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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.

DELL TECHNOLOGIES INC.,

DELL INC., AND EMC 

CORPORATION,

Defendants.

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CIVIL ACTION 6:20-CV-00477-ADA

CIVIL ACTION 6:20-CV-00482-ADA

PATENT CASE

JURY TRIAL DEMANDED

PLAINTIFF’S REPLY CLAIM CONSTRUCTION BRIEF

Case 6:20-cv-00477-ADA Document 84 Filed 03/31/21 Page 1 of 10
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TABLE OF CONTENTS

I. U.S. Patent No. 7,424,020 (Case No. 6:20-cv-00482).......................................................1

A. “removing, at the network node, the protocol data of a portion of 

protocol layers from the received data stream” (claim 1) / “removes 

protocol data from a portion of protocol layers from a data stream” 

(claim 6)...................................................................................................................1

B. “a control unit which removes protocol data from a portion of 

protocol layers from a data stream .... and switches a remaining data 

stream to be transmitted to one of the terminals via the first interface” 

(Claim 6) .................................................................................................................1

1. The term is not indefinite under IPXL.....................................................1

2. The term is not subject to 35 U.S.C. §112, ¶6..........................................3

C. “bus system”...........................................................................................................4

II. U.S. Patent No. 8,913,489 (Case No. 6:20-cv-00477).......................................................4

A. “the first set of port interfaces of the multi-chassis link aggregate”.................4

Case 6:20-cv-00477-ADA Document 84 Filed 03/31/21 Page 2 of 10
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TABLE OF AUTHORITIES

Cases

3M Innovative Properties Co. v. Avery Dennison Corp.,

350 F.3d 1365 (Fed. Cir. 2003)................................................................................................... 4

Canon, Inc. v. TCL Elecs. Holdings Ltd.,

2:18-CV-546-JRG, 2020 WL 2098197 (E.D. Tex. May 1, 2020).............................................. 3

Enzo Biochem, Inc. v. Applera Corp.,

599 F.3d 1325 (Fed. Cir. 2010)................................................................................................... 5

InterDigital Communications, LLC v. Int'l Trade Comm'n,

690 F.3d 1318 (Fed. Cir. 2012)................................................................................................... 1

Johnson Worldwide Assoc., Inc. v. Zebco Corp.,

175 F.3d 985 (Fed. Cir. 1999)..................................................................................................... 1

MasterMine Software, Inc. v. Microsoft Corp.,

874 F.3d 1307 (Fed. Cir. 2017)................................................................................................... 2

SmithKline Beecham Corp. v. Apotex Corp.,

403 F.3d 1331 (Fed. Cir. 2005)................................................................................................... 1

Rules

37 C.F.R. § 42.104(b)(4)................................................................................................................. 5

Case 6:20-cv-00477-ADA Document 84 Filed 03/31/21 Page 3 of 10
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Abbreviations

Abbreviation Description

Br. Plaintiff’s Opening Claim Construction Brief

POSITA Person of ordinary skill in the art

Resp. Defendants’ Responsive Claim Construction Brief

’020 patent U.S. Patent No. 7,424,020

’489 patent U.S. Patent No. 8,913,489

Case 6:20-cv-00477-ADA Document 84 Filed 03/31/21 Page 4 of 10
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I. U.S. Patent No. 7,424,020 (Case No. 6:20-cv-00482)

A. “removing, at the network node, the protocol data of a portion of protocol 

layers from the received data stream” (claim 1) / “removes protocol data 

from a portion of protocol layers from a data stream” (claim 6)

Dell acknowledges that the word “portion” has a plain and ordinary meaning but then 

contradicts itself by maintaining that the term is indefinite. See Resp. at 2-5. First, Dell claims that 

the claims do not “fully inform a POSA about the meaning of ‘a portion.’” See id. at 2. Dell’s 

argument ignores that “[g]eneral descriptive terms will ordinarily be given their full meaning; 

modifiers will not be added to broad terms standing alone.” InterDigital Communications, LLC v. 

Int'l Trade Comm'n, 690 F.3d 1318, 1325 (Fed. Cir. 2012) (cleaned up). Thus, there is no need for 

the claim to “inform” as Dell contends because a POSITA would understand that “portion” (a 

general descriptive term) should be given its plain and ordinary meaning without any modifiers.

Second, Dell argues that the “specification provides no further clarity,” pointing to the 

specification that describes various embodiments. Resp. at 3. Dell confuses breadth with 

indefiniteness. SmithKline Beecham Corp. v. Apotex Corp., 403 F.3d 1331, 1341 (Fed. Cir. 2005)

(“[B]readth is not indefiniteness.”); accord Johnson Worldwide Assoc., Inc. v. Zebco Corp., 175 

F.3d 985, 991 (Fed. Cir. 1999) (“Varied use of a disputed term in the written description 

demonstrates the breadth of the term rather than providing a limited definition.”). Here, the 

portions of the specification cited by Dell merely demonstrate breadth, not indefiniteness.

Third, with respect to prosecution history, Dell’s suggestion that the applicants were 

obligated to expressly define a readily understood term, such as “portion,” borders on the absurd. 

See Resp. at 4. There was no reason for the applicants to expressly define “portion” when a 

POSITA would have understood that term. 

B. “a control unit which removes protocol data from a portion of protocol 

layers from a data stream .... and switches a remaining data stream to be 

transmitted to one of the terminals via the first interface” (Claim 6)

1. The term is not indefinite under IPXL

Dell refuses to acknowledge the MasterMine case, which clarified and limited IPXL

indefiniteness. See Resp. at 6-7. Instead, Dell makes three meritless arguments. First, Dell attempts 

Case 6:20-cv-00477-ADA Document 84 Filed 03/31/21 Page 5 of 10
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to invoke IPXL indefiniteness “[b]ecause claim 6 recites a method step with an apparatus claims.” 

As WSOU had noted (Br. at 5), however, the Federal Circuit has rejected Dell’s rationale. 

MasterMine Software, Inc. v. Microsoft Corp., 874 F.3d 1307, 1316 (Fed. Cir. 2017) (clarifying 

post-IPXL that claims are not indefinite “merely [because the] claim that the system ‘possess[es] 

the recited structure [which is] capable of performing the recited functions.’”).

Second, Dell also argues that WSOU has not explained how the words “which removes” 

in claim 6 indicates capability. See Resp. at 7. The answer to Dell’s question is self-evident: the 

word “which” signals that the control unit claims an apparatus with particular capabilities (i.e., 

“remov[ing]” and “switch[ing]”). See MasterMine, 874 F.3d at 1315 (discussing claims were 

“unlike those in IPXL ... because they ‘do not reflect an attempt to claim both an apparatus and a 

method, but instead claim an apparatus with particular capabilities.’”).1 The term here is even less 

subject to IPXL compared to the claim term in MasterMine. See id. at 1315 (claiming “reporting 

module installed within the CRM software application presents a set ... , receives from the 

user...”). Notably, in MasterMine, the claim recited an apparatus (the “reporting module”) that is 

directly linked to the verb capabilities (“presents,” “receives,” etc.). See id. Nevertheless, 

MasterMine found those actions mere capabilities. See id. Here, the word “which” makes the 

capability even more clear (i.e., the claim does not recite “control unit removes and switches”).

Third, WSOU noted that IPXL indefiniteness does not apply when the claims “focus on 

the capabilities of the system,” as opposed to the claims in IPXL that “focus on specific actions 

performed by the user.” Br. at 5 (quoting MasterMine, 874 F.3d at 1316). Here, the claims are 

focused on the capabilities of the system; the term “user” is not even recited in the claims as it was 

in IPXL. Dell refuses to address MasterMine by name and instead points to the district court case. 

Resp. at 7. Dell’s district court opinion cannot overrule MasterMine. Dell tacitly concedes that the 

claims do not recite any user actions, nor can they as they lack any reference to “user.”

1

Dell’s position that “which removes” does not indicate capability conflicts with its position in its 

alternative construction. See Resp. at 8 (“the claim describes ‘control unit’ solely based on its 

functionality”). Dell’s concession of functionality imputes capability.

Case 6:20-cv-00477-ADA Document 84 Filed 03/31/21 Page 6 of 10
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2. The term is not subject to 35 U.S.C. §112, ¶6

The term is not subject to §112, ¶6 because the term “control unit” would connote sufficient 

structure to a POSITA based on the claim language and specification. See Br. at 5-6. Moreover,

the term “control unit” has been found to recite specific structure in a case very similar to the issue 

here. See id. at 6 (citing Canon, Inc. v. TCL Elecs. Holdings Ltd., 2:18-CV-546-JRG, 2020 WL 

2098197, at *15 (E.D. Tex. May 1, 2020)). In Canon, the district court found the term “control 

unit” to have sufficient structure based on three factors: (i) an extrinsic dictionary definition of 

“control unit” that “strongly supports” a connotation of definite structure to a POSITA; (ii) 

“specific description of the operation of the control unit with the claim further avoids a finding of 

a means-plus-function limitation;” and (iii) “the ‘control’ modifier imparts structural significance 

to the term [unit].” Canon, 2020 WL 2098197, at *15. Dell unilaterally declares Canon

“inapposite” because Canon also looked at the applicant’s intentions during prosecution history, 

and that was not a factor here. But Dell then goes onto argue that the applicant’s intentions are 

irrelevant. Resp. at 9. Canon made clear that prosecution history was only a “further” reason not 

to invoke §112, ¶6. Even if Dell is correct that applicant’s intentions are irrelevant (WSOU does 

not agree), it would not undermine bases (i)-(iii) of the Canon holding.

Dell also wrongly claims that WSOU “reli[es] on a dictionary, which it did not disclose, 

produce, or attach as an exhibit” and it “should be stricken.” Resp. at 9 n.7. WSOU merely cited a 

public Eastern District of Texas opinion that references a dictionary definition. Canon, 2020 

WL20981797, at *15 (citing Microsoft Corporation, Microsoft Computer Dictionary (5th ed. 

2002), at 128 (defining “control unit” as “[a] device or circuit that performs an arbitrating or 

regulating function.”)). WSOU did not disclose the Microsoft Computer Dictionary definition 

because the Canon opinion (which referenced the Microsoft Computer Dictionary) was publiclyavailable legal authority. Dell also fails to explain how the Microsoft Computer Dictionary “should 

be stricken” when Dell acknowledges that WSOU did not attach the definition as an exhibit. See

Resp. at 9.

Case 6:20-cv-00477-ADA Document 84 Filed 03/31/21 Page 7 of 10
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C. “bus system”

First, the specification contradicts Dell’s construction. The specification describes 

“[p]referably the communication network KN is a bus system.” ’020 patent at 2:29. To avoid the 

possibility of “bus system” being unnecessarily restricted (as Dell now attempts), the specification 

then goes onto expressly clarify that it is “possible” that the “communication network KN [which 

is previously disclosed as preferably a bus system] comprises active components, such as 

switching nodes, gateways, routers, [sic] bridges.” Id. at 2:29-32. Dell reads the same passage as 

distinguishing “bus system” from systems including “active components.” Resp. at 10. But Dell

misreads the specification. The specification is stating that the communication network KN can be both 

a (a) “bus system” and (b) “[i]t is however also possible” for communication network KN to include 

“active components such as switching nodes, gateways, routers, [or] bridges.” ’020 patent at 2:29-32.

There is no suggestion that (a) and (b) were being contrasted as Dell suggests.

Second, pointing to a non-precedential Federal Circuit opinion, Dell misstates the law that 

acquiescence can amount to disclaimer. This is contrary to the law. “An applicant's silence in 

response to an examiner's characterization of a claim does not reflect the applicant's clear and 

unmistakable acquiescence to that characterization if the claim is eventually allowed on grounds 

unrelated to the examiner's unrebutted characterization.” 3M Innovative Properties Co. v. Avery 

Dennison Corp., 350 F.3d 1365, 1373–74 (Fed. Cir. 2003). Thus, the applicant’s silence here 

cannot as a matter of law amount to a disavowal. 

II. U.S. Patent No. 8,913,489 (Case No. 6:20-cv-00477) 

A. “the first set of port interfaces of the multi-chassis link aggregate” 

WSOU’s Proposed Construction Defendant’s Proposed Construction

Plain and ordinary meaning Indefinite

The claim language itself provides the full context and antecedent basis for this term. In 

Claim 1,2 the preamble recites “An aggregation switch in a multi-chassis system, comprising...”, 

2 Independent claims 8 and 15 recite similar language, and the analysis herein applies equally.

Case 6:20-cv-00477-ADA Document 84 Filed 03/31/21 Page 8 of 10
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and the first limitation recites “a first set of member port interfaces of the aggregation switch 

grouped with one or more member port interfaces of a remote aggregation switch configured to 

form a multi-chassis link aggregate...” ’489 patent, 22:33-38 (emphasis added). Thus, this term 

refers to the first set of member port interfaces of the aggregation switch which are configured to 

form a multi-chassis link aggregate with a remote aggregation switch, as opposed to “a second set 

of port interfaces” in the second element (see Id., 22:41-42). Defendants’ arguments ignore that 

the term recites “the first set of port interfaces of the multi-chassis link aggregate,” which refers 

back to “a first set of member port interfaces of the aggregation switch.” While the claim begins 

by reciting an aggregation switch and a remote aggregation switch, the claims then recite that the 

first set of member port interfaces of the aggregation switch and one or more port interfaces of the 

remote aggregation switch are configured to form a multi-chassis link aggregate. Thus, there is 

no confusion where there are two separate switches that are configured to form a single logical 

switch – hence the name “multi-chassis link aggregate.” Because the claim term refers back to the 

“first set of port interfaces,” it refers back to the “first set of member port interfaces of the 

aggregation switch.” Finally, Defendants admit, or at least do not deny, that Defendants have found 

the claim term to be definite in Defendants’ IPR petition. Defendants only argue that “there is 

nothing inconsistent with Defendants’ IPR because indefiniteness challenges cannot be raised in 

IPRs.” Resp. at 13, n.11. However, that the IPR forum doesn’t allow indefiniteness challenges is 

inapposite to the fact that Defendants have shown in their IPR filing that Defendants found the 

term to be sufficiently definite. Enzo Biochem, Inc. v. Applera Corp., 599 F.3d 1325, 1332 (Fed. 

Cir. 2010) (“As a preliminary matter, we observe that a claim cannot be both indefinite and 

anticipated.”). In filing their IPR petition, “the petition must specify where each element of the 

claim is found in the prior art patents or printed publications relied upon” 37 C.F.R. § 42.104(b)(4)

(emphasis added). In fact, in the petition, Defendants expressly state that “Pursuant to 37 C.F.R. § 

42.104, each requirement for inter partes review of the ’489 Patent is satisfied.” IPR2021-00272, 

Petition (Paper 2), at 4. Thus, by filing its petition in IPR2021-00272, Defendants have 

demonstrated that they can understand this term and the term is not indefinite. 

Case 6:20-cv-00477-ADA Document 84 Filed 03/31/21 Page 9 of 10
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Dated: March 31, 2021 Respectfully submitted,

By: /s/ Ryan Loveless

James L. Etheridge 

Texas Bar No. 24059147 

Ryan S. Loveless 

Texas Bar No. 24036997 

Brett A. Mangrum 

Texas Bar No. 24065671 

Travis L. Richins 

Texas Bar No. 24061296 

Jeffrey Huang

Brian M. Koide

Etheridge Law Group, PLLC 

2600 E. Southlake Blvd., Suite 120 / 324 

Southlake, TX 76092 

Tel.: (817) 470-7249 

Fax: (817) 887-5950 

Jim@EtheridgeLaw.com 

Ryan@EtheridgeLaw.com 

Brett@EtheridgeLaw.com 

Travis@EtheridgeLaw.com 

Jhuang@EtheridgeLaw.com 

Brian@EtheridgeLaw.com

Mark D. Siegmund

State Bar No. 24117055

mark@waltfairpllc.com

Law Firm of Walt, Fair PLLC.

1508 North Valley Mills Drive 

Waco, Texas 76710

Telephone: (254) 772-6400

Facsimile: (254) 772-6432

Counsel for Plaintiff WSOU Investments, LLC

CERTIFICATE OF SERVICE

A true and correct copy of the foregoing instrument was served or delivered electronically 

via the U.S. District Court [LIVE]- Document Filing System to all counsel of record on March 31, 

2021.

/s/ Ryan Loveless

Ryan Loveless

Case 6:20-cv-00477-ADA Document 84 Filed 03/31/21 Page 10 of 10