DCT

3:22-cv-00363

Lemko Corp v. Microsoft Corp

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 3:22-cv-00363, N.D. Tex., 02/14/2022
  • Venue Allegations: Venue is alleged to be proper based on both Microsoft and its subsidiary, Affirmed Networks, maintaining regular and established places of business within the Northern District of Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s Azure-based multi-access edge computing (MEC) products and virtualized 4G/5G network core solutions infringe eight patents related to distributed mobile network architectures.
  • Technical Context: The technology concerns decentralized mobile network architectures that move computing and switching functions from a central core to the network edge, a foundational concept for modern private 4G/5G, IoT, and edge computing applications.
  • Key Procedural History: The complaint notes Microsoft’s 2020 acquisition of Defendant Affirmed Networks, a provider of virtualized mobile cores. It also alleges pre-suit knowledge of the patents through a key Microsoft employee who, prior to Microsoft’s acquisition of his former company Metaswitch, had engaged in partnership discussions with Plaintiff and evaluated its patented technology.

Case Timeline

Date Event
2005-04-13 U.S. Patent No. 7,548,763 Priority Date
2006-02-24 U.S. Patent No. 7,653,414 Priority Date
2006-03-30 U.S. Patent No. 8,688,111 Priority Date
2008-06-26 U.S. Patent No. 9,191,980 Priority Date
2008-06-27 U.S. Patent No. 9,755,931 Priority Date
2008-07-11 U.S. Patent No. 7,855,988 Priority Date
2008-07-11 U.S. Patent No. 8,107,409 Priority Date
2008-07-11 U.S. Patent No. 9,332,478 Priority Date
2009-06-16 U.S. Patent No. 7,548,763 Issued
2010-01-26 U.S. Patent No. 7,653,414 Issued
2010-12-21 U.S. Patent No. 7,855,988 Issued
2012-01-31 U.S. Patent No. 8,107,409 Issued
2014-04-01 U.S. Patent No. 8,688,111 Issued
2015-11-17 U.S. Patent No. 9,191,980 Issued
2016-05-03 U.S. Patent No. 9,332,478 Issued
2017-09-05 U.S. Patent No. 9,755,931 Issued
2020 Microsoft acquires Affirmed Networks
2020-07 Microsoft acquires Metaswitch Networks
2022-02-14 Complaint Filing Date

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

U.S. Patent No. 7,548,763 - “System, Method, and Device for Providing Communications Using a Distributed Mobile Architecture”

  • Patent Identification: U.S. Patent No. 7,548,763, “System, Method, and Device for Providing Communications Using a Distributed Mobile Architecture,” issued June 16, 2009.

The Invention Explained

  • Problem Addressed: The patent’s background describes the high cost and operational difficulty of deploying traditional, centralized cellular systems—requiring a mobile switching center (MSC) and base station controller (BSC)—in rural or isolated communities where user density is low ( Compl. ¶¶32-33; ’763 Patent, col. 1:11-43).
  • The Patented Solution: The invention proposes a decentralized or "distributed mobile architecture" (DMA) where local, interconnected "DMA servers" perform the functions of a traditional MSC and BSC. These servers are connected in a peer-to-peer fashion over an IP network, creating a scalable and self-healing system that eliminates the need for expensive, centralized hardware. A key claimed feature is the ability to support group calls between four or more participants with full duplex capability (’763 Patent, Abstract; Fig. 1).
  • Technical Importance: This architecture represented a paradigm shift for deploying cellular networks, enabling cost-effective service in underserved areas by replacing monolithic central infrastructure with distributed, commodity hardware and IP networking (Compl. ¶¶33-34).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶52).
  • Claim 1 is a system claim with the following essential elements:
    • A first distributed mobile architecture (DMA) server comprising a first computer readable medium with a first mobile switching center module, a first base station controller module, and a first call detail record generation program, where the server is in direct physical connection with a first wireless transceiver.
    • A second distributed mobile architecture (DMA) server comprising a second computer readable medium with corresponding second modules, and additionally a program to allow a group call among four or more mobile communication devices, where this server is in direct physical connection with a second wireless transceiver.
    • Wherein telephony traffic received at the first wireless transceiver is transmitted from the first DMA server to the second DMA server via a peer-to-peer connection.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 7,653,414 - “System, Method, and Device for Providing Communications Using a Distributed Mobile Architecture”

  • Patent Identification: U.S. Patent No. 7,653,414, “System, Method, and Device for Providing Communications Using a Distributed Mobile Architecture,” issued January 26, 2010.

The Invention Explained

  • Problem Addressed: Within a distributed mobile architecture, there is a need for a sophisticated mechanism to manage subscriber information (e.g., home vs. roaming status) and to intelligently route calls to destinations outside the local DMA network (Compl. ¶17; ’414 Patent, col. 1:12-51).
  • The Patented Solution: The invention discloses a DMA system that includes an Authentication, Authorization, and Accounting (AAA) module containing several types of registers. A “destination preference register” (DPR) stores a preferred call path (e.g., VoIP, MSC, ISDN) for routing calls outside the local network. It also uses a Home Location Register (HLR), a Visitor Location Register (VLR), and a Community Location Register (CLR) to store and share information about mobile subscribers, including whether they are registered with the local DMA system or roaming on another (’414 Patent, Abstract; col. 4:1-12).
  • Technical Importance: This system provides a framework for managing user identity, location, and routing policies in a decentralized network, enabling it to interoperate seamlessly with external legacy communication networks (Compl. ¶¶32, 35).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 11 (Compl. ¶88).
  • Claim 1 is a method claim with the essential elements of:
    • Receiving a call from a first mobile subscriber to a second mobile subscriber at a first DMA system.
    • Determining if the second subscriber is registered with the first DMA system or a second DMA system based on information stored at an AAA module.
    • Wherein the AAA module includes a destination preference register containing a preferred call path for routing calls outside of a DMA network.
  • Claim 11 is a system claim with the essential elements of:
    • A DMA system comprising a base transceiver station, a housing, and a computer readable storage medium.
    • The medium stores an AAA module that includes a home location register (HLR), a visitor location register (VLR), a community location register (CLR), and a destination preference register (DPR).
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 7,855,988 - “System, Method, and Device for Routing Calls Using a Distributed Mobile Architecture”

  • Patent Identification: U.S. Patent No. 7,855,988, “System, Method, and Device for Routing Calls Using a Distributed Mobile Architecture,” issued December 21, 2010 (Compl. ¶18).
  • Technology Synopsis: The patent discloses a system for routing communications between distributed mobile architecture servers using DMA gateways (DMAGs). The system handles routing when communication information indicates a target device is accessible by either a DMA server or a legacy communications network (Compl. ¶19).
  • Asserted Claims: Independent claims 1 and 42 (Compl. ¶123).
  • Accused Features: The complaint alleges that the Core MEC Products, ACE, and APNS provide a network communication system with DMA servers (ASE) and interfaces to private IP networks and gateway communication networks that infringe the ’988 Patent (Compl. ¶¶129-133).

U.S. Patent No. 8,107,409 - “OAMP for Distributed Mobile Architecture”

  • Patent Identification: U.S. Patent No. 8,107,409, “OAMP for Distributed Mobile Architecture,” issued January 31, 2012 (Compl. ¶20).
  • Technology Synopsis: The patent addresses Operations, Administration, Maintenance, and Provisioning (OAMP) for a distributed architecture. It describes a DMAG that routes communications to both home and roaming DMA nodes and includes a "master agent" for receiving performance data from the DMA nodes and an "operations module" for storing and reporting that data (Compl. ¶21; ’409 Patent, Abstract).
  • Asserted Claims: Independent claim 1 (Compl. ¶152).
  • Accused Features: The Core MEC Products and Affirmed vProbe are accused of infringement. Affirmed vProbe is alleged to be the "master agent" that receives performance data from DMA nodes, and its operations module is alleged to report and store this data (Compl. ¶¶158, 166-168).

U.S. Patent No. 8,688,111 - “System, Method, and Device for Providing Communications Using a Distributed Mobile Architecture”

  • Patent Identification: U.S. Patent No. 8,688,111, “System, Method, and Device for Providing Communications Using a Distributed Mobile Architecture,” issued April 1, 2014 (Compl. ¶22).
  • Technology Synopsis: The patent describes a method for handling communications between mobile devices across different DMA systems. It involves a first DMA system receiving a communication for a device and determining whether that device is registered with the first DMA system or a second DMA system based on information stored in an AAA module (Compl. ¶23).
  • Asserted Claims: Independent claims 1 and 10 (Compl. ¶184).
  • Accused Features: The Core MEC Products and ACE are alleged to form a DMA system that receives registration information and location update requests between different DMA systems (a "third" and "second") through components like HSS and MME to determine device location and route communications (Compl. ¶¶190, 197-200).

U.S. Patent No. 9,191,980 - “System and Method to Control Wireless Communications”

  • Patent Identification: U.S. Patent No. 9,191,980, “System and Method to Control Wireless Communications,” issued November 17, 2015 (Compl. ¶24).
  • Technology Synopsis: This patent discloses a system for controlling wireless communications by determining if a first DMAG supports communications with a destination device. This determination is based on registration data stored at a first DMA server, which receives communications from a mobile device at a base transceiver station interface (Compl. ¶25).
  • Asserted Claims: Independent claims 1 and 15 (Compl. ¶218).
  • Accused Features: The Core MEC Products and APNS are accused of infringement. The system is alleged to use HSS/NPLI to identify a subscriber's location (home or roaming) and handle calls based on that location information, determining whether the device is within the wireless coverage of a first DMA server (Compl. ¶¶224, 227, 230).

U.S. Patent No. 9,332,478 - “System, Method, and Device for Routing Calls Using a Distributed Mobile Architecture”

  • Patent Identification: U.S. Patent No. 9,332,478, “System, Method, and Device for Routing Calls Using a Distributed Mobile Architecture,” issued May 3, 2016 (Compl. ¶26).
  • Technology Synopsis: The patent covers a system for transmitting communications information from a first DMAG to a second DMAG within a DMAG communication network. This allows for routing packets between different network instances or slices (Compl. ¶27).
  • Asserted Claims: Independent claims 9 and 16 (Compl. ¶248).
  • Accused Features: The accused products, including Affirmed Network Slicing's vSSF technology, are alleged to use multiple vEPC DMAG instances to serve different use cases. The vSSF is alleged to select between these instances, thereby transmitting subscriber information to a second DMAG and routing packets accordingly (Compl. ¶¶254, 259, 263).

U.S. Patent No. 9,755,931 - “Fault Tolerant Distributed Mobile Architecture”

  • Patent Identification: U.S. Patent No. 9,755,931, “Fault Tolerant Distributed Mobile Architecture,” issued September 5, 2017 (Compl. ¶28).
  • Technology Synopsis: This patent describes a fault-tolerant system where a DMAG management system detects a failure condition in a first DMAG. Upon determining the first DMAG is offline, it selects a second DMAG and sends notifications to both the second DMAG and an external system to reroute calls through the second DMAG (Compl. ¶29).
  • Asserted Claims: Independent claims 7 and 12 (Compl. ¶282).
  • Accused Features: The Core MEC Products and APNS are accused of infringement. The complaint alleges that microservice observability tools like Istio act as the DMAG management system, using its control plane to detect failures and its data plane to notify a second DMAG (SGW) to take over operations from a failed first SGW (Compl. ¶¶288, 290, 294, 297, 300).

III. The Accused Instrumentality

Product Identification

The primary accused products are Microsoft’s Azure Stack Edge ("ASE") servers when used in combination with Affirmed Networks’ Virtual Evolved Packet Core ("vEPC") software, collectively termed the "Core MEC Products" (Compl. ¶40). The complaint also names related technologies including Affirmed Cloud Edge ("ACE"), Azure Network Function Manager, Affirmed Private Network Service ("APNS"), Affirmed vProbe, and Affirmed Network Slicing (Compl. ¶¶44, 46-48, 50).

Functionality and Market Context

The accused instrumentalities combine to form a multi-access edge computing (MEC) platform for private 4G/5G networks (Compl. ¶¶2, 48). ASE hardware provides servers that run applications and perform computation at the network edge, managed via the Azure cloud (Compl. ¶41). vEPC is virtualized software that provides the core functions for managing and controlling a 4G/5G network, such as Control/User Plane Separation (CUPS) and network slicing (Compl. ¶42). Together, they are marketed as a solution to "deliver telco-grade mobile core performance at the edge in a lightweight design," enabling private LTE/5G network services for enterprise customers (Compl. ¶¶60, 48). A schematic diagram shows how vEPC components can be deployed in combination with Azure Stack Edge servers for edge computing. (Compl. Ex. 15 at 1).

IV. Analysis of Infringement Allegations

’763 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a first distributed mobile architecture server comprising: a first computer readable medium; a first mobile switching center module... a first base station controller module... a first call detail record (CDR) generation program The ’763 Accused Products (Core MEC and ACE) provide a first DMA server with computer-readable medium, including the ACE-U gateway functions. vEPC provides the mobile switching center, base station controller, and CDR generation program functions. ¶¶59, 61, 64, 65 col. 4:1-16
wherein the first distributed mobile architecture server is in direct physical connection with a first wireless transceiver The edge service is deployed on premise on an ASE server, which is connected to a transceiver station. ¶67 col. 3:28-31
a second distributed mobile architecture server, comprising... a program to allow a group call among four or more mobile communication devices The ’763 Accused Products provide a second DMA server including the ACE-C gateway functions. vEPC provides 3GPP-compliant functionality for group communications among four or more mobile devices, including through its VoLTE services. ¶¶59, 68, 69 col. 2:38-40
wherein the second distributed mobile architecture server is in direct physical connection with a second wireless transceiver The second DMA server, which includes the MME and ACE components, is in direct physical connection with a wireless transceiver via an "S1-MME" connection. A diagram shows this connection between the radio access network and the MME. ¶71; Ex. 19 at 4 col. 3:28-31
wherein telephony traffic received at the first wireless transceiver... is transmitted from the first distributed mobile architecture server to the second distributed mobile architecture server via a peer-to-peer connection Telephony traffic is transmitted from the first DMA server (ACE-U) to the second DMA server (ACE-C) via an "S5/S8-U" connection, which is alleged to be a peer-to-peer connection between GPRS Tunneling Protocol (GTP) peers. ¶¶72, 73 col. 3:35-40
  • Identified Points of Contention:
    • Scope Questions: A central question may be whether the combination of a general-purpose edge server (ASE) and virtualized network function software (vEPC, ACE) constitutes a "distributed mobile architecture server" as claimed in the patent. The defense may argue the patent describes a specific, integrated hardware device, not a disaggregated software-on-server platform.
    • Technical Questions: The complaint alleges a "peer-to-peer connection" is met by the S5/S8-U interface between SGW and PGW functions in the accused system (Compl. ¶73). A point of contention may be whether this standardized interface in a 4G/5G core architecture is technically equivalent to the "peer-to-peer connection" between distinct DMA servers described in the patent specification (’763 Patent, col. 3:35-40).

’414 Patent Infringement Allegations

Claim Element (from Independent Claim 11) Alleged Infringing Functionality Complaint Citation Patent Citation
A distributed mobile architecture system comprising: a base transceiver station coupled to a housing... a computer readable storage medium... The accused products provide a DMA system with a "virtualized architecture." The ASE server provides the housing and storage medium and can be deployed on-premise coupled to a wireless transceiver, such as a Radio Access Network (RAN). A diagram illustrates the on-premise deployment of an Azure Stack Edge server coupled to a wireless transceiver. ¶¶95, 96, 97, 98; Ex. 28 at 3 col. 3:21-25
an authentication, authorization, and accounting (AAA) module Defendant's vEPC software provides various functions, explicitly including AAA. ¶99 col. 4:5-12
a home location register (HLR) vEPC provides Home Subscriber Server (HSS) functionality, which is alleged to be an HLR. The HSS stores and updates subscription information. ¶¶100, 103 col. 3:56-62
a visitor location register (VLR) The accused products support a virtualized Mobility Management Entity (MME) that connects to a VLR through an SGs interface to register roaming devices. ¶101 col. 3:56-62
a community location register (CLR) vEPC provides an HSS-HLR routing table that is alleged to function as a CLR, which is associated with a second HLR of a second DMA system. ¶102 col. 3:56-62
a destination preference register (DPR) vEPC's "steering feature" is alleged to provide multiple DPRs that establish preferred call paths for routing traffic outside of the local DMA network, such as to a specific next hop or tunnel. ¶105 col. 4:5-12
  • Identified Points of Contention:
    • Scope Questions: The complaint maps modern 4G/5G core network components (HSS, MME) to the patent's claimed registers (HLR, VLR, CLR). A potential dispute is whether these components are structurally and functionally equivalent. For example, does an HSS in a 3GPP architecture perform the distinct functions of both the HLR and CLR as claimed?
    • Technical Questions: What evidence does the complaint provide that the accused "steering feature" is a "register" as claimed? The defense may argue that "steering" is a dynamic, policy-based traffic management function, whereas the patent's "destination preference register" describes a more static table of preferred network path types (VoIP, MSC, ISDN) (’414 Patent, Abstract).

V. Key Claim Terms for Construction

For the ’763 Patent

  • The Term: "distributed mobile architecture server"
  • Context and Importance: This term is the central component of the claimed system. Its construction will determine whether the accused combination of general-purpose hardware (ASE) and virtualized software (vEPC) falls within the scope of the claims, which were filed when network functions were more commonly tied to dedicated hardware. Practitioners may focus on this term because the accused products represent a more disaggregated and software-defined architecture than the embodiments pictured in the patent.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the DMA server as "essentially a processor, or computer, having a housing and a computer readable medium" that contains software modules for MSC and BSC functionality (’763 Patent, col. 4:1-16). This functional description could support reading the term on a general-purpose server running virtualized network functions.
    • Evidence for a Narrower Interpretation: The patent figures consistently depict "DMA servers" as discrete physical units co-located with cellular antennas, suggesting a self-contained, appliance-like device rather than a collection of software services running on a cloud-managed server (’763 Patent, Fig. 1, Fig. 2).

For the ’414 Patent

  • The Term: "destination preference register (DPR)"
  • Context and Importance: Infringement of this element hinges on equating it with the accused "steering feature." The dispute will likely turn on whether modern, flexible traffic "steering" is the same as the patent's more structured concept of a "register" for selecting preferred paths.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The abstract describes the DPR functionally as including "a preferred call path for calls to be routed outside of a distributed mobile architecture network" (’414 Patent, Abstract). This broad language may support an argument that any mechanism performing this function, such as the accused steering feature, meets the limitation.
    • Evidence for a Narrower Interpretation: The detailed description provides specific examples where the DPR stores a hierarchy of path types: "a voice over Internet protocol (VoIP) call path, a mobile switching center (MSC) call path, and an integrated services digital network (ISDN) call path" (’414 Patent, col. 9:18-24). This may support a narrower construction limited to a register that selects between these specific types of legacy network connections.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced and contributory infringement for all asserted patents. The inducement allegations are based on Defendants allegedly instructing customers on how to install and configure the accused products in an infringing manner through user guides, white papers, promotional materials, and dedicated support centers (Compl. ¶¶79-83, 114-118).
  • Willful Infringement: While not pleaded as a separate count, the complaint lays a foundation for willfulness. It alleges pre-suit knowledge based on Lemko's patent markings on competing products and through Martin Taylor, a Microsoft employee who was formerly the CTO of Metaswitch Networks. In that prior role, Mr. Taylor and others allegedly evaluated Lemko's technology and were informed of its patent portfolio during partnership discussions years before Microsoft's acquisition of Metaswitch (Compl. ¶¶38-39, 78, 113). Knowledge is also alleged from the date of the complaint's filing.

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

  • A core issue will be one of technological translation: can claim terms rooted in the context of mid-2000s distributed hardware (e.g., "DMA server") be construed to cover modern, disaggregated, and virtualized cloud-based platforms (e.g., Azure Stack Edge running vEPC)? The case may turn on whether the accused system is seen as a direct technological successor practicing the patented invention or a fundamentally different, non-infringing paradigm.
  • A key evidentiary question will be one of functional mapping: does the complaint’s mapping of modern 4G/5G network functions to the patent’s claimed elements represent a true functional equivalence? For example, does the accused products' dynamic, policy-based "steering feature" perform the specific function of the claimed "destination preference register," or is this an attempt to equate conceptually related but technically distinct technologies?