Uniloc USA Inc v. ZTE

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Uniloc USA, Inc. (Texas), Uniloc 2017 LLC (Delaware), and Uniloc Licensing USA LLC (Delaware)
  • Defendant: ZTE (USA), Inc. (New Jersey) and ZTE (TX), Inc. (Texas)
  • 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: Plaintiff alleges venue is proper because Defendant has a regular and established place of business in the district and has committed acts of infringement there.
• Core Dispute: Plaintiff alleges that Defendant’s electronic devices that comply with the LTE standard infringe a patent related to methods for managing service requests in a radio communication system.
• Technical Context: The technology addresses the need for a reliable method for mobile devices to request network resources from a base station, particularly in wireless systems with dedicated signaling channels.
• Key Procedural History: The operative pleading is a First Amended Complaint. Subsequent to the filing of this complaint, the patent-in-suit was the subject of an Inter Partes Review (IPR2019-00510). As a result of that proceeding, asserted claim 17 was cancelled. Asserted claim 18 remains.

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, issued March 15, 2005

The Invention Explained

• Problem Addressed: The patent’s background section describes the challenge of enabling a mobile station (MS) to request services from a base station (BS) when no dedicated uplink channel is active. Conventional "random access" methods were considered insufficient for the high-traffic requirements of emerging standards like UMTS, and even systems with dedicated time slots for requests could suffer from missed detections and response delays. (’079 Patent, col. 1:16-54).
• The Patented Solution: The invention proposes a system where a secondary station (e.g., a mobile phone) is allocated a specific time slot to send service requests. To ensure the request is received, the secondary station repeatedly re-transmits the request in its consecutive allocated time slots until it receives an acknowledgement from the primary station (e.g., a base station). This repetition allows the primary station to improve detection accuracy, for instance by combining the signals from multiple requests. ('079 Patent, Abstract; col. 2:1-14; col. 4:1-7).
• Technical Importance: This method was intended to create a more robust and efficient signaling mechanism, reducing delays and improving the reliability of service requests in third-generation cellular networks. ('079 Patent, col. 2:1-8).

Key Claims at a Glance

• The complaint asserts claims 17-18 (Compl. ¶20). As noted, claim 17 has since been cancelled via IPR. Claim 18, an independent system claim, remains.
• Independent Claim 18: The essential elements of this system claim are:
  • A primary station and a plurality of respective secondary stations.
  • The primary station has "means for allocating respective time slots in an uplink channel" for the secondary stations to transmit service requests.
  • The secondary stations have "means for re-transmitting the same respective requests in consecutive allocated time slots without waiting for an acknowledgement" until it is received from the primary station.
  • The primary station determines if a request was transmitted by "determining whether a signal strength of the respective transmitted request... exceeds a threshold value."
• The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

The complaint identifies a broad category of "Accused Infringing Devices," comprising a long list of ZTE's LTE-capable electronic devices, including the ZTE nubia V18, ZTE Blade series, and ZTE Axon series smartphones (Compl. ¶15).

Functionality and Market Context

The complaint alleges that the accused devices operate in compliance with LTE standards. Functionally, they are alleged to use a physical uplink control channel (PUCCH) to transmit information to base stations. Specifically, when a device needs to send data, it transmits a "scheduling request (SR) information to the primary device in respective time slots." This SR transmission is allegedly "repeated until the primary device transmits a resource allocation acknowledgement." The complaint further alleges that the primary device (base station) "detects the incoming SR by the presence of a certain energy level on the PUCCH." (Compl. ¶17-18). The complaint does not provide specific details on the products' market positioning beyond their sale in the United States (Compl. ¶7).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

'079 Patent Infringement Allegations

Identified Points of Contention

• Scope Questions: A potential dispute may arise over whether the accused LTE scheduling request (SR) protocol constitutes "re-transmitting... without waiting for an acknowledgement" as the claim requires. The court may need to determine if the specific timing and control mechanisms of the LTE standard differ meaningfully from the process described in the patent.
• Technical Questions: The complaint alleges infringement by asserting that a base station detects an SR by sensing "a certain energy level" (Compl. ¶18). A key technical question is whether this alleged function is the same as determining if a "signal strength... exceeds a threshold value." The analysis may turn on the specific signal processing steps performed by a real-world LTE base station, and whether they go beyond the simple threshold comparison described in the claim.

V. Key Claim Terms for Construction

The Term: "without waiting for an acknowledgement"

• Context and Importance: This phrase is central to the invention's core feature of persistent re-transmission. Its construction will be critical in determining whether the accused LTE protocol, where a Scheduling Request is repeated, falls within the scope of the claim. Practitioners may focus on this term because the specific rules governing the repetition of an LTE SR could be argued to not constitute a process of re-transmitting "without waiting."
• Intrinsic Evidence for a Broader Interpretation: The specification describes a straightforward process where a mobile station sends requests "in successive allocated time slots" until a test to stop is satisfied, which could support a broad reading covering any system with request repetition prior to a final stop signal ('079 Patent, col. 4:62-65; Fig. 3).
• Intrinsic Evidence for a Narrower Interpretation: The patent states that in prior art, a station "has to wait at least long enough for the primary station to have received, processed and acknowledged a request before it is able to retransmit" ('079 Patent, col. 2:5-8). This context may be used to argue that "without waiting" means something more specific than the highly structured and timed request sequence in the LTE standard.

The Term: "signal strength... exceeds a threshold value"

• Context and Importance: This term defines the detection mechanism at the primary station. The infringement analysis for this element depends on whether the accused base stations' actual method for detecting a service request aligns with this language.
• Intrinsic Evidence for a Broader Interpretation: The specification discusses improving detection "if the received signal strength is close to the detection threshold" ('079 Patent, col. 2:9-11) and later describes a simulation where a signal is detected if a filter output's "magnitude... is compared to a threshold value" ('079 Patent, col. 4:50-54), supporting a general energy detection interpretation.
• Intrinsic Evidence for a Narrower Interpretation: The patent also discloses more complex schemes, such as "combining requests" from multiple time slots to "improve the confidence of the decision" ('079 Patent, col. 4:20-26). A party could argue that this context narrows the "threshold value" limitation to a simple magnitude comparison, potentially distinguishing it from more sophisticated signal processing techniques used in modern base stations.

VI. Other Allegations

• Indirect Infringement: The complaint alleges active inducement of claim 18, stating that ZTE "intentionally instructs its customers to infringe" by providing "training videos, demonstrations, brochures, installation and user guides, and other instructional and marketing materials" (Compl. ¶23).
• Willful Infringement: The willfulness allegation is based on post-suit knowledge. The complaint asserts that ZTE has been on notice of the patent "since, at the latest, the service upon it of the Original Complaint in this case" and has "refused to discontinue its infringing acts" despite this knowledge (Compl. ¶25).

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

• A core issue will be one of claim scope and viability: Following the IPR cancellation of method claim 17, the case hinges on the interpretation of the parallel system claim 18. The central question is whether the standardized LTE scheduling request protocol, as implemented in Defendant's products, performs the functions of the "means for re-transmitting... without waiting for an acknowledgement" as required by the claim.
• A key evidentiary question will be one of technical implementation: Does the complaint's allegation that a base station detects a request by sensing "a certain energy level on the PUCCH" accurately map to the claimed function of determining if a "signal strength... exceeds a threshold value"? The resolution will likely depend on detailed evidence of how an actual LTE base station processes uplink control signals and whether that process is functionally equivalent to the mechanism described in the patent.