DCT
1:22-cv-01868
Prestwick Licensing LLC v. Viavi Solutions Inc
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Prestwick Licensing LLC (Texas)
- Defendant: VIAVI Solutions Inc. (Delaware)
- Plaintiff’s Counsel: Direction IP Law
- Case Identification: 1:22-cv-01868, D. Colo., 07/28/2022
- Venue Allegations: Venue is alleged to be proper based on Defendant's established place of business in Colorado Springs and the commission of alleged infringing acts within the district.
- Core Dispute: Plaintiff alleges that Defendant’s CellAdvisor Base Station Analyzer products infringe a patent related to methods and systems for efficiently testing wireless signal propagation models in cellular networks.
- Technical Context: The technology concerns the field of cellular network planning, specifically methods to improve the efficiency of collecting field strength data used to correct and refine signal propagation models.
- Key Procedural History: The complaint does not mention any prior litigation, Inter Partes Review (IPR) proceedings, or other significant procedural events related to the patent-in-suit.
Case Timeline
| Date | Event |
|---|---|
| 2008-03-11 | U.S. Patent No. 9,179,339 Priority Date |
| 2015-11-03 | U.S. Patent No. 9,179,339 Issue Date |
| 2022-07-28 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,179,339 - Method and System for Testing the Wireless Signal Propagation Model of the Cellular Network, issued November 3, 2015
The Invention Explained
- Problem Addressed: The patent describes the process of correcting cellular network signal propagation models as labor-intensive (’339 Patent, col. 2:8-11). The prior art required installing transmission equipment sequentially at numerous testing sites and then measuring the signal strength for each site, a process that resulted in a "heavy workload" due to its repetitive nature (’339 Patent, col. 2:50-56).
- The Patented Solution: The invention proposes a system to make this process more efficient. Instead of moving the transmitter, the invention installs stationary receiving equipment at multiple selected test sites. A mobile transmission apparatus then travels along a testing route, broadcasting a signal. This allows the stationary receivers to collect signal strength data from multiple points simultaneously based on a shared synchronization, completing the test in a single pass (’339 Patent, Abstract; col. 3:1-10). Figure 4 of the patent illustrates this workflow (’339 Patent, Fig. 4).
- Technical Importance: This method aims to significantly reduce the time and effort required to gather the comprehensive field data needed for accurate propagation model correction, a critical step for optimizing cellular network design and performance (’339 Patent, col. 4:20-31).
Key Claims at a Glance
- The complaint asserts independent claim 4 (Compl. ¶16).
- The essential elements of independent claim 4 are:
- A system for testing wireless signal field strength.
- A transmitting apparatus configured to transmit a testing signal while moving along a testing route.
- A receiving testing apparatus, installed at more than one selected testing site, configured to receive the signal and detect its strength.
- Obtaining field strength data along the route based on synchronization between the transmitter and receiver.
- The receiving apparatus is mounted at a selected height and oriented in a specific direction at each site.
- A model analyzing apparatus configured to analyze the data to obtain a wireless propagation model for the area, which includes a merging module and a correcting module.
- The complaint does not explicitly reserve the right to assert dependent claims.
III. The Accused Instrumentality
Product Identification
- The complaint identifies the CellAdvisor JD745B Base Station Analyzer and related products in the JD700B series as the "Accused System" (Compl. ¶¶ 16, 18).
Functionality and Market Context
- The Accused System is described as a test tool for installing and maintaining cell sites for 2G to 4G wireless technologies (Compl. ¶17). Its functions relevant to the allegations include Over-the-Air (OTA) analysis, creating signal strength and coverage maps, and interference analysis (Compl. ¶¶ 7, 9, 27). The complaint alleges the system uses GPS to track its location while collecting data along a "Route Map" (Compl. ¶¶ 11, 20). The "JDMapCreator" feature is alleged to create maps from collected data (Compl. ¶22). A screenshot from the product's user guide illustrates how a directional antenna can be connected to the analyzer's "Spectrum Analyzer RF In port" (Compl. ¶24).
IV. Analysis of Infringement Allegations
’339 Patent Infringement Allegations
| Claim Element (from Independent Claim 4) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a transmitting apparatus, configured to transmit a testing signal upon moving along a testing route | The complaint alleges the Accused System includes a transmitting apparatus (e.g., a base station transmitter) configured to transmit a signal while moving along a testing route. | ¶18 | col. 7:15-18 |
| a receiving testing apparatus, installed at more than one selected testing sites, configured to receive the testing signal and to detect the strength of the received signal | The complaint alleges the Accused System includes a receiving apparatus (e.g., a receiver with an RF IN port) installed at multiple testing sites to receive a testing signal and detect its strength (e.g., RSSI). A product diagram shows the "RF IN for spectrum and signal analysis" port. | ¶19, 13 | col. 7:19-23 |
| and to obtain field strength testing data along the testing route according to a synchronization established between the transmission apparatus and the receiving testing apparatus | The Accused System is alleged to obtain field strength data along a route according to synchronization established between the transmitter and receiver, using GPS for location and timing. A screenshot shows a "Route Map" that plots the OTA metric on a map, tracked with the instrument's GPS. | ¶20, 16 | col. 7:24-30 |
| wherein the more than one selected testing sites to install the receiving testing apparatus comprise at least one height selected in each of the testing sites to mount at least one said receiving testing apparatus, the at least one receiving testing apparatus being respectively oriented in at least one direction | The complaint alleges the receiving apparatus is installed at a selected height and oriented in at least one direction, referencing the use of a directional antenna. A diagram from the user manual shows connecting an "Omni or Yagi antenna" to the device. | ¶20, 24 | col. 7:31-37 |
| a model analyzing apparatus, configured to analyze the field strength testing data to obtain a wireless propagation model about an area of the testing route... comprising: a merging module... and a correcting module | The Accused System is alleged to comprise a "model analyzing apparatus" with "Route map" and "JDMapCreator" features to analyze data, merge it with location data, and perform a "wireless propagation model correction." A screenshot of "JDMapCreator" is provided as evidence of creating geo-coded maps. | ¶21-23, 22, 30 | col. 7:38-48 |
- Identified Points of Contention:
- System Configuration Questions: Claim 4 recites a system with a mobile transmitter and stationary receivers. The complaint's allegations and supporting visuals, such as the "Route Map" screenshot (Compl. ¶16), appear to describe an inverted scenario: a single mobile receiver (the analyzer) moving through an area to measure signals from stationary transmitters (e.g., cell towers). A court may need to resolve whether the claim language can be construed to cover this inverted configuration.
- Scope Questions: A central question may be whether the Defendant "makes, uses, sells, or offers to sell" the complete claimed system. The "Accused System" is a portable analyzer, but the claim requires a mobile transmitter, multiple receivers, and a model analyzer. The complaint frames the single product as comprising all these elements (Compl. ¶¶ 18, 19, 21), which may create a technical mismatch between the product and the claim's architecture. The infringement analysis may turn on whether one product can embody all parts of the claimed system or if infringement requires the combination of multiple devices.
- Technical Questions: The claim requires a "model analyzing apparatus" that performs a "wireless propagation model correction" using a "correcting module" (’339 Patent, cl. 4). A key question is whether the accused "Route Map" or "JDMapCreator" functions perform this specific corrective analysis, or if they primarily plot raw signal strength data on a map without performing the claimed model correction. The evidence provided in the complaint focuses on data mapping and user-defined settings rather than an automated model correction function (Compl. ¶¶ 22, 23).
V. Key Claim Terms for Construction
The Term: "a transmitting apparatus, configured to transmit a testing signal upon moving along a testing route"
- Context and Importance: The patent's stated purpose is to overcome the inefficiency of installing transmitters at multiple fixed locations. The infringement theory appears to rely on a scenario where the receiver moves, not the transmitter. The construction of this phrase is therefore critical to determining if there is a fundamental mismatch between the claim and the accused functionality.
- Intrinsic Evidence for a Broader Interpretation: A party might argue that the claim does not explicitly state the receiver must be stationary, only that the transmitter must be mobile, leaving open other configurations.
- Intrinsic Evidence for a Narrower Interpretation: The patent’s background section explicitly identifies the problem as the "heavy workload caused by repeated installing the transmission apparatus" (’339 Patent, col. 2:60-65). The described solution is to make the transmitter mobile and the receivers stationary (’339 Patent, col. 3:1-10; Abstract). This context strongly suggests the claimed "moving" transmitter and installed "receiving" apparatuses are distinct components with defined roles, potentially limiting the claim to that architecture.
The Term: "a model analyzing apparatus, configured to analyze the field strength testing data to obtain a wireless propagation model"
- Context and Importance: This term's construction will determine whether the accused software features, like "Route Map" and "JDMapCreator," meet the functional requirements of the claim. The dispute may focus on whether plotting data on a map is equivalent to "obtain[ing] a wireless propagation model" through correction, as required by the claim.
- Intrinsic Evidence for a Broader Interpretation: The plain language could be argued to encompass any analysis that results in a "model," such as a visual coverage map derived from the collected data.
- Intrinsic Evidence for a Narrower Interpretation: Claim 4 further defines this apparatus as comprising "a correcting module, configured to perform a wireless propagation model correction" (’339 Patent, cl. 4). The specification details this correction process, which involves modifying model parameters to better match real-world data (’339 Patent, col. 2:38-49). This suggests the apparatus must do more than display data; it must perform an active correction of a propagation model.
VI. Other Allegations
- Indirect Infringement: The complaint does not include separate counts for indirect or contributory infringement. The allegations are framed as the "Accused System" directly infringing the claims of the ’339 Patent (Compl. ¶16).
- Willful Infringement: The complaint does not contain an explicit allegation of willful infringement, nor does the prayer for relief request enhanced damages (Compl. ¶¶ 38a-d).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of architectural configuration: can the system claim, which recites a mobile transmitter and multiple stationary receivers to solve a specific prior art problem, be construed to read on the accused product's apparent use as a mobile receiver for testing signals from stationary transmitters? The resolution will depend on both claim construction and factual evidence of how the accused system operates.
- A second key question will be one of functional scope: does the accused product's software, which creates "Route Maps" and allows for "JDMapCreator," perform the specific function of the claimed "model analyzing apparatus"—namely, using a "correcting module" to "perform a wireless propagation model correction"—or does it perform a more basic function of plotting geolocated signal strength data?
- Finally, the case may turn on a question of direct infringement for a system claim: can the Plaintiff prove that the Defendant's single, portable analyzer constitutes the entire multi-part "system" as claimed, or does the infringement allegation improperly attempt to hold the Defendant directly liable for a system that is only fully constituted when a user combines the accused product with other, non-accused components (such as a separate transmitter and additional receivers)?