DCT

5:25-cv-00089

Pantech Corp v. OnePlus Technology Shenzhen Co Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 5:25-cv-00089, E.D. Tex., 07/03/2025
  • Venue Allegations: Plaintiff alleges venue is proper because Defendant is a foreign corporation not resident in the United States and may be sued in any judicial district. The complaint further alleges Defendant transacts business in the district and previously consented to jurisdiction in prior litigation.
  • Core Dispute: Plaintiff alleges that Defendant’s smartphones and other cellular-capable devices that comply with LTE, LTE-A, and 5G standards infringe four U.S. patents related to fundamental wireless communication procedures.
  • Technical Context: The patents address core functionalities of modern cellular networks, including managing communication channel acknowledgements, synchronizing transmissions across multiple aggregated frequency bands, and handling a device's initial connection to the network.
  • Key Procedural History: The complaint alleges that Plaintiff notified Defendant of infringement of the '839 Patent as early as June 2020. It further states that in prior litigation between the parties in the same district, a jury found Defendant willfully infringed the '839 Patent and a family member of the '503 Patent, with a final judgment entered in January 2025.

Case Timeline

Date Event
2008-01-01 ’344 & ’876 Patents Priority Date
2008-12-08 ’839 Patent Priority Date
2010-02-10 ’503 Patent Priority Date
2017-01-17 ’839 Patent Issue Date
2020-06-12 Pantech initial outreach to OnePlus, identifying ’839 Patent
2020-09-24 Pantech provides notice of ’503 and ’344 patent families to OnePlus
2021-06-29 ’344 Patent Issue Date
2022-06-03 Pantech files prior lawsuit against OnePlus
2023-05-23 ’503 Patent Issue Date
2025-01-23 Final Judgment entered in prior litigation, finding willful infringement of ’839 Patent
2025-04-01 ’876 Patent Issue Date
2025-07-03 Complaint Filing Date

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: In wireless systems like LTE, a user device (UE) needs to know if the data it sent to a base station was received successfully. The base station sends back an acknowledgement signal on a specific channel (the Physical Hybrid ARQ Indicator Channel, or PHICH). The technical problem is efficiently and unambiguously assigning, or "mapping," this PHICH to a specific location within the complex structure of the wireless signal so the UE knows exactly where to look for it (Compl. ¶43).
  • The Patented Solution: The invention provides a method for mapping the PHICH to resource elements within an Orthogonal Frequency Division Multiplexing (OFDM) symbol, which is a basic unit of an LTE signal. The specific location is determined by calculating indices based on "a ratio involving the number of available resource element groups in the OFDM symbol," ensuring a systematic and predictable assignment (Compl. ¶43). This allows the UE to correctly locate and process signals indicating successful or failed uplink transmissions (’839 Patent, Abstract; Compl. ¶43).
  • Technical Importance: This mapping process is a fundamental component of the LTE standard's mechanism for ensuring reliable data transmission and managing retransmissions (Compl. ¶44).

Key Claims at a Glance

  • The complaint asserts claims 9-12 (Compl. ¶45).
  • The complaint does not specify which of the asserted claims are independent and does not provide the claim language.

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: Advanced cellular standards like LTE-A and 5G increase data speeds by using "carrier aggregation," where a device communicates over multiple frequency bands (component carriers or "CCs") simultaneously. A significant technical challenge is ensuring the device's uplink transmissions across all these different CCs arrive at the base station at precisely the same time, a state known as uplink synchronization (Compl. ¶58).
  • The Patented Solution: The patent describes a method to manage synchronization for groups of CCs, called "timing groups." The system designates one CC within a group as a "delegate CC." The user device performs the initial random access procedure on this delegate CC to receive a "timing advance" (TA) value from the base station. This TA value, which corrects for transmission delays, is then applied not just to the delegate CC but to all other secondary CCs within the same timing group, thereby synchronizing the entire group efficiently (’503 Patent, Abstract; Compl. ¶58).
  • Technical Importance: This method provides a structured way to manage the complex timing adjustments required for carrier aggregation, a foundational technology for achieving the high data rates of modern wireless networks (Compl. ¶58).

Key Claims at a Glance

  • The complaint asserts claims 5, 7, and 8 (Compl. ¶59).
  • The complaint does not specify which of the asserted claims are independent.

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 addresses the random access procedure, a device's initial attempt to contact a network. When multiple devices attempt access simultaneously, they can become confused about which response from the base station is theirs. The invention discloses a method where a device receives a response within a specific time period that starts after adding a fixed offset (an offset of three subframes) to the end time of its preamble transmission, and uses subframe information to confirm the response is the correct one (Compl. ¶73; ’344 Patent, col. 17:23-31).
  • Asserted Claims: Claims 2 and 6 (Compl. ¶74).
  • Accused Features: The random access procedures in Defendant's LTE-compatible products, which are alleged to be mandated by 3GPP standards (Compl. ¶¶73, 75).

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 teachings are the same as those of the ’344 Patent (Compl. ¶87). The technology thus concerns the random access procedure, where a device must correctly identify the response to its own preamble from the base station. The method relies on monitoring for the response within a defined time window governed by a specific offset to prevent erroneous synchronization (Compl. ¶¶87-88).
  • Asserted Claims: Claims 4-6 (Compl. ¶89).
  • Accused Features: The random access procedures in Defendant's LTE-compatible products, which are alleged to be mandated by the same 3GPP standards implicated by the ’344 Patent (Compl. ¶¶88, 90).

III. The Accused Instrumentality

Product Identification

The Accused Instrumentalities are Defendant’s mobile phones, including the "OnePlus series" and "Nord series," and other devices capable of operating on LTE, LTE-A, and 5G networks (Compl. ¶11). Specific examples cited include the OnePlus 13, OnePlus 13R, OnePlus 12, OnePlus 12R, OnePlus Nord N30 5G, and OnePlus Open devices (Compl. ¶12).

Functionality and Market Context

The accused products are smartphones and similar devices designed to operate on modern cellular networks by complying with 3GPP standards (Compl. ¶12). The complaint alleges they incorporate chipsets, such as the Qualcomm Snapdragon 8 Elite or Snapdragon 888 5G, that implement the communication protocols at issue (Compl. ¶¶46, 60, 75). The specific functionalities accused of infringement are not user-facing features but are core network communication procedures essential for the devices to connect and transmit data reliably and efficiently over LTE and 5G networks (Compl. ¶¶43, 58, 73). The products are allegedly sold in the U.S. via Defendant's website and major retailers (Compl. ¶¶6-7).

IV. Analysis of Infringement Allegations

The complaint’s infringement theory for all asserted patents is based on standards-essentiality. It alleges that because the Accused Instrumentalities are designed and advertised to be compliant with specific 3GPP cellular standards (e.g., LTE, LTE-A, 5G), they necessarily practice the methods recited in the asserted patents, which are alleged to be mandated by those same standards. The complaint does not provide claim chart exhibits.

  • '839 Patent Infringement Allegations: The complaint alleges that claims 9-12 recite a method for mapping the PHICH to OFDM symbols that is required by 3GPP technical specifications TS 36.211, TS 36.213, and TS 36.331 (Compl. ¶44). Therefore, any device, like the accused OnePlus phones, that complies with the LTE standard is alleged to directly infringe (Compl. ¶45).
  • '503 Patent Infringement Allegations: The complaint alleges that claims 5, 7, and 8 recite a method for establishing uplink synchronization using timing groups and delegate CCs for carrier aggregation, a functionality mandated by the LTE-A standard and 3GPP specifications TS 36.321 and 36.331 (Compl. ¶58). Accordingly, accused devices that support LTE-A carrier aggregation are alleged to directly infringe (Compl. ¶59).

No probative visual evidence provided in complaint.

  • Identified Points of Contention:
    • Scope Questions: A central issue may be whether compliance with the cited 3GPP standards necessarily requires infringement of the asserted patent claims. For example, "Does the LTE standard, as defined in the cited specifications, allow for alternative, non-infringing methods of mapping the PHICH, or is the method of the '839 Patent the only compliant implementation?" Similarly, for the '503 Patent, "Can a device implement carrier aggregation in compliance with the LTE-A standard without using the specific 'delegate CC' and 'timing group' structure as claimed?"
    • Technical Questions: The infringement case rests on the allegation that the accused chipsets implement the standards. A potential technical question is: "What evidence demonstrates that the accused Qualcomm chipsets, as implemented in the OnePlus devices, actually perform the specific steps of determining PHICH resource indices based on a ratio of available resource groups ('839 Patent) and applying a single TA value to a group of secondary CCs ('503 Patent)?"

V. Key Claim Terms for Construction

The complaint does not provide the asserted claim language for the '839 Patent, which precludes an analysis of its key claim terms. The following analysis is based on the '503 Patent.

  • The Term: "delegate CC"
  • Context and Importance: This term appears central to the inventive concept of the ’503 Patent, which describes a method for synchronizing a "timing group" of multiple component carriers by performing the random access procedure on a single, designated "delegate CC" (Compl. ¶58). The construction of this term—what qualifies a component carrier to be a "delegate" and how it is selected—will be critical for determining the scope of the claims and whether the accused devices, which manage multiple carriers, infringe.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the term functionally, referring to a "representative component carrier of the uplink timing groups" (’503 Patent, col. 8:52-54). This language could support a construction where any component carrier designated by the system to perform the random access function for a timing group meets the definition.
    • Evidence for a Narrower Interpretation: The specification provides a specific, exemplary list of criteria for selecting a delegate CC, such as the one with the "lowest center frequency value," the "broadest frequency band," or a CC used for "monitoring DL quality" (’503 Patent, col. 12:30-38). This may support a narrower construction where the term is limited to a component carrier selected based on such specific, predefined technical characteristics.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement. The inducement theory is based on Defendant allegedly advertising and providing instructions for its devices to be used on LTE/5G networks, which purportedly requires use of the patented methods to comply with the relevant standards (Compl. ¶¶50-52, 65-67). Contributory infringement is alleged on the basis that the accused devices are especially made for an infringing use and are not staple articles of commerce with substantial non-infringing uses (Compl. ¶¶53, 68).
  • Willful Infringement: The complaint alleges willful infringement based on pre-suit knowledge. For the ’839 Patent, this knowledge is alleged to stem from a June 2020 notification letter and, significantly, from a January 2025 final judgment in prior litigation where a jury found Defendant’s infringement of the same patent to be willful (Compl. ¶¶47-48). For the ’503 Patent, willfulness is alleged based on September 2020 notice of the patent family, which was also implicated in the prior litigation and willfulness finding (Compl. ¶¶37, 62-63).

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

  1. A central issue will be one of standard essentiality: does compliance with the cited 3GPP LTE and LTE-A standards necessarily require practicing the asserted claims of the Pantech patents, or do non-infringing implementation options exist within those standards that Defendant may have used?
  2. Given the prior jury verdict of willful infringement against Defendant for the ’839 patent and a '503 patent family member, a key question will be one of egregious conduct: does the alleged continued infringement after this adverse verdict constitute the sort of objective recklessness that would compel a finding of willfulness and justify an award of enhanced damages?
  3. A foundational question will be the validity and scope of the claims: can the patents, which claim fundamental aspects of cellular communication, withstand challenges of invalidity over prior art, and can key terms like "delegate CC" be construed with sufficient breadth to read on Defendant’s specific implementation of carrier aggregation?