UNITED STATES DISTRICT COURT

FOR THE EASTERN DISTRICT OF TEXAS

MARSHALL DIVISION

HEADWATER RESEARCH LLC, 

 Plaintiff and Counterclaim-Defendant,

v.

T-MOBILE US, INC., T-MOBILE USA, INC., 

and SPRINT CORP.,

 Defendants and Counterclaimant-Plaintiffs.

Case No. 2:23-CV-00377-JRG-RSP

(MEMBER CASE)

ANSWER TO COUNTERCLAIMS

JURY TRIAL DEMANDED

HEADWATER RESEARCH LLC, 

 Plaintiff and Counterclaim-Defendant,

v.

T-MOBILE US, INC., T-MOBILE USA, INC., 

and SPRINT CORP.,

 Defendants and Counterclaimant-Plaintiffs.

Case No. 2:23-CV-00379-JRG-RSP

(LEAD CASE)

JURY TRIAL DEMANDED

HEADWATER’S ANSWER TO T-MOBILE’S COUNTERCLAIMS

Plaintiff and Counterclaim-Defendant Headwater Research LLC (“Headwater”) hereby 

answers Defendants and Counterclaimant-Plaintiffs T-Mobile US, Inc., T-Mobile USA, Inc., and 

Sprint Corp.’s (collectively, “T-Mobile” or “Defendants and Counterclaim-Plaintiffs”)

counterclaims as follows:

THE PARTIES

1. Headwater does not have knowledge or information sufficient to form a belief as to 

the truth of the allegations contained in Paragraph 1 and on that basis: denied.

2. Admitted that Headwater Research LLC is a Texas limited liability company with 

its headquarters at 110 North College Avenue, Suite 1116, Tyler, Texas 75702.

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JURISDICTION AND VENUE

3. Admitted.

4. Admitted.

5. Admitted.

6. Headwater admits that it has sued T-Mobile for infringement of the ’541 Patent, 

and ’613 Patent and that there is a substantial, actual, and continuing controversy between 

Headwater and T-Mobile as to the infringement of the asserted patents. Headwater denies the 

remaining allegations of paragraph 6.

COUNT 1

(Declaratory Judgment of Non-Infringement of the ’541 Patent)

7. Headwater incorporates the preceding paragraphs by reference, as though fully set 

forth herein.

8. Denied.

9. Denied.

COUNT 2

(Declaratory Judgment of Invalidity of the ’541 Patent)

10. Headwater incorporates the preceding paragraphs by reference, as though fully set 

forth herein.

11. Denied.

12. Denied.

COUNT 3

(Declaratory Judgment of Non-Infringement of the ’613 Patent)

13. Headwater incorporates the preceding paragraphs by reference, as though fully set 

forth herein.

14. Denied.

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15. Denied.

COUNT 4

(Declaratory Judgment of Invalidity of the ’613 Patent)

16. Headwater incorporates the preceding paragraphs by reference, as though fully set 

forth herein.

17. Denied.

18. Denied.

PRAYER FOR RELIEF

In response to T-Mobile’s prayer for relief, Headwater denies that T-Mobile is entitled to 

any relief, including any of the relief requested in paragraphs A–E of T-Mobile’s prayer for relief. 

Further, Headwater requests the following relief:

WHEREFORE, Headwater respectfully requests that this Court enter:

a. A judgment in favor of Headwater that T-Mobile has infringed, either directly or 

indirectly, literally, under the doctrine of equivalents, or otherwise, the’541 Patent and the ’613 

Patent;

b. A permanent injunction prohibiting T-Mobile from further acts of infringement of 

the ’541 Patent and the ’613 Patent;

c. A judgment and order requiring T-Mobile to pay Headwater its damages, enhanced 

damages, costs, expenses, and pre-judgment and post-judgment interest for T-Mobile’s

infringement of the’541 Patent and the ’613 Patent;

d. A judgment and order requiring T-Mobile to provide accountings and to pay 

supplemental damages to Headwater, including without limitation, pre-judgment and postjudgment interest;

e. A judgment and order finding that this is an exceptional case within the meaning 

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of 35 U.S.C. § 285 and awarding to Headwater its reasonable attorneys’ fees against T-Mobile; 

and

f. Any and all other relief as the Court may deem appropriate and just under the 

circumstances.

JURY DEMAND

Headwater, under Rule 38 of the Federal Rules of Civil Procedure, requests a trial by jury 

of any issues so triable by right.

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Dated: August 30, 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

Adam Hoffman

CA State Bar No. 218740

Email: ahoffman@raklaw.com

Dale Chang

CA State Bar No. 248657

Email: dchang@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

Jason M. Wietholter

CA State Bar No. 337139

Email: jwietholter@raklaw.com

Qi (Peter) Tong

TX State Bar No. 24119042 

Email: ptong@raklaw.com

RUSS AUGUST & KABAT

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12424 Wilshire Blvd. 12th Floor

Los Angeles, CA 90025

Telephone: 310-826-7474

ATTORNEYS FOR PLAINTIFF AND 

COUNTERCLAIM-DEFENDANT,

Headwater Research LLC

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CERTIFICATE OF SERVICE

I hereby certify that all counsel of record who are deemed to have consented to electronic 

service are being served this 30th day of August 2024, with a copy of this document via the Court’s 

CM/ECF system per Local Rule CV-5(a)(3).

/s/ Marc Fenster

Marc Fenster

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