RingCentral Inc v. Estech Systems Inc

1. Case Identification

• Case #: IPR2021-00573
• Patent #: 6,067,349
• Filed: March 5, 2021
• Petitioner(s): RingCentral, Inc.
• Patent Owner(s): Estech Systems, Inc.
• Challenged Claims: 1-4, 6-15, and 17-31

2. Patent Overview

• Title: Dialing Using Caller ID
• Brief Description: The ’349 patent discloses a telephone and voicemail system that stores caller ID information in association with a corresponding voicemail message. The system enables a user to automatically dial the telephone number of the party who left the message, for example, by pressing a single key while listening to the voicemail.

3. Grounds for Unpatentability

Ground 1: Claims 1-2, 4, 6, and 19 are obvious over Itoh.

• Prior Art Relied Upon: Itoh (Patent 5,841,838).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Itoh, a patent for a "versatile telephone unit," disclosed all key limitations of the independent claims. Itoh's system receives incoming calls with caller ID (number and name) over a telephone network, connects the call to an internal voicemail system (DRAM) if unanswered, and stores the caller ID information in one-to-one correspondence with the recorded voice message. Critically, Itoh taught that a user listening to a voicemail can press a "redial" key to interrupt playback and automatically dial the phone number associated with that message. Dependent claims were also allegedly taught, such as including the caller's identity (name) and performing the method within a telephone/voice processing system.
  • Motivation to Combine (for §103 grounds): This ground relied on a single reference, arguing Itoh alone taught the claimed invention or rendered it obvious to a POSITA. Petitioner contended that minor implementation details, such as using a conventional switched telephone network with Itoh's switchboard, were well within the knowledge of a POSITA.
  • Expectation of Success (for §103 grounds): As a single-reference ground, this was not a primary focus, but Petitioner argued a POSITA would expect success in implementing Itoh's disclosed features on a standard telephone network.

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

• Prior Art Relied Upon: Itoh (Patent 5,841,838), Turnbull (Patent 5,590,189).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon Itoh by adding features for managing a "calling list." Petitioner asserted Itoh disclosed a basic calling list in its "telephone book" feature, where a user could transfer a caller's number to a speed-dial list while listening to a voicemail. Turnbull, which disclosed a telephone with a microprocessor, was introduced to teach a more advanced "directory list." Turnbull's list could be organized and indexed alphabetically, browsed using scroll keys, and allowed a user to select and dial an entry directly from the displayed list.
  • Motivation to Combine: A POSITA would combine Itoh and Turnbull to improve the user interface and functionality of Itoh's calling list. Itoh’s list required a user to remember an abbreviation number for each contact, which was cumbersome. Turnbull provided a common-sense solution by teaching a browsable, alphabetically indexed directory, a well-known feature that would make Itoh's system more user-friendly and efficient.
  • Expectation of Success: Success was expected as both references described telephone devices with compatible hardware (CPUs, memory, displays). Implementing Turnbull's software-based list management features into Itoh's device would involve straightforward programming.

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

• Prior Art Relied Upon: Itoh (Patent 5,841,838), Ladd (Patent 5,117,451).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground addressed claims requiring the called party to be at an "extension" of a telephone network. While Itoh taught a standalone telephone unit, Ladd disclosed a private branch exchange (PBX) system with multiple extensions and an integrated voice messaging system. Ladd taught receiving an external call, prompting the caller to enter an extension number, and routing the call to the corresponding extension's voice mailbox if unanswered.
  • Motivation to Combine: A POSITA would combine Itoh with Ladd to use Itoh's feature-rich telephone as an endpoint in a standard PBX system. Ladd represented a well-known PBX architecture, and Itoh's device was described as a conventional telephone unit compatible with such systems. The combination would provide the advanced callback and caller ID features of Itoh to users on an office extension, improving upon Ladd's more basic, centralized voicemail system.
  • Expectation of Success: A POSITA would expect success, as using a single-line telephone like Itoh's as an extension on a PBX system was a routine and well-understood practice at the time of the invention.

• Additional Grounds: Petitioner asserted Ground 4, arguing claims 17-18 and 23-31 are obvious over Itoh in view of Turnbull and further in view of Ladd. This ground combined the teachings of all three references to meet the broadest claims, which required dialing from a voicemail, adding the number to an indexed calling list, and doing so on a device operating as an extension of a larger telephone network.

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 claimed function is "for the user to access the calling list," and the corresponding structure disclosed in the ’349 patent is a physical key, such as the "calling list key."
• "Indexing" (Claim 20): Petitioner argued that while the patent provided little detail, a POSITA would understand "indexing" to mean creating a list with reference information (e.g., a number or alphabetic entry) pointing to each stored telephone number, consistent with its well-understood meaning in the art.
• "calling list" (claims 7, 8): In related district court litigation, Petitioner's real-party-in-interest proposed construing this term as "speed dial list."

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under Fintiv was inappropriate. The parallel district court case in the Western District of Texas was in its early stages, with fact discovery not yet open, and the trial date was uncertain due to court backlogs. Petitioner asserted it filed the petition expeditiously after agreeing to indemnify its customer. Further, the overlap between the cases was argued to be minimal, as the IPR challenged more claims than were asserted in the litigation. Petitioner also argued against denial under §325(d), noting that none of the asserted prior art (Itoh, Turnbull, Ladd) was considered by the examiner during the original prosecution.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-4, 6-15, and 17-31 of the ’349 patent as unpatentable.