DCT

3:18-cv-00557

Uniloc USA Inc v. LG Corp

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 3:18-cv-00557, N.D. Tex., 07/02/2018
  • Venue Allegations: Plaintiff alleges venue is proper in the Northern District of Texas because Defendant LG Electronics U.S.A., Inc. maintains a regular and established place of business within the district and offers the accused products for sale to customers located there.
  • Core Dispute: Plaintiff alleges that Defendant’s electronic devices that operate on LTE networks infringe a patent related to a method for a secondary device to repeatedly transmit a service request to a primary device until an acknowledgement is received.
  • Technical Context: The technology concerns uplink signaling protocols in wireless communication systems, a foundational element for managing how mobile devices request network resources from base stations in standards like UMTS and LTE.
  • Key Procedural History: The complaint is a First Amended Complaint. The asserted patent family was the subject of an Inter Partes Review (IPR2019-00510), which resulted in the cancellation of claim 17. The present complaint asserts at least claim 18, which was not cancelled in that proceeding.

Case Timeline

Date Event
1998-12-10 U.S. Patent No. 6,868,079 Priority Date
2005-03-15 U.S. Patent No. 6,868,079 Issue Date
2018-07-02 First Amended Complaint Filing Date
2019-01-10 Inter Partes Review IPR2019-00510 Filed against '079 Patent
2021-08-16 IPR Certificate Issued, Cancelling Claim 17 of '079 Patent

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

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

  • Patent Identification: U.S. Patent No. 6,868,079, "RADIO COMMUNICATION SYSTEM WITH REQUEST RE-TRANSMISSION UNTIL ACKNOWLEDGED," issued March 15, 2005. (’079 Patent, p. 1).

The Invention Explained

  • Problem Addressed: The patent's background describes the challenge for a mobile station (MS) to efficiently and reliably request resources from a base station (BS) when no uplink channel is currently assigned. Conventional methods, such as random access channels, were described as inefficient for high-traffic environments like the then-emerging UMTS standard, while dedicated signaling channels could suffer from significant delays if an initial request was missed by the BS. (’079 Patent, col. 1:16-54).
  • The Patented Solution: The invention proposes a method where a secondary station (e.g., a mobile device) persistently re-transmits a service request in each of its dedicated, allocated time slots until it receives an explicit acknowledgement from the primary station (e.g., a base station). This repetition is intended to reduce the delay associated with a missed request and allows the primary station to use signal combining techniques across multiple slots to improve detection accuracy. (’079 Patent, Abstract; col. 2:3-15). The flowchart in Figure 3 illustrates this loop, showing the process to "REQUEST SERVICE" (304) continuing until an acknowledgement is received (308). (’079 Patent, FIG. 3).
  • Technical Importance: This approach aimed to improve the robustness and reduce the latency of establishing new communication links, a critical function for supporting the more demanding data services of third-generation (3G) wireless networks. (’079 Patent, col. 1:36-42).

Key Claims at a Glance

  • The complaint asserts at least independent claim 18. (Compl. ¶16).
  • The essential elements of independent claim 18 are:
    • A radio communication system with a primary station and multiple secondary stations.
    • The primary station allocates time slots in an uplink channel to the secondary stations for transmitting service requests.
    • The secondary stations re-transmit the same request in consecutive allocated time slots without waiting for an acknowledgement until one is received from the primary station.
    • The primary station determines if a request was transmitted by determining if the signal strength of the request exceeds a threshold value.
  • The complaint does not explicitly reserve the right to assert other claims, though this remains a possibility as the case develops.

III. The Accused Instrumentality

Product Identification

  • The complaint names a wide array of LG electronic devices, including the LG G7 ThinQ, LG V30, LG G Stylo, and dozens of others, collectively identified as the "Accused Infringing Devices." (Compl. ¶14).

Functionality and Market Context

  • The accused products are alleged to be devices that operate in compliance with LTE standards. (Compl. ¶15).
  • The relevant functionality involves the use of the Physical Uplink Control Channel (PUCCH) to transmit information from the device to a base station. (Compl. ¶17). Specifically, the complaint alleges that when using "PUCCH format 1," a device sends a scheduling request (SR) in its allocated time slots, and this transmission "is repeated until the primary device transmits a resource allocation acknowledgement." (Compl. ¶18). The primary station is said to detect this SR "by the presence of a certain energy level on the PUCCH." (Compl. ¶18).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

'079 Patent Infringement Allegations

Claim Element (from Independent Claim 18) Alleged Infringing Functionality Complaint Citation Patent Citation
A radio communication system, comprising: a primary station and a plurality of respective secondary stations; The accused devices operate within an LTE system, which comprises primary devices (base stations) and secondary devices (the Accused Infringing Devices). ¶15, ¶17 col. 8:36-38
the primary station having means for allocating respective time slots in an uplink channel to the plurality of respective secondary stations to transmit respective requests for services to the primary station to establish required services; In an LTE system, a primary device allocates time slots on an uplink channel (PUCCH) where secondary devices can transmit requests for services. ¶15, ¶17, ¶18 col. 8:39-44
wherein the respective secondary stations have means for re-transmitting the same respective requests in consecutive allocated time slots without waiting for an acknowledgement until said acknowledgement is received from the primary station, A secondary device using PUCCH format 1 transmits a scheduling request (SR), and "[t]his is repeated until the primary device transmits a resource allocation acknowledgement." ¶18 col. 8:45-51
wherein said primary station determines whether a request for services has been transmitted... by determining whether a signal strength of the respective transmitted request... exceeds a threshold value. The primary device (base station) is alleged to detect the SR "by the presence of a certain energy level on the PUCCH." ¶18 col. 8:52-58
  • Identified Points of Contention:
    • Scope Questions: Claim 18 requires re-transmission "in consecutive allocated time slots." The complaint alleges the accused scheduling request (SR) is sent "in respective time slots every nth sub-frame." (Compl. ¶18). A central dispute may arise over whether the periodic transmission schedule of an LTE SR qualifies as transmission in "consecutive allocated time slots" under a proper construction of that term.
    • Technical Questions: The asserted claim is for a "radio communication system" that requires both a primary station and secondary stations. The complaint accuses LG, which manufactures the secondary stations, of direct infringement. (Compl. ¶16). This raises the question of whether a party that makes, uses, or sells only one component of a claimed system can be held liable for direct infringement of the entire system claim, or if liability must instead be established through indirect infringement theories.

V. Key Claim Terms for Construction

  • The Term: "re-transmitting... in consecutive allocated time slots"

  • Context and Importance: This phrase is central to the claimed inventive concept and distinguishes it from prior art methods. The infringement analysis will depend heavily on whether the operation of the accused LTE scheduling request protocol falls within the scope of this term.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The patent specification describes the process as making requests "in successive allocated time slots." (’079 Patent, col. 6:61-62). A party could argue that "consecutive" or "successive" refers to the sequence of slots allocated to a specific user, not necessarily slots that are immediately adjacent in the overall radio frame, thereby covering periodic transmissions.
    • Evidence for a Narrower Interpretation: The patent also states a request can be repeated "at the frame rate," for example, every 10 ms. (’079 Patent, col. 6:9-11). A party could argue this language, which implies discrete and separated transmissions, supports a narrower construction where "consecutive" requires immediate temporal adjacency, which may not align with the accused LTE SR protocol.

  • The Term: "without waiting for an acknowledgement"

  • Context and Importance: This limitation defines the persistent nature of the re-transmission. Practitioners may focus on this term because it distinguishes the claimed method from protocols that transmit, pause for a defined acknowledgement window, and then re-transmit only upon a timeout.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The flowchart in Figure 3 depicts a direct loop where a request (304) is made, and a "CONTINUE?" check (306) leads directly back to another request, without an intervening "wait" step before an acknowledgement (308) is received. (’079 Patent, FIG. 3). This may support an interpretation that any protocol that automatically re-transmits in its next available opportunity infringes.
    • Evidence for a Narrower Interpretation: The detailed description notes that in conventional systems, a station "waits for an acknowledgement" before re-transmitting. (’079 Patent, col. 1:47-49). A party might argue that "without waiting" must be interpreted as a complete absence of any programmed delay or timing cycle between transmission attempts, a standard that the complex timing of the LTE standard may not meet.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced infringement (§ 271(b)) and contributory infringement (§ 271(c)). (Compl. ¶¶ 21-22). Inducement is premised on allegations that LG instructs customers on how to use the devices in an infringing manner through materials like user guides and promotional videos. (Compl. ¶21). Contributory infringement is based on the allegation that the devices are especially made to practice the invention and are not staple articles of commerce with substantial non-infringing uses. (Compl. ¶22).
  • Willful Infringement: The complaint pleads post-suit willfulness, alleging that LG will be on notice of the patent at least from the service of the original complaint and that any continued infringement thereafter is willful and deliberate. (Compl. ¶23). No facts supporting pre-suit knowledge are alleged.

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

  • A core issue will be one of definitional scope: can the term "consecutive allocated time slots", as used in the patent, be construed to read on the periodic scheduling request (SR) transmission procedure defined by the LTE standard?
  • A key legal question will be one of infringement liability: as claim 18 is a system claim requiring both primary and secondary stations, can LG be held directly liable for infringement by manufacturing and selling only the secondary station (the handset), or will the outcome of the case depend entirely on the strength of the evidence for indirect infringement?
  • A central evidentiary question will be one of technical mapping: does an LTE base station's process for detecting a scheduling request—alleged to be based on sensing an "energy level on the PUCCH"—satisfy the claim limitation of "determining whether a signal strength... exceeds a threshold value," or is there a functional or operational distinction that a court may find material?