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. 

HUAWEI TECHNOLOGIES USA 

INC.; HUAWEI TECHNOLOGIES 

CO., LTD.,

Defendants.

§

§

§

§

§

§

§

§

§

§

CIVIL ACTION 6:20-cv-00533-ADA

CIVIL ACTION 6:20-cv-00535-ADA

CIVIL ACTION 6:20-cv-00540-ADA

CIVIL ACTION 6:20-cv-00543-ADA

PLAINTIFF’S OPENING CLAIM CONSTRUCTION BRIEF

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 1 of 33
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TABLE OF CONTENTS

I. U.S. Patent No. 6,882,627 (Case No. 6:20-cv-00533) Claim Terms ...............................1

A. Overview of the ’627 Patent..................................................................................1

B. Terms with Constructions Not Contested by Defendants..................................3

C. Terms with Disputed Constructions.....................................................................4

1. “performing a SRG (shared risk group) topology 

transformation of the network topology into a virtual topology 

that discourages the use of network resources” (Claims 1, 29, 

30) ................................................................................................................4

2. “second code means adapted to, for at least one shared risk 

group, determine if any of the at least one shared risk group 

includes any of the first sequence of network resources” (Claim 

29) / “means adapted to, for at least one shared risk group, 

determine if any of the at least one shared risk group includes 

any of the first sequence of network resources” (Claim 30) ..................4

3. “third code means for performing a SRG (shared risk group) 

topology transformation of the network topology into a virtual 

topology which discourages the use of network resources” 

(Claim 29) / “means for performing a SRG (shared risk 

group) topology transformation of the network topology into a 

virtual topology which discourages the use of network 

resources” (Claim 30) ................................................................................6

II. U.S. Patent No. 6,999,727 (Case No. 6:20-cv-00543) Disputed Claim Terms...............8

A. Overview of the ’727 Patent..................................................................................8

B. Terms with Constructions Not Contested by Defendants..................................9

C. Terms with Disputed Constructions.....................................................................9

4. “corrected errors” (Claims 1, 4-7)............................................................9

5. “a number of corrected errors (BCE) in a non-SCS base 

reference time period” (Claims 1, 4-7)...................................................10

6. “means for implementing a Performance Monitoring function 

based on data retrieved through a Forward Error Correction 

function” (Claims 4, 5).............................................................................11

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 2 of 33
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7. “means for classifying said blocks either as corrected or 

uncorrected through the Forward Error Correction function” 

(Claims 4, 5)..............................................................................................12

8. “means for calculating the Performance Monitoring function 

by implementing a correlation of the information regarding 

said corrected and uncorrected blocks” (Claims 4, 5)..........................13

9. “implementing a Performance Monitoring function based on 

data retrieved through a Forward Error Correction Function” 

(Claims 6, 7)..............................................................................................14

10. “classifying said blocks either as corrected or uncorrected 

through the Forward Error Correction function” (Claims 6, 7).........16

III. U.S. Patent No. 7,508,755 (Case No. 6:20-cv-00535) Disputed Claim Terms.............17

A. Overview of the ’755 Patent................................................................................17

B. Terms with Constructions Not Contested by Defendants................................18

C. Terms with Disputed Constructions...................................................................18

11. “originating network device” (Claims 1, 3)...........................................18

12. “switch over message” (Claims 1, 5, 8, 10, 13, 16, 18, 23, 25) ..............19

13. “means for re-routing traffic traveling along the bi-directional 

LSP in the backwards direction to the alternate path in the 

backwards direction based on the switch over message.” 

(Claims 8) / “means for re-routing traffic traveling along a bidirectional LSP in a backwards direction to an alternate path 

in the backwards direction based on the switch over message” 

(Claim 23) / “means for re-routing traffic traveling along the 

bi-directional LSP in a backwards direction to the same 

alternate path in the backwards direction based on the switch 

over message” (Claim 25)........................................................................20

14. “means for re-routing traffic traveling along a bi-directional

LSP in a forward direction to an alternate path in the forward 

direction” (Claim 20)...............................................................................21

15. “means for transmitting a switch over message along the 

alternate path in the forward direction to a merging network 

device responsive for re-routing traffic traveling along the bidirectional LSP in a backward direction to the alternate path 

in the backward direction” (Claim 20) / “means for 

transmitting a switch over message, along the alternate path in 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 3 of 33
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the forward direction, for re-routing traffic traveling along the 

bi-directional LSP in a backward direction” (Claim 25) .....................22

16. “means for means for [sic] receiving traffic traveling along a 

bi-directional LSP in a forward direction to an alternate path 

in the forward direction” (Claim 23) .....................................................24

IV. U.S. Patent No. 8,417,112 (Case No. 6:20-cv-00540) Disputed Claim Terms.............25

A. Overview of the ’112 Patent................................................................................25

B. Terms with Disputed Constructions...................................................................26

17. “determining whether said collected BER values worsen over 

time” (Claims 1, 11) .................................................................................26

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 4 of 33
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TABLE OF AUTHORITIES

Cases

Amdocs (Israel) Limited v. Openet Telecom, Inc.,

2018 Markman 1699429, 2018 WL 1699429 (E.D. Va. 2018)................................................ 16

CLS Bank International v. Alice Corp. Pty. Ltd.,

717 F.3d 1269 (Fed. Cir. 2013)................................................................................................. 16

Farstone Technology, Inc. v. Apple Inc.,

2015 Markman 857706, 2015 WL 857706 (C.D. Cal. 2015)..................................................... 6

In re Katz Interactive Call Processing Patent Litig.,

639 F.3d 1303 (Fed.Cir. 2011).............................................................................................. 6, 25

JVW Enterprises, Inc. v. Interact Accessories, Inc.,

424 F.3d 1324 (Fed. Cir. 2005)................................................................................................. 14

Liebel–Flarsheim Co. v. Medrad, Inc.,

358 F.3d 898 (Fed.Cir.2004)................................................................................................. 4, 19

Micro Chem., Inc. v. Great Plains Chem. Co.,

194 F.3d 1250 (Fed. Cir. 1999).......................................................................................... passim

Samsung Elecs. Am. v. Prisua Eng'g Corp.,

948 F.3d 1342 (Fed. Cir. 2020)................................................................................................. 15

Skky, Inc. v. MindGeek, s.a.r.l.,

859 F. 3d 1014 (Fed. Cir. 2017)................................................................................................ 15

Toshiba Corp. v. Imation Corp.,

681 F.3d 1369 (Fed. Cir. 2012).......................................................................................... passim

Typhoon Touch Technologies, Inc. v. Dell, Inc.,

659 F.3d 1376 (Fed. Cir. 2011)................................................................................................... 6

Virginia Innovation Sciences, Inc. v. Amazon.com, Inc.,

2019 Markman 4259020, 2019 WL 4259020 (E.D. Tex. 2019)............................................... 15

WhitServe LLC v. GoDaddy.Com, Inc.,

2014 WL 5668335 (D. Conn. 2014)......................................................................................... 16

Williamson v. Citrix Online, LLC,

792 F.3d 1339 (Fed. Cir. 2015)................................................................................................. 15

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 5 of 33
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Plaintiff WSOU Investments, LLC d/b/a Brazos License and Development (“WSOU”)

respectfully submits this claim construction brief in support of its proposed constructions.

I. U.S. Patent No. 6,882,627 (Case No. 6:20-cv-00533) Claim Terms

A. Overview of the ’627 Patent

The ’627 patent is generally directed to techniques for facilitating the selection of multiple 

paths through a network represented by a network topology which takes into account shared risk 

which may exist between network resources. ’627 patent, Abstract, 2:5-9. The ’627 patent 

summarizes certain technical problems in the field that existed at the time, over two decades ago. 

Id., 1:13-2:2. At the time of the invention, an approach to providing failure tolerance in networks 

was to identify during initial service configuration a primary path and one or more non-primary 

paths through the network, so called “multi-path routing,” and such that the two or more paths to 

be maximally edge disjoint and maximally node disjoint (meaning the paths share as few links and 

nodes as possible, usually none of either). Id. 1:43-57. However, some links and/or nodes in a 

network may share a common risk of failure. For example, there may be multiple links which at 

some point share a common resource such as a common single cable. Id., 1:58-2:2. Existing route 

definition methods at the time, such as maximally disjoint approaches, do not address the issue of 

shared risk groups, resulting in the possibility that the primary and non-primary paths will share 

some resources even though they do not share any links and/or nodes. Id. 

In a preferred embodiment, the ’627 patent solves certain network-related problems of its 

time through a novel use of determining shared risk groups and performing a shared risk group 

(SRG) topology transformation of the network into a virtual topology which discourages the use 

of network resources in any shared risk group determined to be a part of a first path through the 

network, and then identifying a second path through the virtual topology. Id., 2:10-27. The SRG 

topology transformation for each node requiring such transformation preferably involves 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 6 of 33
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transforming a node into two interconnected nodes, providing a forward unidirectional link 

between two interconnected nodes and assigning the forward unidirectional link a cost, 

transforming any bi-directional link into the node requiring transformation into a first 

unidirectional link into one of the two interconnected nodes and a second unidirectional link out 

of the other of the two interconnected nodes where, preferably, the cost assigned to each forward 

unidirectional link is greater than the sum of costs for all links in the network topology. Id., 2:31-

54. The SRG topology transformation for each link requiring transformation preferably involves 

transforming the link requiring transformation into a forward unidirectional link and a reverse 

unidirectional link each having a respective cost. For each unidirectional link, preferably, a 

respective cost is assigned which is larger than a sum of the costs assigned to all links in the 

topology. Preferably, a larger cost is assigned to transformed links which form part of the first path 

than for transformed unidirectional links which do not form part of the first path. Id.

In another embodiment of the invention, in the event at least two paths cannot be found 

which do not share at least one resource having shared risks, revising the at least one shared risk 

group to be less restrictive and then re-executes the method. This may be done for example by 

defining a hierarchy of resources, the hierarchy having a plurality of levels, with resources assigned 

to a given level in the hierarchy being contained by a resource assigned to a higher level in the 

hierarchy, wherein a shared risk between any two resources in a lower level of the hierarchy is 

also considered a shared risk between any pair of resources in a higher level of the hierarchy which 

contain the two resources in the lower level of the hierarchy. A first attempt is made to define first 

and second paths which do not share any risk at the highest level of the hierarchy of resources. 

Upon failure of the first attempt, at least one subsequent attempt is made to define first and second 

paths which do not share any risk at a level of the hierarchy of resources below the highest level 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 7 of 33
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of the hierarchy of resources. Subsequent attempts are made for respective lower levels of the 

hierarchy of resources until first and second paths are identified which do not share risk at the 

respective lower level. Id., 2:63-3:18.

B. Terms with Constructions Not Contested by Defendants

Term Construction not contested by Defendants

“means for maintaining or obtaining network 

topology information” (Claim 30)

Subject to 35 U.S.C. § 112, ¶6 

Function: maintaining or obtaining network 

topology information

Structure: network management platform, and 

equivalents thereof; see e.g., 5:64-6:22

first code means for identifying a first path 

through the network topology [from a source 

node to a destination node], the first path 

comprising a first sequence of network 

resources” (Claim 29) / 

“means for identifying a first path through the 

network topology [from a source node to a 

destination node], the first path comprising a 

first sequence of network resources” (Claim 

30)

Subject to 35 U.S.C. § 112, ¶6

Function: identifying a first path through the 

network topology from a source node to a 

destination node

Structure: processing platform-readable 

medium, and equivalents thereof (claim 29) / 

a network management platform, and 

equivalents thereof (claim 30)

Algorithm (if required): any suitable method 

of determining a path through network 

topology, and equivalents thereof, see e.g., 

6:38-48, Figs. 2, 3A

“fourth code means adapted to identify a 

second path through the virtual topology from 

the source node to the destination node” 

(Claim 29) / 

“means adapted to identify a second path 

through the virtual topology from the source 

node to the destination node” (Claim 30)

Subject to 35 U.S.C. § 112, ¶6

Function: identify a second path through the 

virtual topology from the source node to the 

destination node

Structure: processing platform-readable 

medium, and equivalents thereof

Algorithm (if required): any suitable method 

of determining a path through network 

topology see e.g., 4:51-5:39, 7:55-62, Fig. 3C, 

and equivalents thereof

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C. Terms with Disputed Constructions

1. “performing a SRG (shared risk group) topology transformation of 

the network topology into a virtual topology that discourages the use 

of network resources” (Claims 1, 29, 30)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Plain and ordinary meaning “performing a transformation of links and/or 

nodes of a SRG (shared risk group) of the 

network into a virtual topology that 

discourages the use of network resources”

This term should be given its plain and ordinary meaning. Defendants’ proposed 

construction should be rejected for improperly importing limitations not required in the claims or 

specification. Toshiba Corp. v. Imation Corp., 681 F.3d 1369 (Fed. Cir. 2012) (“Absent disclaimer 

or lexicography, the plain meaning of the claim controls.”). Defendants’ proposed construction 

improperly seeks to limit the claims to “transformation of links and/or nodes.” While the 

specification discloses embodiments regarding transformation of nodes and transformation of 

links, the specification also first expressly states: “a network represented by a network topology 

representing an interconnected set of network resources.” ’627 patent, 2:11-13 (emphasis 

added). The specification also expressly states that: “[t]he network resources might for example

include nodes and links. The shared risk groups might include groups of nodes and/or groups of 

links.” Id., 2:28-30 (emphasis added). In other words, as the specification states, the network 

resources could include nodes and links, but is expressly not limited to nodes and links. Regardless, 

importing limitations from an embodiment is improper, even if it is the only embodiment. Liebel–

Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 906 (Fed.Cir.2004).

2. “second code means adapted to, for at least one shared risk group, 

determine if any of the at least one shared risk group includes any of 

the first sequence of network resources” (Claim 29) / 

“means adapted to, for at least one shared risk group, determine if 

any of the at least one shared risk group includes any of the first 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 9 of 33
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sequence of network resources” (Claim 30)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Subject to 35 U.S.C. § 112, ¶6 

Function: determine if any of the at least one 

shared risk group includes any of the first 

sequence of network resources

Structure: processing platform-readable 

medium, and equivalents thereof (claim 29) / 

a network management platform, and 

equivalents thereof (claim 30)

Algorithm (if required): see e.g., 2:13-54, 

3:54-4:15, 4:45-5:33, 6:23-37, 6:52-7:52, 

9:18-23, 12:46-50 Figs. 3A, 3B, 6B, and 

equivalents thereof

Subject to 35 U.S.C. § 112, ¶6

Indefinite for failure to disclose sufficient 

structure

But the parties agree that the terms are subject to 35 U.S.C. § 112, ¶ 6. The parties dispute 

whether the terms are indefinite. Defendants’ proposal should be rejected. First, Defendants’

proposed construction does not propose a recited function, and Defendants cannot reasonably 

argue that there is a failure to disclose sufficient structure without identifying a recited function.1

Micro Chem., Inc. v. Great Plains Chem. Co., 194 F.3d 1250, 1258 (Fed. Cir. 1999). (“An error in 

identification of the function can improperly alter the identification of structure in the specification 

corresponding to that function.”). Nonetheless, the correct recited function is “determine if any 

of the at least one shared risk group includes any of the first sequence of network resources.” 

Second, the correct corresponding structure is “processing platform-readable medium, and 

1 Additionally, Defendants filed a petition for inter partes review against this same ’627 patent in 

IPR2021-00222 and against the same claims 29 and 30. In IPR2021-00222, Defendants

proposed to the PTAB that these terms are not indefinite for failing to disclose structure, but 

instead, “includes the corresponding structure—algorithms for identifying shared risk groups

of FIG. 3B and 6B—and equivalents thereof.” Ex. A, p. 16 (IPR2021-00222, Petition (Paper 

2), at 16). Thus in at least IPR2021-00222, Defendants has demonstrated that this term is not 

indefinite. 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.”).

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 10 of 33
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equivalents thereof” for Claim 29 and “a network management platform, and equivalents thereof” 

for Claim 30. Moreover, the Federal Circuit has held that functions like ‘processing,’ ‘receiving,’ 

and ‘storing’ do not require the disclosure of an algorithm. In re Katz Interactive Call Processing 

Patent Litig., 639 F.3d 1303, 1315-16 (Fed.Cir. 2011). The same applies for “determin[ing]”. See 

e.g. Farstone Technology, Inc. v. Apple Inc., 2015 Markman 857706, 2015 WL 857706, *7-*8 

(C.D. Cal. 2015) (finding that the ‘Selecting’ is a common computer function and therefore 

requires no additional structure to be disclosed.); see also Typhoon Touch Technologies, Inc. v. 

Dell, Inc., 659 F.3d 1376, 1384-86 (Fed. Cir. 2011) (holding that the determination whether a 

match exists to be sufficient textual description for a programmer of ordinary skill in the art as one 

of the steps in ‘means for cross-referencing,’ and that “the matching of entered responses with a 

library of possible responses” to be one of known computer-implemented operations and are 

“readily implemented by persons of skill in computer programming.”). However, to the extent an 

algorithm is required, the claim language itself provides all the algorithm that is required, however, 

further exemplary algorithms disclosed in the specification are recited at ’627 patent, 2:13-54, 

3:54-4:15, 4:45-5:33, 6:23-37, 6:52-7:52, 9:18-23, 12:46-50 Figs. 3A, 3B, 6B, and equivalents 

thereof. For example, the specification teaches in an embodiment that once the shared risk groups 

are determined (e.g. ’627 patent, 6:23-37), each primary bi-directional link belonging to a shared 

risk group (SRG) under consideration is determined for transformation (e.g., Id., 6:63-66).

3. “third code means for performing a SRG (shared risk group) topology 

transformation of the network topology into a virtual topology which 

discourages the use of network resources” (Claim 29) / 

“means for performing a SRG (shared risk group) topology 

transformation of the network topology into a virtual topology which 

discourages the use of network resources” (Claim 30)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Subject to 35 U.S.C. § 112, ¶6 Subject to 35 U.S.C. § 112, ¶6

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 11 of 33
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Function: performing a SRG (shared risk 

group) topology transformation of the network 

topology into a virtual topology which 

discourages the use of network resources

Structure: processing platform-readable 

medium, and equivalents thereof (claim 29) / 

a network management platform, and 

equivalents thereof (claim 30)

Algorithm (if required): see e.g., 2:31-3:18, 

6:49-7:52, 7:63-8:28, 8:30-9:35, Figs. 2, 3A3D, 4A, 4B, 5A, 5B, 6A-6E, and equivalents 

thereof

Function: performing a SRG (shard risk 

group) topology transformation of the network 

topology into a virtual topology which 

discourages the use of network resources

Structure: Algorithms for link and node 

transformations such as those described in 

Figures 3C, 3D, 4A, and 4B, and equivalents 

thereof.

The parties agree that the terms are subject to 35 U.S.C. § 112, ¶ 6. The parties also agree 

the recited function is “performing a SRG (shared risk group) topology transformation of the 

network topology into a virtual topology which discourages the use of network resources.” 

However, Defendants’ proposed structure is erroneous because Defendants’ proposed construction 

does not identify a structure; instead Defendants appear to identify an algorithm. The correct 

corresponding structure is “processing platform-readable medium, and equivalents thereof” for 

Claim 29 and “a network management platform, and equivalents thereof” for Claim 30. And to the 

extent an algorithm is required, exemplary algorithms disclosed in the specification are recited at 

’627 patent, 2:31-3:18, 6:49-7:52, 7:63-8:28, 8:30-9:35, Figs. 2, 3A-3D, 4A, 4B, 5A, 5B, 6A-6E, 

and equivalents thereof. For example, the specification teaches exemplary link and node 

transformations:

“Link Transformation

A preferred method of performing link transformation will be 

described with reference to FIG. 4A. Each primary bi-directional 

intermediate link L 100 belonging to an SRG group under 

consideration is transformed into a link L′ 102. Similarly, each 

non-primary bi-directional intermediate link L 100 belonging to an 

SRG group under consideration is transformed into a link L′ 104. 

For non-primary path links, each link L′ 104 is assigned a cost of 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 12 of 33
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Lo+Ls, where Lo=original link cost, Ls=(Slinkcosts)*SRLG, 

where Slinkcosts is arbitrarily defined to be the sum of the costs of 

all of the links in the network. For primary path links, each link L′ 

102 is assigned a cost Lo+Lp, Lp=(Slinkcosts)*SRLG+K. Note, 

Lp>Ls by an amount K, as using a primary link in an SRG is worse 

than using a non-primary in an SRG.

Node Transformation

A preferred method of performing node transformation will be 

described with reference to FIG. 4B. Each node N 120 to be 

transformed is split into two nodes N′ 122, N′′ 124. For a primary 

path node, a new unidirectional link N′→N′′ 126 is added, and for 

a non-primary path node, a new unidirectional link N′→N′′ 128, in 

both cases between the two new nodes 122,124. The links 126,128 

have costs defined as follows: non-primary path node N′→N′′:

cost=Cs=(Slinkcosts)*SRNG primary path node N′→N′′: 

cost=Cp=(Slinkcosts)*SRNG+J The primary path node has a 

higher cost by an amount J to discourage its use over the nonprimary path node.” Id., 6:62-7:23.

II. U.S. Patent No. 6,999,727 (Case No. 6:20-cv-00543) Disputed Claim Terms

A. Overview of the ’727 Patent

The ’727 patent is generally directed to implementing a Performance Monitoring function 

according to data retrieved through Forward Error Correction (FEC) in a telecommunications 

network and based on the correlation of information relating to “corrected” and “uncorrected” 

blocks deriving from the implementation of the FEC function. ’727 patent, Abstract, 1:63-2:3. The 

’727 patent summarizes certain technical problems in the field that existed at the time, nearly two 

decades ago. At the time of the invention, Forward Error Correction mechanisms were known in 

the art as a methodology for correcting transmission errors, and there were substantially two types 

of FEC, in-band FEC and out-of-band FEC. Id., 1:21-38. While the properties of FEC were well 

known in the art, it was also well known that there was a need for defining a procedure for 

Performance Monitoring, which consists of the evaluation of a path (link) quality based on an 

evaluation of the result of the FEC procedure. Id., 1:42-45. The known procedures for Performance 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 13 of 33
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monitoring based on FEC data at the time independently utilized two uncorrelated sets of primitive 

counters for corrected errors in respective information blocks and uncorrected blocks. Id., 1:46-

51. The problem with that approach was it did not deliver sufficient information about the real 

transmission quality of the path (link). For example, under conditions of bad transmission quality, 

the error counter does not provide reliable data, as it refers to information blocks which cannot be 

corrected through the FEC procedure. Furthermore, the evaluation of Bit Error Rate was not 

possible. Id., 1:52-58.

In a preferred embodiment, a Performance Monitoring function is provided that results in 

better indication of the status of path (link) based on a Performance Monitoring function based 

upon the correlation of information regarding “corrected” and “uncorrected” information blocks 

derived from the FEC function. See e.g., Id., 2:36-4:54.

B. Terms with Constructions Not Contested by Defendants

Term Construction not contested by Defendants

“means for receiving blocks of data” (Claims 

4, 5)

Subject to 35 U.S.C. § 112, ¶6 

Function: receiving blocks of data

Structure: telecommunication network 

management system, and equivalents thereof

“means for obtaining data through the 

Forward Error Correction function carried out 

on the blocks of received data” (Claims 4, 5)

Subject to 35 U.S.C. § 112, ¶6 

Function: obtaining data through the Forward 

Error Correction function carried out on the 

blocks of received data

Structure: network node performing Forward 

Error Correction function, and equivalents 

thereof

C. Terms with Disputed Constructions

4. “corrected errors” (Claims 1, 4-7)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 14 of 33
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Plain and ordinary meaning “number of errors that have been corrected by 

the FEC mechanism in the time interval 

considered”

This term should be given its plain and ordinary meaning. Defendants’ proposal to construe 

this term is confusing given Defendants’ proposal to also construe the following term: “a number 

of corrected errors (BCE) in a non-SCS base reference time period.” See Section II.C.5, below.

Specifically, the term “corrected errors” only ever appears in any claim (asserted or otherwise) as 

“a number of corrected errors (BCE)...” in the ’727 patent, Defendants’ proposal to construe 

“corrected errors” and “a number of corrected errors (BCE)...” is especially unclear and 

confusing. See ’727 patent, 5:34-35 (Claim 1), 5:59 (Claim 3), 6:21-22 (Claim 4), 6:45-46 (Claim 

5), 7:1-2 (Claim 6), 8:10-11 (Claim 7). In other words, it is inappropriate to separate the term 

“number of corrected errors (BCE)” to just “corrected errors” in a vacuum. Given the full context 

of the language of the claims, Defendants’ proposal for construction and proposed construction 

are confusing and unhelpful. Defendants’ proposed construction should be rejected. Toshiba, 681 

F.3d 1369 (“Absent disclaimer or lexicography, the plain meaning of the claim controls.”).

5. “a number of corrected errors (BCE) in a non-SCS base reference 

time period” (Claims 1, 4-7)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Plain and ordinary meaning “the number of background corrected errors 

within a base reference time period which is 

different than the base reference time period 

used to calculate uncorrected blocks”

This term should be given its plain and ordinary meaning. The claim language here 

expressly provides the definition of the claim term. Specifically, the term itself recites that it is a 

number of corrected errors, that are in a non-SCS base reference time period. See ’727 patent, 

5:34-35 (Claim 1), 6:21-22 (Claim 4), 6:45-46 (Claim 5), 7:1-2 (Claim 6), 8:10-11 (Claim 7). The 

claims also provide a definition of SCS time period as: “a defected base reference time period 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 15 of 33
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(SCS) or a time period where at least an uncorrected block (UB) has been detected.” See Id., 5:31-

33 (Claim 1), 6:17-19 (Claim 4), 6:41-43 (Claim 5), 6:65-67 (Claim 6), 8:7-9 (Claim 7). Thus, the 

term is expressly defined by the claim language itself, and Defendants’ proposed construction at 

best attempts to re-write the claim language, which is unnecessary and unhelpful. Toshiba, 681 

F.3d 1369 (“Absent disclaimer or lexicography, the plain meaning of the claim controls.”). 

Moreover, Defendants’ proposed construction is improper for limiting the “base reference time 

period” to one that is “different than the base reference time period used to calculate uncorrected 

blocks.” The express language of the claims recites uncorrected blocks being “detected.” In 

addition to the claim language, the specification also provides the example of a “severely corrected 

second”2 to include a time period “wherein at least one uncorrected block UB has been detected.” 

’727 patent, 3:12-14 (emphasis added). Thus, Defendants’ proposed construction is erroneous for 

requiring a “calculation” instead of “detection.” Finally, to the extent a “non-SCS base reference 

time period” were to be re-phrased (and it should not), the specification provides a much clearer 

re-wording in an example of a “non SCS second,” which the specification provides as “namely, a 

[time period] at low frequency of errors, wherein the errors can be corrected.” Id., 3:9-11. 

6. “means for implementing a Performance Monitoring function based 

on data retrieved through a Forward Error Correction function”

(Claims 4, 5)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Subject to 35 U.S.C. § 112, ¶6 

Function: implementing a Performance 

Monitoring function based on data retrieved 

through a Forward Error Correction function

Structure: telecommunication network 

Subject to 35 U.S.C. § 112, ¶6

Function: implementing a Performance 

Monitoring function based on data retrieved 

through a Forward Error Correction function

Structure: Algorithm disclosed in Figure 1, and

2 The specification expressly recites that “[t]he time period of 1 second is to be considered in a 

non-limiting way as base reference for the application of the method according to the present 

invention.” ’727 patent, 2:62-65 (emphasis added).

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 16 of 33
12

management system, and equivalents thereof

Algorithm (if required): see e.g., 1:63-2:21, 

2:36-4:54, Fig. 1, and equivalents thereof

equivalents thereof

The parties agree this term is subject to 35 U.S.C. § 112, ¶6. The parties also agree as to 

the recited function. However, Defendants’ proposed structure is erroneous because Defendants’

proposed construction does not identify a structure; instead Defendants appear to identify an 

algorithm. The correct corresponding structure is “telecommunication network management 

system, and equivalents thereof.” See e.g., ’727 patent, 5:66-67 (Claim 4), 6:23-24 (Claim 5); see 

also Id., 2:10-16. And to the extent an algorithm is required, exemplary algorithms disclosed in 

the specifications are recited at ’727 patent, 1:63-2:21, 2:36-4:54, Fig. 1, and equivalents thereof. 

For example, the specification teaches obtaining certain values from a FEC end function (such as 

CEC, UBC, and DS), based on those FEC values, determining certain other values (such as BCE 

and SCS), determining a summation of values of BCE and SCS events, and correlating the 

information regarding corrected blocks and uncorrected blocks. See e.g., 2:36-4:54, Fig. 1. 

7. “means for classifying said blocks either as corrected or uncorrected 

through the Forward Error Correction function” (Claims 4, 5)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Subject to 35 U.S.C. § 112, ¶6 

Function: classifying said blocks either as 

corrected or uncorrected through the Forward 

Error Correction function

Structure: network node performing Forward 

Error Correction function, and equivalents 

thereof

Subject to 35 U.S.C. § 112, ¶6

Indefinite for lack of structure.

The parties agree this term is subject to 35 U.S.C. § 112, ¶6. Defendants’ contention of 

indefinite for lack of structure is erroneous at least because Defendantsfail to identify any function. 

Micro Chem. Inc., 194 F.3d at 1258. (“An error in identification of the function can improperly 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 17 of 33
13

alter the identification of structure in the specification corresponding to that function.”). The 

correct recited function is “classifying said blocks either as corrected or uncorrected through the 

Forward Error Correction function.” And the correct corresponding structure is “network node 

performing Forward Error Correction function, and equivalents thereof.” See e.g., ’727 patent, 

2:45-65 (“[t]he following primitives can be obtained from a FEC end function, performed in the 

network node: [listing CEC, corrected errors; UBC, uncorrected blocks; DS: defect second]”).

8. “means for calculating the Performance Monitoring function by 

implementing a correlation of the information regarding said 

corrected and uncorrected blocks” (Claims 4, 5)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Subject to 35 U.S.C. § 112, ¶6 

Function: calculating the Performance 

Monitoring function by implementing a 

correlation of the information regarding said 

corrected and uncorrected blocks

Structure: telecommunication network 

management system, and equivalents thereof

Algorithm (if required): see e.g., 1:63-2:21, 

2:36-4:54, Fig. 1, and equivalents thereof

Subject to 35 U.S.C. § 112, ¶6

Function: calculating the Performance 

Monitoring Function by implementing a 

correlation of the information regarding said 

corrected and uncorrected blocks wherein said 

correlation of the information regarding said 

corrected and uncorrected blocks includes

calculating information comprising: a defected 

base reference time period (SCS) or a time 

period where at least an uncorrected block 

(UB) has been detected and a number of 

corrected errors (BCE) in a non-SCS base

reference time period.

Structure: Algorithmic structure:

, and 

equivalents thereof

The parties agree this term is subject to 35 U.S.C. § 112, ¶6. However, Defendants fail to 

recite the correct recited function and structure. Defendants’ proposed function improperly 

includes extraneous elements from the claims’ wherein clauses. See e.g. ’727 patent, 6:14-19 

(Claim 4), 6:38-46 (Claim 5). The Federal Circuit has emphasized that in performing the first step, 

“a court may not construe a means-plus-function limitation 'by adopting a function different from 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 18 of 33
14

that explicitly recited in the claim.'” JVW Enterprises, Inc. v. Interact Accessories, Inc., 424 F.3d 

1324, 1331 (Fed. Cir. 2005) quoting Micro Chem., 194 F.3d at 1258. That is because “[a]n error 

in identification of the function can improperly alter the identification of structure in the 

specification corresponding to that function.” Micro Chem., 194 F.3d at 1258. The correct recited 

function is “calculating the Performance Monitoring function by implementing a correlation of 

the information regarding said corrected and uncorrected blocks.” Further, Defendants’ proposed 

structure is erroneous because Defendants’ proposed construction does not identify a structure, 

instead Defendants appear to identify an algorithm. The correct corresponding structure is

“telecommunication network management system, and equivalents thereof.” And to the extent an 

algorithm is required, exemplary algorithms disclosed in the specification are recited at ’727 

patent, 1:63-2:21, 2:36-4:54, Fig. 1, and equivalents thereof. For example, the specification teaches 

obtaining certain values from a FEC end function (such as CEC, UBC, and DS), based on those 

FEC values, determining certain other values (such as BCE and SCS), determining a summation 

of values of BCE and SCS events, and correlating the information regarding corrected blocks and 

uncorrected blocks. See e.g., 2:36-4:54, Fig. 1.

9. “implementing a Performance Monitoring function based on data 

retrieved through a Forward Error Correction Function” (Claims 6, 

7)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Plain and ordinary meaning Subject to 35 U.S.C. § 112, ¶6

Function: implementing a Performance 

Monitoring function based on data retrieved 

through a Forward Error Correction function

Structure: Algorithm disclosed in Figure 1, 

and equivalents thereof.

This term should be given its plain and ordinary meaning. Because this term does not 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 19 of 33
15

contain the words “means for,” there is a rebuttable presumption that section 112, paragraph 6, 

does not apply to that limitation. Williamson v. Citrix Online, LLC, 792 F.3d 1339, 1348 (Fed. Cir. 

2015) (en banc). That presumption can be overcome, but only "if the challenger demonstrates that 

the claim term fails to ‘recite sufficiently definite structure’ or else recites ‘function without 

reciting sufficient structure for performing that function.’" Id. at 1349. The question whether this 

term invokes section 112, paragraph 6, depends on whether persons skilled in the art would 

understand the claim language to refer to structure, assessed in light of the presumption that flows 

from the drafter’s choice not to employ the word "means."” Samsung Elecs. Am. v. Prisua Eng'g 

Corp., 948 F.3d 1342, 1354 (Fed. Cir. 2020); Skky, Inc. v. MindGeek, s.a.r.l., 859 F. 3d 1014, 1019 

(Fed. Cir. 2017) (‘To determine whether a claim recites sufficient structure, "it is sufficient if the 

claim term is used in common parlance or by persons of skill in the pertinent art to designate

structure, even if the term covers a broad class of structures and even if the term identifies the 

structures by their function.”’). 

Here, the claim language refers to structure, given that the preamble of Claims 6 and 7 

recite “a computer program having a program code... said computer program comprises:” (’727 

patent, 6:47-49 (Claim 6)), and “a computer readable medium having recorded thereon a computer 

code...adapted to enable a computer to perform the steps comprising:” (7:3-5 (Claim 7)). The term 

“program code” of Claim 6 is not a nonce word and connects specific structure.3 See e.g., Virginia 

Innovation Sciences, Inc. v. Amazon.com, Inc., 2019 Markman 4259020, 2019 WL 4259020, *30-

*32 (E.D. Tex. 2019) (term "program code" was not a nonce word but connoted specific structure 

to avoid means-plus-function treatment); WhitServe LLC v. GoDaddy.Com, Inc., 2014 WL 

3 The specification expressly recites that “[t]he present invention can advantageously be 

implemented by a computer software comprising program code... when said program is run 

on an computer.”

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 20 of 33
16

5668335, *3-*4 (D. Conn. 2014) (ruling that claim limitation “software executing on said 

computer” was not a means-plus-function limitation); Amdocs (Israel) Limited v. Openet Telecom, 

Inc., 2018 Markman 1699429, 2018 WL 1699429, *16-*18 (E.D. Va. 2018) (term in limitations 

reciting “computer code” was not a means-plus-function limitation). And Claim 7 is written in a 

Beauregard claim format. See CLS Bank International v. Alice Corp. Pty. Ltd., 717 F.3d 1269, 

1287 (Fed. Cir. 2013) (“named for In re Beauregard, 53 F.3d 1583 (Fed. Cir. 1995) . . . [c]laims 

in Beauregard format formally recite a tangible article of manufacture—a computer-readable 

medium, such as a computer disk or other data storage device—but such claims also require the 

device to contain a computer program for directing a computer to carry out a specified process”).

Accordingly, this term is not subject to 35 U.S.C. § 112, ¶6, but to the extent the Court 

deems that the presumption is overcome, this term should be construed with the same function and 

structure as the analogous claim term discussed in Section II.C.6, above. 

10. “classifying said blocks either as corrected or uncorrected through the 

Forward Error Correction function” (Claims 6, 7)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Plain and ordinary meaning Subject to 35 U.S.C. § 112, ¶6

Indefinite for lack of structure.

This term should be given its plain and ordinary meaning. Because this term does not 

contain the words “means for,” there is a rebuttable presumption that section 112, paragraph 6, 

does not apply to that limitation. Here, the presumption is not overcome and the claim language 

refers to structure for the same reasons discussed in Section II.C.9, above. To the extent the Court 

deems that the presumption is overcome, this term should be construed with the same function and 

structure as the analogous claim term discussed in Section II.C.7, above.

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 21 of 33
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III. U.S. Patent No. 7,508,755 (Case No. 6:20-cv-00535) Disputed Claim Terms

A. Overview of the ’755 Patent

The ’755 patent is generally directed to methods and devices in networking for re-routing 

traffic traveling in both directions from a bi-directional label switched path (LSP) to an alternate 

path using the same network elements. ’755 patent, 1:47-49. The ’755 patent summarizes certain 

technical problems in the field that existed at the time, nearly two decades ago. At the time of the 

invention, a failure in a network device or link occurs downstream of a source network device, socalled existing MPLS Fast Re-routing techniques are employed to bypass the failure. Id., 1:15-17. 

However, while the existing MPLS Fast Re-routing techniques were effective in re-routing MultiProtocol Label Switched (MPLS) traffic in an LSP acting independently relative to other LSPs, 

when LSPs were bundled together to operate in two directions, such as in bi-directional LSPs, 

MPLS Fast Re-routing did not perform well. This is because existing techniques attempted to reroute traffic from a forward LSP to a predetermined alternate path. However, because many times 

there would be no predetermined alternate path for a backward LSP in a bi-directional LSP, once 

a failure occurs, no traffic was allowed to flow in the backward direction. As a result, the bidirectional LSP no longer operated as a bi-directional LSP; it became a uni-directional LSP. Id., 

1:19-33. The existing techniques at the time were also deficient when both the forward and 

backward LSPs had alternate LSPs. In that instance, the existing MPLS Fast Re-routing created 

two separate alternate paths, one for each direction. But creating different alternate paths for the 

forward and backward LSPs of bi-directional LSP made it difficult to ensure the same quality of 

service. Id., 1:34-43. 

In a preferred embodiment, the ’755 patent provides an originating network device 

operable to re-route traffic traveling in a forward direction to an alternate path in the forward 

direction, and to transmit a switch over message along the alternate path in the forward direction 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 22 of 33
18

to a network device responsible for re-routing traffic traveling along the bi-directional LSP in a 

backward direction to the alternate path, where the alternate path in the forward direction and the 

alternate path in the backwards direction uses the same network elements. Id., 1:45-56.

B. Terms with Constructions Not Contested by Defendants

Term Construction not contested by Defendants

“means for receiving the switch over 

message” (Claims 8, 25)

Subject to 35 U.S.C. § 112, ¶6

Function: receiving the switch over message

Structure: merging network device, and 

equivalents thereof

“[means for] receiving a switch over message 

along the alternative path in the forward 

direction” (Claim 23)

Subject to 35 U.S.C. § 112, ¶6

Function: receiving a switch over message 

along the alternative path in the forward 

direction

Structure: merging network device, and 

equivalents thereof

Algorithm (if required): see e.g., 2:7-32, 2:43-

60, 3:13-36, Figs. 1, 2, 3

C. Terms with Disputed Constructions

11. “originating network device” (Claims 1, 3)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Plain and ordinary meaning “a network device of a primary LSP which is 

not a source network device of the same 

primary LSP”

This term should be given its plain and ordinary meaning. The claim language itself 

provides a definition of this term. Specifically, an “originating network device” is operable to reroute traffic along a bi-directional LSP in a forward direction to an alternate path...” and “transmit 

a switch over message...” ’755 patent, 4:12-20. The specification discloses the same. See Id., 1:51-

57. Toshiba, 681 F.3d 1369 (“Absent disclaimer or lexicography, the plain meaning of the claim 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 23 of 33
19

controls.”). Additionally, Defendants’ proposed construction is confusing and unhelpful as there 

is no requirement for “a primary LSP” anywhere in the claim language; instead the claims only 

require “a bi-directional LSP” and an “alternate path.” Moreover, Defendants’ proposed 

construction is improper for attempting to import limitations from the specification into the claim 

language. For example, Defendants seek to require that the term cannot be “a source network 

device,” support for which Defendants will likely point to the disclosure regarding the embodiment 

depicted by Figure 2. But Defendants’ proposed construction should be further rejected. As that 

particular embodiment explains: “This is so, because bi-directional Fast Re-routing uses some of 

the functionality of traditional MPLS Fast Re-routing which does not function at a source network 

device.” ’755 patent, 3:1-3. However, that is just one specific embodiment having specific 

parameters at the time of the invention, and the specification expressly understood that it could 

only describe “so-called existing MPLS Fast Re-routing techniques.” Id., 1:15-17 (emphasis 

added). Further, the patentee expressly states that the described embodiments are “various 

exemplary embodiments of the present invention. Variations of the examples given above may be 

derived without departing from the spirit or scope of the present invention.” Id., 3:64-67. 

Regardless, importing limitations from an embodiment is improper, even if it is the only 

embodiment. Liebel–Flarsheim, 358 F.3d at 906.

12. “switch over message” (Claims 1, 5, 8, 10, 13, 16, 18, 23, 25)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Plain and ordinary meaning “a message which instructs a device to 

perform a switch over to the alternate path and 

which is not a message that indicates a fault 

has occurred in the network”

This term should be given its plain and ordinary meaning. Defendants’ proposed 

construction at best attempts to re-phrase the claim language, which is unnecessary, but also 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 24 of 33
20

attempts to add a negative limitation that the term “is not a message that indicates a fault has 

occurred in the network.” But this negative limitation does not clarify “switch over message,” and 

instead it amounts to an attempt of improper importation of a limitation from the specification. 

Toshiba, 681 F.3d 1369 (“Absent disclaimer or lexicography, the plain meaning of the claim 

controls.”). Indeed, the word “fault” doesn’t appear anywhere in the patent, and to the extent the

negative limitation can be understood, it is unclear how a switch over message would be 

completely exclusive of also being a message that indicates a fault in the network. 

13. “means for re-routing traffic traveling along the bi-directional LSP in 

the backwards direction to the alternate path in the backwards 

direction based on the switch over message.” (Claims 8) /

“means for re-routing traffic traveling along a bi-directional LSP in a 

backwards direction to an alternate path in the backwards direction 

based on the switch over message” (Claim 23) / 

“means for re-routing traffic traveling along the bi-directional LSP in 

a backwards direction to the same alternate path in the backwards 

direction based on the switch over message” (Claim 25)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Subject to 35 U.S.C. § 112, ¶6

Function: re-routing traffic traveling along the 

bi-directional LSP in the backwards direction 

to the alternate path in the backwards 

direction based on the switch over message

(Claim 8)

re-routing traffic traveling along a bidirectional LSP in a backwards direction to an 

alternate path in the backwards direction 

based on the switch over message (Claim 23)

re-routing traffic traveling along the bidirectional LSP in a backwards direction to 

the same alternate path in the backwards 

direction based on the switch over message

(Claim 25)

Subject to 35 U.S.C. § 112, ¶6

Indefinite for failure to disclose sufficient 

structure.

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 25 of 33
21

Structure: merging network device, and 

equivalents thereof

Algorithm (if required): see e.g., 2:7-32, 2:43-

60, 3:13-36, Figs. 1, 2, 3

The parties agree that this term is subject to Subject to 35 U.S.C. § 112, ¶6. Defendants’

contention of indefinite for failure to disclose sufficient structure is erroneous at least because 

Defendants fail to identify any function. Micro Chem. Inc., 194 F.3d at 1258. (“An error in 

identification of the function can improperly alter the identification of structure in the specification 

corresponding to that function.”). The analogous terms in Claims 8, 23, and 25 are essentially 

identical except for a minor variation. For each of the claims, the correct recited function is “rerouting traffic traveling along the bi-directional LSP in the backwards direction to the alternate 

path in the backwards direction based on the switch over message” (Claim 8); re-routing traffic 

traveling along a bi-directional LSP in a backwards direction to an alternate path in the backwards 

direction based on the switch over message (Claim 23); and re-routing traffic traveling along the 

bi-directional LSP in a backwards direction to the same alternate path in the backwards direction 

based on the switch over message (Claim 25). And the correct corresponding structure is

“merging network device, and equivalents thereof.” See e.g., ’755 patent, 4:44-45, 6:20, 2:19-25, 

2:52-60, 3:13-16. And to the extent an algorithm is required, the claim language itself sets out an 

algorithm, and further exemplary algorithms disclosed in the specification are recited at Id., 2:7-

32, 2:43-60, 3:13-36, Figs. 1, 2, 3, and equivalents thereof. For example, the specification teaches

a merging network device receiving a switch over message having an alternate path that may be 

predetermined, and based on the switch over message, the merging network device creates an 

alternate path in the backward direction using the same network elements and switches backward 

flowing traffic to the alternate path. Id.

14. “means for re-routing traffic traveling along a bi-directional LSP in a 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 26 of 33
22

forward direction to an alternate path in the forward direction” 

(Claim 20)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Subject to 35 U.S.C. § 112, ¶6

Function: re-routing traffic traveling along a 

bi-directional LSP in a forward direction to an 

alternate path in the forward direction

Structure: originating network device, and 

equivalents thereof

Algorithm (if required): see e.g., 1:51-56, 2:7-

32, 2:43-60, Figs. 1, 2, 3

Subject to 35 U.S.C. § 112, ¶6

Indefinite for failure to disclose sufficient 

structure.

The parties agree that this term is subject to Subject to 35 U.S.C. § 112, ¶6. Defendants’

contention of indefinite for failure to disclose sufficient structure is erroneous at least because 

Defendants fail to identify any function. Micro Chem. Inc., 194 F.3d at 1258. (“An error in 

identification of the function can improperly alter the identification of structure in the specification 

corresponding to that function.”). The correct recited function is “re-routing traffic traveling 

along a bi-directional LSP in a forward direction to an alternate path in the forward direction.” 

And the correct corresponding structure is “originating network device, and equivalents

thereof.” See e.g., ’755 patent, 6:1-2, 1:51-56, 2:7-32, 2:43-60. To the extent an algorithm is 

required, the claim language itself sets out an algorithm, and further exemplary algorithms 

disclosed in the specification are recited at Id., 1:51-56, 2:7-32, 2:43-60, Figs. 1, 2, 3, and 

equivalents thereof. For example, the specification teaches an originating network device 

determining an alternate path or using a stored predetermined alternate path, then sending a switch 

over message along the alternate path to the merging network device, and then performing a switch 

over so that traffic flowing in the forward direction can travel along the alternate path. Id.

15. “means for transmitting a switch over message along the alternate 

path in the forward direction to a merging network device responsive 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 27 of 33
23

for re-routing traffic traveling along the bi-directional LSP in a 

backward direction to the alternate path in the backward direction” 

(Claim 20) / 

“means for transmitting a switch over message, along the alternate 

path in the forward direction, for re-routing traffic traveling along 

the bi-directional LSP in a backward direction” (Claim 25)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Subject to 35 U.S.C. § 112, ¶6

Function: transmitting a switch over message 

along the alternate path in the forward 

direction to a merging network device 

responsive for re-routing traffic traveling 

along the bi-directional LSP in a backward 

direction to the alternate path in the backward 

direction (Claim 29)

transmitting a switch over message, along the 

alternate path in the forward direction, for rerouting traffic traveling along the bidirectional LSP in a backward direction” 

(Claim 25)

Structure: originating network device, and 

equivalents thereof

Algorithm (if required): see e.g., 1:51-56, 2:7-

32, 2:43-60, 3:9-36, Figs. 1, 2, 3

Subject to 35 U.S.C. § 112, ¶6

Indefinite for failure to disclose sufficient 

structure.

The parties agree that these terms are subject to Subject to 35 U.S.C. § 112, ¶6. Defendants’

contention of indefinite for lack of structure is erroneous at least because Defendantsfail to identify 

any function. Micro Chem. Inc., 194 F.3d at 1258. (“An error in identification of the function can 

improperly alter the identification of structure in the specification corresponding to that 

function.”). The analogous terms in Claims 20 and 25 are very similar and share the same 

corresponding structure. For each of the claims, the correct recited function is “transmitting a 

switch over message along the alternate path in the forward direction to a merging network device 

responsive for re-routing traffic traveling along the bi-directional LSP in a backward direction to 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 28 of 33
24

the alternate path in the backward direction” (Claim 20); and “transmitting a switch over message, 

along the alternate path in the forward direction, for re-routing traffic traveling along the bidirectional LSP in a backward direction” (Claim 25). And the correct corresponding structure 

is “originating network device, and equivalents thereof.” See e.g., ’755 patent, 6:1-2, 1:51-56, 2:7-

32, 2:43-60. And to the extent an algorithm is required, the claim language itself sets out an 

algorithm, and further exemplary algorithms disclosed in the specification are recited at Id., 1:51-

56, 2:7-32, 2:43-60, 3:9-36, Figs. 1, 2, 3, and equivalents thereof. For example, the specification 

teaches an originating network device determining an alternate path or using a stored 

predetermined alternate path and sending a switch over message along the alternate path to the 

merging network device. And based on the switch over message, the merging network device 

creates an alternate path in the backward direction using the same network elements and switches 

backward flowing traffic to the alternate path. Id.

16. “means for means for [sic] receiving traffic traveling along a bidirectional LSP in a forward direction to an alternate path in the 

forward direction” (Claim 23)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Subject to 35 U.S.C. § 112, ¶6

Function: receiving traffic traveling along a 

bi-directional LSP in a forward direction to an 

alternate path in the forward direction

Structure: merging network device, and 

equivalents thereof

Algorithm (if required): see e.g., 2:7-32, 2:43-

60, 3:13-36, Figs. 1, 2, 3

Subject to 35 U.S.C. § 112, ¶6

Indefinite for failure to disclose sufficient 

structure.

The parties agree that this term is subject to Subject to 35 U.S.C. § 112, ¶6. Defendants’

contention of indefinite for lack of structure is erroneous at least because Defendantsfail to identify 

any function. Micro Chem. Inc., 194 F.3d at 1258. (“An error in identification of the function can 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 29 of 33
25

improperly alter the identification of structure in the specification corresponding to that 

function.”). The correct recited function is “receiving traffic traveling along a bi-directional LSP 

in a forward direction to an alternate path in the forward direction.” And the correct 

corresponding structure is “merging network device, and equivalents thereof.” See e.g., ’755 

patent, 6:20, 2:7-32, 2:43-60, 3:13-36. And to the extent an algorithm is required, 4the claim 

language itself sets out an algorithm, and further exemplary algorithms disclosed in the 

specification are recited at Id., 2:7-32, 2:43-60, 3:13-36, Figs. 1, 2, 3, and equivalents thereof. For 

example, the specification teaches a merging network device receiving a switch over message in 

the forward direction via an alternate path after a failure is detected. Id. 

IV. U.S. Patent No. 8,417,112 (Case No. 6:20-cv-00540) Disputed Claim Terms

A. Overview of the ’112 Patent

The ’112 patent is generally directed to improving accuracy in monitoring in an optical 

network to determine when to switch, or re-route traffic. ’112 patent, Abstract, 1:6-10. The ’112

patent summarizes certain technical problems in the field that existed at the time, nearly two 

decades ago. At the time of the invention, the standardized optical digital transmission systems 

that were used generally specified that the protection time (the time it takes to re-route client traffic 

after detection of a failure) must be 50 milliseconds (ms) or less; that the number of network 

elements (Nodes) in the ring is 16 or fewer; and that the total fiber distance around the ring is 1200 

kilometers (km) or less. However, factors existed which caused the detection and initiation of the 

switching time to exceed 50 ms. For example, the size of the network and the length of optical 

fiber traversed are factors which could cause the time to exceed 50 ms. Id., 1:38-46. Exemplary 

factors that could induce switching were a loss of signal (LOS) or bit error rate (BER) that was too 

4 The Federal Circuit has held that for functions such as “receiving,” no algorithm is required. In 

re Katz Interactive Call Proc. Patent, 639 F.3d 1303, 1316 (Fed. Cir. 2011).

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 30 of 33
26

high. Systems at the time did not distinguish between a BER that exceeds the threshold due to a 

true line failure or a BER transient that momentarily causes the BER value to exceed the BER 

threshold. Id., 1:47-59. Without knowledge of the actual maximum switch time to an alternate 

transmission path, it was difficult to guarantee the initiation of a switch within 50 ms. Id., 1:60-67. 

In a preferred embodiment, the ’112 patent a switching method is provided having 

improved accuracy in monitoring a network to determine when to switch. The method collects and 

stores a plurality of bit error rate (BER) values. The BER values are analyzed using a BER 

hysteresis algorithm to check BER degradation. Thereafter, the method switches a transmission 

port when the degradation exceeds a predetermined BER threshold level for a predetermined time 

period. In another embodiment, a feature which transmits a switch polling signal for a 

predetermined duration is used with the switching method. Id., 2:1-15.

B. Terms with Disputed Constructions

17. “determining whether said collected BER values worsen over time” 

(Claims 1, 11)

WSOU’s Proposed Construction Defendants’ Proposed Construction

Plain and ordinary meaning “determining whether said collected BER 

values worsen over time by comparing one or 

more of said recent ones of said collected 

BER values with said other collected BER 

values”

This term should be given its plain and ordinary meaning. The claim language itself 

provides a definition of this term, which is evidenced by Defendants reciting the claim language 

verbatim in their proposed construction. Defendants’ additional recitation in their proposal is 

confusing, as it simply states that some value(s) should be compared with other value(s), but that 

concept is already included in the term itself. Moreover, Defendants’ proposed construction is 

unnecessarily duplicative, more verbose, and deficient. Specifically, it is unclear how merely 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 31 of 33
27

“comparing one or more of said recent of said collected BER values with said other collected BER 

values” helps in “determining whether said collected BER values worsen over time.” For example, 

it is unclear how comparing merely one recent value can show “worsen over time.” Defendants’

proposed construction should be rejected. Toshiba, 681 F.3d 1369 (“Absent disclaimer or 

lexicography, the plain meaning of the claim controls.”).

Dated: February 5, 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 

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 

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

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 32 of 33
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Counsel for Plaintiff WSOU Investments, LLC

CERTIFICATE OF SERVICE

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

via U.S. District Court [LIVE]- Document Filing System, to all counsel of record, on this the 30th 

day of February 5, 2021.

/s/ James L. Etheridge

James L. Etheridge 

Case 6:20-cv-00543-ADA Document 44 Filed 02/05/21 Page 33 of 33