DCT

2:22-cv-00477

Cobblestone Wireless LLC v. T-Mobile USA Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:22-cv-00477, E.D. Tex., 12/16/2022
  • Venue Allegations: Plaintiff alleges venue is proper because T-Mobile has regular and established places of business in the Eastern District of Texas, including retail locations and cellular base stations, and has committed acts of infringement within the district.
  • Core Dispute: Plaintiff alleges that Defendant’s 4G/5G cellular network infrastructure and compatible mobile devices infringe four patents related to advanced wireless communication technologies, including signal focusing, network handoffs, and dynamic resource allocation.
  • Technical Context: The technologies at issue concern methods for managing radio resources and network operations in modern, high-traffic wireless communication networks to improve signal quality, efficiency, and reliability.
  • Key Procedural History: The complaint does not allege any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the patents-in-suit.

Case Timeline

Date Event
2011-04-29 Earliest Priority Date for ’888 Patent
2011-07-28 Earliest Priority Date for ’347 Patent
2011-08-24 Earliest Priority Date for ’196 Patent
2013-10-08 ’196 Patent Issued
2014-08-01 Earliest Priority Date for ’361 Patent
2014-11-18 ’347 Patent Issued
2015-07-28 ’888 Patent Issued
2019-07-30 ’361 Patent Issued
2022-12-16 Complaint Filed

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

U.S. Patent No. 8,891,347 - "User-Focusing Technique for Wireless Communication Systems", issued November 18, 2014

The Invention Explained

  • Problem Addressed: The patent describes the challenge of signal distortion and interference in wireless systems caused by signals traveling along multiple paths (multipath propagation) between a transmitter and a receiver, which can degrade system performance (Compl. Ex. 1; ’347 Patent, col. 1:7-41).
  • The Patented Solution: The invention proposes a "user-focusing" method where the equalization burden is shifted from the receiver to the transmitter. The transmitter receives detailed channel parameter information from the receiver, and then "pre-distorts" the subsequent signal it sends. This pre-distortion is calculated to counteract the effects of the propagation paths, causing the multiple signal waves to arrive at the receiver's location in-phase and combine constructively, thereby "focusing" the signal energy on the user ('347 Patent, Abstract; col. 3:48-54).
  • Technical Importance: This technique sought to improve signal quality and reduce interference without requiring more complex or power-hungry receiver-side hardware, which could enhance network capacity and device battery life ('347 Patent, col. 3:55-66).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶18).
  • The essential elements of independent claim 1 are:
    • A method for wireless communication in a system with a transmitter, a receiver, and multiple propagation paths.
    • Transmitting a first signal from the transmitter to the receiver via a first propagation path.
    • Receiving the first signal at the receiver.
    • Performing a channel estimation based on the first signal to obtain path parameter information.
    • Sending the channel estimation from the receiver to the transmitter.
    • Predistorting a second signal at the transmitter in time, frequency, and spatial domains according to the channel estimation.
    • Transmitting the predistorted second signal from the transmitter to the receiver.
    • Receiving the predistorted second signal at the receiver.
  • The complaint alleges infringement of "at least Claim 1," reserving the right to assert other claims (Compl. ¶18).

U.S. Patent No. 9,094,888 - "Wireless Device Handoff Between Wireless Networks", issued July 28, 2015

The Invention Explained

  • Problem Addressed: In "heterogeneous" wireless environments with overlapping networks using dynamic beamforming, a device's ability to connect to a given network can change moment-to-moment as coverage areas shift, making reliable handoffs between networks challenging (Compl. Ex. 2; ’888 Patent, col. 1:15-32).
  • The Patented Solution: The patent describes a coordinated handoff system. A first network receives "coverage information" (which may include historical data) indicating a device is potentially capable of being covered by a second network. The first network then transmits a handoff request to the second network, which can then adapt its antenna beams to facilitate coverage for the device and complete the handoff ('888 Patent, Abstract; col. 2:9-26).
  • Technical Importance: The invention provides a method for proactive and coordinated handoffs in dynamic, multi-network environments, aiming to improve connection reliability for users moving between different coverage areas ('888 Patent, col. 4:32-41).

Key Claims at a Glance

  • The complaint asserts independent claim 9 (Compl. ¶26).
  • The essential elements of independent claim 9 are:
    • A method at a first wireless network for a mobile device handoff.
    • Receiving a handoff request from a second wireless network, based on a determination that the device is not currently covered but is capable of being covered by the first network.
    • Based on the request, adapting one or more beams of an antenna array to facilitate coverage of the device by the first network.
    • Transmitting a confirmation to the second network to indicate acceptance of the request.
    • The wireless device is then handed off from the second network to the first network.
  • The complaint alleges infringement of "at least Claim 9," reserving the right to assert other claims (Compl. ¶26).

U.S. Patent No. 10,368,361 - "Adaptive Communication Resource Allocation in a Wireless Network", issued July 30, 2019

  • Technology Synopsis: The patent addresses the problem of inefficiently allocated radio spectrum when traffic is asymmetric (e.g., heavy download, light upload). It proposes assigning frequency resources to dedicated uplink, dedicated downlink, or "shared" resource pools based on their quality characteristics. Resources in the shared pool can then be dynamically scheduled for either uplink or downlink to flexibly match real-time traffic demands ('361 Patent, Abstract; col. 2:37-58).
  • Asserted Claims: Independent claim 10 (Compl. ¶34).
  • Accused Features: The complaint accuses cellular base stations that support 3GPP Next-Generation Radio Access Network (NG-RAN) with directional Supplementary Uplink (SUL) functionality (Compl. ¶34).

U.S. Patent No. 8,554,196 - "Network Coverage By Cycling Through Beam Shape Coverage Configurations", issued October 8, 2013

  • Technology Synopsis: The patent addresses the need to efficiently serve a mix of devices, some requiring "continuous use" (e.g., a voice call) and others "interval use" (e.g., background updates). It proposes cycling between a wide, lower-power beam to provide coverage for all devices and a narrow, high-power beam focused on the continuous-use devices to ensure their service quality, thereby conserving power while maintaining connectivity ('196 Patent, Abstract; col. 2:26-34).
  • Asserted Claims: Independent claim 23 (Compl. ¶42).
  • Accused Features: The complaint accuses cellular handsets, including various Apple and Samsung models, that support "wifi-only automatic updates" (Compl. ¶42).

III. The Accused Instrumentality

Product Identification

The complaint identifies two broad categories of Accused Instrumentalities: (1) T-Mobile's cellular network infrastructure, including base stations that support 3GPP 5G NR beamforming, handover between 4G LTE and 5G NR networks, and NG-RAN Supplementary Uplink (SUL) functionality; and (2) cellular handsets sold by T-Mobile that support 5G NR beamforming and specific update functionalities, with numerous Apple iPhone and Samsung Galaxy models explicitly named (Compl. ¶¶18, 26, 34, 42).

Functionality and Market Context

The accused network functionality relates to advanced features of modern 4G and 5G cellular systems designed to manage radio signals and network transitions efficiently (Compl. ¶¶18, 26, 34). The complaint alleges T-Mobile operates these networks, offers 4G and 5G services extensively within the district, and derives substantial revenue from these services and the sale of the accused handsets (Compl. ¶¶9, 13-15). The accused handsets are commercially significant, high-volume products from major manufacturers (Compl. ¶¶18, 42).

IV. Analysis of Infringement Allegations

The complaint references claim chart exhibits that are not provided; therefore, the infringement theory is summarized below in prose. No probative visual evidence provided in complaint.

’347 Patent Infringement Allegations

The complaint alleges that T-Mobile's network infrastructure and compatible handsets infringe at least claim 1 (Compl. ¶18). The infringement theory appears to be that the use of "3GPP 5G NR beamforming" by the accused products inherently practices the claimed method of receiving channel information and "predistorting" a subsequent signal to focus it on the user (Compl. ¶18).

  • Identified Points of Contention:
    • Scope Question: A primary point of contention may be whether standard 5G NR beamforming, which directs signal energy, performs the specific act of "predistorting a... signal... in a time domain, a frequency domain, and a spatial domain" as required by the claim. The defense could argue that beamforming is primarily spatial direction, not the multi-domain pre-distortion taught in the patent to counteract multipath effects.
    • Technical Question: The complaint asserts infringement at a high level. A key technical question will be what evidence shows that the accused base stations receive specific "path parameter information" from a handset and then computationally pre-distort the next transmitted signal based on that feedback, as opposed to using more generalized beam-steering techniques.

’888 Patent Infringement Allegations

The complaint alleges that T-Mobile's cellular base stations infringe at least claim 9 by supporting handovers between 4G LTE and 5G NR networks (Compl. ¶26). The narrative theory is that the management of device transitions between these heterogeneous networks constitutes the claimed method of receiving a handoff request and adapting antenna beams to facilitate coverage (Compl. ¶26).

  • Identified Points of Contention:
    • Scope Question: Does the term "coverage information," which the patent describes in the context of creating a "coverage map" from past data ('888 Patent, col. 5:58-6:10), read on the real-time signal strength measurements typically used in standard 4G/5G handover decisions? A central dispute may be whether the claimed method requires reliance on historical data, which may differ from standard handover procedures.
    • Technical Question: The patent discloses distinct functional blocks like a "coverage manager" and an "adaption manager." Plaintiff will need to map these claimed functional blocks to specific components and processes within T-Mobile's actual network architecture.

V. Key Claim Terms for Construction

’347 Patent, Claim 1: "predistorting a second signal at the transmitter according to the channel estimation"

  • Context and Importance: This term is the central inventive concept. The outcome of the infringement analysis for the ’347 patent hinges on whether the functionality of the accused 5G NR beamforming systems falls within the scope of this term.
  • Intrinsic Evidence for a Broader Interpretation: The specification states that the transmitted signal is modulated so that waves arriving from different paths "have the same phase, and may be superimposed coherently" ('347 Patent, col. 3:51-54). A party could argue that any transmitter-side operation that uses channel feedback to achieve coherent addition at the receiver constitutes "predistorting."
  • Intrinsic Evidence for a Narrower Interpretation: The detailed description provides a specific mathematical formula for creating the pre-distorted signal, involving complex conjugates of antenna array responses and Kronecker products ('347 Patent, col. 9:20-45). A party could argue the term is limited to this specific implementation or its structural equivalent, rather than any general beam-steering technique.

’888 Patent, Claim 9: a determination that the wireless device is "not currently covered by the first wireless network but is capable of being covered"

  • Context and Importance: This term defines the trigger for the claimed handoff process. Its construction is critical because standard handovers are typically triggered by weakening signals from a current cell and strengthening signals from a target cell, which may not align with the patent's "not covered, but capable" paradigm.
  • Intrinsic Evidence for a Broader Interpretation: The specification discusses using a "coverage map" that indicates "possible coverage areas" (Compl. Ex. 2; ’888 Patent, col. 6:1-5). A party might argue this broadly covers any predictive information the network uses to assess potential connectivity, including extrapolations from recent signal measurements.
  • Intrinsic Evidence for a Narrower Interpretation: The specification contrasts "past coverage area" with "current coverage area," suggesting a system that relies on historical data to know a device is "capable of being covered" even if it is not "currently covered" (Compl. Ex. 2; ’888 Patent, col. 5:32-41). A party could argue the term requires a system that explicitly stores and consults historical coverage data, distinguishing it from systems that rely solely on real-time signal detection.

VI. Other Allegations

  • Indirect Infringement: For all four patents, the complaint alleges induced infringement. The stated basis is that T-Mobile provides "user manuals and online instruction materials on their website" that instruct customers on how to use the Accused Instrumentalities in ways that allegedly infringe (e.g., Compl. ¶19, ¶27).
  • Willful Infringement: The complaint does not allege pre-suit knowledge of the patents. However, it alleges that T-Mobile has knowledge of the patents and infringement "Through at least the filing and service of this Complaint" and continues to infringe, which establishes a basis for post-filing willfulness (e.g., Compl. ¶19, ¶27).

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

  • Standards vs. Patented Methods: A core issue across the case will be one of technical mapping: do the accused functionalities, which are based on public 4G/5G standards, operate in the specific manner required by the patent claims? For example, does standard 5G beamforming perform the multi-domain "predistorting" claimed in the ’347 patent, or is there a fundamental mismatch in the underlying technical operations?
  • The Scope of "Information": The dispute over the ’888 patent will likely focus on definitional scope: can the patent's concept of "coverage information," which is described in the context of historical coverage maps, be construed to encompass the real-time signal strength measurements that typically govern standard network handovers? The resolution of this question will be critical to the infringement analysis.
  • The Evidentiary Challenge: Plaintiff faces the significant evidentiary task of demonstrating how T-Mobile's complex and proprietary network infrastructure—from base station software to handset chipsets—implements the specific steps of the asserted claims. The case will likely depend on whether discovery produces concrete evidence to support the complaint's high-level allegations of infringement.