PTAB

IPR2026-00127

Cisco Systems Inc v. Dynamic Mesh Networks Inc

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Data Network Supporting VoIP Communications
  • Brief Description: The ’762 patent discloses a data network for Voice over Internet Protocol (VoIP) communications that eliminates dependency on a central server. The system uses distributed Session Initiation Protocol (SIP) registries, where each VoIP node in a cluster maintains its own local SIP registry and acts as an autonomous SIP server.

3. Grounds for Unpatentability

Ground 1: Claims 1-4, 8, and 9 are obvious over Saridakis in view of Wu.

  • Prior Art Relied Upon: Saridakis (Application # 2005/0138119) and Wu (Application # 2008/0098121).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Saridakis taught a peer-to-peer ad hoc network where each mobile phone acts as a single, integrated peer device containing a SIP User Agent (UA), a local proxy, and a local registrar in the form of a Distributed User-Location Service (DULS). Wu taught separating these functions, where Access Points (APs) perform proxy and registrar roles, and separate User Terminals (UTs) act as SIP UAs. The proposed combination modified Saridakis by implementing its local proxy and DULS registry within APs and its SIP UA within UTs, as taught by Wu. This combined structure allegedly met the limitations of independent claim 1, which requires distinct VoIP client devices (the UTs) and VoIP nodes (the APs) that form a cluster and maintain local SIP registries (the DULS instance in each AP).
    • Motivation to Combine: A POSITA would combine the references to create a more scalable and cost-effective network. The modification would allow standard mobile devices to use Saridakis’s distributed functionality and would permit multiple devices to share a single AP, reducing deployment complexity.
    • Expectation of Success: Petitioner asserted a high expectation of success because both references are based on the same SIP framework for peer-to-peer environments and aim to distribute SIP functionality. The combination amounted to a predictable substitution of components to achieve known benefits.

Ground 2: Claims 1-4, 7-10, 12-13, and 15-17 are obvious over Saridakis, Wu, and Bauer.

  • Prior Art Relied Upon: Saridakis (Application # 2005/0138119), Wu (Application # 2008/0098121), and Bauer (Application # 2007/0140239).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground augmented the Saridakis-Wu combination with Bauer. Petitioner argued that to the extent Saridakis-Wu failed to explicitly teach an "isolated cluster," Bauer supplied this limitation. Bauer disclosed a mesh network that dynamically switches between accessing centralized internet services when available and providing those services locally when disconnected. Applying this teaching to Saridakis-Wu would result in a network that operates in a truly "isolated" mode when disconnected from its external cellular network. In this isolated mode, the network would provide SIP services entirely by itself, without communication with the external network, thereby meeting the "isolated cluster" limitation of the challenged claims.
    • Motivation to Combine: A POSITA would combine Bauer's dynamic switching capability with the Saridakis-Wu network because Saridakis-Wu already contemplated both isolated and connected operation. Bauer’s technique was known to be applicable to analogous services (DNS vs. user-location), and the underlying network architectures (wireless mesh vs. ad hoc) were substantially similar.
    • Expectation of Success: Success would be predictable, as the modification would only require adding known techniques for detecting network connectivity to disable reliance on external SIP entities when the network is isolated.

Ground 3: Claims 5, 6, 9, 14, and 18-21 are obvious over Saridakis, Wu, Bauer, and Kelly.

  • Prior Art Relied Upon: Saridakis (Application # 2005/0138119), Wu (Application # 2008/0098121), Bauer (Application # 2007/0140239), and Kelly (Application # 2006/0126611).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground added Kelly to address claims requiring DHCP server functionality and random IP address assignment. Petitioner argued that the Saridakis-Wu-Bauer combination, when operating in an isolated mode, lacked a mechanism for IP address assignment. Kelly taught a distributed DHCP service where peer nodes ("mesh boxes") in an ad hoc network assign IP addresses to their clients. Petitioner proposed incorporating Kelly’s distributed DHCP functionality into the APs of the primary combination, thereby teaching claim 5's limitation of a VoIP node functioning as a DHCP server. Kelly also explicitly taught assigning IP addresses from a range produced by a random number generator, directly mapping to the limitations of dependent claims 6, 19, and 21.
    • Motivation to Combine: A POSITA would have been motivated to integrate Kelly to solve the known problem of IP address assignment in an ad hoc network operating without a centralized infrastructure. The systems were highly compatible, as both relied on peer nodes (APs or mesh boxes) to provide distributed network services.
    • Expectation of Success: Petitioner argued for a high expectation of success, as implementing Kelly’s distributed DHCP logic within the peer nodes of the Saridakis-Wu-Bauer combination was a straightforward application of a known solution to a known problem, yielding predictable results.

4. Key Claim Construction Positions

  • “means of connecting the isolated cluster to an external network” (Claim 7): Petitioner argued this term should be interpreted under 35 U.S.C. §112 ¶6. The recited function is "connecting the isolated cluster to an external network," and the corresponding structure disclosed in the specification is "software and/or hardware elements."
  • “VoIP optimized services” (Claim 9): Based on statements made during prosecution, Petitioner contended this term must be interpreted to include, at a minimum, a SIP Server Service or a DHCP Server service.
  • “communications means” (Claim 15): Petitioner argued that although this term uses the word "means," it should be given its plain and ordinary meaning and not be governed by §112 ¶6 because the claim fails to recite a corresponding function for the means to perform.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-10 and 12-21 of the ’762 patent as unpatentable.