PTAB

IPR2021-00574

RingCentral Inc v. Estech Systems Inc

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1. Case Identification

2. Patent Overview

  • Title: Phone Directory In A Voice Over IP Telephone System
  • Brief Description: The ’298 patent describes a Voice over IP (VoIP) system with a directory feature that connects multiple local area networks (LANs) via a wide area network (WAN). The technology enables a user on a first LAN to observe, select between, and automatically call telecommunications extensions located on second and third remote LANs by accessing lists stored on servers in those respective networks.

3. Grounds for Unpatentability

Ground 1: Obviousness over Chang and Byrne - Claims 1-5, 7-12, and 17-19 are obvious over Chang in view of Byrne.

  • Prior Art Relied Upon: Chang (International Publication No. WO 99/05590) and Byrne (Patent 6,490,619).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Chang teaches the foundational system architecture claimed in the ’298 patent. This includes an "integrated voice gateway system" comprising multiple gateway networks (the claimed LANs) connected by an IP network (the claimed WAN). Chang further disclosed that each gateway network contains workstations (telecommunications devices) and a server that stores a partition of a company-wide "enterprise directory," or "white pages." While Chang teaches accessing these distributed directories, Petitioner contended that Byrne supplies the specific user interface (UI) functionality. Byrne describes a graphical user interface (GUI) for a distributed directory system that uses tabs to represent different servers. A user can click a tab to select a server and then browse a list of directory entries associated with that specific server. Petitioner asserted this directly maps to the ’298 patent’s limitation of enabling a user to select between observing lists of extensions from different LANs.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Byrne’s user-friendly GUI with Chang’s underlying system to improve its functionality. Both references address the same technical problem of accessing distributed enterprise directories over a network. Petitioner argued that implementing Byrne’s tabbed interface, which organizes directory information by server, was an obvious and logical way to allow users of Chang's system to efficiently browse directories by physical location or company division (represented by each gateway network/LAN).
    • Expectation of Success: A POSITA would have had a high expectation of success because both systems are technologically compatible. They both describe web-based interfaces for distributed directories that support the Lightweight Directory Access Protocol (LDAP), making their integration straightforward.

Ground 2: Obviousness over Chang, Byrne, and Imielinski - Claim 6 is obvious over Chang in view of Byrne and Imielinski.

  • Prior Art Relied Upon: Chang (International Publication No. WO 99/05590), Byrne (Patent 6,490,619), and Imielinski (Patent 6,240,558).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds upon the combination in Ground 1 to address the additional limitation of dependent claim 6, which requires the list of telecommunications extensions to be "played as audio to the user." Petitioner argued that Imielinski teaches a method for creating interactive audio-enabled web pages. Specifically, Imielinski describes converting the content of a web page, such as a table or database, into an audio format that a user can access and navigate via a standard telephone call. This, Petitioner contended, would allow the white pages directory from the Chang/Byrne system to be read aloud to a user.
    • Motivation to Combine: A POSITA would combine Imielinski's teachings to provide more flexible access to the enterprise directory. This addition would serve users who are remote and without computer access, a scenario Chang contemplates with its "virtual desktop" feature. It would also serve as an accessibility feature for visually impaired users, which Petitioner asserted was a routine design consideration at the time. Imielinski’s technology directly enhances the goal of providing widespread, flexible access to directory information.
    • Expectation of Success: A POSITA would have reasonably expected success because Imielinski is explicitly designed to convert database-driven web pages into an audio format. Since Chang’s white pages are stored in a gateway database and accessed via a web application, the technical implementation would have been a well-understood and achievable task.

4. Key Claim Construction Positions

  • "IP telephone": Petitioner proposed this term be construed as "any apparatus, device, system, or computer that can communicate multimedia traffic using IP telephony technology." This construction is broad enough to include the computer workstations described in the prior art.
  • "Touch input": Petitioner proposed this term means "an input entered by touching a physical input device." This interpretation was argued to be consistent with the prosecution history and would encompass conventional inputs like pressing a key on a keyboard or clicking a mouse button, not just interacting with a modern touchscreen.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §314(a) and the Fintiv factors would be inappropriate. The petition asserted that the parallel district court litigation was in its very early stages, with discovery not yet open and a trial date that was highly uncertain due to significant backlogs in the Western District of Texas. Petitioner also argued there was minimal overlap between the 11 patent claims asserted in litigation and the 18 claims challenged in the IPR, and that Petitioner was not a party to the litigation, having only recently agreed to indemnify a customer.

6. Relief Requested

  • Petitioner requests the institution of an inter partes review and the cancellation of claims 1-12 and 17-19 of the ’298 patent as unpatentable.