DCT

2:17-cv-00079

Cellular Communications Equipment LLC v. ZTE Corp

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:17-cv-00079, E.D. Tex., 01/25/2017
  • Venue Allegations: Plaintiff alleges venue is proper because each Defendant is deemed to reside in the district, has committed alleged acts of infringement in the district, and/or has a regular and established place of business in the district.
  • Core Dispute: Plaintiff alleges that a wide range of Defendants' LTE-capable mobile devices and related services infringe three patents related to mobile communication standards for managing power headroom reporting and signaling channel quality information.
  • Technical Context: The technology concerns fundamental aspects of 4G LTE network efficiency, specifically how mobile devices report their available transmission power and channel conditions to the network to enable optimal resource allocation.
  • Key Procedural History: The complaint alleges that Defendants had pre-suit knowledge of the patents-in-suit due to their membership in the 3rd Generation Partnership Project (3GPP) and disclosures made to the European Telecommunications Standards Institute (ETSI). The complaint also references a prior lawsuit, [Cellular Communications Equipment LLC](https://ai-lab.exparte.com/party/cellular-communications-equipment-llc) v. AT&T Inc, et al., Case No. 2:15-cv-00576 (E.D. Tex.), as a basis for knowledge. Subsequent to the filing of this complaint, Inter Partes Review (IPR) proceedings at the U.S. Patent and Trademark Office resulted in the cancellation of all asserted claims of U.S. Patent No. 8,867,472 and the key independent claims (1 and 19) of U.S. Patent No. 8,457,676. These IPR outcomes may substantially impact the viability of Counts II and III of the complaint.

Case Timeline

Date Event
2007-06-20 ’676 Patent Priority Date
2008-03-26 ’957 Patent Priority Date
2010-03-25 ’472 Patent Priority Date
2010-08-01 Alleged knowledge of ’957 patent via ETSI disclosure (approx.)
2012-12-01 Alleged knowledge of ’676 patent via ETSI disclosure (approx.)
2013-03-01 Alleged knowledge of ’472 patent via ETSI disclosure (approx.)
2013-06-04 ’676 Patent Issue Date
2013-10-29 ’957 Patent Issue Date
2014-10-21 ’472 Patent Issue Date
2017-01-25 Complaint Filing Date

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

U.S. Patent No. 8,570,957 - "Extension of Power Headroom Reporting and Trigger Conditions," issued October 29, 2013

The Invention Explained

  • Problem Addressed: In wireless networks like LTE, a base station (eNodeB) scheduler needs to know the available transmission power ("power headroom") of a user equipment (UE) to efficiently allocate network resources. The patent notes that conventional systems do not adequately inform the scheduler when a UE lacks sufficient power to meet transmission requirements, which can lead to wasted resources and poor performance. ('957 Patent, col. 5:6-14).
  • The Patented Solution: The invention describes a method and apparatus for a UE to generate a power headroom report that can represent both positive values (indicating surplus power) and negative values. A negative value explicitly quantifies the "missing power in dB to fulfill transmission requirements," giving the network scheduler precise information to make more efficient adjustments, such as reducing the allocated bandwidth. ('957 Patent, Abstract; col. 2:2-7).
  • Technical Importance: This extended reporting mechanism allows for more granular and efficient radio resource management, which can improve overall network capacity and the performance of UEs, particularly those at the edge of a cell or with limited power budgets. ('957 Patent, col.5:5-12).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 7, along with dependent claims 2-3 and 8-9. (Compl. ¶22).
  • Independent Claim 1 (Apparatus): An apparatus comprising:
    • a processor configured to determine a power headroom report with both positive and negative values
    • wherein the processor determines the headroom by subtracting the nominal maximum transmission power and the power the apparatus would use if it did not apply maximum power limitations
    • wherein the result of the subtraction is not limited to zero and positive values
    • a transmitter configured to transmit the report
  • Independent Claim 7 (Method): A method with steps corresponding to the elements of claim 1.

U.S. Patent No. 8,867,472 - "Signalling of Channel Information," issued October 21, 2014

The Invention Explained

  • Problem Addressed: Modern LTE-Advanced systems use "carrier aggregation" to combine multiple frequency bands (component carriers or CCs) to increase data rates. Requiring a UE to provide detailed channel state information (CSI) for every active CC would create significant signaling overhead on the uplink, consuming valuable network resources. ('472 Patent, col. 3:20-28).
  • The Patented Solution: The patent discloses a system where a network element can request a detailed, aperiodic CSI report for a single, specific downlink CC. The invention proposes that the UE determines which CC to report on based on which CC carried the uplink grant containing the request. This avoids the need for explicit signaling of the target CC, thereby reducing overhead. ('472 Patent, Abstract; col. 5:26-34).
  • Technical Importance: This method provides a mechanism for targeted, on-demand channel quality feedback in multi-carrier systems, reducing uplink control channel congestion and improving overall system efficiency. ('472 Patent, col. 5:45-50).

Key Claims at a Glance

  • The complaint asserts independent claims 1, 28, and 41, along with dependent claims 10, 11, and 14. (Compl. ¶39). As noted in Section I, these claims were cancelled in a subsequent IPR proceeding.
  • Independent Claim 1 (Apparatus): An apparatus (UE) comprising:
    • a receiver configured to receive a request for aperiodic channel information for a selected downlink component carrier
    • a processor configured to determine the selected carrier "based on which component carrier...carried the request"
    • the processor is also configured to establish channel information for that carrier
    • a sender configured to send the established channel information
  • Independent Claim 28 (Method): A method with steps corresponding to the apparatus of claim 1.

U.S. Patent No. 8,457,676 - "Power Headroom Reporting Method," issued June 4, 2013

Technology Synopsis

This patent focuses on when a UE should send a power headroom report. It describes a method where reporting is triggered only when specific criteria are met, such as a pre-configured number of transmission time intervals passing since the last report or a significant change in the measured path-loss between the UE and the base station. The patent specifies that these triggering thresholds are configurable by the network, allowing for a trade-off between signaling overhead and the timeliness of the power information. ('676 Patent, Abstract; col. 4:36-65).

Asserted Claims

Claims 1, 3, 19, and 21. (Compl. ¶56). Independent claims 1 and 19 were cancelled in a subsequent IPR proceeding.

Accused Features

The complaint alleges that the Accused Devices transmit power headroom reports based on the expiration of "prohibit and periodic power headroom report timers," which allegedly correspond to the claimed adjustable triggering criteria. (Compl. ¶58).

III. The Accused Instrumentality

Product Identification

The complaint identifies dozens of specific models of LTE-capable mobile devices, including smartphones, tablets, and mobile hotspots manufactured by ZTE and sold or distributed through U.S. carriers AT&T, Sprint, and T-Mobile. These are collectively referred to as the "Accused Devices." (Compl. ¶22, ¶39, ¶56).

Functionality and Market Context

The complaint alleges that the Accused Devices are designed to be compliant with 3GPP LTE standards. (Compl. ¶24, ¶41, ¶58). The core of the infringement allegation is that the standard-compliant operation of these devices—specifically their implementation of power headroom reporting and aperiodic CSI reporting—practices the methods claimed in the patents-in-suit. (Compl. ¶24, ¶41, ¶58). The complaint alleges the Defendants are major participants in the U.S. mobile telecommunications market. (Compl. ¶2-12).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’957 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a processor configured to determine a power headroom report...with both positive and negative values of power headroom, as applicable... The Accused Devices monitor power headroom and generate a report that "supports both positive and negative values." ¶24 col. 2:2-7
wherein the processor is configured to determine the power headroom by subtracting the nominal maximum transmission power and the power that the apparatus would use if it did not apply maximum power limitations... The Accused Devices contain a baseband processor and software configured to perform this function as part of their standard operation. ¶30 col. 9:18-24
...wherein the result of said subtracting is not limited to zero and positive values. The "negative power headroom indicates the missing power in dB to fulfill transmission requirements," which implies the result is not artificially limited to be positive. ¶24 col. 9:22-24
a transmitter configured to transmit the headroom report... The Accused Devices contain a transceiver configured to transmit the power headroom report to the network. ¶24, ¶30 col. 1:53-54
  • Identified Points of Contention:
    • Scope Questions: A central question will be whether the method of calculating power headroom as implemented in the 3GPP standard (allegedly practiced by the Accused Devices) is the same as the specific method recited in the claim: "subtracting the nominal maximum transmission power and the power that the apparatus would use if it did not apply maximum power limitations." The dispute may focus on whether the standard requires this exact calculation or allows for other methods that may not align with the claim language.
    • Technical Questions: What evidence demonstrates that the accused products' functionality, which the complaint links to 3GPP TS 36.321 (Compl. ¶24), maps directly onto each limitation of the claim, particularly the specific subtraction operation that results in a non-limited value?

’472 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a receiver configured to receive a request for providing aperiodic channel information with respect to a selected downlink component carrier... The Accused Devices are configured to receive a request for aperiodic channel information via their transceivers. ¶41, ¶47 col. 8:1-5
a processor configured to: determine the selected downlink component carrier based on which component carrier of the plurality of component carriers carried the request... The Accused Devices are "specifically programmed and/or configured" to determine the channel information for the selected downlink component carrier. ¶47 col. 5:26-30
...and establish channel information with respect to the selected downlink component carrier; and The Accused Devices establish the channel information for the selected carrier. ¶41, ¶47 col. 5:30-34
a sender configured to send the channel information with respect to the selected downlink component carrier. The Accused Devices are configured to "generate a report, and to transmit the report containing the aperiodic channel information." ¶41 col. 8:4-6
  • Identified Points of Contention:
    • Scope Questions: The primary dispute, were the claims still valid, would concern the limitation "based on which component carrier...carried the request." A key question is whether this language can be construed to read on the standardized procedure for triggering aperiodic CSI reports, which the complaint alleges the Accused Devices implement. (Compl. ¶41).
    • Technical Questions: What evidence does the complaint provide to show that the processor in an accused device performs a specific logical step of "determining" the target carrier from the grant-carrying carrier, as opposed to simply following a default, pre-configured rule dictated by the standard?

V. Key Claim Terms for Construction

’957 Patent

  • The Term: "subtracting the nominal maximum transmission power and the power that the apparatus would use if it did not apply maximum power limitations"
  • Context and Importance: This term defines the core technical operation of the invention. Its construction will be dispositive for infringement, as the analysis will turn on whether the accused devices perform this specific calculation. Practitioners may focus on this term because it appears to describe a precise mathematical formula, and any deviation in the accused devices' actual operation could be a basis for a non-infringement argument.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification generally describes the invention as extending reporting to "both directions," including "negative headroom if the required transmit power...requires higher power than the nominal maximum transmit power." ('957 Patent, col. 5:15-24). This could support an interpretation covering any calculation that produces a negative value representing a power deficit.
    • Evidence for a Narrower Interpretation: The specification provides a specific formula (Equation 1) and defines its components. ('957 Patent, col. 4:35-51). An argument could be made that the claim term must be limited to this explicitly disclosed formula and its precise inputs.

’472 Patent

  • The Term: "determine the selected downlink component carrier based on which component carrier...carried the request"
  • Context and Importance: This term is critical because it defines the mechanism linking the request to the specific carrier being reported on. Infringement hinges on whether the accused devices perform this "based on" determination. Practitioners may focus on this term because it implies a causal and determinative link, not just a correlation.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification states that "when the UE...receives UL grant on which the trigger...on a particular component carrier, it knows that it has to detect the channel state...on this particular component carrier." ('472 Patent, col. 5:26-30). This suggests the location of the grant is sufficient to "determine" the carrier.
    • Evidence for a Narrower Interpretation: The figures show "DETERMINE DL CC" as a distinct step (Fig. 2A, S2), which could support an argument that this requires an active processing step beyond merely following a default rule. The abstract also refers to receiving a request "with respect to a selected downlink component carrier," which could imply the selection is part of the request itself.

VI. Other Allegations

  • Indirect Infringement: For all three patents, the complaint alleges inducement by providing "user guides, owner manuals, and similar online resources" that instruct end-users to operate the Accused Devices in an infringing manner. (Compl. ¶28, ¶45, ¶62). It also alleges contributory infringement, stating that the devices contain non-staple components (e.g., baseband processors with specific code) that are a material part of the inventions and have no substantial non-infringing use. (Compl. ¶29, ¶46, ¶63).
  • Willful Infringement: The complaint alleges willful infringement for all three patents. The basis for willfulness is Defendants' alleged pre-suit knowledge of the patents, derived from (1) service in a prior lawsuit involving the same plaintiff and defendants, and (2) Defendants' participation in 3GPP and awareness of SEP declarations made to ETSI concerning the patents-in-suit or their applications. (Compl. ¶26, ¶43, ¶60).

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

  1. Impact of IPR Proceedings: The most significant development affecting this case is the post-filing cancellation of all asserted claims of the '472 patent and the independent claims of the '676 patent. A threshold question for the court will be the legal effect of these IPR decisions on Counts II and III of the complaint, which are now predicated on invalid or cancelled claims.
  2. Claim Scope vs. Standard Implementation: For the surviving claims of the '957 patent, the case will likely center on a classic SEP dispute. A core issue will be one of definitional scope: does compliance with the 3GPP standard, as alleged, necessarily equate to infringement of the specific method claimed in the patent, or did the patentee claim a specific implementation that is distinct from what the standard mandates?
  3. Knowledge and Willfulness: Should infringement of any valid claims be established, a key evidentiary question will be whether the Defendants' alleged knowledge from prior litigation and SEP declarations rises to the level required to support a finding of willful infringement, which could expose them to enhanced damages.