PTAB

IPR2021-00573

RingCentral, Inc. v. Estech Systems, Inc.

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1. Case Identification

2. Patent Overview

  • Title: Dialing Using Caller ID
  • Brief Description: The ’349 patent relates to a telephone and voicemail system that stores caller ID information with corresponding voicemail messages. The system is designed to enable a user to automatically call back the party who left a message, for instance, by pressing a single key on their telephone while listening to the voicemail.

3. Grounds for Unpatentability

Ground 1: Obviousness over Itoh - Claims 1-2, 4, 6, and 19 are obvious over Itoh in view of POSITA knowledge.

  • Prior Art Relied Upon: Itoh (U.S. Patent No. 5,841,838).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Itoh teaches the core functionality claimed in the ’349 patent. Itoh’s telephone unit receives an incoming call with caller ID, connects the call to a voicemail system if unanswered, stores the caller’s number in association with the recorded message, and allows a user to automatically dial that number by pressing a “redial” key during message playback. Petitioner argued Itoh’s disclosed components (CPU, NCU, DRAM) provide the circuitry required by system claims 6 and 19.
    • Motivation to Combine: This ground relies on a single reference. However, Petitioner argued a POSITA would find it obvious to use Itoh’s system with a conventional switched telephone network. Such networks were ubiquitous, and Itoh’s system was described as a “versatile telephone unit” compatible with them, making the implementation straightforward.
    • Expectation of Success: This was not argued as a separate point, as it is inherent in the single-reference obviousness argument based on conventional technology.

Ground 2: Obviousness over Itoh and Turnbull - Claims 7-11 and 20-22 are obvious over Itoh in view of Turnbull.

  • Prior Art Relied Upon: Itoh (’838 patent) and Turnbull (U.S. Patent No. 5,590,189).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed claims requiring the transfer of caller ID to a “calling list” and the indexing of entries on that list. Petitioner argued Itoh discloses a basic calling list via its “telephone book” feature. Turnbull was introduced to teach a more advanced, user-friendly “directory list” that is scrollable and can be indexed alphabetically by the caller’s name, thereby satisfying the limitation of indexing as a function of identifying data.
    • Motivation to Combine: A POSITA would combine Turnbull’s superior user interface with Itoh’s system as a common-sense improvement. Itoh’s system required a user to remember an abbreviation number to use its calling list, which is burdensome, whereas Turnbull’s browsable, indexed list offered a more convenient and intuitive solution to improve usability.
    • Expectation of Success: Petitioner asserted a high expectation of success, as both references describe telephone devices with compatible hardware (e.g., CPU, memory, display, dialing apparatus). Integrating Turnbull’s features into Itoh’s device would only require simple programming modifications and the addition of common keys like scroll buttons.

Ground 3: Obviousness over Itoh and Ladd - Claims 3 and 12-15 are obvious over Itoh in view of Ladd.

  • Prior Art Relied Upon: Itoh (’838 patent) and Ladd (U.S. Patent No. 5,117,451).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground addressed claims requiring the called party to be located at a telephone “extension.” Petitioner argued Ladd teaches this limitation by disclosing a private branch exchange (PBX) system with multiple extensions. Ladd’s system prompts callers for an extension number, routes the call accordingly, and connects to the designated extension’s mailbox if the call is unanswered.
    • Motivation to Combine: A POSITA would be motivated to use Itoh’s feature-rich telephone as an extension phone within a PBX system like that of Ladd. This combination would improve Ladd’s system, which used a cumbersome centralized voicemail requiring a user login, by providing local voicemail storage and direct playback at the Itoh extension, thus eliminating the login process.
    • Expectation of Success: Petitioner argued a high expectation of success because Ladd already discloses using telephone devices at extensions. The combination would simply involve using the Itoh device at an extension and configuring Ladd’s PBX to forward caller ID to it, which was a known capability for PBX systems at the time of the invention.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge for claims 17-18 and 23-31 based on the combination of Itoh, Turnbull, and Ladd, arguing this three-way combination renders obvious claims that combine the requirements of the first three grounds (call-back, indexed calling list, and use at an extension).

4. Key Claim Construction Positions

  • "Means for the user to access the calling list" (Claim 31): Petitioner contended this is a means-plus-function term. The asserted function is “for the user to access the calling list,” and the corresponding structure disclosed in the ’349 patent is a single physical key. This construction is central to arguing that the “Directory” key in the Turnbull reference is an equivalent structure.
  • "Indexing" (Claim 20): Petitioner argued that a POSITA would understand this term’s well-understood technical meaning of creating a list that contains reference information (like an abbreviation number or name) pointing to each entry. This supports the argument that Itoh’s abbreviation number system and Turnbull’s alphabetical sorting both meet the “indexing” limitation.

5. Arguments Regarding Discretionary Denial

  • §314(a) (Fintiv Factors): Petitioner argued against discretionary denial, asserting that the parallel district court case was in its early stages with no firm trial date and significant scheduling uncertainty due to court backlogs. Petitioner also argued there is minimal overlap between the small number of claims asserted in court and the broader set of claims challenged in the IPR, and that Petitioner is not a party to the litigation (though it is indemnifying a customer).
  • §325(d): Petitioner argued this section does not apply because the prior art references central to the petition (Itoh, Turnbull, and Ladd) and the combinations thereof were never considered by the USPTO during the original prosecution of the ’349 patent, and thus the petition raises new arguments that have not been previously addressed.

6. Relief Requested

  • Petitioner requested that the Board institute an inter partes review and cancel claims 1-4, 6-15, and 17-31 of Patent 6,067,349 as unpatentable.