DCT

5:23-cv-00091

Pantech Corp v. LG Electronics Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 5:22-cv-00093, E.D. Tex., 09/02/2022
  • Venue Allegations: Venue is alleged to be proper based on Defendant LG Electronics U.S.A. having regular and established places of business within the Eastern District of Texas, and Defendant LG Electronics Inc. being a foreign resident.
  • Core Dispute: Plaintiffs allege that Defendant’s mobile phones, tablets, and other devices capable of operating on LTE and 5G cellular networks infringe seven U.S. patents related to wireless communication standards and mobile device user interface features.
  • Technical Context: The patents address foundational technologies in modern cellular communication, including methods for improving data transmission efficiency and reliability in 4G/5G networks, as well as user interface designs for messaging and multitasking.
  • Key Procedural History: The complaint describes a long history of licensing negotiations, beginning in February 2015 between Defendant and Signal Trust, a predecessor-in-interest to some of the asserted patents. Pantech alleges it took over negotiations in September 2020, making multiple license offers on Fair, Reasonable, and Non-Discriminatory (FRAND) terms for patents it claims are essential to cellular standards, which Defendant allegedly refused.

Case Timeline

Date Event
2002-12-16 ’486 Patent Priority Date
2003-11-05 ’247 Patent Priority Date
2004-04-14 ’839 Patent Priority Date
2005-08-11 ’631 Patent Priority Date
2007-09-28 ’809 Patent Priority Date
2007-10-16 ’839 Patent Issued
2010-01-28 ’545 Patent Priority Date
2010-07-05 ’924 Patent Priority Date
2015-02-27 Signal Trust (predecessor) sends first license offer letter to LG
2015-06-23 ’486 Patent Issued
2015-09-15 ’924 Patent Issued
2016-04-12 ’809 Patent Issued
2016-04-29 Signal Trust provides notice of ’809 Patent to LG
2017-02-15 Signal Trust provides notice of ’486 Patent to LG
2017-02-21 ’631 Patent Issued
2017-12-26 ’545 Patent Issued
2020-09-22 Pantech sends first letter to LG, identifying ’545 and ’839 Patents
2020-12-15 ’247 Patent Issued
2021-01-27 Pantech sends letter identifying ’924 and ’631 Patents to LG
2021-07-12 Pantech sends letter identifying ’247 Patent to LG
2022-09-02 Complaint Filed

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

U.S. Patent No. 9,136,924 - “Transmitting device and a method of communicating therewith, and receiving device and a method of communicating therewith,” Issued September 15, 2015

The Invention Explained

  • Problem Addressed: In advanced wireless systems using Multiple-Input Multiple-Output (MIMO) antennas, a large set of possible transmission configurations (a "codebook") is available. The patent addresses the technical challenges of efficiently managing this codebook to reduce interference between cells and minimize the data overhead required for a mobile device to report channel conditions back to the base station. (Compl. ¶51; ’924 Patent, col. 4:15-29).
  • The Patented Solution: The invention proposes a "codebook restriction" method where the base station transmits information to the mobile device that restricts which transmission configurations (precoding matrices) from the larger codebook are permitted for use. (Compl. ¶51). This allows the system to tailor the available codebook for specific cells or users, thereby improving communication quality and managing interference in a coordinated manner. (’924 Patent, col. 4:15-29).
  • Technical Importance: This technique enables more efficient and reliable MIMO communications, which is a cornerstone technology for achieving the high data rates required by LTE and 5G standards. (Compl. ¶51).

Key Claims at a Glance

  • The complaint asserts independent claims 22 and 28, among other dependent claims. (Compl. ¶52).
  • Essential elements of independent method claim 22 include:
    • Receiving codebook restricting information including first information (to restrict a first precoding matrix) and second information (to restrict a second precoding matrix).
    • Transmitting first channel status information indicating a first precoding matrix selected from among non-restricted matrices.
    • Transmitting second channel status information indicating a second precoding matrix selected from among non-restricted matrices.
  • The complaint reserves the right to assert additional claims, including dependent claims. (Compl. ¶52).

U.S. Patent No. 9,854,545 - “Apparatus and method for establishing uplink synchronization in a wireless communication system,” Issued December 26, 2017

The Invention Explained

  • Problem Addressed: Wireless standards like LTE-Advanced and 5G increase data speeds by allowing a single device to communicate over multiple frequency bands (Component Carriers, or CCs) simultaneously, a technique known as carrier aggregation. This creates a technical problem of maintaining proper uplink timing synchronization across different CCs, which may have different transmission characteristics. (Compl. ¶65).
  • The Patented Solution: The patent describes a method for managing this complexity by organizing CCs into one or more "uplink timing groups." A mobile device receives configuration information from the network, transmits a Random Access Preamble on a CC within a group, and then receives a specific "timing advance value" to apply to all uplink CCs within that same timing group, ensuring they remain synchronized. (Compl. ¶65; ’545 Patent, Abstract).
  • Technical Importance: This method provides a systematic way to manage synchronization across multiple carriers, which is a fundamental requirement for implementing carrier aggregation in LTE-Advanced and multi-radio connectivity in 5G networks. (Compl. ¶¶65-66).

Key Claims at a Glance

  • The complaint asserts dependent claims 2 and 3. (Compl. ¶67). These depend from independent claim 1.
  • Essential elements of independent apparatus claim 1 include:
    • A transceiver configured to receive Radio Resource Control (RRC) signaling including a UL timing group information set.
    • A controller configured to configure one or more UL timing groups based on the information set.
    • The transceiver transmits a Random Access Preamble (RAP) through a delegate CC in a timing group.
    • The transceiver receives a Random Access Response (RAR) including a Timing Advance (TA) value.
    • The controller applies the TA value to the CCs in the respective UL timing group.
  • The complaint reserves the right to assert additional claims. (Compl. ¶67).

U.S. Patent No. 10,869,247 - “Supporting Uplink Transmissions,” Issued December 15, 2020 (Multi-Patent Capsule)

  • Technology Synopsis: The patent describes a method for managing data retransmissions in a Hybrid Automatic Repeat Request (H-ARQ) process. It discloses determining whether to retransmit a data block based on received uplink scheduling information from a base station, rather than waiting for a negative acknowledgment (NACK), aiming to improve efficiency. (Compl. ¶81; ’247 Patent, Abstract).
  • Asserted Claims: Claims 1, 2, 8, 11, 12, and 18. (Compl. ¶82).
  • Accused Features: The complaint alleges that 5G-compatible products that transmit data using an H-ARQ process in compliance with 3GPP standards infringe this patent. (Compl. ¶83).

U.S. Patent No. 9,313,809 - “Method and apparatus for terminating transmission of a message in an enhanced random access channel,” Issued April 12, 2016 (Multi-Patent Capsule)

  • Technology Synopsis: The patent discloses a method for efficiently managing network resources on an Enhanced Dedicated Channel (E-DCH). The technology involves a device transmitting its buffer status to a base station and determining when to release the channel resource, specifically after its transmission buffer and H-ARQ buffer are empty, to prevent unnecessary resource occupation. (Compl. ¶95; ’809 Patent, Abstract).
  • Asserted Claims: Claims 1-10. (Compl. ¶96).
  • Accused Features: The complaint accuses WDCMA-compatible devices, such as the LG G7 ThinQ, that support enhanced uplink resource requests in compliance with 3GPP standards. (Compl. ¶97).

U.S. Patent No. 9,065,486 - “Detection, avoidance and/or correction of problematic puncturing patterns in parity bit streams used when implementing turbo codes,” Issued June 23, 2015 (Multi-Patent Capsule)

  • Technology Synopsis: The patent addresses performance degradation in "punctured" Turbo codes, which are used for error correction in standards like LTE. It describes methods for detecting and correcting issues that arise from specific "puncturing patterns"—the process of removing bits to match a desired data rate—which can otherwise degrade communication reliability. (Compl. ¶109; ’486 Patent, Abstract).
  • Asserted Claims: Claims 3-4. (Compl. ¶110).
  • Accused Features: The complaint accuses LTE-compatible devices, such as the LG G7 ThinQ, that implement punctured Turbo codes as mandated by the LTE standard. (Compl. ¶111).

U.S. Patent No. 7,283,839 - “Wireless communicating terminal for providing integrated messaging service and method thereof,” Issued October 16, 2007 (Multi-Patent Capsule)

  • Technology Synopsis: The patent addresses a user interface problem where different message types (e.g., text vs. multimedia) required separate applications. The invention provides a single, "integrated messaging service" that manages both incoming and outgoing messages of different types within a unified user interface, analogized to an internet messenger rather than separate in-boxes and out-boxes. (Compl. ¶¶124-125). A screenshot shows an annotated example of a received multimedia message within a threaded conversation view. (Compl. p. 36).
  • Asserted Claims: Claims 1-5. (Compl. ¶126).
  • Accused Features: The complaint accuses the LG V60 ThinQ 5G and other products that provide an integrated user interface for sending and receiving both text and multimedia messages. (Compl. ¶¶127-128).

U.S. Patent No. 9,575,631 - “Method for selecting and controlling second work process during first work process in multitasking mobile terminal,” Issued February 21, 2017 (Multi-Patent Capsule)

  • Technology Synopsis: The patent addresses usability issues in mobile multitasking where changing from one process to another would terminate the first. The invention provides a method for controlling a function of a second, background process (e.g., audio playback) while a first, foreground process (e.g., text message creation) is active, without terminating the first process. (Compl. ¶¶141-142). A screenshot shows a control menu for an audio player pulled down over another application screen. (Compl. p. 40).
  • Asserted Claims: Claims 1-4, 8, and 9. (Compl. ¶143).
  • Accused Features: The complaint accuses the LG V60 ThinQ 5G and other products that allow users to control a background process, such as an audio player, while a foreground process, such as the Messages application, is concurrently displayed. (Compl. ¶145).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are broadly defined as "mobile phones, tablets, and certain other devices capable of operating on LTE and 5G cellular networks" sold by LG. (Compl. ¶11). Specific exemplary products identified include the LG V60 ThinQ 5G and the LG G7 ThinQ. (Compl. ¶53, ¶97).

Functionality and Market Context

The infringement allegations focus on two categories of functionality:

  • Standards Compliance: The complaint alleges that the accused devices implement core functionalities mandated by 3GPP standards for WDCMA, LTE, LTE-Advanced, and 5G networks. These functionalities include carrier aggregation, multi-radio dual connectivity, H-ARQ processes, codebook restriction for MIMO, and punctured turbo codes. (Compl. ¶51, ¶65, ¶83, ¶97, ¶109).
  • User Interface Features: The complaint alleges that devices like the LG V60 ThinQ 5G incorporate specific user-facing software, such as an integrated messaging application for text and multimedia messages and multitasking controls for managing background applications (e.g., an audio player) from a foreground task. (Compl. ¶128, ¶145).

IV. Analysis of Infringement Allegations

’924 Patent Infringement Allegations

Claim Element (from Independent Claim 22) Alleged Infringing Functionality Complaint Citation Patent Citation
a receiving device in a wireless communication system, the method comprising: receiving codebook restricting information... The accused 5G devices receive codebook restriction information to restrict precoding matrices, as mandated by 3GPP standards. ¶51 col. 4:15-29
transmitting ... 1st channel status information indicating a first precoding matrix, the first precoding matrix being selected, based on the codebook restricting information, from among precoding matrices that are not restricted... The accused 5G devices transmit channel status information (CSI) indicating a selected precoding matrix based on the codebook restriction. ¶51 col. 6:52-59
transmitting ... 2nd channel status information indicating a second precoding matrix, the second precoding matrix being selected, based on the codebook restricting information, from among precoding matrices that are not restricted... The accused 5G devices transmit CSI indicating a second selected precoding matrix based on the same codebook restriction scheme. ¶51 col. 6:60-67

’545 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
an apparatus comprising: a transceiver configured to receive ... RRC signaling including a UL timing group information set... Accused LTE-Advanced and 5G devices receive RRC signaling containing configuration information for timing advance groups (TAGs). ¶65 col. 8:1-5
a controller configured to configure one or more UL timing groups based on the UL timing group information set... The processor in the accused devices configures one or more uplink timing groups based on the received RRC signaling. ¶65 col. 8:6-9
the transceiver transmits a Random Access Preamble... through one or more CCs in a respective timing group... The accused devices transmit a Random Access Preamble (RAP) through component carriers in a respective timing group to establish synchronization. ¶65 col. 8:13-17
the transceiver receives a Random Access Response ... including a Timing Advance (TA) value to apply to UL CCs in the timing group The accused devices receive a TA value in response, which is used for uplink timing adjustment for the CCs in that group. ¶65 col. 8:18-22

Identified Points of Contention

  • Standards-Essentiality: For the five patents related to cellular standards ('924, '545, '247, '809, and '486), a primary point of contention will be whether compliance with the cited 3GPP technical specifications necessarily requires practicing the asserted claims. The analysis will depend on whether the standards permit non-infringing alternatives for implementing the required functionality.
  • Scope Questions: For the user interface patents ('839 and '631), disputes may arise over claim scope. For the ’839 Patent, a key question is whether LG’s messaging application, which presents different message types in a single conversational thread, meets the specific limitations of an “integrated messaging service” as defined in the patent. For the ’631 Patent, the question is whether the accused multitasking feature performs the specific sequence of steps recited in the claims for selecting and controlling a second work process.

V. Key Claim Terms for Construction

’924 Patent: "codebook restricting information"

  • The Term: "codebook restricting information"
  • Context and Importance: The definition of this term is central to the infringement analysis. The dispute may turn on what type of data qualifies as "information" that "restricts" the codebook and how it must be transmitted and used by the receiving device.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the information as enabling the use of "different codebooks for each cell or each user equipment," suggesting any signal that results in a subset of the main codebook being used could qualify. (’924 Patent, col. 4:21-25).
    • Evidence for a Narrower Interpretation: The patent provides a specific example where the restriction is conveyed via a "bitmap format" where a bit corresponds to each precoding matrix. (’924 Patent, col. 4:60-64). A defendant may argue the term should be limited to such explicit, bit-mapped instructions rather than more general signaling.

’545 Patent: "uplink timing group"

  • The Term: "uplink timing group"
  • Context and Importance: This term defines the core concept of the patent. The infringement case hinges on whether the way the accused LTE-Advanced and 5G devices group component carriers for synchronization purposes falls within the patent’s definition of this term.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The abstract describes the invention broadly as establishing synchronization "through the use of timing groups," which could encompass any logical grouping of carriers for applying a common timing advance value. (’545 Patent, Abstract).
    • Evidence for a Narrower Interpretation: The detailed description repeatedly ties the configuration of these groups to information received via "Radio Resource Control (RRC) signaling." (’545 Patent, col. 8:1-5). An argument could be made that a "timing group" must be formed specifically in response to this type of signaling, as opposed to other methods of carrier management.

VI. Other Allegations

Indirect Infringement

The complaint alleges induced infringement for all asserted patents, based on Defendant’s advertising of the devices as compliant with the relevant cellular standards (e.g., 5G, LTE) or possessing the accused user interface features. (Compl. ¶57, ¶73, ¶87, ¶101, ¶115, ¶132, ¶149). It further alleges contributory infringement on the basis that the accused devices are material components especially made or adapted for practicing the patents and are not staple articles of commerce suitable for substantial non-infringing use. (Compl. ¶60, ¶76, ¶90, ¶104, ¶118, ¶135, ¶152).

Willful Infringement

Willfulness is alleged for all patents based on pre-suit knowledge. The complaint alleges Defendant was made aware of the asserted patent families through correspondence and licensing negotiations with Pantech and its predecessor-in-interest, Signal Trust, with specific notice dates ranging from April 2016 to July 2021 depending on the patent. (Compl. ¶55, ¶71, ¶85, ¶99, ¶113, ¶130, ¶147).

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

This litigation presents several central questions for the court:

  • A core issue for a majority of the asserted patents will be one of standards-essentiality: does compliance with the 3GPP standards for LTE, LTE-Advanced, and 5G, as implemented in the accused LG devices, inherently and necessarily result in infringement of the claims of the ’924, ’545, ’247, ’809, and ’486 patents?
  • A key question for the user-facing patents will be one of definitional scope and factual mapping: can the term “integrated messaging service” in the ’839 patent be construed to cover the accused LG messaging application, and does the accused multitasking functionality in LG’s software perform the specific method steps required by the claims of the ’631 patent?
  • Finally, given the extensive history of alleged licensing negotiations detailed in the complaint, a central issue related to damages will be willfulness and the nature of FRAND: did the Defendant have pre-suit knowledge sufficient to support a finding of willful infringement, and what constitutes a FRAND royalty for the patents alleged to be essential to cellular standards?