Coretek Licensing LLC v. TangoMe Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Coretek Licensing LLC (Texas)
  • Defendant: TangoMe, Inc. (Delaware)
  • Plaintiff’s Counsel: Chong Law Firm PA; SAND, SEBOLT & WERNOW CO., LPA
• Case Identification: 1:20-cv-01757, D. Del., 12/23/2020
• Venue Allegations: Plaintiff alleges venue is proper in the District of Delaware because Defendant is a Delaware corporation and thus resides in the district for purposes of patent venue under TC Heartland.
• Core Dispute: Plaintiff alleges that Defendant’s "Tango" communications application infringes four patents related to methods for initiating network connections (e.g., VoIP calls) that bypass a traditional mobile network operator's Home Location Register (HLR) and for dynamically tracking a device's network location.
• Technical Context: The technology concerns "over-the-top" (OTT) communication services, which operate over public internet infrastructure rather than relying on the core call-control systems of traditional telecommunication carriers.
• Key Procedural History: The complaint does not allege any prior litigation, inter partes review proceedings, or licensing history related to the patents-in-suit.

Case Timeline

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

U.S. Patent No. 8,861,512 (the '512 Patent) - "METHOD OF ENABLING A WIRELESS DEVICE TO MAKE A NETWORK CONNECTION WITHOUT USING A NETWORK OPERATOR'S HOME LOCATION REGISTER," Issued October 14, 2014

The Invention Explained

• Problem Addressed: The patent describes a telecommunications environment where mobile network operators exert significant control over subscribers through a central database called a Home Location Register (HLR). This control restricts a user's ability to choose cheaper or alternative call routing options and creates a high barrier to entry for competing service providers ('512 Patent, col. 1:40-2:4).
• The Patented Solution: The invention proposes a system that bypasses the HLR. A software "module" on a wireless device communicates directly with a third-party server over a wireless link (e.g., SMS or HTTP) to initiate a call. This server, rather than the operator's HLR, then determines the appropriate, and potentially lowest-cost, routing for the connection across any available network ('512 Patent, Abstract; col. 2:51-61). The overall architecture is depicted in Figure 1, showing a device-side "Proprietary Application Module" (PAM) communicating with a server-side "Proprietary Application Server Calls Manager" (PASCM).
• Technical Importance: This architecture provided a technical framework for "over-the-top" (OTT) communication applications to function independently of a mobile carrier's core call-management infrastructure, thereby increasing user choice and competition ('512 Patent, col. 8:12-22).

Key Claims at a Glance

• The complaint asserts independent claims 1, 23, and 24, and dependent claim 12 (Compl. ¶21).
• Independent Claim 1 requires:
  • A method for a wireless device to initiate a network connection without using a network operator's HLR.
  • The wireless device uses a downloadable software module to contact a server over a wireless link.
  • The module sends data to the server defining a call request.
  • In response, a software application on the server decides on the routing for the call request over available networks, without using the HLR.
• The complaint reserves the right to assert additional claims (Compl. ¶144).

U.S. Patent No. 9,173,154 (the '154 Patent) - "METHOD OF ENABLING A WIRELESS DEVICE TO MAKE A NETWORK CONNECTION WITHOUT USING A NETWORK OPERATOR'S HOME LOCATION REGISTER," Issued October 27, 2015

The Invention Explained

• Problem Addressed: The '154 patent, a continuation of the application leading to the '512 patent, addresses the same problem of operator control via the HLR, but focuses specifically on a "wireless handheld cellular phone device" ('154 Patent, col. 2:40-50).
• The Patented Solution: The solution is functionally identical to that of the '512 patent: a downloadable software module on a cellular phone allows the device to communicate with an independent server to set up network connections, bypassing the mobile operator's HLR for call routing decisions ('154 Patent, Abstract; col. 2:54-64).
• Technical Importance: The invention is significant for enabling OTT services specifically on the ubiquitous platform of the cellular phone, decoupling communication services from the cellular network provider ('154 Patent, col. 8:12-22).

Key Claims at a Glance

• The complaint asserts independent claims 1, 22, 23, and 24, and dependent claim 11 (Compl. ¶35).
• Independent Claim 1 requires:
  • A method for a "wireless handheld cellular phone device" to initiate a network connection without using an HLR.
  • The device uses a downloadable software module to contact a server.
  • The module sends a call request to the server.
  • A server-side application decides on routing without using the HLR.
• The complaint reserves the right to assert additional claims (Compl. ¶144).

Multi-Patent Capsule: U.S. Patent No. 9,369,575 (the '575 Patent) - "DYNAMIC VOIP LOCATION SYSTEM," Issued June 14, 2016

• Technology Synopsis: This patent addresses the technical challenge of reliably determining the current network address (the "VoIP location" or "return path") of a mobile device for VoIP communications, particularly given power consumption constraints and network changes ('575 Patent, col. 1:15-24; col. 2:15-23). The invention is a system where a software module on the device periodically connects with a server to report its current network address, enabling the server to maintain an up-to-date location database for dynamically routing calls ('575 Patent, Abstract).
• Asserted Claims: Independent claim 1 (Compl. ¶42).
• Accused Features: The complaint alleges the "Tango App" infringes by detecting the IP address of a user's device, treating it as the "VoIP address or return path," and extracting and storing this address in a database on a "Tango Server" to facilitate call routing (Compl. ¶101, 104-105).

Multi-Patent Capsule: U.S. Patent No. 9,591,551 (the '551 Patent) - "METHOD OF ENABLING A WIRELESS DEVICE TO MAKE A NETWORK CONNECTION WITHOUT USING A NETWORK OPERATOR'S HOME LOCATION REGISTER," Issued March 7, 2017

• Technology Synopsis: This patent is from the same family as the '512 and '154 patents and claims a similar HLR-bypass system. However, its claims are directed to a "computer program product embodied on a non-transitory storage medium" ('551 Patent, cl. 1). The invention is the software itself, which, when executed on a wireless device, performs the steps of contacting a server and sending a call request to initiate a connection without using the network operator's HLR ('551 Patent, Abstract).
• Asserted Claims: Independent claims 1, 22, 23, and 24 (Compl. ¶62).
• Accused Features: The complaint accuses the "Tango" software, a downloadable computer program product, which allegedly enables a wireless device to initiate a network connection (e.g., a SIP Invite) over an IP network, thereby bypassing the cellular operator's HLR (Compl. ¶111, 122).

III. The Accused Instrumentality

• Product Identification: The accused instrumentality is the "Tango" communications software, also referred to as the "Tango App" or "Tango application" (Compl. ¶63, 99).
• Functionality and Market Context: The complaint alleges the Tango application is a downloadable software module for smartphones that enables users to make voice calls over IP networks, such as Wi-Fi (Compl. ¶66, 82). The alleged functionality involves the Tango app sending a "call request," identified as a "SIP Invite signal," from a user's device to a "Tango Server" (Compl. ¶67). This server, allegedly including a "Tango SIP proxy Server," then determines how to route the call to another Tango user over an available IP network, a process that allegedly occurs without using the mobile network operator's Home Location Register (HLR) (Compl. ¶68, 84). The system is also accused of dynamically determining and collecting the IP address of the user's device to facilitate this communication (Compl. ¶101, 104). The complaint does not provide specific allegations regarding the product's market positioning.

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'512 Patent Infringement Allegations

'154 Patent Infringement Allegations

• Identified Points of Contention:
  • Scope Questions: A central dispute may arise over whether the claims, which are rooted in a 2006-era telecommunications framework, can be construed to read on a modern "over-the-top" (OTT) application architecture. For instance, does the negative limitation "without using a network operator's home location register" read on a system that is IP-native and would never have contemplated using an HLR, or is it confined to systems that are specific alternatives to the HLR-based functions described in the specification?
  • Technical Questions: A key factual question for the '575 patent will be what evidence demonstrates that the Tango system performs the specific dynamic tracking of a "VoIP address or return path" as required by claim 1. The complaint alleges the system does this to provide "seamless and smooth voice calling functionality even when the user device changes the network" (Compl. ¶107), a factual assertion that will require technical evidence to substantiate.

V. Key Claim Terms for Construction

• The Term: "without using a network operator's home location register" ('512 Patent, cl. 1; '154 Patent, cl. 1)

  • Context and Importance: This negative limitation is the central inventive concept of the '512, '154, and '551 patents. The outcome of the infringement analysis for these patents hinges on whether the accused Tango system, an IP-native OTT application, is properly characterized as functioning "without using" an HLR. Practitioners may focus on this term because the defense could argue that the term implies a direct alternative to the specific HLR functions described in the patent, whereas modern OTT apps represent a completely different technological paradigm that renders the comparison moot.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification broadly states, "In the present invention, a wireless device can initiate a network connection without using a network operator's home location register (HLR)" ('512 Patent, col. 2:51-54). This language may support a straightforward interpretation where any system that does not rely on an HLR for call routing meets the limitation.
    • Evidence for a Narrower Interpretation: The Background section provides a detailed technical description of an HLR in the context of IMSI, VLRs, and SS7 messaging ('512 Patent, col. 2:5-40). A party could argue that "without using" should be construed in light of this specific context, limiting the claim to systems designed to circumvent that particular legacy architecture, not all non-HLR systems.

• The Term: "VoIP address or return path" ('575 Patent, cl. 1)

  • Context and Importance: This term is critical to the '575 patent's infringement theory, as Plaintiff must show that the Tango system extracts and reports information meeting this definition. The complaint equates this term with a device's IP address (Compl. ¶101). Its construction will determine whether simply using an IP address is sufficient for infringement or if a more specific type of dynamically managed location identifier is required.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides an explicit link, stating, "This 'return path' is what we refer to in this invention as the user's device VoIP location" ('575 Patent, col. 1:36-38). This could support the view that any network address that allows data to be returned to the device qualifies.
    • Evidence for a Narrower Interpretation: The term is described in the context of a system that dynamically updates its location in response to network changes, such as switching from cellular to Wi-Fi, to ensure reliability ('575 Patent, col. 3:9-24, col. 3:45-54). This may support a narrower construction requiring more than just a static IP address, but rather an address that is actively monitored and reported to a server as part of a dynamic location management scheme.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that Defendant has induced infringement by "encouraging infringement" (Compl. ¶139). The pleading does not specify the acts constituting encouragement, such as references to user manuals, advertisements, or other instructional materials.
• Willful Infringement: The willfulness allegation is based on knowledge of the patents "at least as of the service of the present Complaint" (Compl. ¶137). The complaint does not allege any pre-suit knowledge of the patents or the alleged infringement.

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

• A core issue will be one of technological scope: can the claims of the '512, '154, and '551 patents, which are defined by their circumvention of a legacy telecommunications component (the HLR) and have a 2006 priority date, be construed to cover a modern, IP-native "over-the-top" application that was architected without any reference to the HLR system?
• A key evidentiary question for the '575 patent will be one of functional operation: does the accused Tango application and server perform the specific, dynamic process of extracting, reporting, and using a "VoIP address or return path" in response to network changes, as described in the patent, or does it employ a more generalized method of IP-based communication that is technically distinct from the claimed invention?