference frame index data.
    • Motivation to Combine: A POSITA would combine Caglar with Duvivier to improve the efficiency and structure of the bit-stream transmission. Duvivier’s method of partitioning video data into macroblocks was a known technique for reducing bandwidth, and a POSITA would have recognized it as a predictable way to implement the hierarchical bit-stream described by Caglar.
    • Expectation of Success: Petitioner asserted a high expectation of success, as both Caglar and Duvivier operate within the context of well-known video coding standards (e.g., H.263/H.264) and address the common goal of efficient video transmission between an encoder and a decoder.

Ground 2: Obviousness over Caglar, Duvivier, and Youn - Claims 3-5 and 17-19 are obvious over Caglar alone or in combination with Duvivier and Youn.

  • Prior Art Relied Upon: Caglar (Application # 2006/0146934), Duvivier (Application # 2005/0286634), and Youn (Application # 2008/0151999).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the teachings of Caglar and Duvivier from Ground 1 to address the additional limitations of claims 3-5. These claims require generating virtual reference data by identifying a set of video blocks and doing so to "minimize differences" between the identified blocks and the generated virtual data. Petitioner argued that Caglar’s use of virtual frames to enhance error resilience inherently sought to create a reference with high similarity (i.e., minimal difference) to the frame being predicted. To further support this, Petitioner introduced Youn, which disclosed a method for bypassing computationally intensive transform and quantization steps in video compression. Youn’s method involved calculating the sum of absolute transformed differences (SATD) to determine if a predicted macroblock was similar enough to a current macroblock, which Petitioner argued was a direct teaching of minimizing differences. Youn also disclosed determining "modal coefficient values" based on a threshold to decide whether to perform a full quantization, mapping to the ’960 patent’s claim language.
    • Motivation to Combine: A POSITA implementing the Caglar system would be motivated to incorporate Youn's techniques to achieve greater compression efficiency. Youn’s method for efficiently determining whether to bypass computationally intensive steps directly aligned with the primary industry goal of reducing computational load and bandwidth in video coding, a goal inherent in Caglar's system.
    • Expectation of Success: Success was expected because Youn’s methods were designed for standard video coding environments like H.26x, making them readily applicable and compatible with the block-based encoding framework taught by Caglar.

4. Key Claim Construction Positions

  • For the purposes of the IPR, Petitioner adopted the Patent Owner's proposed constructions.
  • The construction for "virtual reference data" was central to the petition's arguments. It was defined as "a group of pixels (e.g., a block) that is used as reference material for encoding portions of the video signal... but that does not comprise or represent any portion of the actual video sequence to be displayed." This construction allowed Petitioner to map the non-displayed "virtual frames" disclosed in Caglar to the claimed invention.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued against discretionary denial under Fintiv, asserting that a parallel district court trial was scheduled for June 2022, more than a year after the petition filing date, making it likely a Final Written Decision would issue first.
  • Petitioner stated that investment in the parallel litigation was minimal, as substantive fact discovery had not yet begun and no significant orders on the patent's substance had been issued.
  • Regarding §325(d), Petitioner contended that the primary references—Caglar, Duvivier, and Youn—were never cited or considered during the original prosecution and were materially different from the prior art of record, making the petition non-cumulative.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-28 of Patent 8,179,960 as unpatentable.