Tot Power Control SL v. AT&T Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: TOT Power Control, S.L. (Spain)
  • Defendant: AT&T Mobility LLC (Delaware)
  • Plaintiff’s Counsel: DINOVO PRICE LLP
• Case Identification: 6:21-cv-00107, W.D. Tex., 01/29/2026
• Venue Allegations: Plaintiff alleges venue is proper based on Defendant maintaining regular and established places of business, such as retail stores, and operating and controlling CDMA-based wireless network infrastructure, including cellular towers, within the Western District of Texas.
• Core Dispute: Plaintiff alleges that Defendant’s WCDMA-based wireless networks infringe a patent related to methods and systems for outer loop power control in wireless communications.
• Technical Context: The technology at issue addresses dynamic power control in 3rd Generation (WCDMA/UMTS) cellular networks, a critical function for managing interference to optimize network capacity and maintain quality of service.
• Key Procedural History: The complaint is a Second Amended Complaint. It notes that Nokia of America Corporation and Ericsson Inc. are Intervenor-Defendants. The complaint alleges that Plaintiff shared its patented techniques with these equipment suppliers, who then allegedly implemented them in equipment supplied to Defendant. Plaintiff also states it served infringement contentions on December 19, 2025.

Case Timeline

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

U.S. Patent No. 7,496,376 - "Outer Loop Power Control Method and Apparatus for Wireless Communications Systems"

Issued February 24, 2009. Compl. ¶13

The Invention Explained

• Problem Addressed: The patent addresses the inefficiency of conventional outer loop power control (OLPC) in WCDMA systems. These systems slowly adjust a target Signal-to-Interference Ratio (SIR_target) based on a target Block Error Rate (BLER). This slow reaction is particularly wasteful when channel conditions improve, as the system continues to transmit at an unnecessarily high power level for too long, causing excess interference and reducing overall network capacity. Compl. ¶12 ’376 Patent, col. 3:1-21
• The Patented Solution: The invention proposes a more adaptive OLPC method that supplements the slow BLER-based quality criterion with a faster-reacting criterion based on outage probability. It claims a method and apparatus that establishes a target SIR by using a "dynamic adjusting function" to map inputs based on outage probabilities and fading characteristics to the desired target BLER. This allows the system to adapt power levels "quickly and dynamically to the propagation conditions of the data signal." (’376 Patent, col. 6:7-12, FIG. 7).
• Technical Importance: By enabling more rapid and precise power adjustments, the technology aimed to satisfy the required quality of service using the minimum necessary power, thereby optimizing the capacity of interference-limited cellular networks. ’376 Patent, col. 6:7-12

Key Claims at a Glance

• The complaint asserts independent claims 1 (method) and 6 (apparatus). Compl. ¶22
• The essential elements of independent apparatus Claim 6 include a programmable electronic device operable to perform steps comprising:
  • establishing a target block error rate (BLER_target);
  • calculating an estimate of a desired signal to interference ratio (SIR_rec) and of fading parameters in the channel;
  • estimating fading margins associated with outage probabilities and the fading parameters;
  • indicating a status of data blocks based on a Cyclic Redundancy Code (CRC) check; and
  • establishing a target SIR (SIR_target) based on the data block status, the fading margins, and the target BLER, by means of a "dynamic adjusting function which performs a mapping" between a quality criterion based on outage probabilities and a quality criterion based on the target BLER. ’376 Patent, col. 15:28-52
• The complaint reserves the right to assert other claims. Compl. ¶22

III. The Accused Instrumentality

Product Identification

Defendant’s "WCDMA-based wireless networks," including "WCDMA base stations (including for example Node-Bs), and controlled by Radio Network Controllers ('RNCs')." Compl. ¶¶ 22, 24

Functionality and Market Context

The accused instrumentalities are components of Defendant's 3G cellular network infrastructure that are alleged to manage the inner and outer loop power control processes for the network. Compl. ¶25 The complaint alleges these components operate according to the 3GPP UMTS standard and that the use of the patented techniques provides "significant capacity gains" for Defendant's networks. Compl. ¶¶ 17, 26

IV. Analysis of Infringement Allegations

The complaint provides a narrative infringement theory for Claim 6 of the ’376 Patent. A figure in the complaint illustrates how the convergence rate for adjusting the target SIR slows as the target Block Error Rate decreases, highlighting the inefficiency the patent claims to address. Compl. p. 6

’376 Patent Infringement Allegations

Identified Points of Contention

• Scope Questions: The complaint alleges that the claimed "dynamic adjusting function" is met by the accused "software implementation of OLPC." Compl. ¶31 A central question may be whether a standard-compliant OLPC algorithm performs the specific "mapping between a quality criterion based on the outage probabilities... and the quality criterion based on the target block error rate" as required by the claim, or if the claim requires a more specialized function not present in the accused systems.
• Technical Questions: The complaint alleges that "fading parameters" are calculated by "averaging the SIRTarget values." Compl. ¶28 Analysis may focus on whether this averaging process is technically equivalent to calculating the specific "statistical moments" disclosed as fading parameters in the patent’s specification (e.g., standard deviation of log-normal fading, Rice factor). ’376 Patent, col. 11:39-45

V. Key Claim Terms for Construction

• The Term: "dynamic adjusting function"

• Context and Importance: This term appears in the final, and arguably most critical, limitation of Claim 6. Its construction will be central to determining whether the accused systems, which implement standard OLPC, fall within the scope of the claims.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The claim language itself is functional, defining the term by what it does: "performs a mapping between a quality criterion based on the outage probabilities... and the quality criterion based on the target block error rate." ’376 Patent, col. 16:62-65 This could support an interpretation covering any software function that uses inputs related to both criteria to determine an output SIR_target.
  • Evidence for a Narrower Interpretation: The specification's preferred embodiment "consists preferentially of a neural network." ’376 Patent, col. 6:17-18 The detailed description of the invention and associated figures focus almost exclusively on a neural network implementation. ’376 Patent, FIG. 5 col. 11:31-col. 12:65 This repeated emphasis may be used to argue for a narrower construction limited to neural networks or functionally similar adaptive structures.

• The Term: "fading parameters"

• Context and Importance: The infringement allegation for this term relies on the accused systems "averaging the SIRTarget values." Compl. ¶28 Whether this constitutes calculating "fading parameters" as understood in the patent will be a key technical dispute.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent does not provide an explicit definition for the term in a standalone glossary. An argument could be made that any calculated value reflecting channel fade, including an average SIR_target, could qualify as a "fading parameter."
  • Evidence for a Narrower Interpretation: The specification gives specific examples, stating that "fading parameters in the channel (706) can be statistical moments such as... the standard deviation corresponding to log-normal fading (σn), the Rice factor (K) of the desired signal and the standard deviation (σI) corresponding to the distribution which describes the variations of the interference signals." ’376 Patent, col. 11:39-45 This may support a construction limiting the term to these or similar statistical characterizations of the channel.

VI. Other Allegations

• Indirect Infringement: The complaint focuses on direct infringement under 35 U.S.C. § 271(a) and does not plead a separate count for indirect infringement. Compl. ¶23
• Willful Infringement: The complaint alleges willfulness based on Defendant’s continued infringement after receiving notice of the ’376 Patent via the filing and service of the complaint. Compl. ¶¶ 34-36 It further seeks enhanced damages. Compl. ¶37

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

• A core issue will be one of definitional scope: can the term "dynamic adjusting function," which the patent’s specification describes as "preferentially... a neural network," be construed to cover the accused "software implementation of OLPC" in Defendant’s standard-compliant WCDMA equipment?
• A key evidentiary question will be one of technical equivalence: does the accused network’s alleged process of "averaging the SIRTarget values" meet the claim limitations requiring the calculation of "fading parameters" and estimation of "fading margins," or is there a fundamental mismatch between the accused functionality and the specific statistical calculations disclosed in the patent?