Uniloc USA Inc v. ZTE

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Uniloc USA, Inc. (TX), Uniloc 2017 LLC (DE), and Uniloc Licensing USA LLC (DE)
  • Defendant: ZTE (USA), Inc. (NJ) and ZTE (TX), Inc. (TX)
  • Plaintiff’s Counsel: Prince Lobel Tye LLP; Nelson Bumgardner Albrittion PC
• Case Identification: 2:18-cv-00304, E.D. Tex., 08/08/2018
• Venue Allegations: Venue is alleged to be proper based on Defendant ZTE having a regular and established place of business in the district and having committed acts of infringement there.
• Core Dispute: Plaintiff alleges that Defendant’s electronic devices that operate in accordance with LTE standards infringe a patent related to methods for managing service requests in a radio communication system.
• Technical Context: The technology concerns managing uplink requests from mobile devices to a network base station, a fundamental process for initiating data or voice services in modern wireless networks.
• Key Procedural History: Post-filing, the asserted patent was the subject of an Inter Partes Review (IPR2019-00510). The resulting IPR certificate, issued August 16, 2021, cancelled claim 17. As the complaint asserts claims 17-18, the cause of action as to claim 17 is moot, focusing the dispute entirely on claim 18.

Case Timeline

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

U.S. Patent No. 6,868,079 - "RADIO COMMUNICATION SYSTEM WITH REQUEST RE-TRANSMISSION UNTIL ACKNOWLEDGED"

The Invention Explained

• Problem Addressed: In wireless systems like UMTS, a mobile station (MS) needing to initiate a service (e.g., a call) must send a request to a base station (BS). The patent notes that prior art random-access channel protocols, where multiple devices compete for access, work poorly under high traffic loads and are not ideal for emerging third-generation standards (’079 Patent, col. 1:32-41).
• The Patented Solution: The invention proposes a system where each mobile station is allocated its own dedicated time slots on an uplink channel to send service requests. To increase reliability, the mobile station is configured to re-transmit its service request in each of its successive allocated time slots until it receives an acknowledgement from the base station (’079 Patent, col. 2:42-49; Abstract). This avoids the collisions inherent in random-access systems and allows the base station to use signal combining techniques across multiple slots to more accurately detect weak request signals (’079 Patent, col. 2:8-14).
• Technical Importance: This approach provides a more robust and orderly mechanism for handling service requests compared to contention-based protocols, which was a key consideration for ensuring quality of service in increasingly crowded wireless environments.

Key Claims at a Glance

• The complaint asserts claims 17-18 (Compl. ¶20). Claim 17 has since been cancelled by an IPR proceeding. The analysis therefore focuses on asserted dependent claim 18 and its independent base claim, claim 8.
• Independent Claim 8 (System Claim):
  • A radio communication system comprising a primary station and a plurality of respective secondary stations;
  • The primary station having means for allocating respective time slots in an uplink channel to the secondary stations to transmit requests;
  • The secondary stations having means for re-transmitting the same respective requests in consecutive allocated time slots without waiting for an acknowledgement;
  • This re-transmission continues until an acknowledgement is received from the primary station.
• Dependent Claim 18: Modifies claim 8 by specifying that the primary station determines if a request was sent by determining whether the signal strength of the transmitted request exceeds a threshold value.

III. The Accused Instrumentality

Product Identification

• The complaint identifies a long list of ZTE's electronic devices, including smartphones and tablets from its nubia, Blade, Axon, and Grand series, that operate in compliance with LTE standards (collectively "Accused Infringing Devices") (Compl. ¶15).

Functionality and Market Context

• The accused functionality is the devices' implementation of the LTE standard for communicating with network base stations (Compl. ¶16). Specifically, the complaint focuses on the use of the Physical Uplink Control Channel (PUCCH) for transmitting a "scheduling request (SR)" from the device (a secondary station) to a base station (a primary station) (Compl. ¶17). The complaint alleges that this SR is repeated until the device receives a "resource allocation acknowledgement" from the base station (Compl. ¶18).
  No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'079 Patent Infringement Allegations

• Identified Points of Contention:
  • Scope Questions (Means-Plus-Function): Claim 8 recites "means for allocating" and "means for re-transmitting." Under 35 U.S.C. § 112, ¶ 6, the scope of these terms is limited to the corresponding structures disclosed in the patent's specification (e.g., a microcontroller programmed with specific logic) and their equivalents. A central question will be whether the processors and software implementing the LTE standard's PUCCH procedures in ZTE's devices are structurally equivalent to the specific embodiments described in the '079 patent (’079 Patent, col. 3:12-21, FIG. 3).
  • Technical Questions: The complaint alleges the SR is sent "every nth sub-frame" and, as an example, "twice in consecutive .5ms subframe time slots" (Compl. ¶18). Claim 8 requires re-transmission in "consecutive allocated time slots." A factual dispute may arise over whether the LTE standard's SR repetition scheme, as implemented by ZTE, meets the "consecutive" limitation as it would be construed by the court.

V. Key Claim Terms for Construction

• The Term: "means for re-transmitting the same respective requests in consecutive allocated time slots without waiting for an acknowledgement"
• Context and Importance: This is a means-plus-function limitation at the core of the invention. Its construction will define the scope of infringement. Practitioners may focus on this term because the infringement analysis will depend entirely on identifying the function (the repeated re-transmission loop) and its corresponding structure in the specification, then comparing that structure to the accused LTE implementation.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification describes the purpose of re-transmission as improving the robustness of the signaling scheme (’079 Patent, col. 4:26-28). A party might argue that any structure in the accused device that achieves this function through repeated transmissions, regardless of its specific hardware or software architecture, should be considered an equivalent.
  • Evidence for a Narrower Interpretation: The specification discloses a specific structure for implementing this function: a microcontroller (µC 112) connected to a transceiver (114) and executing the logic shown in the flowchart of Figure 3 (’079 Patent, col. 3:15-21; col. 3:53-65). A party could argue the term's scope should be narrowly limited to this disclosed microcontroller-based architecture and its close technological equivalents.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that ZTE induces infringement of at least claim 18 by providing customers with the Accused Infringing Devices along with "training videos, demonstrations, brochures, installation and user guides, and other instructional and marketing materials" that instruct on the use of the devices' infringing LTE functionality (Compl. ¶23). The complaint provides a list of URLs for such materials (Compl. ¶23).
• Willful Infringement: The willfulness allegation is based on alleged post-suit knowledge. The complaint asserts that ZTE has been on notice of its infringement since, at the latest, the service of the original complaint in the case and has "refused to discontinue its infringing acts" (Compl. ¶25).

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

With the cancellation of claim 17, the case is narrowed to claim 18. The resolution will likely depend on the following questions:

1. A central issue will be one of structural equivalence: For the "means for re-transmitting" limitation, will the court determine that the hardware and software architecture used to implement the Scheduling Request (SR) procedure in ZTE's LTE-compliant devices is equivalent to the specific microcontroller-based structure disclosed in the '079 patent?
2. A key question of claim scope will be: How will the court construe the term "consecutive allocated time slots"? The outcome will determine whether the alleged practice of repeating a request "every nth sub-frame" (Compl. ¶18) literally meets this limitation.
3. An evidentiary question will be one of inducement: Can the plaintiff demonstrate that ZTE’s user manuals and marketing materials (Compl. ¶23) contain specific instructions that would lead an ordinary user to perform the patented method, and that ZTE possessed the requisite intent for those actions to cause infringement?