WSOU Investments LLC v. F5 Networks Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: WSOU Investments, LLC d/b/a Brazos Licensing and Development (Delaware)
  • Defendant: F5 Networks, Inc. (Washington)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: WSOU Investments, LLC v. [F5 Networks, Inc.](https://ai-lab.exparte.com/party/f5-networks-inc), 1:20-cv-01085, E.D. Va., 09/15/2020
• Venue Allegations: Venue is alleged to be proper based on Defendant having an established place of business in the district and having committed alleged acts of patent infringement there.
• Core Dispute: Plaintiff alleges that Defendant’s network products infringe a patent related to methods for generating real-time billing information in converged telecommunications networks.
• Technical Context: The technology addresses the challenge of real-time billing for calls that cross between traditional circuit-switched telephone networks and modern packet-switched (IP-based) networks.
• Key Procedural History: The complaint does not allege any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the patent-in-suit.

Case Timeline

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

U.S. Patent No. 9,584,330 - "Method for generating a real time billing information in a packet switching based network and network element"

Patent Identification: U.S. Patent No. 9,584,330, “Method for generating a real time billing information in a packet switching based network and network element,” issued February 28, 2017 (Compl. ¶8; ’330 Patent, front page).

The Invention Explained

• Problem Addressed: The patent addresses the complexity and cost of generating real-time billing information in IP Multimedia Subsystem (IMS) networks, particularly for calls originating from a traditional Public Switched Telephone Network (PSTN). Conventional methods relied on post-call data processing or required application servers to perform complex, country-specific decoding of legacy billing messages encapsulated within modern network protocols (’330 Patent, col. 2:18-24, col. 2:41-47).
• The Patented Solution: The invention proposes a method where a network element, such as a Media Gateway Control Function (MGCF), receives billing messages from the legacy network. In response, it generates standardized messages for the IP network. Specifically, it generates a first message containing a "first token" (e.g., "Tariff") to inform a billing server of the call's billing rate, and later, a second message with a "second token" (e.g., "Meter-Pulse") to inform the server of the billing interval. This two-step, token-based approach simplifies the process, allowing the billing server to generate real-time information without needing complex decoding capabilities (’330 Patent, Abstract; Fig. 4).
• Technical Importance: The method was designed to standardize and streamline real-time billing in hybrid telecom environments, reducing the technical burden on application servers and enhancing interoperability across different network standards (’330 Patent, col. 5:11-19).

Key Claims at a Glance

• The complaint asserts "one or more claims" of the ’330 Patent, with specific claims identified in an external chart not attached to the complaint (Compl. ¶11). The patent’s independent claims are Claim 1 (a method claim) and Claim 10 (a network element claim).
• Independent Claim 1 recites the core method, including the following essential elements:
  • A method for generating real-time billing information for a call between a packet-switched network user and a circuit-switched network user.
  • Generating, via a network element, a first message with a first token indicating a billing rate, based on a first charge message from the circuit-switched network.
  • Informing a billing server of the billing rate.
  • After the call is set up, generating a second message with a second token indicating a billing interval, based on a subsequent charge message.
  • Informing the billing server of the billing interval.
  • Continuously generating real-time billing information at the billing server.
• The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

The complaint refers to "Exemplary Defendant Products" identified in charts that were not filed with the complaint (Compl. ¶11, ¶17). It does cite a document titled "f5-handbook-for-service-providers-guide.pdf" as an example of product literature (Compl. ¶14).

Functionality and Market Context

The complaint alleges that Defendant's products practice the technology claimed by the ’330 Patent (Compl. ¶17). Based on the cited handbook, the accused instrumentalities are likely network infrastructure products that F5 markets to telecommunications service providers. The complaint alleges these products are used in a manner that "satisfy all elements of the Exemplary ’330 Patent Claims," suggesting they are involved in managing network traffic and generating billing-related information as part of their operation (Compl. ¶17). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges infringement but incorporates the detailed allegations by reference to an external document, Exhibit 2, which was not provided with the public filing (Compl. ¶17, ¶18). The narrative theory asserts that Defendant’s products practice the technology claimed in the ’330 Patent by performing a method that satisfies all claim elements (Compl. ¶17). This allegedly includes the generation of messages with tokens to convey billing rate and billing interval information in a telecommunications network, consistent with the method of Claim 1. The complaint lacks specific factual allegations detailing how the accused products perform each step of the claimed method.

• Identified Points of Contention:
  • Technical Questions: A primary question will be what evidence demonstrates that Defendant's products perform the specific functions of the claimed "network element." Specifically, what proof shows that the accused products (1) receive a "charge message" from a circuit-switched network and (2) in response, generate the distinct "first message" with a billing rate token and "second message" with a billing interval token, as required by the claims?
  • Scope Questions: The infringement analysis may focus on whether the functionality of Defendant’s products, which may operate as Application Delivery Controllers or other high-level network devices, falls within the scope of the claimed "network element," which the patent specification primarily describes as a Media Gateway Control Function (MGCF) (’330 Patent, col. 3:1-3).

V. Key Claim Terms for Construction

The Term: "network element" (Claim 1)

• Context and Importance: This term defines the apparatus that performs the central steps of the claimed method. The infringement case depends on whether Defendant's accused products can be characterized as such an element. Practitioners may focus on this term because the patent’s specification consistently uses the Media Gateway Control Function (MGCF) as the primary example of the "network element" (’330 Patent, Fig. 6; col. 2:29-32).
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim language itself is broad, using the generic term "network element" without further limitation, which could support an interpretation covering any network device capable of performing the recited functions.
  • Evidence for a Narrower Interpretation: The specification repeatedly and almost exclusively describes the invention in the context of an MGCF that serves as an interface between an IP-based IMS network and a legacy PSTN (’330 Patent, col. 1:35-41). This consistent description could be used to argue for a narrower construction limited to devices performing that specific architectural role.

The Term: "token" (Claim 1)

• Context and Importance: The infringement analysis will turn on whether any feature in the messages generated by Defendant's products constitutes a "token" that indicates a "billing rate" or "interval of billing." The patent provides specific examples of what it considers tokens.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party might argue that "token" should be given a broad, functional definition, encompassing any data field or parameter in a network message that serves to convey the required billing information.
  • Evidence for a Narrower Interpretation: The specification provides specific examples, namely the "Tariff" and "Meter-Pulse" parameters added to a "P-DCS-BILLING-INFO" header (’330 Patent, col. 4:2-22). A party could argue that the term "token" should be construed as being limited to these or structurally similar parameter-based indicators, rather than any arbitrary data field.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Defendant distributes "product literature and website materials," such as a service provider handbook, that allegedly instruct customers on how to use the accused products in an infringing manner (Compl. ¶14-15).
• Willful Infringement: The allegation of willfulness appears to be based on post-suit knowledge. The complaint asserts that "[t]he service of this Complaint upon Defendant constitutes actual knowledge of infringement" and that Defendant's continued infringement thereafter is willful (Compl. ¶13-14). No facts supporting pre-suit knowledge are alleged.

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

• A core issue will be one of definitional scope: can the term "network element," described throughout the patent’s specification in the specific context of a Media Gateway Control Function (MGCF) bridging legacy PSTN and modern IP networks, be construed to read on the functionality of Defendant’s accused network products?
• A key evidentiary question will be one of technical operation: what factual evidence will be presented to demonstrate that Defendant's products perform the specific, two-part method of receiving legacy charge messages and, in response, generating two distinct types of tokenized messages—one for billing rate and a subsequent one for billing interval—as strictly required by the patent’s independent claims?