DCT

2:23-cv-00487

ASUS Technology Licensing Inc v. T-Mobile USA

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:23-cv-00487, E.D. Tex., 10/19/2023
  • Venue Allegations: Plaintiffs allege venue is proper in the Eastern District of Texas because Defendant T-Mobile has committed acts of infringement in the District and maintains regular and established places of business there, including corporate offices and numerous retail stores.
  • Core Dispute: Plaintiffs allege that Defendant’s 4G and 5G wireless networks infringe a patent related to the configuration of control resource sets in a wireless communication system.
  • Technical Context: The technology concerns methods for efficiently and unambiguously allocating control channel resources to mobile devices, a foundational process for reliable operation in modern 4G and 5G/NR wireless networks.
  • Key Procedural History: The complaint alleges that the patent-in-suit is essential to wireless standards and subject to Fair, Reasonable, and Non-Discriminatory (FRAND) licensing obligations under the European Telecommunications Standards Institute (ETSI) IPR Policy. Plaintiffs allege they engaged in good-faith licensing negotiations beginning in August 2022 and provided T-Mobile with notice of infringement via claim charts by February 1, 2023, but that negotiations were unsuccessful. The complaint includes a count seeking a declaratory judgment that Plaintiffs have complied with their FRAND obligations while Defendant has not.

Case Timeline

Date Event
2018-01-18 Priority Date for ’359 Patent
2018-02-01 T-Mobile announces plans to build out 5G in 30 cities
2019-12-02 T-Mobile announces its first nationwide 5G network
2021-03-16 U.S. Patent No. 10,951,359 issues
2022-08-25 Plaintiffs allegedly initiate FRAND licensing correspondence with T-Mobile
2023-02-01 Plaintiffs allegedly provide T-Mobile with claim charts evidencing infringement
2023-10-19 Complaint filed

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

U.S. Patent No. 10,951,359 - "Method and Apparatus For Providing Control Resource Set Configuration In A Wireless Communication System" (Issued March 16, 2021)

The Invention Explained

  • Problem Addressed: In advanced wireless systems like 5G New Radio (NR), a network must tell a user device (UE) where and when to "listen" for control signals. This is done by configuring a Control Resource Set (CORESET). The standards provide flexibility in this configuration, allowing the network to specify a CORESET's duration (e.g., how many symbols it lasts) and its potential starting times within a transmission slot using a bitmap. The patent identifies a potential ambiguity: if the network configures a CORESET with a duration of 2 symbols and the bitmap indicates a start time so late in the slot that the CORESET would overlap with the next one, the UE may be "confused about the configuration" (’359 Patent, col. 17:58-65).
  • The Patented Solution: The invention proposes a rule to prevent this ambiguity. It describes a method where a network node transmits a signal that defines a CORESET's duration and its possible start times (the bitmap). The core of the solution is a negative limitation: the network is "not allowed to transmit the signal such that an interval between any two" active start positions in the bitmap "is smaller than the first duration" (’359 Patent, Claim 1). This ensures that monitoring occasions for a UE cannot overlap, thereby preventing configuration errors (’359 Patent, FIG. 7).
  • Technical Importance: This rule-based approach to resource configuration ensures reliability and prevents errors in the crucial downlink control signaling process, which is fundamental to managing data traffic, scheduling, and overall network performance in 5G systems (’359 Patent, col. 1:28-34).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶51).
  • Independent Claim 1 Elements:
    • A method performed by a network node.
    • Transmitting a signal indicating at least a first duration and a bit map.
    • The first duration is the time duration of a control resource set (CORESET).
    • The bit map includes bit positions where a value of "one" indicates a starting symbol for a monitoring occasion of the CORESET.
    • Not allowing the signal to be transmitted if the interval between any two bit positions with a value of "one" is smaller than the first duration.
  • The complaint reserves the right to assert additional claims (Compl. ¶45).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are the "T-Mobile Wireless Networks," which include the infrastructure and services for T-Mobile's 4G and 5G wireless networks (Compl. ¶¶10, 32, 50). This encompasses services branded as "T-Mobile," "Metro by T-Mobile," "Sprint Mobile," and "Assurance Wireless" (Compl. ¶10).

Functionality and Market Context

The complaint alleges that T-Mobile’s networks provide nationwide wireless services, including in the Eastern District of Texas (Compl. ¶10). A screenshot of T-Mobile's coverage map is provided as evidence of its advertised 4G and 5G wireless coverage in and around Marshall, Texas (Compl. ¶11). The functionality accused of infringement is the networks' method of providing 5G wireless services, which allegedly requires configuring CORESETs for user devices in a manner that practices the patented method (Compl. ¶¶51-55). T-Mobile is positioned in the complaint as operating one of "America's largest and fastest 5G network[s]" (Compl. ¶35).

IV. Analysis of Infringement Allegations

’359 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of a network node... The T-Mobile Wireless Networks practice a method of a network node in providing 5G wireless services. ¶51 col. 1:42-44
transmitting a signal indicating at least a first duration and a bit map, The T-Mobile Wireless Networks transmit a radio resource control ("RRC") reconfiguration message indicating a first duration of a control resource set ("CORESET") and a bitmap for monitoring symbols within a slot. ¶52 col. 17:29-34
wherein the first duration is time duration of a control resource set (CORESET), The first duration is the time duration of the CORESET in number of symbols. ¶53 col. 17:29-31
wherein the bit map includes a set of bit positions, where each bit position has a value of one or zero and each bit position with the value of one indicates a starting Orthogonal Frequency Division Multiplexing (OFDM) symbol of a monitoring occasion of the CORESET within a slot; The bitmap includes bit positions where a value of one indicates a starting OFDM symbol of a monitoring occasion of the CORESET within a slot. ¶54 col. 17:31-34
and not allowing to transmit the signal such that an interval between any two bit positions with the value of one in the set of bit positions in the bit map is smaller than the first duration. The T-Mobile Wireless Networks practice the step of not allowing transmission of a bitmap for monitoring symbols if the interval between any two bit positions with a value of one is smaller than the defined time duration of the CORESET. ¶55 col. 18:7-12

Identified Points of Contention

  • Technical Question: The complaint's allegations regarding the core technical steps are made "on information and belief" (Compl. ¶¶51-55). A key question for the court will be what evidence demonstrates that T-Mobile's networks, which are comprised of equipment from various third-party vendors, actually implement the specific negative limitation of "not allowing" the transmission of certain bitmap configurations as required by claim 1.
  • Scope Questions: The final limitation, "not allowing to transmit," is a negative limitation. A potential dispute is whether infringement requires proof of an affirmative mechanism that prevents such transmissions, or whether the mere absence of such transmissions from the network is sufficient. This raises the question of how a patentee can prove that a system does not do something.

V. Key Claim Terms for Construction

  • The Term: "not allowing to transmit"

  • Context and Importance: This negative limitation is the core inventive concept alleged to solve the ambiguity problem. Its construction is critical because it defines the nature of the infringing act. If construed narrowly to require a specific blocking mechanism, infringement could be difficult to prove. If construed broadly, the mere operational state of the network could suffice. Practitioners may focus on this term because proving a negative—that the system is prevented from acting in a certain way—presents unique evidentiary challenges.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: Claim 1 is a method claim that simply states the step of "not allowing." An argument could be made that if the network node, as a matter of operation, never transmits a signal with the forbidden characteristic, it is "not allowing" it, regardless of the underlying mechanism.
    • Evidence for a Narrower Interpretation: The specification describes this as a "restriction on the configuration of a CORESET" (’359 Patent, col. 17:19-20) and the flow chart in FIG. 7 depicts an explicit step where the network node acts based on whether the interval is smaller than a duration. This may support an argument that the term requires a designed, affirmative constraint within the system's logic, not just an operational artifact.

  • The Term: "interval between any two bit positions"

  • Context and Importance: The infringement analysis hinges on comparing this "interval" to the "first duration." The patent itself suggests potential ambiguity in how this could be measured, making it a likely subject of dispute.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The plain and ordinary meaning might suggest the simple difference in the numerical indices of the two bit positions.
    • Evidence for a Narrower Interpretation: The specification states an "interval or distance between two bit positions could be a number of bits between the two bit positions," and that the two positions themselves "could be neglected when calculating the interval or distance" (’359 Patent, col. 17:41-46). This language could be used to argue for a more specific calculation method (e.g., counting only the "0"s between two "1"s) that might not be met by the accused system.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement by asserting that T-Mobile provides instructions, advertising, and technical support that "encourage and teach" customers to use the infringing networks (Compl. ¶41). Contributory infringement is alleged on the basis that T-Mobile's network components are material to the invention, not staple articles of commerce, and are known to be especially adapted for infringement (Compl. ¶42).
  • Willful Infringement: Willfulness is alleged based on T-Mobile's purported knowledge of the ’359 Patent and its infringement since at least February 1, 2023, when Plaintiffs allegedly provided T-Mobile with access to infringement claim charts during licensing negotiations (Compl. ¶44).

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

  1. A core issue will be one of evidentiary proof: Can Plaintiffs produce evidence from T-Mobile's network operations or its vendors' technical specifications to demonstrate that the systems affirmatively practice the negative limitation of "not allowing" the transmission of specific bitmap configurations, as required by the patent, or will the allegations remain based on "information and belief"?
  2. The case will likely involve a significant dispute over claim construction: How will the court define "not allowing to transmit"? Will it require proof of a specific, designed-in software or hardware rule that prevents the forbidden transmission, or will the observed absence of such transmissions from the network be sufficient to establish infringement?
  3. Underlying the patent dispute is a battle over FRAND obligations: The complaint dedicates a separate count to the parties' conduct during licensing negotiations. The resolution of the case may therefore depend not only on the technical infringement analysis but also on the court's determination of whether the parties have met their respective obligations to negotiate in good faith for a license on fair, reasonable, and non-discriminatory terms.