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. 

MICROSOFT CORPORATION,

Defendant.

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CIVIL ACTION 6:20-cv-00454-ADA

CIVIL ACTION 6:20-cv-00461-ADA

CIVIL ACTION 6:20-cv-00465-ADA

PLAINTIFF’S SUPPLEMENTAL CLAIM CONSTRUCTION BRIEF 

ADDRESSING “TIME-AVERAGING INTERVAL”

“packet loss rate”1

WSOU’s Proposed Construction Defendant’s Proposed Construction

the fraction of packets that are lost over a

time interval suitable for the collected “data”

to be probative of the “at least one path”

the fraction of packets that are lost over a 

suitable interval of time over which an 

average is taken

1 In the table above, WSOU has inserted the parties’ respective definitions for “suitable timeaveraging interval” (as stated in lexicography for the “packet loss rate” term) into the parties’ 

previously proposed constructions for the “packet loss rate” term. 

Case 6:20-cv-00461-ADA Document 59 Filed 03/16/21 Page 1 of 4
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Anticipating that the Court may seek input on how the lexicography in the specification for 

“packet loss rate” should itself be interpreted, WSOU’s response brief states that “suitable timeaveraging interval” at least encompasses the following embodiments: (1) a fixed time interval and 

(2) an adaptively determined time interval. Dkt. 52, 21.2

 Now that the Court has requested a 

proposed definition, a “suitable time-averaging interval” means “a time interval suitable for the 

collected ‘data’ to be probative of the ‘at least one path’” (where quotation marks indicate claim 

language). Microsoft incorrectly proposes “an interval of time over which an average is taken.” 

Microsoft leaves the Court (and ultimately the jury) to guess as to what exactly must be averaged 

over the time interval. Microsoft also overlooks that in the phrase “suitable time-averaging 

interval” the couplet “time-averaging” modifies “interval”—i.e., the couplet refers to time (not 

averaged values). Indeed, the word “averaging” is itself expressly tethered to “time” by a hyphen. 

WSOU’s refined construction accurately reflects disclosure in the specification 

surrounding the acknowledged lexicography (at 3:46-47). The paragraph immediately preceding 

the lexicographic statement explicitly addresses the “time interval” concept as follows: 

One important observation we have made is that information collected at one 

link of the network, relating to losses of correlated pairs of packets, may be 

probative of loss rates on other, downstream links of the network. To put this 

observation into practice, we have defined a “pair” as two packets, destined 

for different end nodes, that were both transmitted from the root node within a 

time interval δ. The value of δ may be specified by the operator, or it may be 

determined adaptively. In many networks, there will be s high correlation 

between the losses of packets transmitted sufficiently close in time, not least 

because if one packet is dropped due to buffer overflow, a packet following a 

short time later is likely to meet the same fate. Although useful values for δ 

will depend on the properties of the specific network of interest, typical values 

in a W-CDMA network could lie in the range 50-100 ms.

3:30-44 (emphasis added). Consistent with claims 1 and 6, this paragraph discloses the “important 

observation” that information collected at one point in a network may be probative of packet loss 

rates elsewhere along the same path. Id. The paragraph further teaches that the correlation will 

be “high” for “losses of packets transmitted sufficiently close in time, not least because if one 

2 WSOU still maintains the claim language should encompass all disclosed embodiments.

Case 6:20-cv-00461-ADA Document 59 Filed 03/16/21 Page 2 of 4
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packet is dropped due to buffer overflow, a packet following a short time later is likely to meet the 

same fate.” Id. An example time range is also provided. Id. 

Consistent with the above disclosure, claim 1 recites “collecting data on downstream 

packet losses at a single collection point in a network” (8:13-14). Claim 6 recites analogous 

limitations in the context of a “monitoring device” (8:40-41). Claim 1 further recites, in part, 

“from the collected data, estimating a packet loss rate on at least one path . . . .” (8:20-21); and, 

again, claim 6 recites analogous limitations (8:47-48). This claim language reflects certain 

concepts in the block quotation above—i.e., that information collected at one point in a network 

may be probative of packet loss rates on a downstream path, provided a suitable time interval is 

used in measuring data at the collection point. In view of this intrinsic evidence, the statement 

“suitable time-averaging interval” (appearing in the lexicography) should be interpreted as “time 

interval suitable for the collected ‘data’ to be probative of the ‘at least one path’” (where probative 

in this context refers to the “packet loss rate,” which is the claim term being defined).

Importantly, “packet loss rate” is repeatedly described in the specification as something 

that is measured as a fraction of packets that are lost. See, e.g., 3:46-47 (lexicographic statement 

in question); 5:35-36 (“The end-to-end loss rate from n0 to n4 is measurable”); 3:58-60 (“one 

quantity that is measurable . . . is the end-to-end packet loss rate”). The specification contains no 

unambiguous requirement or disclaimer to support an interpretation that the measurements 

themselves must be averaged over a given time interval, as Microsoft newly seeks to require 

through claim construction. Indeed, it would appear Microsoft’s extraneous requirement would 

exclude preferred embodiments where a count of dropped packets is used to measure the faction 

of packets that are lost (e.g., 3:45-5:27, including the discussion of “Algorithm 1” and Algorithm 

2”). The question of packet loss may be binary (e.g., a packet is either lost or it is not). This 

further underscores that averaging over an interval of time (as Microsoft proposes) is not 

necessarily required. For this additional reason, Microsoft’s untethered construction should be 

rejected.

Case 6:20-cv-00461-ADA Document 59 Filed 03/16/21 Page 3 of 4
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Dated: March 16, 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 U.S. District Court [LIVE]- Document Filing System, to all counsel of record, on March 16, 

2021.

/s/ James L. Etheridge

James L. Etheridge 

Case 6:20-cv-00461-ADA Document 59 Filed 03/16/21 Page 4 of 4