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IN THE UNITED STATES DISTRICT COURT 

FOR THE WESTERN DISTRICT OF TEXAS

WACO DIVISION

WSOU INVESTMENTS, LLC d/b/a 

BRAZOS LICENSING AND 

DEVELOPMENT,

Plaintiff,

v.

ZTE CORPORATION, ZTE (USA) 

INC., AND ZTE (TX), INC. 

Defendants.

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CIVIL ACTION NO. 6:20-cv-242

JURY TRIAL DEMANDED

ORIGINAL COMPLAINT FOR PATENT 

INFRINGEMENT

Plaintiff WSOU Investments, LLC d/b/a Brazos Licensing and Development (“Brazos” 

or “Plaintiff”), by and through its attorneys, files this Complaint for Patent Infringement against 

Defendants ZTE Corporation, ZTE (USA), Inc. and ZTE (TX), Inc. (collectively “ZTE” or 

“Defendants”) and alleges:

NATURE OF THE ACTION

1. This is a civil action for patent infringement arising under the Patent Laws of the 

United States, 35 U.S.C. §§ 1, et seq., including §§ 271, 281, 284, and 285.

THE PARTIES

2. Brazos is a limited liability corporation organized and existing under the laws of 

Delaware, with its principal place of business at 605 Austin Ave, Ste 6, Waco, TX 76701.

3. On information and belief, Defendant Zhongxing Telecommunications 

Equipment (abbreviated as “ZTE”) Corporation is a Chinese corporation that does business in 

Texas, directly or through intermediaries, with a principal place of business at ZTE Plaza, Keji 

Road South, Hi-Tech Industrial Park, Nanshan District, Shenzhen China.

Case 6:20-cv-00242-ADA Document 1 Filed 03/27/20 Page 1 of 16
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4. On information and belief, Defendant ZTE (USA) Inc. is a New Jersey 

corporation that does business in Texas, directly or through intermediaries, with a principal place 

of business in business in Richardson, Texas.

5. On information and belief, Defendant ZTE (TX) Inc. is a Texas corporation that 

does business in Texas, directly or through intermediaries, with a principal place of business in 

business in Austin, Texas.

6. All of the Defendants operate under and identify with the trade name “ZTE.” 

Each of the Defendants may be referred to individually as a “ZTE Defendant” and, collectively, 

Defendants may be referred to below as “ZTE” or as the “ZTE Defendants.”

JURISDICTION AND VENUE

7. This is an action for patent infringement which arises under the Patent Laws of 

the United States, in particular, 35 U.S.C. §§271, 281, 284, and 285.

8. This Court has jurisdiction over the subject matter of this action under 28 U.S.C.

§§ 1331 and 1338(a).

9. This Court has specific and general personal jurisdiction over each ZTE

Defendant pursuant to due process and/or the Texas Long Arm Statute, because each ZTE

Defendant has committed acts giving rise to this action within Texas and within this judicial 

district. The Court’s exercise of jurisdiction over each ZTE Defendant would not offend 

traditional notions of fair play and substantial justice because ZTE has established minimum 

contacts with the forum. For example, on information and belief, ZTE Defendants have 

committed acts of infringement in this judicial district, by among other things, selling and 

offering for sale products that infringe the asserted patent, directly or through intermediaries, as 

alleged herein.

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10. Venue in the Western District of Texas is proper pursuant to 28 U.S.C. §§1391

and/or 1400(b). The ZTE Defendants have committed acts of infringement and have places of 

businesses in this District and/or are foreign entities for purpose of §1391. As non-limiting 

examples, ZTE (TX) has maintained a place of business at 7000 N MO-PAC EXPRESSWAY 

200 AUSTIN, TX 7873; and, ZTE (USA) has maintained a place of business at 6500 River Place 

Blvd., Austin, TX 78730. ZTE Corporation also describes a “research-and-development center 

in Austin, Texas.”1

COUNT ONE - INFRINGEMENT OF 

U.S. PATENT NO. 9,258,232

11. Brazos re-alleges and incorporates by reference the preceding paragraphs of this 

Complaint.

12. On February 9, 2016, the United States Patent and Trademark Office duly and 

legally issued U.S. Patent No. 9,258,232 (“the ’232 Patent”), entitled “INGRESS TRAFFIC 

FLOW CONTROL IN A DATA COMMUNICATIONS SYSTEM.” A true and correct copy of 

the ’232 Patent is attached as Exhibit A to this Complaint.

13. Brazos is the owner of all rights, title, and interest in and to the ’232 Patent, 

including the right to assert all causes of action arising under the ’232 Patent and the right to any 

remedies for the infringement of the ’232 Patent.

14. ZTE makes, uses, sells, offers for sale, imports, and/or distributes, in the United 

States, networking products including routing switches supporting the Quantized Congestion 

Notification (QCN) protocol (collectively, the “Accused Products”). 

1

https://res-www.zte.com.cn/mediares/magazine/publication/tech_en/pdf/201009.pdf

Case 6:20-cv-00242-ADA Document 1 Filed 03/27/20 Page 3 of 16
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15. The Accused Products include the ZXR10 5900 series routing switches, including 

the ZXR10 5960-32DL, 5960-64DL, and 5960-52TM, and the ZXR10 5960-H series routing 

switches, including the ZXR10 5960-4M-HC, 5960-32LC-H, 5960-64DL-H, 5960-72DL-H, 

5960-72NL-H, and 5960-56QU-HC routing switches. 

...

...

Case 6:20-cv-00242-ADA Document 1 Filed 03/27/20 Page 4 of 16
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https://www.zte.com.cn/global/products/bearer/data_communication/ethernet_switch/5960-

EN; 

Case 6:20-cv-00242-ADA Document 1 Filed 03/27/20 Page 5 of 16
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https://www.zte.com.cn/global/products/bearer/data_communication/ethernet_switch/5960-HEN.

https://www.asit.it/wp-content/uploads/2018/04/zte_ZXR10_5960_serie.pdf (Page 4).

https://www.zte.com.cn/global/products/bearer/data_communication/ethernet_switch/5960-

EN. 

16. ZXR10 5960 series and ZXR10 5960-H series switches implement the IEEE 

802.1Q (Media Access Control (MAC) Bridges and Virtual Bridged Local Area Networks) 

standard (also referred to as IEEE 802.1q) for detection and control of a congestion condition in 

the network. IEEE 802.1Q includes the Quantized Congestion Notification protocol.

https://www.asit.it/wp-content/uploads/2018/04/zte_ZXR10_5960_serie.pdf, (Page 8).

Case 6:20-cv-00242-ADA Document 1 Filed 03/27/20 Page 6 of 16
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...

https://sdnfv.zte.com.cn/upload_files/440ed336-3d3f-11e9-abd7-744aa4020e29.pdf (Page 11).

...

https://ieeexplore.ieee.org/document/6009146 (Page 1100).

17. The Accused Products supports the Quantized Congestion Notification (QCN) 

protocol for traffic flow control. The QCN protocol include a QCN Algorithm that has (1) a 

Congestion Point Algorithm and (2) a Reaction Point Algorithm. The Congestion Point 

Algorithm can generate a feedback message (Congestion Notification Message(CNM)) to 

indicate a period of congestion. The feedback message contains information about the extent of 

congestion at the congestion point. The Reaction Point Algorithm in the Accused Products 

changes its Flow Rate to control the flow of data packets using the feedback message received 

Case 6:20-cv-00242-ADA Document 1 Filed 03/27/20 Page 7 of 16
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from the Congestion Point.

https://ieeexplore.ieee.org/document/6009146 (Page 1101).

18. The Congestion Point Algorithm maintains the check on the incoming and 

outgoing packets with the help of buffer queue size calculation. The Congestion point feedback 

message contains a Congestion measure (Fb), which determines the amount of buffer queue 

filled or not. For example, if the Fb is less than 0, the congestion message is sent to the source, 

Case 6:20-cv-00242-ADA Document 1 Filed 03/27/20 Page 8 of 16
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and if the Fb is greater than or equal to 0, the congestion message is not sent.

https://ieeexplore.ieee.org/document/6009146 (Page 1101).

19. The Congestion Point Algorithm configures various congestion point variables. 

One such variable is cpW (Congestion Point Weight), a real number which is equivalent to the 

weight factor that applies to the change in queue length. cpW is used in the calculation of 

Congestion Point Quantized Feedback (cpFb). 

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https://ieeexplore.ieee.org/document/6009146 (Page 856).

https://ieeexplore.ieee.org/document/6009146 (Page 1127).

20. The Congestion Point Quantized Feedback (cpFb) is calculated with the use of 

cpW. With an increase in cpW, cpFb decreases, and vice versa. 

https://ieeexplore.ieee.org/document/6009146 (Page 1101).

21. The Congestion Notification Message - Protocol Data Unit (CNM PDU) contains 

a Quantized Feedback Field. The Quantized Feedback field calculations include the values of 

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the congestion point weight parameter (cpW) and the Congestion Point Quantized Feedback 

(cpFb) parameter. 

https://ieeexplore.ieee.org/document/6009146 (Page 1130).

22. Similar to the Congestion Point variables, the QCN Protocol in the Accused 

Products also has Reaction Point variables such as rpFb (Reaction Point Quantized Feedback). 

rpFb is the value last received in the Quantized Feedback Field of a CNM PDU or 0. 

https://ieeexplore.ieee.org/document/6009146 (Page 1134).

23. The ReceiveCnm function in the Accused Products performs various actions. One 

of the actions is that it sets the rpFb variable from the CNM’s Quantized Feedback Field.

https://ieeexplore.ieee.org/document/6009146 (Page 1135).

24. As the Quantized Feedback field calculations include the values of the 

Congestion Point weight parameter (cpW) and the Congestion Point Quantized Feedback (cpFb) 

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parameter, the Reaction Point variable rpFb incorporates the Congestion Point Weight (cpW) as 

per the feedback (CNM) received from the Congestion Point. rpFb is further used in adjusting 

the flow by Rate Limiter. 

https://ieeexplore.ieee.org/document/6009146 (Page 1101).

25. The ProcessCnm function in the Accused Products performs actions that are 

dependent on reaction point variables such as dec_factor. The dec_factor is further dependent on 

the rpFb parameter. Also, the reaction point Current Rate (rpCurrentRate) is a function of 

dec_factor (decrement).

https://ieeexplore.ieee.org/document/6009146 (Page 1136).

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26. A function in the Reaction Point algorithm, AdjustsRates function, is used to 

adjust the rate limit of packet flow with the help of rpCurrentRate and rpTargetRate wherein 

rpCurrentRate is dependent on rpFb. These rate parameters are associated with the Rate Limiter 

(RL). The Current Rate is the transmission rate of the Rate Limiter (RL) at any time, and the 

Target Rate is the sending rate of the RL just before the arrival of the last feedback message and 

the new goal for the current rate. 

https://ieeexplore.ieee.org/document/6009146 (Page 1102).

27. An AdjustsRates function in the Accused Products is used to adjust the rate of the 

packet flow with the help of rpCurrentRate and rpTarget Rate, which are rate parameters 

associated with the Rate Limiter. The rpCurrentRate is dependent on the rpFb variable, which is 

calculated with the help of cpW (Congestion Point Weight), as explained above. Hence, 

AdjustRates is a function of cpW (Congestion Point Weight).

https://ieeexplore.ieee.org/document/6009146 (Page 1136).

Case 6:20-cv-00242-ADA Document 1 Filed 03/27/20 Page 13 of 16
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https://ieeexplore.ieee.org/document/6009146 (Page 1101).

28. In view of preceding paragraphs, each and every element of at least claim 1 of the 

’232 Patent is found in the Accused Products.

29. ZTE has and continues to directly infringe at least one claim of the ’232 Patent, 

literally or under the doctrine of equivalents, by making, using, selling, offering for sale, 

importing, and/or distributing the Accused Products in the United States, including within this 

judicial district, without the authority of Brazos.

30. ZTE has received notice and actual or constructive knowledge of the ’232 Patent 

since at least the date of service of this Complaint.

31. Since at least the date of service of this Complaint, through its actions, ZTE has 

actively induced product makers, distributors, retailers, and/or end users of the Accused Products 

to infringe the ’232 Patent throughout the United States, including within this judicial district, 

by, among other things, advertising and promoting the use of the Accused Products in various 

websites, including providing and disseminating product descriptions, operating manuals, and 

other instructions on how to implement and configure the Accused Products. Examples of such 

advertising, promoting, and/or instructing include the documents at:

• https://www.zte.com.cn/global/products/bearer/data_communication/ethernet_swit

ch/5960-EN

• https://www.zte.com.cn/global/products/bearer/data_communication/ethernet_swit

ch/5960-H-EN

• https://www.asit.it/wp-content/uploads/2018/04/zte_ZXR10_5960_serie.pdf

• https://sdnfv.zte.com.cn/upload_files/440ed336-3d3f-11e9-abd7-

744aa4020e29.pdf

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32. Since at least the date of service of this Complaint, through its actions, ZTE has 

contributed to the infringement of the ’232 Patent by having others sell, offer for sale, or use the 

Accused Products throughout the United States, including within this judicial district, with

knowledge that the Accused Products infringe the ’232 Patent. The Accused Products are 

especially made or adapted for infringing the ’232 Patent and have no substantial non-infringing 

use. For example, in view of the preceding paragraphs, the Accused Products contain 

functionality which is material to at least one claim of the ’232 Patent.

JURY DEMAND

Brazos hereby demands a jury on all issues so triable.

REQUEST FOR RELIEF

WHEREFORE, Brazos respectfully requests that the Court:

(A) Enter judgment that ZTE infringes one or more claims of the ’232 Patent literally 

and/or under the doctrine of equivalents;

(B) Enter judgment that ZTE has induced infringement and continues to induce 

infringement of one or more claims of the ’232 Patent;

(C) Enter judgment that ZTE has contributed to and continues to contribute to the 

infringement of one or more claims of the ’232 Patent;

(D) Award Brazos damages, to be paid by ZTE in an amount adequate to compensate 

Brazos for such damages, together with pre-judgment and post-judgment interest for the 

infringement by ZTE of the ’232 Patent through the date such judgment is entered in accordance 

with 35 U.S.C. §284, and increase such award by up to three times the amount found or assessed 

in accordance with 35 U.S.C. §284;

(E) Declare this case exceptional pursuant to 35 U.S.C. §285; and

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(F) Award Brazos its costs, disbursements, attorneys’ fees, and such further and 

additional relief as is deemed appropriate by this Court.

Dated: March 27, 2020 Respectfully submitted,

/s/ James L. Etheridge

James L. Etheridge

Texas State Bar No. 24059147 

Ryan S. Loveless

Texas State Bar No. 24036997 

Travis L. Richins

Texas State Bar No. 24061296

ETHERIDGE LAW GROUP, PLLC

2600 E. Southlake Blvd., Suite 120 / 324

Southlake, Texas 76092

Telephone: (817) 470-7249

Facsimile: (817) 887-5950

Jim@EtheridgeLaw.com

Ryan@EtheridgeLaw.com

Travis@EtheridgeLaw.com

COUNSEL FOR PLAINTIFF

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