DCT

5:25-cv-00093

Pantech Corp v. Lenovo Group Ltd

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Key Events
Amended Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 5:25-cv-00093, E.D. Tex., 08/28/2025
  • Venue Allegations: Venue is alleged to be proper as Defendants are not residents of the United States and may be sued in any judicial district. The complaint also alleges that Lenovo Group conducts extensive business, maintains places of business, and sells the accused products within the Eastern District of Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s smartphones, laptops, and tablets that are compliant with LTE, LTE-A, and 5G cellular standards infringe four U.S. patents related to wireless communication protocols.
  • Technical Context: The technology at issue concerns fundamental methods for managing data transmission, synchronization, and error-checking in modern 4G/5G cellular networks, which are essential for the operation of virtually all modern mobile devices.
  • Key Procedural History: The complaint alleges that Plaintiff and its predecessor-in-interest, Goldpeak Innovations, Inc., made repeated efforts to license the patent portfolio to Lenovo Group, beginning with initial outreach in March 2018. These efforts, which allegedly included providing technical details and claim charts, were purportedly met with delays and a lack of substantive response from Lenovo Group. The patents are alleged to be essential to the 3GPP cellular standards.

Case Timeline

Date Event
2008-01-01 Earliest Priority Date for ’344 and ’876 Patents
2008-12-08 Priority Date for ’839 Patent
2010-02-10 Priority Date for ’503 Patent
2017-01-17 ’839 Patent Issued
2018-03-22 Plaintiff’s predecessor allegedly sent first notice letter to Defendant
2020-06-12 Plaintiff allegedly sent follow-up notice letter to Defendant
2021-01-08 Plaintiff allegedly continued licensing communications with Defendant
2021-04-07 Plaintiff allegedly continued licensing communications with Defendant
2021-05-28 Plaintiff allegedly continued licensing communications with Defendant
2021-06-29 ’344 Patent Issued
2023-05-23 ’503 Patent Issued
2025-01-02 Plaintiff allegedly sent final pre-suit letter to Defendant
2025-04-01 ’876 Patent Issued
2025-08-28 Complaint Filed

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

U.S. Patent No. 9,548,839 - "Method for mapping physical hybrid automatic repeat request indicator channel," Issued January 17, 2017

The Invention Explained

  • Problem Addressed: The complaint explains that in wireless communication, it is critical for a mobile device (user equipment or UE) to know if its uplink transmissions (data sent from the device to the base station) were successfully received. The patent addresses the need for an efficient and reliable method for the base station to signal this success or failure back to the device (Compl. ¶54).
  • The Patented Solution: The invention provides a method for mapping the channel that carries this success/failure signal—the Physical Hybrid Automatic Repeat Request Indicator Channel (PHICH)—onto Orthogonal Frequency Division Multiplexing (OFDM) symbols, which are the basic data-carrying units in LTE. The core of the solution is a method to determine the specific location (indices of resource element groups) for the PHICH based on a ratio involving the number of currently available resource element groups within the OFDM symbol (Compl. ¶54). This allows the system to adaptively place the critical PHICH signal within the available resources.
  • Technical Importance: This mapping method is a fundamental component of the LTE standard's uplink data management process, ensuring that devices can efficiently re-transmit failed data packets, which is essential for maintaining a reliable connection (Compl. ¶55).

Key Claims at a Glance

  • The complaint asserts infringement of at least claims 9-12 (Compl. ¶56). Claim 9 is an independent apparatus claim.
  • Key elements of independent claim 9 include:
    • A user equipment apparatus comprising a processor and memory.
    • The processor configured to determine an index of a resource element group for transmitting a repetitive pattern of a PHICH.
    • The determination is based on a ratio of the number of available resource element groups in a given OFDM symbol relative to the number of available resource element groups in a first or second OFDM symbol.
    • The processor is further configured to map the PHICH to the symbol according to the determined index.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 11,659,503 - "Apparatus and method for establishing uplink synchronization in a wireless communication system," Issued May 23, 2023

The Invention Explained

  • Problem Addressed: In advanced wireless systems that use "carrier aggregation" (combining multiple frequency bands to increase speed), transmissions from a mobile device across these different bands must arrive at the base station simultaneously. The patent addresses the technical challenge of synchronizing these multiple uplink transmissions (Compl. ¶69).
  • The Patented Solution: The invention proposes a method for establishing uplink synchronization using "timing groups." A processor in the user equipment is configured to receive control messaging that defines a timing group for a secondary component carrier (CC). The device then transmits a random access preamble (RAP) on a designated "delegate CC" for that group and, in response, receives a specific timing advance (TA) value. This TA value is then applied to the secondary CC within that timing group to align its transmissions (Compl. ¶69; ’503 Patent, Abstract). Figure 5 of the patent illustrates the signal flow where an eNB sends timing group information (S510) and the UE later transmits a RAP on a delegate CC (S540).
  • Technical Importance: This method provides a structured way to manage synchronization across multiple carriers, a foundational requirement for carrier aggregation in LTE-Advanced and 5G networks, which enables higher data rates and more efficient use of spectrum (Compl. ¶¶69, 71).

Key Claims at a Glance

  • The complaint asserts infringement of at least claims 5, 7, and 8 (Compl. ¶70). Claim 5 is an independent apparatus claim.
  • Key elements of independent claim 5 include:
    • A communication apparatus (UE) with a processor and memory.
    • The processor is configured to cause the apparatus to receive an RRC message through a primary CC belonging to a first uplink timing group, the message comprising information related to a second uplink timing group.
    • Receive information indicating a random access preamble (RAP).
    • Transmit the RAP through one or more uplink CCs, each set as a delegate CC for a respective second uplink timing group.
    • Receive a random access response (RAR) including a timing advance (TA) value based on the RAP.
    • Apply the TA value to the secondary CC for the respective second uplink timing group.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 11,051,344 - "Method for transmitting and receiving random access request and transmitting and receiving random access response," Issued June 29, 2021

  • Technology Synopsis: This patent discloses a method for a user device to receive a random access response from a base station. The device is configured to listen for the response within a specific time window that begins at a time point calculated by adding a fixed offset (equal to three) to the subframe number corresponding to the end of its preamble transmission (Compl. ¶84). This timing mechanism helps prevent the device from incorrectly identifying a response intended for another device.
  • Asserted Claims: Claims 2 and 6 are asserted (Compl. ¶85).
  • Accused Features: The complaint alleges that smartphones and other products compatible with the LTE cellular standard (Release 8 or higher) infringe by implementing the mandated random access procedures defined in 3GPP standards such as TS 36.321 and TS 36.331 (Compl. ¶¶84, 86).

U.S. Patent No. 12,267,876 - "Method for Transmitting and Receiving Random Access Request and Transmitting and Receiving Random Access Response," Issued April 1, 2025

  • Technology Synopsis: The complaint alleges that this patent's written description contains the same teachings as the ’344 Patent (Compl. ¶98). It concerns a method for a user device to process a random access response within a defined time window, which starts after a specific offset from its preamble transmission, in order to correctly identify the response intended for it and avoid ambiguity (Compl. ¶¶84, 98).
  • Asserted Claims: Claims 4-6 are asserted (Compl. ¶100).
  • Accused Features: The complaint accuses products compatible with LTE cellular standards (Release 8 or higher) of infringement, on the basis that compliance with relevant 3GPP standards (e.g., TS 36.321) requires practicing the patented method (Compl. ¶¶99, 101).

III. The Accused Instrumentality

Product Identification

The accused products include a wide range of mobile phones, tablets, and mobile workstations, such as the Motorola razr 50, motorola edge+ 2023, Lenovo Tab K11 LTE, and Lenovo ThinkPad P16s Gen 3 Intel (16") Mobile Workstation (collectively, the "Accused Instrumentalities") (Compl. ¶24).

Functionality and Market Context

The complaint alleges that the Accused Instrumentalities are devices capable of operating on LTE, LTE-A, and/or 5G cellular networks (Compl. ¶24). Their relevant functionality is their compliance with the 3GPP technical standards that govern these networks. The complaint alleges that each accused device incorporates a chipset (e.g., Qualcomm Snapdragon 8 Elite Mobile Platform) with a processor and modem that implements these communication protocols (Compl. ¶¶57, 71). The infringement theory is predicated on the allegation that by complying with these standards, the devices necessarily practice the methods claimed in the patents-in-suit (Compl. ¶¶55, 69).

IV. Analysis of Infringement Allegations

’839 Patent Infringement Allegations

Claim Element (from Independent Claim 9) Alleged Infringing Functionality Complaint Citation Patent Citation
an user equipment (UE) apparatus comprising: a processor; and a memory operably coupled to the processor... The Accused Instrumentalities are UE devices containing chipsets that incorporate a processor and/or modem. ¶57 col. 8:51-54
wherein the processor is configured to: determine an index of a resource element group... for transmitting a repetitive pattern of a physical hybrid automatic repeat request indicator channel (PHICH)... The Accused Instrumentalities comply with 3GPP standards that mandate the determination of resource element group indexes for PHICH mapping. ¶55 col. 1:21-26
...wherein the determination is based on a ratio of the number of available resource element groups in an Orthogonal Frequency Division Multiplexing (OFDM) symbol... and the number of available resource element groups in a first or a second OFDM symbol... The Accused Instrumentalities implement 3GPP TS 36.211, which allegedly requires this ratio-based determination to locate the PHICH within OFDM symbols that contain a plurality of resource element groups. ¶55 col. 5:10-21
...and map the PHICH to the symbol according to the determined index. The Accused Instrumentalities, in complying with 3GPP TS 36.211, map the PHICH to OFDM symbols based on the determined indexes. ¶55 col. 6:49-54

’503 Patent Infringement Allegations

Claim Element (from Independent Claim 5) Alleged Infringing Functionality Complaint Citation Patent Citation
A communication apparatus for a user equipment (UE), the communication apparatus comprising: a memory; and a processor operably coupled to the memory... The Accused Instrumentalities are UE devices containing chipsets that incorporate a processor and modem. ¶71 col. 27:60-62
...to receive, through a primary Component Carrier (CC) belonging to a first uplink timing group, a Radio Resource Control (RRC) message comprising information related to a second uplink timing group... The Accused Instrumentalities, compliant with LTE-A standards, support RRC messaging for carrier aggregation and are configured with primary and secondary CCs organized into timing groups. ¶69 col. 1:49-55
...transmit a random access preamble (RAP) through one or more uplink CCs, each of the one or more uplink CCs being set as a delegate CC for a respective second uplink timing group... The Accused Instrumentalities perform random access procedures on a delegate CC to establish synchronization for a timing group as part of carrier aggregation functionality. ¶69 col. 16:45-55
...receive a random access response (RAR) including a timing advance (TA) value based on the RAP associated with the delegate CC... The Accused Instrumentalities receive a RAR with a TA value in response to the RAP transmission, as mandated by 3GPP standards for uplink synchronization. ¶69 col. 20:30-36
...and apply each TA value to the secondary CC for the respective second uplink timing group. The Accused Instrumentalities apply the received TA value to the secondary CCs within the corresponding timing group to synchronize their uplink transmissions. ¶69 col. 2:1-4
  • Identified Points of Contention:
    • Scope Questions: The core of the infringement case appears to rest on the assertion that compliance with 3GPP standards necessitates infringement. A primary point of contention may be whether the cited standards mandate the specific methods recited in the claims, or whether standard-compliant, non-infringing alternatives exist or are used in the accused devices. For example, regarding the ’503 patent, a question is whether the term "delegate CC" as defined and used in the patent claims reads on the specific functionality of the carriers used for random access in the accused devices' implementation of carrier aggregation.
    • Technical Questions: For the ’839 patent, a technical question is whether the accused devices' chipsets actually perform the index determination using the specific "ratio" calculation required by the claim, or if they use a different, albeit standard-compliant, algorithm. For the ’344 and ’876 patents, a question may arise as to whether the "offset equals three" limitation is a fixed requirement of the standard implemented by the devices, or if other offset values are permissible and used.

No probative visual evidence provided in complaint.

V. Key Claim Terms for Construction

For the ’839 Patent

  • The Term: "a ratio involving the number of available resource element groups" (from claim 9)
  • Context and Importance: This term is the central technical limitation describing how the location for the PHICH signal is calculated. The infringement analysis will depend on whether the algorithm implemented in the accused devices' chipsets calculates a "ratio" that falls within the scope of this term. Practitioners may focus on this term because if "involving" is construed narrowly to require a specific formula disclosed in the patent, it may provide a basis for a non-infringement argument if the accused devices use a different formula.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The use of the general term "involving" rather than a more specific mathematical term like "equal to" or "defined by" may suggest that any calculation that considers the relative number of available resources could be covered (’839 Patent, col. 6:50-54).
    • Evidence for a Narrower Interpretation: The specification provides specific equations for determining the resource element group index, such as n_i = ([(N_ID_cell * n'_li / n'_l0)] + m') mod n'_li (’839 Patent, col. 5:10-21). A defendant may argue that these specific embodiments define the scope of the claimed "ratio."

For the ’503 Patent

  • The Term: "delegate CC" (from claim 5)
  • Context and Importance: This term defines the specific carrier through which the user equipment initiates synchronization for a timing group. The question of infringement will turn on whether the accused devices, in performing carrier aggregation, utilize a component carrier that performs the functions of the claimed "delegate CC."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the delegate CC as one through which a synchronization request message is transmitted for a timing group (’503 Patent, col. 16:30-35). This functional description could be argued to cover any CC used for this purpose in an aggregated system.
    • Evidence for a Narrower Interpretation: The patent describes a specific selection process where the UE selects the delegate CC based on certain criteria, such as having the lowest center frequency or being used for monitoring downlink quality (’503 Patent, col. 21:32-38). A defendant could argue that a carrier must be selected via this specific process to qualify as a "delegate CC."

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement on the grounds that Lenovo Group advertises its products as compliant with LTE and 5G standards and provides instruction materials, knowing that use by customers in accordance with these standards would infringe the patents (Compl. ¶¶61-63, 76-78). Contributory infringement is alleged on the basis that the accused devices are especially made for an infringing use (i.e., operating on LTE/5G networks) and are not staple articles of commerce with substantial non-infringing uses (Compl. ¶¶64, 79).
  • Willful Infringement: The willfulness allegations are based on alleged pre-suit knowledge of the patents. The complaint claims that Lenovo Group was made aware of the ’839 Patent and the families of the ’503, ’344, and ’876 patents through correspondence beginning as early as June 12, 2020 (Compl. ¶¶58-59, 73-74, 87-88, 102-103). The complaint alleges that infringement continued despite this knowledge.

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

  • A core issue will be one of essentiality and claim scope: Does compliance with the cited 3GPP cellular standards necessarily require practicing every limitation of the asserted independent claims? The case may turn on whether the accused devices can be fully standard-compliant while utilizing alternative, non-infringing methods for PHICH mapping, carrier aggregation synchronization, or random access procedures.
  • A second central question will concern claim construction: The viability of the infringement claims will heavily depend on the court's interpretation of key technical terms such as "a ratio involving the number of available resource element groups" (’839 Patent) and "delegate CC" (’503 Patent). A narrow construction of these terms, tied closely to the specific embodiments in the patent specifications, could provide a path to non-infringement for the accused devices.
  • Finally, the history of licensing negotiations raises a critical question regarding FRAND obligations: Given the patents are alleged to be standard-essential, the focus may shift from pure technical infringement to the conduct of the parties. The court may need to evaluate whether Plaintiff's licensing offers were consistent with Fair, Reasonable, and Non-Discriminatory (FRAND) principles and whether Defendant's alleged unresponsiveness constitutes a failure to negotiate in good faith.