DCT

2:23-cv-00638

Pegasus Wireless Innovation LLC v. AT&T Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:23-cv-00638, E.D. Tex., 12/29/2023
  • Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas because AT&T maintains a "regular and established place of business" in the district, including retail stores, infringing cellular base stations, and other facilities. The complaint also cites recent patent cases in the same district where AT&T allegedly admitted or did not contest that venue was proper.
  • Core Dispute: Plaintiff alleges that Defendant’s 4G/LTE and 5G mobile networks and the devices operating on them infringe eleven patents related to foundational wireless telecommunications technologies.
  • Technical Context: The technologies at issue are allegedly essential to the 4G/LTE and 5G wireless communication standards, which form the technical backbone of modern mobile data and voice services.
  • Key Procedural History: The asserted patents were invented by researchers at KT Corporation and subsequently licensed exclusively to Pegasus. Plaintiff alleges that prior to filing suit, it notified AT&T of the patents and offered to negotiate a license on Fair, Reasonable, and Non-Discriminatory (FRAND) terms, but the parties were unable to reach an agreement. The complaint alleges the patents were declared essential to standards developed by the Third Generation Partnership Project (3GPP), of which AT&T is a member.

Case Timeline

Date Event
2013-09-27 U.S. Patent No. 10,181,931 Priority Date
2014-03-21 U.S. Patent No. 10,009,161 Priority Date
2015-03-01 KT's "5G Vision" announced at Mobile World Congress
2015-07-14 U.S. Patent No. 10,616,932 Priority Date
2015-07-16 KT opens 5G R&D Center in Seoul
2016-03-05 U.S. Patent No. 9,894,644 Priority Date
2016-10-31 U.S. Patent No. 11,540,272 Priority Date
2016-11-03 U.S. Patent No. 11,627,631 Priority Date
2016-11-16 U.S. Patent No. 11,405,942 Priority Date
2017-05-08 U.S. Patent No. 10,721,118 Priority Date
2017-07-28 U.S. Patent No. 10,594,460 Priority Date
2017-07-28 U.S. Patent No. 11,219,000 Priority Date
2017-07-28 U.S. Patent No. 10,638,463 Priority Date
2018-01-01 KT conducts broad-scale 5G trial at Winter Olympics
2018-02-13 U.S. Patent No. 9,894,644 Issued
2018-06-26 U.S. Patent No. 10,638,463 Issued
2018-06-26 U.S. Patent No. 10,009,161 Issued
2019-01-15 U.S. Patent No. 10,181,931 Issued
2019-04-03 KT launches first commercial 5G network
2020-03-17 U.S. Patent No. 10,594,460 Issued
2020-04-07 U.S. Patent No. 10,616,932 Issued
2020-07-21 U.S. Patent No. 10,721,118 Issued
2022-01-04 U.S. Patent No. 11,219,000 Issued
2022-08-02 U.S. Patent No. 11,405,942 Issued
2022-09-07 Pegasus acquires rights to Asserted Patents from KT
2022-12-16 Pegasus sends notice letter to AT&T
2022-12-27 U.S. Patent No. 11,540,272 Issued
2023-04-11 U.S. Patent No. 11,627,631 Issued
2023-12-29 Complaint Filing Date

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

U.S. Patent No. 11,627,631 - "Method for Processing Data on Basis of Network Slide, and Apparatus Therefor"

  • Patent Identification: U.S. Patent No. 11,627,631, "Method for Processing Data on Basis of Network Slide, and Apparatus Therefor," issued April 11, 2023 (’631 Patent).

The Invention Explained

  • Problem Addressed: The complaint describes the patent as relating to the technical challenge of "maintaining service continuity and service stability while user equipment is moving between two base stations and when network slicing technology is employed" (Compl. ¶60).
  • The Patented Solution: The invention provides a method for a source base station to manage a handover process that accounts for network slices. The method involves determining whether to perform a handover, transmitting a handover request that includes network slice information to a target base station, and receiving a confirmation message that may indicate rejection of data sessions associated with slices not supported by the target base station (’631 Patent, Abstract; Compl. ¶¶61, 64). The specification describes this process as ensuring that a terminal moving to a new base station maintains service for its configured network slices (’631 Patent, col. 1:44-59).
  • Technical Importance: Network slicing, a key feature of 5G, allows a single physical network to support diverse services with different performance requirements, and ensuring seamless handovers between base stations is critical to maintaining quality of service for those varied applications (Compl. ¶¶60-61).

Key Claims at a Glance

  • Independent claims 1, 7, and 13 are asserted in the complaint (Compl. ¶61).
  • Independent Claim 1 requires a method performed by a source base station, comprising the elements of:
    • Determining to perform a handover of a terminal from the source base station to a target base station.
    • Transmitting, to the target base station, a handover request message including network slice information.
    • Receiving, from the target base station, a handover request confirmation message in response to the handover request message.
    • Wherein the handover request confirmation message includes information for indicating a rejection of one or more protocol data unit (PDU) sessions by the target base station if the PDU sessions are associated with one or more network slices that are not supported by the target base station.
  • The complaint generally alleges infringement of these and potentially other claims (Compl. ¶63).

U.S. Patent No. 10,181,931 - "Method for Uplink Control Channel Resource Allocation of Terminal and Apparatus Thereof"

  • Patent Identification: U.S. Patent No. 10,181,931, "Method for Uplink Control Channel Resource Allocation of Terminal and Apparatus Thereof," issued January 15, 2019 (’931 Patent).

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of allocating uplink control channel (PUCCH) resources for Machine-Type Communication (MTC) terminals, such as IoT devices, in an LTE/LTE-Advanced system (’931 Patent, col. 1:19-24; Compl. ¶82). These devices often operate in poor radio environments and require repeated transmissions, which can create resource conflicts with typical terminals (’931 Patent, col. 1:33-51).
  • The Patented Solution: The invention provides a method for a base station to configure a resource for response information (e.g., HARQ ACK/NACK) from an MTC terminal. This involves transmitting structural information to the terminal, including information on the uplink control channel resource and an offset value, and then transmitting downlink control information and data. The resource for the uplink control channel is determined based on specific information related to the downlink control channel, the uplink channel itself, and the offset (’931 Patent, Abstract; Compl. ¶83).
  • Technical Importance: Efficiently managing uplink resources for a massive number of MTC devices, which have different characteristics than smartphones, is critical for the overall capacity and reliability of 4G/LTE networks (Compl. ¶82).

Key Claims at a Glance

  • Independent claims 1, 3, 5, and 7 are asserted in the complaint (Compl. ¶83).
  • Independent Claim 3 requires a method performed by a base station for configuring a resource of response information of downlink data of an MTC terminal, comprising the elements of:
    • Transmitting structural information containing at least one of (i) information on a resource allocated to an uplink control channel for transmitting the response information and (ii) offset information of the resource.
    • Transmitting downlink control information for scheduling the downlink data.
    • Transmitting the downlink data.
    • Wherein the resource of the uplink control channel is determined based on at least one of (i) information on a resource of a downlink control channel for scheduling the downlink data, (ii) the information on the resource allocated to the uplink control channel, and (iii) the offset information on the resource allocated to the uplink control channel.
  • The complaint generally alleges infringement of these and potentially other claims (Compl. ¶85).

U.S. Patent No. 10,616,932 - "Method for Configuring Wireless Connection of Terminal Apparatus Therefor"

  • Patent Identification: U.S. Patent No. 10,616,932, "Method for Configuring Wireless Connection of Terminal Apparatus Therefor," issued April 7, 2020 (’932 Patent).
  • Technology Synopsis: The patent relates to methods for configuring a wireless connection in a network where base station functions are split between a central unit and an access unit. The invention is described as a novel wireless access network structure to reduce deployment costs and an inventive procedure for radio connection setup (Compl. ¶103).
  • Asserted Claims: Independent claims 1 and 8 are asserted (Compl. ¶104).
  • Accused Features: The accused features are functionalities within AT&T's 5G network and devices, compliant with Release 15 or later, that allegedly practice the claimed signaling method for radio resource control (Compl. ¶¶105-107).

U.S. Patent No. 11,405,942 - "Method and Apparatus for Transmitting and Receiving Downlink Signal in Next Generation Wireless Network"

  • Patent Identification: U.S. Patent No. 11,405,942, "Method and Apparatus for Transmitting and Receiving Downlink Signal in Next Generation Wireless Network," issued August 2, 2022 (’942 Patent).
  • Technology Synopsis: The patent relates to efficiently multiplexing data traffic for services with different Quality of Service (QoS) requirements in a 5G network. The invention claims to prevent unnecessary processing and data loss by using a "downlink pre-emption indication" to manage radio resource multiplexing (Compl. ¶124).
  • Asserted Claims: Independent claims 1, 5, and 9 are asserted (Compl. ¶125).
  • Accused Features: The accused features are functionalities within AT&T's 5G network and devices, compliant with Release 15 or later, that allegedly support efficient multiplexing through the use of preemption indication (Compl. ¶¶126-127).

U.S. Patent No. 10,594,460 - "Apparatus and Method for Transmitting and Receiving Uplink Channel"

  • Patent Identification: U.S. Patent No. 10,594,460, "Apparatus and Method for Transmitting and Receiving Uplink Channel," issued March 17, 2020 (’460 Patent).
  • Technology Synopsis: The patent relates to methods for frequency hopping for uplink channel transmission in a 5G network. The invention involves a user equipment receiving bandwidth part and frequency hopping configuration information from a base station and transmitting on the uplink based on that information (Compl. ¶¶146-147).
  • Asserted Claims: Independent claims 1, 5, and 9 are asserted (Compl. ¶147).
  • Accused Features: The accused features are functionalities within AT&T's 5G network and devices, compliant with Release 15 or later, that allegedly perform frequency hopping to prevent collisions between resources used by different user equipments (Compl. ¶¶148-149).

U.S. Patent No. 10,721,118 - "Method for Configuring Dual-Connectivity by Terminal, and Apparatus Therefor"

  • Patent Identification: U.S. Patent No. 10,721,118, "Method for Configuring Dual-Connectivity by Terminal, and Apparatus Therefor," issued July 21, 2020 (’118 Patent).
  • Technology Synopsis: The patent relates to configuring dual-connectivity, which enables a user device to connect simultaneously to a base station using a legacy network technology and one using a next-generation technology. The claimed method involves adding a secondary base station signaling radio bearer (SRB) and transmitting a failure message if the device cannot comply with the configuration (Compl. ¶¶168-169).
  • Asserted Claims: Independent claims 1, 7, and 10 are asserted (Compl. ¶169).
  • Accused Features: The accused features are functionalities within AT&T's 5G network and devices, compliant with Release 15 or later, that allegedly configure dual-connectivity as described in the patent (Compl. ¶¶170-171).

U.S. Patent No. 11,219,000 - "Apparatus and Method of Uplink Control Channel Resource Allocation for New Radio"

  • Patent Identification: U.S. Patent No. 11,219,000, "Apparatus and Method of Uplink Control Channel Resource Allocation for New Radio," issued January 4, 2022 (’000 Patent).
  • Technology Synopsis: The patent relates to allocating uplink control channel resources in a 5G network when a user device uses various bandwidth parts (BWPs). The claims describe methods for a user device to transmit on an uplink channel to a base station based on a BWP (Compl. ¶¶189-190).
  • Asserted Claims: Independent claims 1, 5, and 9 are asserted (Compl. ¶190).
  • Accused Features: The accused features are functionalities within AT&T's 5G network and devices, compliant with Release 15 or later, that perform uplink control channel resource allocation as described in the patent (Compl. ¶¶191-192).

U.S. Patent No. 10,638,463 - "Apparatus and Method of Uplink Control Channel Resource Allocation for New Radio"

  • Patent Identification: U.S. Patent No. 10,638,463, "Apparatus and Method of Uplink Control Channel Resource Allocation for New Radio," issued June 26, 2018 (’463 Patent).
  • Technology Synopsis: The patent relates to a method for a user device to transmit uplink control information in a 5G network by receiving resource set configuration information from a base station and then determining and using a specific resource from that set. The invention is alleged to address uplink control channel resource allocation (Compl. ¶¶210-211).
  • Asserted Claims: Independent claims 1, 4, and 7 are asserted (Compl. ¶211).
  • Accused Features: The accused features are functionalities within AT&T's 5G network and devices, compliant with Release 15 or later, that perform uplink control channel resource allocation, including activation of bandwidth parts through downlink control information (Compl. ¶¶212-214).

U.S. Patent No. 11,540,272 - "Method and Device for Allocating Data Channel Resource for Next-Generation Wireless Access Network"

  • Patent Identification: U.S. Patent No. 11,540,272, "Method and Device for Allocating Data Channel Resource for Next-Generation Wireless Access Network," issued December 27, 2022 (’272 Patent).
  • Technology Synopsis: The patent relates to a method for a base station to allocate time interval resources for downlink or uplink data channels in a 5G network. The claimed invention involves allocating resources for each OFDM symbol on a slot or mini-slot basis and transmitting configuration and control information to the terminal (Compl. ¶¶231-232).
  • Asserted Claims: Independent claims 1, 8, and 15 are asserted (Compl. ¶232).
  • Accused Features: The accused features are functionalities within AT&T's 5G network, mobile network, and devices, compliant with Release 15 or later, that have the ability to allocate time-domain resources as described in the patent (Compl. ¶¶233-234).

U.S. Patent No. 9,894,644 - "Method for Transceiving Downlink Control Information and Apparatus for Same"

  • Patent Identification: U.S. Patent No. 9,894,644, "Method for Transceiving Downlink Control Information and Apparatus for Same," issued February 13, 2018 (’644 Patent).
  • Technology Synopsis: The patent relates to methods for transceiving downlink control information for a terminal in an enhanced coverage mode. The invention involves a base station providing configuration information to a terminal so it can receive downlink control channels repeatedly over a plurality of subframes (Compl. ¶¶252-253).
  • Asserted Claims: Claims 1, 2, and 3 are asserted (Compl. ¶253).
  • Accused Features: The accused features are functionalities within AT&T's 4G/LTE network and devices, compliant with Release 13 or later, that have the ability to transceive downlink control information as described in the patent (Compl. ¶¶254-255).

U.S. Patent No. 10,009,161 - "Method for Transmitting and Receiving the Channel State Information and Apparatus Thereof"

  • Patent Identification: U.S. Patent No. 10,009,161, "Method for Transmitting and Receiving the Channel State Information and Apparatus Thereof," issued June 26, 2018 (’161 Patent).
  • Technology Synopsis: The patent relates to transmitting and receiving channel state information for user equipment that supports 256-state quadrature amplitude modulation (256QAM). The invention claims methods for modulating and processing data traffic between terminals and base stations that can handle large amounts of data (Compl. ¶¶273-274).
  • Asserted Claims: Independent claims 1, 3, and 5 are asserted (Compl. ¶274).
  • Accused Features: The accused features are functionalities within AT&T's 4G/LTE and 5G network and devices, compliant with Release 12 or 15 or later, that have the ability to transmit and receive channel state information using 256QAM modulation (Compl. ¶¶275-276).

III. The Accused Instrumentality

  • Product Identification: The accused instrumentalities are AT&T's 4G/LTE and 5G mobile networks, including the "AT&T Base Stations" and associated equipment, as well as the "Accused Devices" (e.g., smartphones, tablets, mobile hotspots) that AT&T sells and that operate on its network (Compl. ¶¶39-40, 43, 62).
  • Functionality and Market Context: The complaint alleges that AT&T's network and the Accused Devices operate in compliance with 3GPP 4G/LTE and 5G standards, including Releases 8 through 15 and later (Compl. ¶¶39, 41, 45). The complaint asserts that these standard-compliant operations directly practice the methods claimed in the asserted patents (Compl. ¶¶63, 85). AT&T is alleged to operate a "market-leading 4G/LTE and 5G mobile network" that covers "more than 99% of the U.S. population" (Compl. ¶41). Figure 1 presents a coverage map from AT&T's website, which purports to show extensive 5G and 4G/LTE coverage in East Texas and beyond (Compl. p. 13, Fig. 1).

IV. Analysis of Infringement Allegations

’631 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
determining, by a source base station (BS), to perform a handover of a terminal from the source BS to a target BS An AT&T 5G base station, operating per the 5G standard, determines whether to perform a handover from a source to a target base station. ¶64 col. 2:10-12
transmitting, by the source BS to the target BS, a handover request message including network slice information The source base station transmits a handover request message containing network slice information to the target base station, as required by the 5G standard. ¶64 col. 2:13-16
receiving, by the source BS from the target BS, a handover request confirmation message in response to the handover request message The source base station receives a handover request confirmation message from the target base station in response. ¶64 col. 2:17-19
wherein the handover request confirmation message includes information for indicating a rejection of the one or more protocol data unit (PDU) sessions by the target BS if the PDU sessions are associated with one or more network slices that are not supported by the target BS The confirmation message includes information indicating rejection of PDU sessions if those sessions are linked to network slices unsupported by the target base station. ¶64 col. 2:20-27
  • Identified Points of Contention:
    • Scope Questions: A potential point of contention may be whether the term "network slice information" as used in the patent is coextensive with how that information is defined and transmitted in the 3GPP standards allegedly practiced by AT&T.
    • Technical Questions: The analysis may turn on what evidence shows that AT&T's standard-compliant handover confirmation messages perform the specific function of "indicating a rejection of... PDU sessions" based on unsupported network slices, as opposed to providing a more general failure or cause code.

’931 Patent Infringement Allegations

Claim Element (from Independent Claim 3) Alleged Infringing Functionality Complaint Citation Patent Citation
transmitting, by a base station (BS) to a Machine Type Communication (MTC) terminal, structural information that contains at least one piece of i) information on a resource allocated to an uplink control channel for transmitting the response information and ii) offset information of the resource allocated to the uplink control channel An AT&T 4G/LTE base station transmits structural information, such as PUCCH-Config, via higher layer signaling to an MTC terminal. ¶86 col. 13:2-7
transmitting, by the BS to the MTC terminal, downlink control information for scheduling the downlink data The base station transmits downlink control information to schedule downlink data for the MTC terminal. ¶86 col. 13:8-9
transmitting, by the BS to the MTC terminal, the downlink data The base station transmits the scheduled downlink data to the MTC terminal. ¶86 col. 13:10-11
wherein the resource of the uplink control channel...is determined based on at least one piece of i) information on a resource of a downlink control channel..., ii) the information on the resource allocated to the uplink control channel, and iii) the offset information on the resource allocated to the uplink control channel The uplink control channel resource is determined based on the specified set of inputs, consistent with 4G/LTE standard procedures for MTC devices. ¶86 col. 13:12-21
  • Identified Points of Contention:
    • Scope Questions: A central question may be whether the "Accused Devices" that AT&T sells, which include general-purpose smartphones, qualify as "Machine Type Communication (MTC) terminals" within the meaning of the patent claims.
    • Technical Questions: The dispute may focus on evidence demonstrating that the accused system's determination of the uplink control channel resource is based on the specific three types of information required by the claim, rather than a subset or a different set of inputs permitted by the 4G/LTE standard.

V. Key Claim Terms for Construction

  • Term from ’631 Patent: "network slice"

    • Context and Importance: This term is central to the technology of the ’631 Patent. The definition will determine what types of virtual network configurations fall within the claim scope. Practitioners may focus on this term because its definition could either limit the claims to specific, narrowly defined network partitions or broaden them to cover any logical separation of network resources.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification states that a "network slice may provide a specific capability and a specific characteristic," which could be argued to encompass any logical network partition that delivers a defined service or quality level (’631 Patent, col. 3:1-2).
      • Evidence for a Narrower Interpretation: The detailed description provides examples of network slices for specific use cases like "plain old MBB" (Mobile Broadband) and "MTC Power Meters" (’631 Patent, FIG. 1). A defendant may argue these examples limit the term to formally defined, end-to-end network partitions for distinct service categories.

  • Term from ’931 Patent: "Machine Type Communication (MTC) terminal"

    • Context and Importance: The claims of the ’931 Patent are explicitly directed to methods involving an "MTC terminal." The definition is critical because if the term is construed narrowly to mean only low-power, low-complexity IoT-type devices, it may not read on the full range of "Accused Devices," which includes smartphones.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The background section defines MTC as "a type of data communication in which one or more machines or objects communicate with each other... without human interaction," which could be argued to include automated communications from any device, including a smartphone app (’931 Patent, col. 1:25-29).
      • Evidence for a Narrower Interpretation: The background also notes that "MTC terminals may be installed in an area where a radio wave environment is not good compared to general terminals," suggesting they are a distinct class of device designed for enhanced coverage and potentially lower performance than a "general terminal" like a smartphone (’931 Patent, col. 1:33-36).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement by asserting that AT&T takes active steps to encourage infringement by selling access to its 4G/LTE and 5G networks and encouraging customers to operate standard-compliant Accused Devices on those networks (Compl. ¶¶67-68, 88-89). Contributory infringement is alleged on the basis that the standard-compliant communication functionalities of the Accused Devices have no substantial non-infringing use other than to operate on AT&T's network in an infringing manner (Compl. ¶¶71-72, 92-93).
  • Willful Infringement: Willfulness allegations are based on both pre-suit and post-suit knowledge. The complaint alleges pre-suit knowledge stemming from AT&T's membership in 3GPP, where the patents were allegedly declared essential to the standards, and from a notice letter sent by Pegasus to AT&T in December 2022. Post-suit knowledge is based on the filing of the complaint itself (Compl. ¶¶74-75, 95-96).

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

  • A central issue will be one of standard essentiality and claim mapping: Does compliance with the 3GPP 4G/LTE and 5G standards, as alleged, inherently require practicing every limitation of the asserted claims? The case will likely involve a technical analysis of whether the standards mandate the specific methods claimed by the patents or merely provide a framework where non-infringing alternatives are possible.
  • A key question will be one of definitional scope: Can terms rooted in specific technical contexts, such as "Machine Type Communication (MTC) terminal" (primarily associated with IoT) and "network slice," be construed broadly enough to cover the full range of accused instrumentalities, including general-purpose smartphones and any logical network partition?
  • An evidentiary question will be one of knowledge and intent: Regarding willfulness and indirect infringement, the case may explore what level of knowledge can be imputed to AT&T based on its participation in a standards body and receipt of a notice letter, and whether its actions in marketing and operating its public network constitute specific intent to induce infringement by its customers.