DCT

2:23-cv-00639

Pegasus Wireless Innovation LLC v. T-Mobile US Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:23-cv-00639, E.D. Tex., 12/29/2023
  • Venue Allegations: Plaintiff alleges venue is proper because Defendant T-Mobile maintains a regular and established place of business in the district, including retail stores, infringing base stations, and corporate offices.
  • Core Dispute: Plaintiff alleges that Defendant’s 4G/LTE and 5G mobile networks and compatible devices infringe eleven patents related to wireless telecommunications standards.
  • Technical Context: The patents-in-suit relate to foundational technologies for 4G/LTE and 5G mobile networks, including network slicing, resource allocation for machine-type communications, and dual-connectivity.
  • Key Procedural History: Plaintiff states that the asserted patents were developed by KT Corporation and declared as essential to various 4G/LTE and 5G standards developed by the 3GPP standards-setting organization. Plaintiff alleges it provided notice of the asserted patents and Defendant's infringement to Defendant in a letter dated December 16, 2022, and subsequently attempted to negotiate a license on fair, reasonable, and non-discriminatory (FRAND) terms.

Case Timeline

Date Event
2013-09-26 Priority Date for ’644 Patent
2013-09-27 Priority Date for ’931 Patent
2014-03-21 Priority Date for ’161 Patent
2015-07-14 Priority Date for ’932 Patent
2016-05-12 Priority Date for ’118 Patent
2016-11-03 Priority Date for ’631 Patent
2016-11-16 Priority Date for ’942 Patent
2017-07-28 Priority Date for ’460 Patent
2017-09-29 Priority Date for ’463 and ’000 Patents
2018-02-13 ’644 Patent Issued
2018-06-26 ’463 and ’161 Patents Issued
2018-07-27 Priority Date for ’272 Patent
2019-01-15 ’931 Patent Issued
2020-03-17 ’460 Patent Issued
2020-04-07 ’932 Patent Issued
2020-07-21 ’118 Patent Issued
2022-01-04 ’000 Patent Issued
2022-08-02 ’942 Patent Issued
2022-09-07 Pegasus acquires rights in Asserted Patents from KT Corporation
2022-12-16 Pegasus sends notice letter to T-Mobile alleging infringement
2022-12-27 ’272 Patent Issued
2023-04-11 ’631 Patent 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

The Invention Explained

  • Problem Addressed: The patent addresses the technical challenge of maintaining continuous and stable service for a mobile device user as the device moves between two different base stations in a network that employs "network slicing" technology (Compl. ¶59; ’631 Patent, col. 1:15-28). Network slicing allows a physical network to be partitioned into multiple virtual networks, each tailored to a specific application or service type.
  • The Patented Solution: The invention provides a method for a base station to manage this transition. It involves receiving a "network slice request" from a user device, forwarding that request to the core network, and then processing handover commands that are generated based on the specific slice information received back from the core network ('631 Patent, Abstract). A key part of the solution is how the source and target base stations communicate during a handover to ensure the target base station can support the specific network slice(s) required by the user's active data sessions, and to reject sessions for unsupported slices (’631 Patent, col. 16:21-39).
  • Technical Importance: This technology is foundational for 5G networks, which are designed to support a wide variety of services (e.g., high-speed mobile broadband, low-latency communications for vehicles, massive IoT deployments) on a single physical infrastructure through network slicing (Compl. ¶59).

Key Claims at a Glance

  • The complaint asserts independent claims 1, 7, and 13 (Compl. ¶60).
  • Independent Claim 1 (A method performed by a source base station) includes these essential elements:
    • determining whether to perform a handover of one or more protocol data unit (PDU) sessions for a terminal from the source base station to a target base station;
    • transmitting, to the target base station, a handover request message which includes network slice information; and
    • receiving, from the target base station, a handover request confirmation message that includes information indicating a rejection of PDU sessions if those sessions are associated with network slices not supported by the target base station.
  • The complaint does not explicitly reserve the right to assert dependent claims.

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

The Invention Explained

  • Problem Addressed: The patent identifies the need for an efficient method to allocate uplink control channel (PUCCH) resources for a specific class of devices known as Machine-Type Communication (MTC) terminals (’931 Patent, col. 1:41-52). MTC devices, often used in IoT applications, may operate in poor radio environments and require repeated transmissions to ensure reliability, complicating standard resource allocation (Compl. ¶80; ’931 Patent, col. 1:31-40).
  • The Patented Solution: The invention discloses a method for a terminal to transmit response information (like an ACK/NACK for received data) by determining the correct uplink resource based on a combination of information. This includes structural information received via higher-layer signaling (e.g., information on the uplink resource and "start offset" information) and control information received on a downlink channel that scheduled the original data transmission (’931 Patent, Abstract; col. 2:1-15).
  • Technical Importance: This method provides a structured way to manage control channel resources for MTC devices, which are a key component of 4G/LTE-Advanced systems and the broader Internet of Things (IoT) ecosystem (Compl. ¶80).

Key Claims at a Glance

  • The complaint asserts independent claims 1, 3, 5, and 7 (Compl. ¶81). The infringement allegations focus on claim 3.
  • Independent Claim 3 (A method for transmitting response information of a MTC terminal) includes these essential elements:
    • receiving structural information comprising at least one of (i) information on a resource allocated to an uplink control channel and (ii) start offset information for that resource;
    • receiving downlink control information for scheduling downlink data;
    • receiving the downlink data; and
    • transmitting the response information using an uplink control channel resource that is determined based on at least one of (i) information on the downlink control channel resource used for scheduling, (ii) the received information on the uplink control channel resource, and (iii) the received start offset information.
  • The complaint does not explicitly reserve the right to assert dependent claims.

Multi-Patent Capsule: U.S. Patent No. 10,616,932

  • Patent Identification: U.S. Patent No. 10,616,932, Method for Configuring Wireless Connection of Terminal Apparatus Therefor, issued April 7, 2020 (Compl. ¶96).
  • 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 (CU) and an access unit (AU). The invention provides a procedure for radio connection setup in this disaggregated network architecture to reduce investment and operating costs (Compl. ¶101).
  • Asserted Claims: Independent claims 1 and 8 (Compl. ¶102).
  • Accused Features: T-Mobile's 5G network, which allegedly implements the claimed methods for transmitting Radio Resource Control (RRC) messages between the terminal, an access unit, and a central unit as required by 5G standards (Compl. ¶¶102, 105).

Multi-Patent Capsule: U.S. Patent No. 11,405,942

  • 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 (Compl. ¶117).
  • 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 provides a method for a terminal to monitor for and receive "downlink pre-emption indication data," which signals that resources scheduled for one type of service are being pre-empted for a higher-priority service (Compl. ¶122).
  • Asserted Claims: Independent claims 1, 5, and 9 (Compl. ¶123).
  • Accused Features: T-Mobile's 5G network and devices, which are alleged to use a specific radio network temporary identifier (RNTI) to signal downlink preemption information, allowing for efficient multiplexing of different data traffic types (Compl. ¶¶123, 126).

Multi-Patent Capsule: U.S. Patent No. 10,594,460

  • Patent Identification: U.S. Patent No. 10,594,460, Apparatus and Method for Transmitting and Receiving Uplink Channel, issued March 17, 2020 (Compl. ¶138).
  • Technology Synopsis: The patent relates to methods for frequency hopping for uplink channel transmissions in a 5G network. The invention enables user equipment to transmit on an uplink control and data channel using a single "bandwidth part" based on configuration information received from the base station, preventing collisions between resources (Compl. ¶¶143, 147).
  • Asserted Claims: Independent claims 1, 5, and 9 (Compl. ¶144).
  • Accused Features: T-Mobile's 5G network and devices, which allegedly perform frequency hopping for uplink transmissions within a configured bandwidth part (BWP) based on configuration information and downlink control information (DCI) (Compl. ¶¶144, 147).

Multi-Patent Capsule: U.S. Patent No. 10,721,118

  • Patent Identification: U.S. Patent No. 10,721,118, Method for Configuring Dual-Connectivity by Terminal, and Apparatus Therefor, issued July 21, 2020 (Compl. ¶159).
  • Technology Synopsis: The patent discloses a method for configuring dual-connectivity, which enables a user device to connect simultaneously to a master base station (e.g., LTE) and a secondary base station (e.g., 5G). The invention covers receiving configuration messages via a secondary base station signaling radio bearer (SRB) and transmitting a failure message if the configuration cannot be complied with (Compl. ¶¶164, 165).
  • Asserted Claims: Independent claims 1, 7, and 10 (Compl. ¶165).
  • Accused Features: T-Mobile's 5G network and devices, which allegedly configure dual-connectivity by adding a secondary base station SRB and exchanging RRC messages to configure resources on the secondary base station (Compl. ¶¶165, 168).

Multi-Patent Capsule: U.S. Patent No. 11,219,000

  • 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 (Compl. ¶180).
  • Technology Synopsis: The patent relates to a method for a user device to transmit uplink control information in a 5G network. The invention enables a user device to select an appropriate uplink control channel resource from a set of resources based on the size of the control information to be transmitted (Compl. ¶¶185, 189).
  • Asserted Claims: Independent claims 1, 5, and 9 (Compl. ¶186).
  • Accused Features: T-Mobile's 5G network and devices, which are alleged to transmit and receive uplink control channel resource set configuration information, from which a specific resource set is selected based on the size of the uplink control information to be sent (Compl. ¶¶186, 189).

Multi-Patent Capsule: U.S. Patent No. 10,638,463

  • 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 (Compl. ¶201).
  • Technology Synopsis: This patent is related to the ’000 Patent and also addresses uplink control channel resource allocation in a 5G network. The invention involves receiving resource set configuration information and determining which resource set and specific resource to use, with the configuration being tied to specific uplink bandwidth parts (BWPs) (Compl. ¶¶206, 210).
  • Asserted Claims: Independent claims 1, 4, and 7 (Compl. ¶207).
  • Accused Features: T-Mobile's 5G network and devices, which allegedly configure uplink control channel resource sets for each uplink BWP, allowing the network to manage resource allocation dynamically as different BWPs are activated (Compl. ¶¶207, 210).

Multi-Patent Capsule: U.S. Patent No. 11,540,272

  • 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 (Compl. ¶222).
  • Technology Synopsis: The patent relates to allocating time-domain resources for data channels in a 5G network. The invention provides for a base station to transmit time interval resource configuration information (defining allocations of OFDM symbols within a slot or mini-slot) and then transmit control information that selects one of the pre-configured allocations for a given transmission (Compl. ¶227).
  • Asserted Claims: Independent claims 1, 8, and 15 (Compl. ¶228).
  • Accused Features: T-Mobile's 5G network and devices, which are alleged to use RRC signaling to transmit tables of time-domain resource allocations and then use downlink control information (DCI) to select a specific allocation from the table for a given data transmission (Compl. ¶¶228, 231).

Multi-Patent Capsule: U.S. Patent No. 9,894,644

  • Patent Identification: U.S. Patent No. 9,894,644, Method for Transceiving Downlink Control Information and Apparatus for Same, issued February 13, 2018 (Compl. ¶243).
  • Technology Synopsis: The patent relates to repeatedly transmitting downlink control information over multiple subframes to a terminal in an area of enhanced coverage (e.g., for MTC). The invention provides for a base station to send configuration information (e.g., a start subframe and number of subframes) so the terminal knows how to combine the repeated transmissions to decode the control information (Compl. ¶¶248, 249).
  • Asserted Claims: Independent claims 1, 2, and 3 (Compl. ¶249).
  • Accused Features: T-Mobile's 4G/LTE network and devices, which are alleged to transmit configuration information via higher layer signaling and then repeatedly transmit downlink control information across multiple subframes to devices requiring enhanced coverage (Compl. ¶¶249, 252).

Multi-Patent Capsule: U.S. Patent No. 10,009,161

  • 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 (Compl. ¶264).
  • Technology Synopsis: The patent relates to transmitting and receiving channel state information (CSI) for systems supporting 256-state quadrature amplitude modulation (256QAM). The invention provides a method and specific Channel Quality Indicator (CQI) index table that includes values for 256QAM, allowing a terminal to report channel quality to the base station so it can select an appropriate high-order modulation scheme (Compl. ¶269).
  • Asserted Claims: Independent claims 1, 3, and 5 (Compl. ¶270).
  • Accused Features: T-Mobile's 4G/LTE and 5G networks and devices, which are alleged to use a 256QAM modulation CQI index table to transmit and receive channel state information, enabling high-speed data processing (Compl. ¶¶270, 273, 275).

III. The Accused Instrumentality

  • Product Identification: The accused instrumentalities are T-Mobile's mobile telecommunications network and the devices that operate on it (Compl. ¶¶36-37). This includes T-Mobile's 4G/LTE and 5G networks, T-Mobile Base Stations, and all compatible "Accused Devices" such as smartphones and mobile hotspots sold or used by T-Mobile (Compl. ¶¶37, 39, 61, 82).
  • Functionality and Market Context: The complaint alleges that T-Mobile's network and the Accused Devices operate in compliance with global 3GPP technical standards for 4G/LTE and 5G, including Releases 8 through 15 (Compl. ¶¶36, 41). The complaint cites T-Mobile's public statements that its network is a "market-leading 4G/LTE and 5G mobile network" covering 99% of Americans with 4G LTE and 98% with 5G (Compl. ¶¶38, 40). A coverage map from T-Mobile's website is included as Figure 1, showing 4G/LTE and 5G coverage within the Eastern District of Texas (Compl. ¶40, p. 12). The complaint also provides a table showing KT Corporation's, the original inventor, participation in 3GPP meetings related to the development of these standards (Compl. ¶33, p. 9).

IV. Analysis of Infringement Allegations

’631 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
determining whether to perform a handover of one or more protocol data unit (PDU) sessions for a terminal from the source base station to a target base station T-Mobile's 5G network determines whether to perform a handover from a source to a target base station, consistent with 5G standards. ¶63 col. 16:21-25
transmitting, to the target base station, a handover request message... wherein the handover request message includes network slice information When a handover is initiated, the source base station transmits a handover request message containing network slice information to the target base station. ¶63 col. 16:26-30
receiving, from the target base station, a handover request confirmation message... wherein the handover request confirmation message includes information for indicating a rejection of the one or more protocol data unit (PDU) sessions... if the PDU sessions are associated with one or more network slices that are not supported by the target base station The source base station receives a confirmation message from the target base station, which includes information rejecting any PDU sessions linked to network slices that the target station cannot support. ¶63 col. 16:31-39
  • Identified Points of Contention:
    • Scope Questions: The central dispute may concern whether T-Mobile's implementation of the 3GPP standards (specifically TS 38.300 and TS 38.423) maps directly onto every limitation of the asserted claims. A key question for the court may be whether the "handover request confirmation message" in T-Mobile's network performs the specific function of including "information for indicating a rejection" of PDU sessions based on unsupported network slices, as claimed.
    • Technical Questions: What evidence does the complaint provide that T-Mobile's base stations actually execute each step of the claimed method? The complaint relies on compliance with the 5G standard, raising the question of how Plaintiff will prove the accused instrumentalities perform the claimed steps in practice, beyond mere capability.

’931 Patent Infringement Allegations

Claim Element (from Independent Claim 3) Alleged Infringing Functionality Complaint Citation Patent Citation
receiving structural information that contains at least one piece of i) information on a resource allocated to an uplink control channel... and ii) start offset information of the resource allocated to the uplink control channel T-Mobile's 4G/LTE MTC terminals receive structural information, including uplink control channel resource and start offset information, via higher layer signaling. ¶84 col. 14:1-5
receiving downlink control information for scheduling the downlink data The MTC terminal receives downlink control information (DCI) that schedules the downlink data transmission. ¶84 col. 14:6-7
receiving the downlink data The MTC terminal receives the downlink data as scheduled by the DCI. ¶84 col. 14:8-8
transmitting the response information on the downlink data by using the resource of the uplink control channel, wherein the resource... is determined based on at least one piece 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 start offset information... The MTC terminal determines the specific PUCCH resource for transmitting its ACK/NACK response based on a combination of the DCI resource, the configured uplink channel resource information, and the configured start offset information. ¶84 col. 14:9-15
  • Identified Points of Contention:
    • Scope Questions: The analysis may focus on whether the term "Machine Type Communication (MTC) terminal" as defined in the patent encompasses all of the "Accused Devices" that T-Mobile sells and operates on its network.
    • Technical Questions: A factual question will be whether the accused system's method for determining the uplink control channel resource relies on the specific three-part basis required by the claim (downlink control channel resource, uplink control channel resource information, and start offset information). The complaint alleges this functionality is required by the 4G/LTE standard (TS 36.213 and TS 36.331), which T-Mobile practices; the dispute may center on whether the standard mandates this exact technical operation.

V. Key Claim Terms for Construction

’631 Patent

  • The Term: "network slice"
  • Context and Importance: This term is the central technological concept of the patent. Its construction will determine whether the virtual network partitioning implemented in T-Mobile’s 5G network falls within the scope of the claims. Practitioners may focus on this term because the patent's definition will be compared against the 3GPP standard's definition and T-Mobile's implementation.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes a network slice as being "configured for a service to be provided to the UE" and may be identified by "Single-Network Slice Selection Assistance Information (S-NSSAI)" ('631 Patent, col. 11:39-44). This could support a broad reading covering any form of virtual network partitioning identified by S-NSSAI.
    • Evidence for a Narrower Interpretation: The detailed description often discusses network slices in the context of specific examples like "plain old MBB" (Mobile Broadband), MTC, and police video services ('631 Patent, Fig. 1). A defendant may argue this context limits the term to virtual networks created for distinct, high-level service categories, not just any logical partitioning.

’931 Patent

  • The Term: "start offset information"
  • Context and Importance: This term is a critical input for the claimed method of determining the uplink control channel resource. Its definition is key to the infringement analysis, as Plaintiff must show that the accused system uses a parameter corresponding to this claimed "start offset information" in its resource allocation calculation.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: Claim 1 describes the "offset information" as being part of the "structural information" received by the terminal. This suggests it could be any numerical offset value configured by the network used in the resource calculation formula (’931 Patent, col. 13:3-5).
    • Evidence for a Narrower Interpretation: Claim 3 specifies that the "start offset information... is configured separated from start offset information for a terminal different from the MTC terminal" and that a "plurality of pieces of start offset information... are provided." This language could be argued to narrow the term to a specific implementation where multiple, distinct offset values are maintained and selected from, potentially excluding systems that use a single, universally applied offset parameter.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement on the basis that T-Mobile provides its 4G/LTE and 5G network and sells Accused Devices with instructions and promotional materials that encourage end users to use the network in an infringing manner (e.g., Compl. ¶¶65-66, 86-87). Knowledge and intent are alleged to arise from at least the December 2022 notice letter (Compl. ¶¶67, 88). Contributory infringement is alleged on the grounds that the Accused Devices are especially designed to operate on the infringing network and are not staple articles of commerce suitable for substantial non-infringing use (Compl. ¶¶68, 89).
  • Willful Infringement: Willfulness is alleged based on T-Mobile's knowledge of the patents. This knowledge is asserted to stem from two sources: (1) KT Corporation’s declarations of the patents as essential to 3GPP standards, of which T-Mobile is a member, and (2) direct notice provided by Plaintiff in the December 16, 2022 letter and subsequent correspondence (e.g., Compl. ¶¶72, 93).

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

  • A core issue will be one of standards interpretation: do the functionalities mandated by the 3GPP 4G/LTE and 5G standards, which T-Mobile's network allegedly practices, contain every element of the asserted patent claims? The case may depend not on whether T-Mobile practices the standard, but whether the standard itself requires infringement.
  • A key evidentiary question will be one of proof of practice: beyond asserting compliance with standards, what specific evidence will be presented to demonstrate that T-Mobile’s vast and complex array of base stations and network equipment actually performs the patented methods as claimed across the eleven asserted patents?
  • A central question for damages will be the impact of the patents' FRAND encumbrance: given that the patents are alleged to be essential to industry standards and offered under FRAND terms, the dispute will likely involve complex arguments over what constitutes a reasonable royalty, separate from traditional infringement damages calculations.