PTAB

IPR2016-00851

Dropbox Inc v. Synchronoss Technologies Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Data Transfer and Synchronization System
  • Brief Description: The ’757 patent discloses a bidirectional data synchronization system involving multiple devices coupled to a network. The system is designed to improve network efficiency by having each device use "differencing code" to generate and transmit "data change transactions," which represent only the modifications to a data file, rather than the entire file. These transactions are exchanged between devices via a central data store or storage server.

3. Grounds for Unpatentability

Ground 1: Anticipation over Nichols - Claims 16-20, 23-25, 27, and 29 are anticipated under 35 U.S.C. § 102 by Nichols.

  • Prior Art Relied Upon: Nichols (David A. Nichols et al., “High-Latency, Low-Bandwidth Windowing in the Jupiter Collaboration System,” Nov. 1995).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Nichols, which describes the "Jupiter" remote collaboration system, discloses every limitation of the challenged claims. The Jupiter system synchronizes shared data ("widgets") between multiple clients via a central server. To function effectively on high-latency networks, Jupiter transmits only "incremental state update messages" describing modifications, which Petitioner equated to the claimed "difference information." This architecture was asserted to directly map to the claimed system of two devices, a central data store, and the generation and transmission of change transactions. Petitioner further contended that Nichols's description of client and server operations inherently discloses all components of the claimed "sync engine."
    • Key Aspects: Petitioner emphasized that Nichols addressed the same problem as the ’757 patent—efficient data synchronization over slow networks—and arrived at the same solution years earlier.

Ground 2: Anticipation over CVS Documentation - Claims 16-21 and 24-28 are anticipated under 35 U.S.C. § 102 by the CVS Documentation.

  • Prior Art Relied Upon: The CVS Documentation, comprising two documents distributed together as a single printed publication: "CVS Client/Server" and "Version Management with CVS" (publicly available by Dec. 2, 1998).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that the Concurrent Versions System (CVS) documentation describes the claimed invention in the context of version control software. In the CVS system, users on client machines ("devices") connect over a network to a central "repository" ("data store"). A user "commits" changes to a file, and other users can then "update" their local copies to receive those changes. Critically, Petitioner argued that the CVS documentation teaches transmitting only the differences using "diffs" (equivalent to "change transactions") generated by the standard GNU diff utility, rather than sending entire files. The documentation was also shown to disclose the system's use over the Internet, satisfying limitations in dependent claims.

Ground 3: Obviousness over Kistler in view of Burns - Claims 16-19, 22, 24, and 27 are obvious over Kistler in view of Burns.

  • Prior Art Relied Upon: Kistler (James J. Kistler & M. Satyanarayanan, “Disconnected Operation in the Coda File System,” 1992) and Burns (Randal C. Burns & Darrell D.E. Long, “Efficient Distributed Backup with Delta Compression,” 1997).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Kistler discloses the general architecture of the claimed invention through its Coda distributed file system. Coda allows clients to work on locally cached files while disconnected from a network and later synchronize those files with a central server. However, Kistler's synchronization process involves transferring entire files, which is inefficient. Burns was presented as teaching the solution to this inefficiency: a "delta backup" technique that significantly reduces network traffic by generating and transmitting only a "delta file" containing the differences between file versions.
    • Motivation to Combine: A POSITA would combine Kistler's system architecture with Burns's delta compression method to solve a problem explicitly recognized in the art and even hinted at in Kistler. Kistler itself suggested that "partial file transfer" would be useful in environments with low-bandwidth or intermittent connectivity. Burns provided a well-known and direct method for implementing this partial transfer. The combination would have been a predictable way to improve the performance of the Coda system by reducing bandwidth consumption and synchronization time.
    • Expectation of Success: Petitioner contended there was a high expectation of success because Burns taught a specific algorithm for generating difference information that was well within the skill of a POSITA to apply to Kistler's file synchronization process. The motivation was strong, the solution was known, and no technological hurdles were identified.

  • Additional Grounds: Petitioner asserted duplicative obviousness challenges over Nichols (Ground 2) and the CVS Documentation (Ground 4), arguing that even if these references did not anticipate every limitation, any missing element would have been obvious to a POSITA.

4. Key Claim Construction Positions

  • "Difference Information": Petitioner argued this term should be construed as "information that comprises only the changes to one system's data... and instructions for implementing those changes." This proposed construction was based on the patent's specification and, critically, on a "clear and unmistakable disclaimer" Petitioner alleged the Patent Owner made during a prior inter partes reexamination to distinguish the claims from other art.
  • "Difference Transaction": Flowing from the proposed construction above, Petitioner argued this term should be construed as "one or more pieces of difference information communicated together." This construction was central to Petitioner's arguments for mapping the prior art's transmission of "diffs," "deltas," or "incremental updates" to the specific language of the claims.

5. Relief Requested

  • Petitioner requests the institution of an inter partes review and the cancellation of claims 16-29 of Patent 6,671,757 as unpatentable.