DCT

6:21-cv-00128

WSOU Investments, LLC v. Cisco Systems, Inc.

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 6:21-cv-00128, W.D. Tex., 02/05/2021
  • Venue Allegations: Plaintiff alleges venue is proper in the Western District of Texas because Defendant Cisco Systems is registered to do business in Texas, has transacted business in the district, and maintains a regular and established place of business within the district, including campuses in Austin and San Antonio.
  • Core Dispute: Plaintiff alleges that a range of Defendant’s networking products and software solutions infringe five patents related to telecommunications network management, security, and performance monitoring.
  • Technical Context: The technologies at issue concern foundational aspects of modern telecommunications, including protocol interoperability, secure address allocation, dynamic security policy enforcement, and network performance monitoring for mobile and converged data networks.
  • Key Procedural History: Subsequent to the filing of this complaint, two of the asserted patents—U.S. Patent Nos. 8,191,106 and 8,665,733—were challenged in inter partes review (IPR) proceedings before the Patent Trial and Appeal Board. In both IPRs, all claims of each patent, including all claims asserted in this litigation, were found unpatentable and cancelled. These cancellations may render the infringement counts for the ’106 and ’733 patents moot.

Case Timeline

Date Event
2001-12-18 '859 Patent Priority Date
2007-06-07 '106 Patent Priority Date
2008-10-28 '859 Patent Issue Date
2011-09-30 '733 Patent Priority Date
2012-03-30 '216 Patent Priority Date
2012-05-29 '106 Patent Issue Date
2014-03-04 '733 Patent Issue Date
2014-04-29 '014 Patent Priority Date
2015-03-24 '216 Patent Issue Date
2016-05-31 '014 Patent Issue Date
2021-02-05 Complaint Filing Date
2021-05-21 IPR filed against '733 Patent (IPR2021-00960)
2021-06-17 IPR filed against '106 Patent (IPR2021-01117)
2023-03-06 IPR Certificate issues cancelling claims of '733 Patent
2023-03-29 IPR Certificate issues cancelling claims of '106 Patent

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,989,216 - "Diameter versioning dictionary," issued March 24, 2015.

The Invention Explained

  • Problem Addressed: The patent’s background section describes incompatibility issues in 3GPP networks where different network nodes may run different versions of the Diameter protocol, leading to communication failures because commands and their parameters (Attribute Value Pairs or AVPs) are defined differently across versions (’216 Patent, col. 1:20-44).
  • The Patented Solution: The invention proposes a flexible "Diameter versioning dictionary" that contains not only a default definition for a command or AVP, but also one or more "context-specific definitions" (’216 Patent, col. 3:8-12). When a network node communicates with a peer, it can select the appropriate definition based on the "context" (e.g., the peer's software release or vendor), enabling a single node to interoperate with multiple, otherwise incompatible, protocol versions (’216 Patent, col. 3:12-22).
  • Technical Importance: This approach allows for greater flexibility and interoperability in complex, multi-vendor telecommunication networks as standards evolve over time (’216 Patent, col. 2:50-54).

Key Claims at a Glance

  • The complaint asserts independent claim 4 and reserves the right to assert others (Compl. ¶11).
  • Claim 4 of the ’216 Patent recites:
    • A network node comprising a Diameter protocol command dictionary comprising:
    • a first definition for a Diameter protocol command, wherein said command is defined by a first default definition unless a first context applies, in which case it is defined by a context-specific definition, with the dictionary supporting multiple standard versions;
    • a second definition for a Diameter protocol attribute value pair (AVP), wherein said command or AVP is defined by a second default definition unless a second context applies, in which case it is defined by a second context-specific definition;
    • wherein the dictionary interoperates with a Diameter protocol stack to perform functions for processing Diameter messages.

U.S. Patent No. 7,443,859 - "Method and apparatus for address allocation in GPRS networks that facilitates end-to-end security," issued October 28, 2008.

The Invention Explained

  • Problem Addressed: The patent identifies that using private IP addresses in GPRS networks requires Network Address Translators (NATs) at the network edge, which can break end-to-end security protocols (like IPsec) and interfere with applications that embed IP addresses in their data payloads (’859 Patent, col. 1:57-col. 2:24).
  • The Patented Solution: The invention proposes a method where a mobile station, in its "Activate PDP Context Request" message, includes information in the Access Point Name (APN) field that "explicitly indicates" whether it is requesting a private or a public IP address (’859 Patent, col. 7:47-52). The network's Serving GPRS Support Node (SGSN) receives this request and, based on the explicit information, assigns the appropriate address type, thereby avoiding NAT-related issues when a public address is required (’859 Patent, Abstract).
  • Technical Importance: This technique provides a mechanism within the GPRS framework for a mobile device to signal its IP addressing needs, enhancing support for secure communications and other specialized applications (’859 Patent, col. 4:1-9).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and reserves the right to assert others (Compl. ¶26).
  • Claim 1 of the ’859 Patent recites:
    • A method comprising:
    • receiving an Activate PDP Context Request message at an SGSN from a mobile station, the message having an APN field containing information that explicitly indicates a request for either a private or a public network address; and
    • sending an Activate PDP Context Accept message to the mobile station assigning one of a private or public network address based on the information in the APN field.

U.S. Patent No. 8,191,106 - "System and method of network access security policy management for multimodal device," issued May 29, 2012.

  • Patent Identification: U.S. Patent No. 8,191,106, "System and method of network access security policy management for multimodal device," issued May 29, 2012 (Compl. ¶38).
  • Technology Synopsis: The patent discloses a system for managing security policies for devices capable of connecting to a network via multiple technologies (e.g., Wi-Fi, cellular). An "inter-technology change-off monitoring entity" (ICME) detects when a device switches access technologies and notifies a policy manager. The policy manager then retrieves and distributes the appropriate security policies for the new technology from a database to enforcement points in the network, ensuring continuous and context-appropriate security (’106 Patent, Abstract).
  • Asserted Claims: At least independent claim 1 (Compl. ¶41).
  • Accused Features: Cisco’s converged network architecture is accused of infringement, where a DHCP sequence allegedly signals a technology change-off, PCRF/AAA servers act as a policy database, and the Intelligent Wireless Access Gateway (ISG/WAG) serves as the policy manager and enforcement point (Compl. ¶¶43-46).

U.S. Patent No. 8,665,733 - "Method and apparatus for round trip delay KPI monitoring in live network using user plane probe session," issued March 4, 2014.

  • Patent Identification: U.S. Patent No. 8,665,733, "Method and apparatus for round trip delay KPI monitoring in live network using user plane probe session," issued March 4, 2014 (Compl. ¶56).
  • Technology Synopsis: The patent describes a method to measure and isolate network latency. A user device transmits a "loopback packet" marked with a "probe session indicator." Each network element along the packet's round-trip path detects this indicator, logs timestamps upon the packet's receipt and retransmission, and reports these timestamps to a central network management system for analysis (’733 Patent, Abstract). This allows operators to pinpoint specific sources of delay within the network.
  • Asserted Claims: At least independent claim 1 (Compl. ¶59).
  • Accused Features: Cisco's IP Service Level Agreements (SLA) functionality is accused of infringement. The complaint alleges that IP SLA uses test packets with time indicators to record round-trip timestamps at source and target devices, which are then reported for network performance analysis (Compl. ¶¶61-64).

U.S. Patent No. 9,357,014 - "Service-based networking," issued May 31, 2016.

  • Patent Identification: U.S. Patent No. 9,357,014, "Service-based networking," issued May 31, 2016 (Compl. ¶73).
  • Technology Synopsis: The patent presents a "service-based networking" model using a "connected services layer" situated between the application and transport layers. This layer enables applications to establish connections based on logical "service names" rather than physical IP addresses. An endpoint requests a connection by name from a central server, which resolves the name to an IP address and facilitates the creation of a "service connection," abstracting the underlying network topology from the application (’014 Patent, Abstract).
  • Asserted Claims: At least independent claim 18 (Compl. ¶76).
  • Accused Features: Cisco's Ultra 5G packet core solution, which utilizes the 3GPP 5G Service-Based Architecture, is accused of infringement. The complaint alleges this architecture uses a Network Repository Function (NRF) as a server to allow network components to discover and connect to each other using service names, mirroring the claimed method (Compl. ¶¶78-80).

III. The Accused Instrumentality

Product Identification

  • The complaint accuses a broad range of Cisco's networking products, including its ASR 5000 series routers, Virtual Packet Core solutions, switches running Cisco Star OS, various other routers and wireless controllers implementing Cisco IOS, and the Cisco Ultra 5G packet core solution (Compl. ¶¶ 11, 26, 41, 59, 76).

Functionality and Market Context

  • The accused products form the core infrastructure for mobile and converged telecommunications networks. Their functionalities, as described in the complaint, include implementing the Diameter protocol for authentication, authorization, and accounting (AAA) (Compl. ¶13); providing SGSN and GGSN functions for mobile data networks (Compl. ¶28); managing network access and security policies in converged Wi-Fi/cellular environments (Compl. ¶43); monitoring network performance via Service Level Agreements (SLAs) (Compl. ¶61); and enabling the 3GPP 5G Service-Based Architecture (Compl. ¶78).
  • The complaint alleges these functionalities are central to the operation of modern networks sold and operated by Cisco and its customers. No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’216 Patent Infringement Allegations

Claim Element (from Independent Claim 4) Alleged Infringing Functionality Complaint Citation Patent Citation
A network node comprising a Diameter protocol command dictionary comprising: a first definition for a Diameter protocol command, wherein said Diameter protocol command is defined by a first default definition unless a first context applies in which case said command is defined by a context-specific definition... The accused products are network nodes that provide various Diameter dictionaries (DPCA, DCCA, etc.). A "standard dictionary" is allegedly used as a default, and "custom-defined dictionaries" are allegedly used for specific contexts. ¶13 col. 3:8-12
...a second definition for a Diameter protocol attribute value pair (AVP), wherein said command or AVP is defined by a second default definition unless a second context applies in which case said AVP is defined by a second context-specific definition... The accused products use Diameter AVPs to carry specific information for authentication, routing, etc. The complaint alleges the same default/context-specific dictionary structure applies to these AVPs. ¶14 col. 3:12-16
...wherein said Diameter protocol command dictionary interoperates with a Diameter protocol stack to perform functions for processing Diameter messages. The accused products' Diameter dictionary allegedly "interoperates with multiple dictionary protocols (e.g., a Diameter protocol stack) to perform functions for processing Diameter messages." ¶14 col. 3:31-33
  • Identified Points of Contention:
    • Scope Questions: A central question is whether Cisco’s use of separate "custom-defined dictionaries" (Compl. ¶13) is equivalent to the claimed dictionary that comprises both a "default definition" and a "context-specific definition" within a unified structure. The defense may argue that simply loading different dictionary files does not meet the claim limitation of a single dictionary containing both types of definitions.
    • Technical Questions: The complaint alleges a standard dictionary is used "until there is a specific context" (Compl. ¶13). A key factual question is what evidence demonstrates that the accused products dynamically select between a default and a custom definition for the same command or AVP based on a detected "context," as opposed to simply using different, pre-configured dictionaries for different overall system configurations.

’859 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
receiving an Activate Packet Data Protocol (PDP) Context Request message at a Serving General Packet Radio System (GPRS) Support Node (SGSN)... the Activate PDP Context Request message having an APN (Access Point Name) field containing information that explicitly indicates requesting either a private network address or a public network address... The accused products provide an SGSN application that receives PDP Context Request messages. To resolve the APN, the SGSN sends a request to the GGSN that includes an "APN restriction value," which allegedly "defines the type of APN access, whether private or public." ¶¶28-29 col. 7:47-52
sending an Activate PDP Context Accept message to the mobile station containing information assigning one of a private network address and a public network address... based on the information contained in the APN field... After the GGSN assigns an IP address based on the "APN restriction value," the SGSN sends an "Activate PDP Context Accept message" back to the mobile station with the assigned address. ¶29 col. 7:53-59
  • Identified Points of Contention:
    • Scope Questions: The claim requires the request for a private or public address to be "explicitly" indicated in information "contained in the APN field" of the message from the mobile station. The infringement theory hinges on whether the "APN restriction value" is part of this APN field as received from the mobile station, or if it is a separate parameter derived or configured on the network side based on an interpretation of the APN.
    • Technical Questions: What evidence does the complaint provide to show that the "APN restriction value" is data that is resident within the APN field string itself, as opposed to being a policy parameter that the SGSN or GGSN associates with a received APN string? The complaint's allegations do not specify the origin or format of this value.

V. Key Claim Terms for Construction

’216 Patent Term

  • The Term: "context-specific definition"
  • Context and Importance: This term is the central inventive concept of the ’216 Patent. The outcome of the infringement analysis for this patent will likely depend on whether Cisco's alleged use of "custom-defined dictionaries" falls within the scope of this term. Practitioners may focus on this term because it distinguishes the invention from prior art static dictionaries.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification defines "context" broadly to include "a specific 3GPP standard such as a major release," a "minor release," or even a "custom or proprietary implementation... from a specific vendor" (’216 Patent, col. 3:16-22). This could support an argument that any mechanism that selects a different definition based on vendor or version information meets the limitation.
    • Evidence for a Narrower Interpretation: The claim states the "dictionary" itself "compris[es]" the default and context-specific definitions. Figure 2 depicts a single "Diameter Versioning Dictionary" data structure (200) containing entries for both. This may support an argument that the claimed invention requires a specific integrated data structure, not merely the ability to load different, separate dictionary files.

’859 Patent Term

  • The Term: "APN (Access Point Name) field containing information that explicitly indicates requesting" [a private or public] "network address"
  • Context and Importance: This limitation defines how the mobile station communicates its addressing preference to the network. The infringement case rests on showing that the accused products process this specific type of information from within the APN field.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language is functional. Plaintiff may argue that as long as the APN string received from the mobile station contains data that the SGSN uses to "explicitly" determine the address type, the limitation is met, regardless of the specific format.
    • Evidence for a Narrower Interpretation: The specification describes the invention as "inserting information into the APN field" (’859 Patent, col. 7:9-10). This could support a narrower construction requiring the explicit indicator to be a specific flag or sub-field formatted within the APN string itself, rather than a network-side policy (the "APN restriction value") that is triggered by the identity of the entire APN string.

VI. Other Allegations

Indirect Infringement

  • For each asserted patent, the complaint alleges induced infringement under 35 U.S.C. § 271(b). The allegations are based on Cisco providing and disseminating product descriptions, operating manuals, and other instructions that allegedly guide customers and end-users to implement and configure the accused products in an infringing manner (e.g., Compl. ¶¶ 16-17, 31-32, 49-50, 66-67, 82-83).

Willful Infringement

  • The complaint alleges that Cisco has had "notice and actual or constructive knowledge" of the asserted patents "since at least the date of service of this Complaint" (e.g., Compl. ¶¶ 15, 30, 48, 65, 81). This forms the basis for a claim of post-suit willful infringement, alleging that any continued infringement after receiving notice via the lawsuit is deliberate and willful. No allegations of pre-suit knowledge are made.

VII. Analyst’s Conclusion: Key Questions for the Case

  • A dispositive threshold issue will be one of procedural finality: what is the legal effect of the inter partes review proceedings that resulted in the cancellation of all asserted claims for the ’106 and ’733 patents? This raises the immediate question for the court of whether the infringement counts related to these two patents are moot and must be dismissed.
  • For the surviving patents, a core issue will be one of definitional scope: can terms rooted in the patent specifications, such as an APN field "containing information that explicitly indicates" a choice of address type (’859 Patent), be construed to read on the alleged network-side policy parameters like an "APN restriction value" used in the accused systems?
  • A key evidentiary question will be one of functional implementation: for the ’216 patent, does the accused system’s use of separate "custom dictionaries" operate in the same way as the claimed invention's integrated dictionary comprising both "default" and "context-specific" definitions that are dynamically chosen based on a detected context, or is there a fundamental mismatch in technical architecture and operation?