DCT
2:21-cv-00243
KMizra LLC v. Verizon Communications
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: K.Mizra LLC (Delaware)
- Defendant: Verizon Communications Inc., et al. (Delaware)
- Plaintiff’s Counsel: Folio Law Group PLLC
- Case Identification: 2:21-cv-00243, E.D. Tex., 06/30/2021
- Venue Allegations: Venue is based on allegations that Verizon has committed acts of infringement in the Eastern District of Texas and maintains multiple regular and established places of business in the district, including retail stores and technology-focused employment positions.
- Core Dispute: Plaintiff alleges that Defendant’s mobile location services infrastructure, which operates within its 4G and 5G networks, infringes a patent related to methods for improving mobile device location accuracy in heterogeneous networks.
- Technical Context: The technology addresses the challenge of accurately locating mobile devices in environments where GPS signals are weak or unavailable, such as indoors, by combining location data from both large-scale macro base stations and smaller, localized femto base stations.
- Key Procedural History: Post-filing, the asserted patent was subject to an inter partes review (IPR) proceeding (IPR2022-00730). An IPR certificate issued on April 9, 2024, confirmed the patentability of all challenged claims, including claim 30, which is the primary claim asserted in this complaint. This proceeding and its outcome may significantly narrow the scope of available invalidity defenses for the defendant.
Case Timeline
| Date | Event |
|---|---|
| 2012-12-11 | ’819 Patent Priority Date |
| 2015-02-17 | ’819 Patent Issue Date |
| 2021-06-30 | Complaint Filing Date |
| 2022-03-23 | IPR Proceeding (IPR2022-00730) Filed against the ’819 Patent |
| 2024-04-09 | IPR Certificate Issued, Confirming Patentability of Asserted Claims |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,958,819 - "Femto-Assisted Location Estimation in Macro-Femto Heterogeneous Networks"
- Patent Identification: U.S. Patent No. 8,958,819, "Femto-Assisted Location Estimation in Macro-Femto Heterogeneous Networks," issued February 17, 2015 (Compl. ¶¶21-22).
The Invention Explained
- Problem Addressed: The patent addresses the inability of conventional location systems like GPS to accurately determine a mobile device's position in "non-line-of-sight (NLOS) environments such as inside buildings" or areas with significant signal obstruction (Compl. ¶25; ’819 Patent, col. 1:31-36).
- The Patented Solution: The invention leverages a "heterogeneous network" composed of both traditional, wide-area macro base stations (mBS) and short-range femto base stations (fBS) to improve positioning accuracy (Compl. ¶26). By incorporating information from nearby femto base stations, which suffer from less signal attenuation, and applying statistical "particle filtering" techniques, the system claims to achieve a more precise location estimate than systems relying on GPS or macro base stations alone (Compl. ¶¶27-29; ’819 Patent, Abstract).
- Technical Importance: This method provides a technical solution for reliable indoor location-based services (LBS), which are critical for applications like Enhanced 911 (E911) emergency calls originating from within buildings (Compl. ¶25; ’819 Patent, col. 1:24-27, col. 1:55-57).
Key Claims at a Glance
- The complaint asserts "at least claim 30" of the ’819 Patent (Compl. ¶34).
- Independent Claim 30 is a method claim comprising the following essential elements:
- receiving femto base station timing information related to a user equipment;
- receiving macro base station timing information related to the user equipment;
- receiving particle information for a first set of particles corresponding to possible user equipment locations;
- receiving femto base station position information; and
- determining user equipment location information based on a first particle filtering for particle filtering the first set of particles based on the base station information.
- The complaint's use of "one or more claims, including at least claim 30" suggests the right to assert additional claims, including dependent claims, may be reserved (Compl. ¶34).
III. The Accused Instrumentality
Product Identification
The accused instrumentalities are Verizon's "mobile location services" and the underlying infrastructure within its CDMA, LTE, and 5G networks (Compl. ¶32). This specifically includes location server equipment such as Verizon's Enhanced Serving Mobile Location Center (“E-SMLC”), Serving Mobile Location Centers (“SMLC”), Secure User Plane Location Platform (“SLP”), and Location Management Function (“LMF”) (Compl. ¶33).
Functionality and Market Context
The complaint alleges that this infrastructure is used to determine a mobile user's location for services like E911, location-based mobile applications, and roadside assistance (Compl. ¶32). The system allegedly functions by having location servers communicate with both macro base stations and femto base stations (such as Verizon's "4G LTE Network Extenders") to obtain timing and position data (Compl. ¶¶38-39). A diagram in the complaint titled "How does Verizon 4G location work?" depicts a system where the Verizon network provides assistance data to a mobile device via a "SUPL Location Center" to improve the speed and accuracy of location fixes (Compl. p. 9).
IV. Analysis of Infringement Allegations
’819 Patent Infringement Allegations
| Claim Element (from Independent Claim 30) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| receiving femto base station timing information related to a user equipment | Verizon's location servers, such as E-SMLCs, allegedly communicate with femto base stations (e.g., "4G LTE Network Extenders") to obtain timing information related to a mobile device. | ¶38 | col. 2:15-18 |
| receiving macro base station timing information related to the user equipment | Verizon's E-SMLCs are alleged to communicate with reachable macro base stations to obtain timing information related to a mobile device. | ¶39 | col. 2:18-20 |
| receiving particle information for a first set of particles corresponding to possible user equipment locations | Verizon's location servers allegedly receive "possible locations" from a mobile device, which the plaintiff equates to "particle information." A visual in the complaint shows a "ProvideLocationInformation" message structure alleged to carry this data (Compl. p. 11). | ¶40 | col. 2:20-22 |
| receiving femto base station position information | Verizon's location servers allegedly receive position information of femto base stations, either from the stations themselves (which may use GPS) or from a network database. | ¶¶41-42 | col. 10:8-10 |
| determining user equipment location information based on a first particle filtering for particle filtering the first set of particles based on the base station information | The complaint alleges that as location servers continuously accumulate "estimated location samples or particles" which have a statistical distribution, these particles are "filtered for determining the location of the mobile device." | ¶43 | col. 2:22-29 |
Identified Points of Contention
- Technical Question: The complaint's allegation for the "particle filtering" limitation appears to be inferential. This raises the question: what evidence does the complaint provide that Verizon’s process of accumulating and refining location estimates constitutes the specific statistical method of "particle filtering" as required by the claim, as opposed to another form of statistical estimation?
- Scope Question: The infringement theory equates a standardized message containing "possible locations" with the claimed "particle information." This raises the question of whether the data in the accused "ProvideLocationInformation" message satisfies the claim requirement for "particle information," a term the patent specification links to a "recursive Bayesian estimation" process (Compl. ¶40; ’819 Patent, col. 9:18-21).
V. Key Claim Terms for Construction
The Term: "particle filtering"
- Context and Importance: This term describes the core computational method of claim 30. The viability of the infringement case largely depends on whether Verizon's accused location determination process falls within the construed scope of this term. Practitioners may focus on this term as its construction could be dispositive.
- Intrinsic Evidence for a Broader Interpretation: The patent summary refers to a "first particle filtering scheme" and "first particle filtering algorithm," which could suggest that the term is not limited to a single, specific implementation but encompasses a class of related methods (e.g., ’819 Patent, col. 2:9, 2:23).
- Intrinsic Evidence for a Narrower Interpretation: The detailed description repeatedly associates the "particle filter" with a "sequential Monte Carlo (MC) method" and a "recursive Bayesian estimation" framework (’819 Patent, col. 6:49-52, col. 9:18-21). Figure 5 illustrates a specific flow involving "Importance Sampling," "Weights calculation," and "Resampling," which are characteristic of a Sampling Importance Resampling (SIR) filter, potentially supporting a narrower definition.
The Term: "particle information"
- Context and Importance: This term defines a key data input for the claimed method. The dispute may turn on whether the location data Verizon's system allegedly receives is properly characterized as "particle information".
- Intrinsic Evidence for a Broader Interpretation: Claim 30 itself describes the information as "for a first set of particles corresponding to possible user equipment locations," which could be argued to cover any data set representing multiple potential locations (’819 Patent, col. 34:47-48).
- Intrinsic Evidence for a Narrower Interpretation: The specification describes particles as weighted samples used to "approximate a posterior PDF for UE position" within a specific estimation scheme (’819 Patent, col. 10:50-54). This could support an argument that "particle information" is not just any set of possible locations, but a structured data set with specific properties tied to the particle filtering process.
VI. Other Allegations
Willful Infringement
The complaint alleges that Verizon will be on notice of its infringement "at least as of the service of this complaint" (Compl. ¶46). It seeks a judgment that infringement is willful "dated from the filing of this Complaint," indicating a claim for post-filing willfulness based on the notice provided by the lawsuit itself (Compl. Prayer for Relief ¶D).
VII. Analyst’s Conclusion: Key Questions for the Case
- A key evidentiary question will be one of technical operation: does the complaint provide a sufficient factual basis to allege that Verizon's location services perform the specific statistical method of "particle filtering" as required by claim 30, or do they use a different, non-infringing estimation technique?
- A central issue will be one of definitional scope: can the term "particle information," which the patent links to a recursive Bayesian estimation framework, be construed to cover the standardized location data messages allegedly received by Verizon's servers?
- Given that asserted claim 30 has been confirmed as patentable in an inter partes review, a pivotal question for the litigation will be how the prosecution history and estoppel from that proceeding will influence the court's claim construction and limit the defendant's available validity defenses.