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UNITED STATES DISTRICT COURT

FOR THE EASTERN DISTRICT OF TEXAS

MARSHALL DIVISION

HEADWATER RESEARCH LLC,

Plaintiff,

 v.

VERIZON COMMUNICATIONS, INC.

ET AL.,

Defendants.

Civil Action No. 2:23-cv-00352-JRG-RSP

JURY TRIAL DEMANDED

PLAINTIFF HEADWATER RESEARCH LLC’S UNOPPOSED MOTION FOR LEAVE 

TO AMEND INFRINGEMENT CONTENTIONS

Plaintiff Headwater Research LLC (“Headwater”) respectfully seeks leave, pursuant to 

P.R. 3-6(b), to amend its infringement contentions for good cause. Defendants Cellco Partnership, 

d/b/a Verizon Wireless and Verizon Corporate Services Group Inc. (collectively, “Defendants” or 

“Verizon”) do not oppose this motion.

This is Headwater’s first request to amend its infringement contentions, and the proposed 

amendments do not change the scope of Headwater’s infringement allegations. Instead, the 

proposed amendments were prepared to address concerns raised by Verizon and were provided to 

Verizon on January 12, 2024, and the parties subsequently continued to confer about Headwater’s 

amendments and Verizon’s contemporaneous motion for leave to amend invalidity contentions 

(filed as Dkt. No. 59). The parties do not oppose one another’s amendments. 

Headwater’s proposed amendments include essentially two changes. First, Verizon

requested that Headwater provide, for two of the asserted patents, a separate infringement chart 

for each group of accused products. For example, Headwater previously provided one chart for 

U.S. Patent No. 8,589,541 that encompassed mobile devices sold by Verizon, including devices 

manufactured by Samsung, Apple, Google, Motorola, and Kyocera. In the proposed amended 

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contentions, Headwater provides a separate chart for each such group (e.g., one chart for Samsung 

devices sold by Verizon, one chart for Apple devices sold by Verizon, etc.). This amendment does 

not change the scope of Headwater’s infringement contentions; it merely provides consistent 

citations for each device manufacturer.

As to the second change, Verizon expressed to Headwater its belief that Headwater’s 

original infringement contentions did not clearly accuse Verizon’s server-side functionality. 

Headwater disagreed but, after the parties met and conferred, agreed to amend its contentions to 

provide further clarity for the avoidance of doubt. In conjunction with this change, Headwater also 

added exemplary citations to certain confidential documents produced by Verizon several months 

after Headwater’s original contentions deadline.

Good cause exists for the proposed amendments, which were prepared in response to 

requests from Verizon. Verizon does not oppose the amendments.

ARGUMENT

A party may amend or supplement infringement contentions “by order of the Court, which

shall be entered only upon a showing of good cause.” P.R. 3-6(b). “Good cause...requires a

showing of diligence.” O2 Micro Int’l Ltd. v. Monolithic Power Sys., Inc., 467 F.3d 1355, 1366

(Fed. Cir. 2006). Courts apply the following four-factor test to determine whether good cause has

been shown: (1) the explanation for the failure to meet the deadline; (2) potential prejudice in

allowing the thing that would be excluded; (3) the importance of the thing that would be excluded;

and (4) the availability of a continuance to cure such prejudice. Good cause exists here because all 

four factors weigh in favor of granting Headwater leave to amend.

A. Headwater acted diligently and in good faith

The proposed amendments originate from requests and feedback from Verizon. When 

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Verizon questioned whether Headwater was accusing Verizon’s server-side functionality of 

infringement and requested that Headwater separate certain of its infringement contentions into 

additional charts, Headwater met and conferred with Verizon on January 12, 2024 and provided 

the proposed amendments to Verizon that same day to address Verizon’s concerns. After that time, 

the parties continued to correspond for several weeks about Headwater’s amended contentions and 

also about proposed amended invalidity contentions prepared by Verizon. Ultimately, the parties 

confirmed that they would not oppose one another’s amendments, as noted in Verizon’s recently 

filed motion to amend invalidity contentions. See Dkt. No. 59 at 1. Thus, Headwater acted 

diligently and in good faith to address Verizon’s concerns in the proposed amendments.

B. Verizon prompted the amendments and will not be prejudiced by them

Verizon does not oppose this motion and will not be prejudiced by the proposed 

amendments. The first change made by the proposed amendments (i.e., separating Headwater’s 

existing contentions into separate charts for each device manufacturer), the change does not change 

the scope of Headwater’s infringement contentions. It merely provides consistent citations for each 

device manufacturer in manufacturer-specific charts, and thus cannot be prejudicial. Verizon has 

been aware of Headwater’s proposed amendments since January 12, 2024 when it was first 

provided copies of them. The parties continued to confer after that time about the proposed 

amendments of both Headwater and Verizon, but Verizon has long been aware of Headwater’s 

amendments. In addition, the claim construction process is not scheduled to begin for another four 

months, and fact discovery is not scheduled to close for nine months, leaving ample time for 

Verizon to consider Headwater’s amended contentions. Dkt. No. 40; see Ax Wireless, LLC v. HP, 

Inc., No. 2:22-cv-0279-JRG-RSP, Dkt. No. 99, at *4-5 (E.D. Tex. Dec. 11, 2023) (prejudice is 

minimal when amending contentions four months before the close of fact discovery). Thus, 

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Verizon will not be prejudiced by the proposed amendments.

C. The proposed amendments are important, in light of Verizon’s feedback

Because the proposed amendments were prompted by Verizon, they are important. The 

first change made by the proposed amendments (i.e., separating Headwater’s existing contentions 

into separate charts for each device manufacturer) does not change the scope of Headwater’s 

contentions but was made at Verizon’s request because, presumably, the change was important to 

Verizon. The second change is also important because, although Headwater maintains that its 

original contentions sufficiently disclosed that Verizon’s server-side functionality is accused of 

infringement, Verizon believed that this was not sufficiently clear. It is important that the parties 

avoid any disagreement about the fundamental scope of this case, so Headwater’s proposed 

amendment is important in that it clarifies for the avoidance of doubt that Verizon’s server-side 

functionality is accused.

D. No continuance is necessary

No continuance is needed. Because the proposed amendments do not change the scope of 

Headwater’s infringement theories and were prepared to address Verizon’s concerns, there is no 

prejudice and nothing to cure with a continuance. Where no continuance is sought, this factor 

weighs in favor of leave to amend. E.g., Arigna Tech. Ltd. v. Volkswagen AG, No. 2:21-CV-00054-

JRG-RSP, 2022 WL 2761288, at *3 (E.D. Tex. Jan. 19, 2022).

CONCLUSION

Accordingly, Plaintiff Headwater respectfully requests that the Court grant its Unopposed 

Motion for Leave to Amend Infringement Contentions.

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Dated: March 19, 2024 Respectfully submitted,

/s/ Marc Fenster

Marc Fenster

CA State Bar No. 181067

Email: mfenster@raklaw.com

Reza Mirzaie

CA State Bar No. 246953

Email: rmirzaie@raklaw.com

Brian Ledahl

CA State Bar No. 186579

Email: bledahl@raklaw.com

Ben Wang

CA State Bar No. 228712

Email: bwang@raklaw.com

Paul Kroeger

CA State Bar No. 229074

Email: pkroeger@raklaw.com

Neil A. Rubin

CA State Bar No. 250761

Email: nrubin@raklaw.com

Kristopher Davis

CA State Bar No. 329627

Email: kdavis@raklaw.com

James S. Tsuei

CA State Bar No. 285530

Email: jtsuei@raklaw.com

Philip Wang

CA State Bar No. 262239

Email: pwang@raklaw.com

Amy Hayden

CA State Bar No. 287026

Email: ahayden@raklaw.com

James Milkey

CA State Bar No. 281283

Email: jmilkey@raklaw.com

Jason M. Wietholter

CA State Bar No. 337139

Email: jwietholter@raklaw.com

RUSS AUGUST & KABAT

12424 Wilshire Blvd. 12th Floor

Los Angeles, CA 90025

Telephone: 310-826-7474

ATTORNEYS FOR PLAINTIFF,

Headwater Research LLC

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CERTIFICATE OF SERVICE

The undersigned certifies that on March 19, 2024, all counsel of record who are deemed to 

have consented to electronic service are being served with a copy of this document via electronic 

mail.

/s/ Marc Fenster

Marc Fenster

CERTIFICATE OF CONFERENCE

The undersigned certifies that on January 12, 2024 and February 22, 2024, counsel for all 

parties met and conferred in accordance with L.R. CV-7(h). This motion is unopposed.

/s/ Marc Fenster

Marc Fenster

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