DCT
5:21-cv-00105
Pantech Wireless LLC v. ASUSTeK Computer Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Pantech Corporation (South Korea) and Pantech Wireless, LLC (Texas)
- Defendant: ASUSTeK Computer Inc. (Taiwan)
- Plaintiff’s Counsel: Mayer Brown LLP
- Case Identification: 5:21-cv-00105, E.D. Tex., 10/25/2021
- Venue Allegations: Plaintiff alleges venue is proper because the Defendant is a foreign corporation not resident in the United States and may therefore be sued in any judicial district.
- Core Dispute: Plaintiff alleges that Defendant’s LTE and 5G-capable devices, including smartphones, tablets, laptops, and routers, infringe six U.S. patents related to foundational wireless communication technologies.
- Technical Context: The patents-in-suit relate to methods for managing data transmission, channel mapping, and device connectivity essential for the operation of devices on modern LTE and 5G cellular networks.
- Key Procedural History: The complaint alleges that Plaintiff and its predecessors-in-interest engaged in licensing negotiations with Defendant beginning in March 2018. Plaintiff asserts that it made multiple offers to license its portfolio, which it contends includes Standard Essential Patents (SEPs), on Fair, Reasonable, and Non-Discriminatory (FRAND) terms, but that Defendant has refused to take a license. Willfulness allegations are based on both this pre-suit history and notice provided on specific dates for several patents, as well as the filing of the original complaint on August 27, 2021 for others.
Case Timeline
| Date | Event |
|---|---|
| 2003-11-05 | ’247 Patent Priority Date |
| 2008-12-08 | ’839 Patent Priority Date |
| 2009-10-30 | ’582 Patent Priority Date |
| 2012-03-23 | ’776 Patent Priority Date |
| 2012-05-11 | ’142 Patent Priority Date |
| 2013-04-05 | ’283 Patent Priority Date |
| 2016-07-12 | ’582 Patent Issue Date |
| 2017-01-17 | ’839 Patent Issue Date |
| 2017-09-12 | ’283 Patent Issue Date |
| 2017-09-19 | ’776 Patent Issue Date |
| 2018-03-22 | Pantech's predecessor allegedly sends first license offer letter to ASUSTeK |
| 2020-09-17 | ASUSTeK allegedly made aware of ’839 Patent infringement |
| 2020-11-17 | ’142 Patent Issue Date |
| 2020-12-15 | ’247 Patent Issue Date |
| 2020-12-22 | ASUSTeK allegedly made aware of ’582 Patent infringement |
| 2021-03-31 | ASUSTeK allegedly made aware of ’142 Patent infringement |
| 2021-08-27 | Original Complaint Filed |
| 2021-10-25 | First Amended 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 does not specify the technical problem addressed by the patent.
- The Patented Solution: The patent discloses methods for mapping a physical hybrid automatic repeat request indicator channel (PHICH) onto one or more orthogonal frequency division multiplexing (OFDM) symbols (Compl. ¶45). The PHICH is a critical downlink channel used in LTE to acknowledge receipt of uplink data from a user device. The invention determines the specific indexes of resource element groups for transmitting the PHICH based on a ratio involving the number of available resource element groups in the OFDM symbol (Compl. ¶45). This mapping is alleged to be mandated by the LTE standard (Compl. ¶45).
- Technical Importance: Efficient and correct mapping of the PHICH is fundamental to the operation of the Hybrid Automatic Repeat Request (H-ARQ) process, which ensures reliable data transmission in LTE networks (Compl. ¶45).
Key Claims at a Glance
- The complaint asserts at least independent claim 9 (Compl. ¶46).
- The complaint does not provide the language of claim 9, but alleges that it recites elements of PHICH mapping mandated by the LTE standard, including 3GPP TS 36.211, TS 36.331, and TS 36.213 (Compl. ¶45).
U.S. Patent No. 10,841,142, "Method and Apparatus for Transmitting and Receiving Reference Signal in Wireless Communication System," issued November 17, 2020
The Invention Explained
- Problem Addressed: In advanced cellular systems using techniques like Cooperative Multiple Point (CoMP) transmission, there is a need to dynamically switch how uplink reference signals are generated to properly manage interference and ensure accurate channel estimation (’142 Patent, col. 1:35-48, 1:60-65). This requires a method to make uplink reference signals from different user devices either identical or distinct depending on the specific communication scenario (’142 Patent, col. 1:60-65).
- The Patented Solution: The invention provides a method where a user device (UE) receives a parameter set for generating an uplink reference signal, such as a Demodulation-Reference Signal (DM-RS) (’142 Patent, Abstract). This parameter set includes a "Virtual Cell Identifier (VCID)" and a "cyclic shift hopping initial value parameter," which are used to generate the base sequence and determine the cyclic shift of the reference signal (’142 Patent, col. 2:25-38; Fig. 4). This allows the network to dynamically control the reference signal characteristics to suit different communication environments like CoMP or Multi-User MIMO (’142 Patent, Abstract).
- Technical Importance: This method for dynamic reference signal configuration enables the efficient implementation of advanced cellular technologies that improve performance and capacity, particularly for users at the cell edge (’142 Patent, col. 1:42-52).
Key Claims at a Glance
- The complaint asserts at least independent claim 1 (Compl. ¶60).
- The essential elements of claim 1, a method at a user equipment, include:
- Receiving a message via Radio Resource Control (RRC) signaling containing a "virtual cell identifier parameter" and a "cyclic shift hopping initial parameter."
- Generating a base sequence based on the virtual cell identifier parameter.
- Determining an initial value for a pseudo random sequence for cyclic shift hopping based on the cyclic shift hopping initial parameter.
- Determining a cyclic shift value based on that initial value.
- Generating a demodulation reference signal by cyclically shifting the base sequence based on the determined cyclic shift value.
- Transmitting the demodulation reference signal.
U.S. Patent No. 9,769,776, "Apparatus and Method for Uplink Synchronizing in Multiple Component Carrier System," issued September 19, 2017
- Technology Synopsis: The patent addresses uplink synchronization when a device is connected to multiple component carriers. It describes a user equipment receiving information to add or release a serving cell, along with an identifier for a "timing advance group" (TAG) associated with the cell being added (Compl. ¶74). The user equipment then associates the newly added cell with other available cells that share the same TAG identifier, ensuring proper uplink timing alignment (Compl. ¶74).
- Asserted Claims: At least claim 5 (Compl. ¶75).
- Accused Features: The complaint accuses 5G-compatible products, such as the ZenFone 8 smartphone, that are configured to support uplink synchronization in a multiple component carrier system as mandated by the 5G/NR standard (Compl. ¶76).
U.S. Patent No. 9,392,582, "Apparatus and Method for Transmitting/Receiving Activation Indicator Regarding Component Carrier in Wireless Communication System," issued July 12, 2016
- Technology Synopsis: The patent discloses a method for activating and deactivating component carriers (CCs) to manage power consumption and overhead (’582 Patent, Abstract). A user equipment receives configuration information for CCs via Radio Resource Control (RRC) signaling, and subsequently receives Medium Access Control (MAC) signaling in an eight-bit bit-stream that provides indicators for the configured CCs (Compl. ¶88). The user equipment uses this MAC signaling to activate a corresponding CC and begin monitoring its control and data channels (Compl. ¶88).
- Asserted Claims: At least claims 5-7 (Compl. ¶89).
- Accused Features: The complaint accuses LTE and 5G-compatible products, like the ZenFone 2 Deluxe smartphone, that are configured to support the activation and deactivation of component carriers in a wireless communication system (Compl. ¶90).
U.S. Patent No. 9,763,283, "Method and Apparatus for Wireless Link Control in Wireless Communication System Supporting Dual Connectivity," issued September 12, 2017
- Technology Synopsis: The patent is directed to radio link control in a dual connectivity scenario where a user equipment is connected to both a master and a secondary base station. The invention describes the user equipment detecting a radio link failure (RLF) for the secondary serving cell, generating an RLF indicator that includes the cell's identifier, and transmitting that indicator to the master base station (Compl. ¶102). Upon detecting the RLF, the user equipment stops certain uplink transmissions to the secondary serving cell (Compl. ¶102).
- Asserted Claims: At least claims 9-10 (Compl. ¶103).
- Accused Features: The complaint accuses 5G-compatible products, such as the ZenFone 8 smartphone, that support dual connectivity and are configured to perform the claimed radio link control functions (Compl. ¶104).
U.S. Patent No. 10,869,247, "Supporting Uplink Transmissions," issued December 15, 2020
- Technology Synopsis: The patent discloses a method for managing data retransmissions in a Hybrid Automatic Repeat Request (H-ARQ) process. A user equipment transmits a data block and receives uplink scheduling information from the base station (’247 Patent, Abstract). The user equipment then determines whether to retransmit the data block based on the contents of the received uplink scheduling information, rather than being dependent on receiving a negative acknowledgement (NACK) from the base station (Compl. ¶116).
- Asserted Claims: At least claims 11, 12, and 18 (Compl. ¶117).
- Accused Features: The complaint accuses LTE-compatible products, such as the ZenFone 2 Deluxe smartphone, that transmit data using an H-ARQ process in compliance with 3GPP standards (Compl. ¶118).
III. The Accused Instrumentality
- Product Identification: The accused instrumentalities are a broad category of ASUSTeK’s LTE and 5G-capable devices, including smartphones (ZenFone series, ROG Phone series), tablets (ZenPad series), PCs and laptops (NovaGo series), and routers (Compl. ¶9-10).
- Functionality and Market Context: The core accused functionality is the devices' alleged compliance with various 3rd Generation Partnership Project (3GPP) cellular standards for LTE, LTE-Advanced, and 5G/NR (Compl. ¶10, ¶45, ¶59). The complaint alleges these devices incorporate chipsets, processors, or SoCs configured to perform functions mandated by these standards, such as mapping PHICH channels, generating reference signals, managing multiple component carriers, handling dual connectivity, and performing H-ARQ processes (Compl. ¶47, ¶61, ¶76, ¶90, ¶104, ¶118). The complaint asserts that Defendant advertises these products as being compliant with the relevant cellular standards (Compl. ¶53, ¶68). No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The complaint does not provide a claim chart or a detailed element-by-element mapping for U.S. Patent No. 9,548,839. It alleges infringement based on the accused products' compliance with LTE standards that allegedly require the use of PHICH mapping as recited in claim 9 (Compl. ¶45-47).
'142 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| receiving, at a User Equipment (UE), a message through Radio Resource Control (RRC) signaling, wherein the message comprises a virtual cell identifier parameter and a cyclic shift hopping initial parameter | The accused products are alleged to receive RRC signaling compliant with 3GPP standards, which require the use of these parameters for reference signal generation. | ¶59 | col. 10:50-54 |
| generating, at the UE, a base sequence at least based on the virtual cell identifier parameter | The accused products are alleged to generate reference signal base sequences using the virtual cell identifier parameter as required by 3GPP standards. | ¶59 | col. 13:1-8 |
| determining an initial value of a pseudo random sequence relating to a cyclic shift hopping based on the received cyclic shift hopping initial value parameter | The accused products are alleged to determine an initial value for the cyclic shift hopping sequence based on the received parameter, per 3GPP standards. | ¶59 | col. 18:48-54 |
| determining a cyclic shift value based on the determined initial value of the pseudo random sequence relating to the cyclic shift hopping | The accused products are alleged to determine a cyclic shift value for the reference signal based on the initialized pseudo random sequence, per 3GPP standards. | ¶59 | col. 18:48-54 |
| generating, at the UE, a demodulation reference signal at least by cyclically shifting the base sequence at least based on the determined cyclic shift value; and transmitting... the demodulation reference signal | The accused products are alleged to generate and transmit the final demodulation reference signal using the calculated sequence and shift values, in compliance with 3GPP standards. | ¶59, ¶61 | col. 19:1-3 |
- Identified Points of Contention:
- Scope Questions: A central question for the case may be whether compliance with the cited 3GPP standards (TS 36.211 and TS 36.331) necessarily requires practicing every limitation of the asserted claims. The complaint's theory appears to be that the patented methods are essential to the standard, raising the question of whether standard-compliant, non-infringing alternatives exist.
- Technical Questions: The complaint bases its infringement allegations on the accused products' compliance with cellular standards rather than on a direct analysis of the products' specific implementation. This raises the evidentiary question of what proof Plaintiff will offer to demonstrate that the accused products' processors and chipsets actually perform the specific steps of generating a base sequence from a "virtual cell identifier parameter" and determining a "cyclic shift value" from a "cyclic shift hopping initial parameter" in the manner required by the claim.
V. Key Claim Terms for Construction
The complaint does not provide sufficient detail for analysis of key claim terms for the '839 Patent. The following analysis is based on the asserted claim of the '142 Patent.
The Term: "virtual cell identifier parameter"
- Context and Importance: This parameter is a primary input for generating the claimed reference signal. The definition of this term is critical because the infringement case hinges on whether the identifiers used by the accused products for reference signal generation, as dictated by the 3GPP standards, fall within the patent's definition of a "virtual" cell identifier. Practitioners may focus on this term because Defendant could argue that its devices use a standard physical cell identifier, not a "virtual" one as contemplated by the patent.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification suggests the term can be applied functionally "in place of the parameter N_ID^cell" (the physical cell ID) and may be separately configured to have a common value within a cooperative transmission set or different values for each user device (’142 Patent, col. 12:47-49, col. 13:5-9).
- Evidence for a Narrower Interpretation: The specification describes the parameter in the context of specific CoMP scenarios and provides detailed configuration schemes, including that it can be represented by 9 bits for a value from 0 to 509 (’142 Patent, col. 14:1-26). This could support an argument that the term is limited to these specific implementations.
The Term: "cyclic shift hopping initial parameter"
- Context and Importance: This is the second key input parameter for the claimed method, used to initialize the cyclic shift hopping sequence. The dispute may turn on whether the parameters used in accused devices for this purpose match the patent's definition.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes this parameter functionally as being "applied in place of the parameter C_init in Equation (4)," which is the standard initialization value (’142 Patent, col. 13:9-12). This supports a construction covering any parameter that serves this initialization function.
- Evidence for a Narrower Interpretation: The patent details four specific configuration schemes for this parameter (denoted C_init^CSH), including defined integer ranges and bit lengths (e.g., 9 bits for values 0-509) (’142 Patent, col. 14:55-col. 17:68). This may support a narrower construction limited to these specific numerical and structural characteristics.
VI. Other Allegations
- Indirect Infringement: The complaint alleges both induced and contributory infringement for all asserted patents. Inducement is alleged based on Defendant’s advertising of its products as compliant with LTE and 5G standards and providing instruction materials, which allegedly instructs and encourages customers and partners to perform the infringing acts (Compl. ¶51-52, ¶66-67). Contributory infringement is alleged on the basis that the accused devices are material components especially made for infringing use and are not staple articles of commerce suitable for substantial non-infringing use (Compl. ¶54, ¶69).
- Willful Infringement: The complaint alleges willful infringement for all asserted patents. The basis for willfulness varies: for the '839, '142, and '582 patents, it is based on alleged pre-suit knowledge from specific notice dates in 2020 and 2021 (Compl. ¶48, ¶63, ¶91). For the '776, '283, and '247 patents, it is based on knowledge gained no later than the filing of the original or amended complaints in this litigation (Compl. ¶77, ¶105, ¶120). The willfulness claims are also supported by allegations of a multi-year history of unsuccessful licensing negotiations (Compl. ¶36-41).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of necessary implementation: does compliance with the cited 3GPP cellular standards, as alleged by the Plaintiff, require practicing the specific methods recited in the asserted claims? This question goes to the core of both direct infringement and the patents' potential status as Standard Essential Patents.
- The case will likely involve a significant dispute over claim scope: can claim terms rooted in the patent's specific embodiments, such as "virtual cell identifier parameter" ('142 Patent), be construed broadly enough to read on the parameters and values mandated by the public 3GPP standards, or are they limited to the particular CoMP and MU-MIMO scenarios detailed in the specification?
- A key question for damages and potential enhancement will be the parties' pre-suit conduct: did the Plaintiff's licensing offers adhere to FRAND principles for SEPs, and does the Defendant's alleged refusal to engage and accept such an offer rise to the level of objective recklessness required for a finding of willful infringement?