TC Technology LLC v. Sprint Corporation et al

Filing 354

MEMORANDUM OPINION. Signed by Judge Richard G. Andrews on 4/15/2019. (nms)

IN THE UNITED STATES DISTRICT COURT
FOR THE DISTRICT OF DELAWARE

TC TECHNOLOGY LLC,
Plaintiff,
V.

No. 16-cv-153-RGA
SPRINT CORPORATION and SPRINT
SPECTRUM L.P .,
Defendants.

MEMORANDUM OPINION
Kelly E. Farnan, Katharine L. Mowery, RICHARDS , LAYTON & FINGER, P.A. , Wilmington,
DE; Lawrence J. Gotts, Saswat Misra, LATHAM & WATKINS LLP, Washington, D.C. ; Kevin
L. Mallen, LATHAM & WATKINS LLP, New York, NY; Gabriel S. Gross, LATHAM &
WATKINS LLP, Menlo Park, CA; Stephanie N. Solomon, QUINN EMANUEL URQUHART &
SULLIVAN, LLP, New York, NY; David S. Benyacar, Daniel L. Reisner (argued), Maxwell C.
Preston, Michael J. Block, ARNOLD & PORTER KA YE SCHOLER LLP, New York, NY.
Attorneys for Plaintiff.
Shanti M. Katona, Christina M . Belitz, POLSINELLI PC, Wilmington, DE; Robert Reckers
(argued), David Morehan (argued), SHOOK, HARDY & BACON LLP, Houston, TX; Christine
A. Guastello, Jordan T. Bergsten, Colman D. McCarthy, Thomas M. Patton, SHOOK, HARDY
& BACON LLP, Kansas City, MO.
Attorneys for Defendants.

April

/5, 2019

Presently before the Court are Defendants' motion for summary judgment of
noninfringement (D.I. 257) and Plaintiff's motion for partial summary judgment (D.I. 266). I
have reviewed the parties' briefing. (D.I. 258,267,288, 293, 304, 306). I heard oral argument
on March 7, 2019. 1
I.

BACKGROUND
Plaintiff TC Technology LLC ("TC Tech") filed this action on March 10, 2016, alleging

that Defendants Sprint Corporation and Sprint Spectrum, L.P. (collectively, "Sprint") infringed
U.S. Patent No. 5,815,488 ("the ' 488 patent") with certain wireless services on its LTE network.
(D.I. 1).
The ' 488 patent has two independent method claims, both of which are asserted. The
claims provide:
1. A method for enabling a plurality of remote locations to transmit data to a
central location comprising the steps of:
at each remote location, coding data to be transmitted by translating each
group of one or more bits of said data into a transform coefficient
associated with a particular baseband frequency in a particular subset of
orthogonal baseband frequencies allocated to the remote location, the
particular subset of orthogonal baseband frequencies allocated to each
remote location being chosen from a set of orthogonal baseband
frequencies, the subsets of baseband frequencies allocated to each remote
location being mutually exclusive[;]
at each remote location, using an electronic processor, performing an
inverse orthogonal transformation on said transform coefficients to
obtain a block oftime domain data;
at each remote location, utilizing a modulator to modulate said block of
time domain data onto a carrier signal for transmission to said central
location, said carrier signal having the same carrier frequency for each
remote location;

1

I cite to the transcript as "Oral Argument."

2

receiving at said central location from one or more of said remote
locations, one or more blocks of time domain data modulated on one or
more of said carrier signals;
using a demodulator, demodulating said one or more blocks of time
domain data from the carrier frequency signal[;]
performing said orthogonal transformation on said demodulated time
domain data to reconstruct said transform coefficients, and
translating said transform coefficients into said data to be translated from
each remote location.
2. A method for enabling a plurality of remote locations to transmit data to a
central location comprising the steps of:
at each remote location, coding data to be transmitted by translating each
group of one or more bits of said data into a transform coefficient
associated with a particular baseband frequency in a particular subset of
orthogonal baseband frequencies allocated to the remote location, the
particular subset of orthogonal baseband frequencies allocated to each
remote location being chosen from a set of orthogonal baseband
frequencies, the subsets of baseband frequencies allocated to each remote
location being mutually exclusive;
at each remote location, using an electronic processor, performing an
inverse orthogonal transformation on said transform coefficients to
obtain a block oftime domain data;
at each remote location, utilizing a modulator to modulate said block of
time domain data onto a carrier signal for transmission to said central
location, said carrier signal having the same carrier frequency for each
remote location[;]
receiving at said central location from one or more of said remote
locations, one or more blocks of time domain data modulated on one or
more of said carrier signals;
using a demodulator, multiplying said received one or more blocks of
time domain data with in-phase and quadrature carrier signals to obtain
in-phase and quadrature baseband signals, converting said in-phase and
quadrature baseband signals to digital form, and using an electronic
processor, performing said orthogonal transform using said in-phase and
quadrature baseband signals as real and imaginary values, respectively,
to demodulate said one or more blocks of time domain data from the
carrier frequency signal, and

3

performing said orthogonal transformation on the demodulated time
domain data to reconstruct said transform coefficients.
'488 patent at 10:47-12 :24.
Sprint' s LTE network operates through a series of "cell sites." Each cell site consists of a
cell tower with antennas connected to a computer that is referred to as a "base station" or
"eNodeB." (D.I. 259, Ex. A at 36:8-37:6; D.I. 294, Ex.21167). Each base station is divided
into three "sectors," where each sector roughly corresponds to a 120-degree arc around the cell
site. (D.I. 268, Ex. 2, Ex. A 11112-113 ; D.I. 294, Ex.21103). Each sector has dedicated
hardware and software to receive and process information from, as well as to allocate
frequencies to, user devices such as cellular phones. (Id. , Ex. 5 1 34 ). The following is a
simplified illustration of a cell site and its three sectors:
Sector
3

,

-------~

/

Sector

'

"

1

(Id. , Ex.21103 , Ex.5135). The parties focus on the operations of a single base station in
Sprint' s LTE network.

II.

LEGAL STANDARD
"The court shall grant summary judgment if the movant shows that there is no genuine

dispute as to any material fact and the movant is entitled to judgment as a matter of law." Fed.
R. Civ. P. 56(a). Material facts are those "that could affect the outcome" of the proceeding.

Lamont v. New Jersey, 637 F.3d 177, 181 (3d Cir. 2011) (quoting Anderson v. Liberty Lobby,
Inc. , 477 U.S. 242, 248 (1986)). " [A] dispute about a material fact is ' genuine ' if the evidence is
4

sufficient to permit a reasonable jury to return a verdict for the nonmoving party." Id. The
burden on the moving party may be discharged by pointing out to the district court that there is
an absence of evidence supporting the non-moving party' s case. Celotex Corp. v. Catrett, 477
U.S. 317, 323 (1986).
The burden then shifts to the non-movant to demonstrate the existence of a genuine issue
for trial. Matsushita Elec. Indus. Co. , Ltd. v. Zenith Radio Corp. , 475 U.S. 574, 586-87 (1986);
Williams v. Borough of West Chester, Pa. , 891 F.2d 458, 460-61 (3d Cir. 1989). A non-moving
party asserting that a fact is genuinely disputed must support such an assertion by: "(A) citing to
particular parts of materials in the record, including depositions, documents, electronically stored
information, affidavits or declarations, stipulations .. . , admissions, interrogatory answers, or
other materials; or (B) showing that the materials cited [by the opposing party] do not establish
the absence . .. of a genuine dispute . ... " Fed. R. Civ. P. 56(c)(l). The non-moving party' s
evidence "must amount to more than a scintilla, but may amount to less (in the evaluation of the
court) than a preponderance." Williams , 891 F.2d at 461.
When determining whether a genuine issue of material fact exists, the court must view
the evidence in the light most favorable to the non-moving party and draw all reasonable
inferences in that party' s favor. Wishldn v. Potter, 476 F.3d 180, 184 (3d Cir. 2007). If the nonmoving party fails to make a sufficient showing on an essential element of its case with respect
to which it has the burden of proof, the moving party is entitled to judgment as a matter of law.
See Celotex Corp., 477 U .S. at 322.

III.

SPRINT'S MOTION FOR SUMMARY JUDGMENT OF NONINFRINGEMENT
A patent is infringed when a person "without authority makes, uses, offers to sell, or sells

any patented invention, within the United States ... during the term of the patent ... ." 35

5

U.S .C. § 271(a). A two-step analysis is employed in making an infringement determination. See
Markman v. Westview Instruments, Inc., 52 F.3d 967, 976 (Fed. Cir. 1995) (en bane), aff'd, 517

U.S. 370 (1996). First, the court must construe the asserted claims to ascertain their meaning and
scope. See id. The trier of fact must then compare the properly construed claims with the
accused infringing product. See id. at 976. This second step is a question of fact. See Bai v. L &
L Wings, Inc. , 160 F.3d 1350, 1353 (Fed. Cir. 1998).

"Literal infringement of a claim exists when every limitation recited in the claim is found
in the accused device." Kahn v. Gen. Motors Corp., 135 F.3d 1472, 1477 (Fed. Cir. 1998). "If
any claim limitation is absent from the accused device, there is no literal infringement as a matter
of law." Bayer AG v. Elan Pharm. Research Corp., 212 F.3d 1241 , 1247 (Fed. Cir. 2000). If an
accused product does not infringe an independent claim, it also does not infringe any claim
depending thereon. See Wahpeton Canvas Co. v. Frontier, Inc. , 870 F.2d 1546, 1553 (Fed. Cir.
1989). However, "[ o]ne may infringe an independent claim and not infringe a claim dependent
on that claim." Monsanto Co. v. Syngenta Seeds, Inc., 503 F.3d 1352, 1359 (Fed. Cir. 2007). A
product that does not literally infringe a patent claim may still infringe under the doctrine of
equivalents if the differences between an individual limitation of the claimed invention and an
element of the accused product are insubstantial. See Warner-Jenkinson Co. v. Hilton Davis
Chem. Co., 520 U.S. 17, 24 (1997). The patent owner has the burden of proving infringement

and must meet its burden by a preponderance of the evidence. See SmithK!ine Diagnostics, Inc.
v. Helena Lab. Corp., 859 F.2d 878, 889 (Fed. Cir. 1988).

When an accused infringer moves for summary judgment of non-infringement, such
relief may be granted only if at least one limitation of the claim in question does not read on an
element of the accused product, either literally or under the doctrine of equivalents. See Chimie

6

v. PPG Indus., Inc., 402 F.3d 1371 , 1376 (Fed. Cir. 2005); see also TechSearch, L.L.C. v. Intel
Corp., 286 F.3d 1360, 1369 (Fed. Cir. 2002) ("Summary judgment of noninfringement is ...

appropriate where the patent owner's proof is deficient in meeting an essential part of the legal
standard for infringement, because such failure will render all other facts immaterial."). Thus,
summary judgment of noninfringement can only be granted if, after viewing the facts in the light
most favorable to the non-movant, there is no genuine issue as to whether the accused product is
covered by the claims (as construed by the court). See Pitney Bowes, Inc. v. Hewlett-Packard
Co., 182 F.3d 1298, 1304 (Fed. Cir. 1999).

Sprint moves for summary judgment of noninfringement of claims 1 and 2 of the '488
patent. Sprint argues that its LTE network does not meet two claim limitations-(1) "subsets of
baseband frequencies allocated to each remote location being mutually exclusive" and (2)
"carrier signal having the same carrier frequency for each remote location." (D.I. 258).
For the following reasons, Sprint's motion is GRANTED with respect to TC Tech's
doctrine of equivalents theory relating to the Physical Uplink Control Channel ("PUCCH") and
the "mutually exclusive" limitation. The rest of the motion is DENIED.
A. "subsets of baseband frequencies allocated to each remote location being mutually
exclusive"
The Court has construed "subsets of baseband frequencies allocated to each remote
location being mutually exclusive," as "for any given time slot, no individual baseband
frequency is allocated to more than one location." (D.I. 95). Sprint makes two noninfringement
arguments. First, Sprint addresses the base station as a whole. Each base station in Sprint's LTE
network is divided into three sectors. Sprint argues that baseband frequencies are not "mutually
exclusive" across all three sectors. (D.I. 258 at 10-13). Second, Sprint focuses on the individual
base station sectors. Sprint argues that baseband frequencies are also not "mutually exclusive"
7

within each sector due to the frequencies on the Physical Uplink Control Channel ("PUCCH").
(Id. at 13-20).
1. Frequencies Across Base Station Sectors

For the following reasons, Sprint' s motion is DENIED with respect to frequencies across
base station sectors.

It is undisputed that, viewing all three sectors together, a base station does not meet the
"mutually exclusive" limitation, because different sectors may simultaneously allocate the same
baseband frequency to different locations. (D.I. 258 at 10; D.I. 293 at 5-7). The key issue is
whether infringement should be determined based on the sectors together or individually.
The preamble of both claims states, "A method for enabling a plurality of remote
locations to transmit data to a central location comprising the steps of .... " ' 488 patent at
10:47-48, 11:12-13 (emphasis added). The Court has not construed "central location." (D.I. 95).
Sprint asserts that it is undisputed that the "central location" is an entire base station in Sprint's
LTE network. (D.I. 304 at 4). I disagree. TC Tech' s expert, Mr. Bates, makes clear that he
believes each individual base station sector may be a "central location" as required by the ' 488
patent. (D.I. 294, Ex. 5 ,r 31 -32 (opining that Sprint meets the "mutually exclusive" limitation by
"using its network on a sector-by-sector basis, not collectively across sectors as [Sprint's expert,
Mr. Proctor,] would require").
Sprint argues that to view the "central location" as a single sector, rather than the entire
base station, would improperly limit the term. (D.I. 258 at 11-12). I think what constitutes a
"central location" is a question of fact. The ' 488 patent does not give any special meaning to
"central location." The specification merely provides, "At the central location, data is received
from a plurality of remote locations," and, "The central location keeps track of which baseband

8

frequencies are allocated to which remote locations." '488 patent at 4:1 -7. The ' 488 patent does
not consider sectorization like that in Sprint' s LTE network.
I do not think this is a claim construction issue. The parties do not dispute the meaning
of "central location," but whether certain parts of Sprint' s LTE network meet the limitation.
Based on the parties' expert testimony, whether an individual base station sector in Sprint's LTE
network can be considered a "central location" such that it meets the "mutually exclusive"
limitation is a disputed question of fact. Sprint' s noninfringement theory assumes that an
individual sector cannot be a "central location." Therefore, Sprint fails to meet its burden on
summary judgment.

2. PUCCH Frequencies
For the following reasons, Sprint's motion, as related to the PUCCH, is DENIED with
respect to literal noninfringement, and GRANTED with respect to noninfringement under the
doctrine of equivalents.
Sprint' s LTE network allocates frequencies on several channels. The two relevant
channels are the Physical Uplink Shared Channel ("PUSCH") and the Physical Uplink Control
Channel ("PUCCH"). (D.I. 268, Ex. 1, Ex. A 1117; D.I. 294, Ex. 2186). Sprint argues that it
does not infringe because the PUCCH does not allocate "mutually exclusive" frequencies, even
within a single base station sector. (D.I. 258 at 13-20). TC Tech argues that it is only asserting
infringement with respect to the PUSCH frequencies, and regardless, the PUCCH frequencies
meet the "mutually exclusive" limitation literally and under the doctrine of equivalents. (D.I.
293 at 7-10).
Sprint's noninfringement theory requires the PUCCH frequencies to be considered when
determining whether its LTE network meets the "mutually exclusive" limitation. Sprint argues

9

that to exclude the PUCCH frequencies, TC Tech improperly limits the claim term "data" to
"data other than the control data sent over the PUCCH." (DJ. 258 at 14). TC Tech argues,
however, that the claims do not require the PUSCH and PUCCH frequencies to be considered
together. Rather, the PUCCH frequencies are a set of frequencies distinct from the "set of
orthogonal baseband frequencies" from which the "mutually exclusive" allocations are made on
the PUSCH. (DJ. 293 at 8; DJ. 294 ,r 86). Therefore, the "mutually exclusive" limitation can
be met by the PUSCH frequencies alone. (DJ. 293 at 8).
This appears to be a factual dispute over whether certain elements of Sprint' s LTE
network meet the "mutually exclusive" limitation. Specifically, whether the frequencies on the
PUSCH alone can meet the "mutually exclusive" limitation. Sprint' s noninfringement theory
assumes that the limitation must be met by both the PUSCH and PUCCH frequencies. Because
Sprint has failed to show that the limitation must be met by the PUCCH frequencies, it has failed
to meet its burden on summary judgment with respect to literal infringement. Thus, I do not
need to address TC Tech's argument that the PUCCH frequencies literally meet the "mutually
exclusive" limitation.
I will address, however, Sprint's argument that TC Tech has provided insufficient
evidence for its theory under the doctrine of equivalents. (DJ. 258 at 18-20). TC Tech asserts
that to the extent the "mutually exclusive" limitation is not literally satisfied, it is satisfied under
the doctrine of equivalents. (DJ. 294, Ex. 9 ,r,r 168-169). " A finding of infringement under the
doctrine of equivalents requires a showing that the difference between the claimed invention and
the accused product was insubstantial." Stumbo v. Eastman Outdoors, Inc., 508 F.3d 1358, 1364
(Fed. Cir. 2007) (citing Graver Tank & Mfg. Co. v. Linde A ir Prods. Co. , 339 U.S . 605, 608
(1950)). TC Tech relies solely on Mr. Bates ' testimony, which states in relevant part:

10

[A] person having ordinary skill in the art would have considered any
differences between the claim language of "the subsets of baseband
frequencies allocated to each remote location being mutually exclusive" and
the features of Sprint' s LTE [network system], to be insubstantial and would
have found that the two perform substantially the same function and work in
substantially the same way to achieve substantially the same result as required
by the claim language. . .. [T]he vast majority of uplink transmission in an
LTE network occurs in the PUSCH channel. . .. Variations in the
implementation of the PUCCH channel, which consists of certain types of
control information I have identified ... , amount to at best an insubstantial
difference in the overall uplink transmission of an LTE network. This is both
because the fraction of data that is PUCCH data is small, . .. and because the
purpose of an uplink LTE system is to transmit user data, at high rates, which
is conveyed in the PUSCH, not to implement any particular control structure in
PUCCH for implementation's sake.
(D.I. 294, Ex. 9 ,r 169). The bulk of Mr. Bates' testimony is conclusory. The non-conclusory
testimony essentially says, meeting the "mutually exclusive" limitation with the PUSCH
frequencies is equivalent to meeting the limitation with both the PUSCH and PUCCH
frequencies, because the "vast majority" of data is transmitted on the PUSCH. That is
insufficient to support a finding of equivalence. Novartis Pharm. Corp. v. Abbott Labs. , 294 F.
Supp. 2d 557, 564 (D. Del. 2003), ajf'd, 375 F.3d 1328 (Fed. Cir. 2004) (" [A] plaintiff must
' articulate the comparison' between the claimed elements and the elements of the accused device
and present ' substantial evidence' comparing the claimed elements and the accused device in
each of the three aspects of equivalency, i.e. the function, way, and result inquiry.") (citing Malta
v. Schulmerich Carillons, Inc., 952 F.2d 1320, 1329 (Fed. Cir. 1991); Lear Siegler v. Sealy
Mattress Co. of Mich. , 873 F.2d 1422, 1427 (Fed. Cir. 1989)).
B. "carrier signal having the same carrier frequency for each remote location"

For the following reasons, Sprint' s motion is DENIED with respect to the "same carrier
frequency" limitation.
Sprint argues that its LTE network does not meet the "same carrier frequency" limitation
because it is undisputed that not all "remote locations" (e.g. , mobile devices) in the network have
11

the same carrier frequency. (D.I. 258 at 20-22). It is also undisputed, however, that some
"remote locations" have the same carrier frequency. (D.I. 293 at 20-21; D.I. 304 at 10-12).
Sprint relies on the Federal Circuit' s claim construction in Apple Inc. v. Samsung
Electronics Co. , 695 F.3d 1370 (Fed. Cir. 2012). The claim in Apple required an apparatus with
"a plurality of heuristic modules ... wherein . .. each heuristic module ... employs a different,
predetermined heuristic algorithm." Id. at 1377. The parties disagreed over whether the
"different ... algorithm" limitation applied to every heuristic module in the accused device or
whether it could be limited to a subset of modules. The district court found that "plurality"
means "at least two," or "simply the state of being plural," and that " each" modified "a plurality
of heuristic modules." Id. at 1378. Thus, the district court concluded that the claim only
required a unique algorithm for "each of at least two modules," not "each of every module." Id.
The Federal Circuit disagreed. First, the Federal Circuit held that "each" did not modify the term
"a plurality of heuristic modules," but the term "heuristic modules" that immediately follows
"each." Id. Second, the Federal Circuit rejected Apple ' s argument that the claim limitation was
satisfied so long as one "plurality" of modules employed unique algorithms. The Federal Circuit
found Apple' s argument unsupported by both the specification and prosecution history of the
asserted patent. Id. at 1379.
Sprint argues that the disputed claim language here is nearly identical to that in Apple,
and thus the Apple construction should apply. (D.I. 258 at 21). Claims 1 and 2 of the '488
patent both require "a plurality of remote locations to transmit data to a central location
comprising ... at each remote location, utilizing a modulator to modulate . .. time domain data
onto a carrier signal for transmission to said central location, said carrier signal having the same
carrier frequency for each remote location." '488 patent at 10:47-48, 10:63-67, 11: 12-13, 12: 1-

12

6 (emphasis added). Sprint argues that the claims therefore require every "remote location" in
Sprint's LTE network to use the same carrier frequency when communicating with the same
"central location." (D.I. 258 at 20).
I do not think Apple controls here. Claim construction is a fact specific inquiry. "A
claim construction is persuasive, not because it follows a certain rule, but because it defines
terms in the context of the whole patent." Renishaw PLC v. Marposs Societa ' p er Azioni, 158
F.3d 1243, 1250 (Fed. Cir. 1998). Apple addressed a different patent and considered the proper
construction in light of that patent's claim language, specification, and prosecution history. 695
F .3d at 13 77-79. I do not think the Federal Circuit meant to establish a general rule for
construing the terms "plurality" and "each." Nevertheless, the reasoning in Apple appears to be
applicable to the claims here.
Sprint also relies on the ' 488 patent specification. (D.I. 258 at 21-22). The specification
states, "It is desirable for all remote locations which transmit data to the headend [central
location] to use the same carrier frequency." '488 patent at 8:9-10. Sprint further notes, the
specification does not disclose embodiments in which only some "remote locations" use the
same carrier frequency. (D.I. 258 at 22).
Based on the claim language and specification, I think Sprint' s construction is correct,
particularly given the similarities between this case and Apple. Therefore, I construe "having the
same carrier frequency for each remote location" to mean the same carrier frequency is used by
each and every "remote location" that transmits data to the "central location."
Although I conclude that Sprint' s claim construction is correct, I do not think Sprint has
met its burden on summary judgment. Sprint merely argues that not all "remote locations" in its
entire LTE network use the same carrier frequency. (D.I. 258 at 20-22). Sprint does not address

13

whether all "remote locations" transmitting data to the "central location" use the same carrier
frequency, where what constitutes a "central location" is a disputed material fact. See supra§
III.A.I.

IV.

TC TECH'S MOTION FOR PARTIAL SUMMARY JUDGMENT
TC Tech moves for summary judgment of (1) no invalidity under 35 U.S.C. § 102(g)2 for

no reduction to practice of Dr. Jacobsen's alleged prior invention, (2) no anticipation, (3) no
license and patent exhaustion, and (4) no prosecution history estoppel. (D.I. 266,267).
For the following reasons, TC Tech's motion is GRANTED with respect to (1) the use of
computer simulations to prove actual reduction to practice of Dr. Jacobsen's prior invention
under§ 102(g), (2) no anticipation for failure to disclose modulation onto a carrier, (3) Sprint's
license and patent exhaustion defenses, and (4) Sprint's prosecution history estoppel defense and
related prosecution disclaimer arguments. The rest of the motion is DENIED.

A. Section 102(g)
Dr. Jacobsen opines that both claims of the '488 patent are anticipated under§ 102(g) by
her team's invention conceived of in May 1994 ("the Jacobsen invention"), before the September
28, 1995 filing date of the '488 patent. (D.I. 267, at 6; D.I. 268, Ex. 4 at 127:4-10, 130:19131: 11 ). Section 102(g) provides:
A person shall be entitled to a patent unless ... before the applicant's
invention thereof the invention was made in this country by another who had
not abandoned, suppressed, or concealed it. In determining priority of
invention there shall be considered not only the respective dates of conception
and reduction to practice of the invention, but also the reasonable diligence of

2 The '488 patent was filed on September 28 , 1995, before the enactment of the Leahy- Smith America
Invents Act ("AIA"), Pub. L. No. 112- 29, § 3, 125 Stat 284, 285-93 (2011) . Post-AIA § 102 no longer includes
subsection (g) . All references to§ 102 here refer to the pre-AIA version of the statute. See AIA § 3(n)(l), 125 Stat.
at 293 (providing that AIA amendments apply only to applications and patents with an effective filing date of March
16, 2013 , or later).

14

one who was first to conceive and last to reduce to practice, from a time prior
to conception by the other.
35 U.S.C. § 102(g) (1994).3 Therefore, a patent is invalid under§ 102(g) "if the claimed
invention was made in this country by another inventor before the patent' s priority date. Making
the invention requires conception and reduction to practice." Solvay S.A . v. Honeywell Int 'l Inc. ,
742 F.3d 998, 1000 (Fed. Cir. 2014) ("Solvay If') (applying post-amendment§ 102(g)(2)).
TC Tech argues that Sprint has failed to show reduction to practice. Dr. Jacobsen alleges
that her team reduced the invention to practice through actual reduction to practice by computer
simulations and constructive reduction to practice by filing patent applications for U.S. Patent
Nos. 5,625,651 ("Cioffi ' 651 "), 5,644,573 ("Bingham ' 573"), and 5,557,612 ("Bingham ' 612").
(D.I. 268, Ex. 4 at 132:15-138:23). TC Tech argues that neither constitutes reduction to practice
under§ 102(g). (D.I. 267 at 6, 7-10).
1. Computer Simulations

For the following reasons, TC Tech's motion is GRANTED with respect to actual
reduction to practice through computer simulations.
To prove actual reduction to practice, a party must show that it "(1) constructed an
embodiment or performed a process that met all the limitations of the claim and (2) determined
that the invention would work for its intended purpose." In re Steed, 802 F .3d 1311 , 1318 (Fed.
Cir. 2015). TC Tech argues that Dr. Jacobsen's simulations fail to meet to the first requirement.
(D.I. 267 at 8-9).

3

Section 102(g) was later amended to add subsections (g)(l) and (g)(2) . The amendment does not apply to
the '488 patent. 35 U.S.C. § 102(g) (Supp. V 2000) (made applicable to patent applications filed on or after
November 29 , 2000); Act of November 29, 1999, Pub. L. No. 106-11 3, div. B, § 1000(a)(9), 113 Stat. 1536.
However, post-amendment§ 102(g)(2) is substantively identical to pre-amendment § 102(g). Compare 35 U. S.C. §
102(g) (1994), with 35 U.S.C. § 102(g)(2) (2000) . Therefore, I believe more recent caselaw under post-amendment
§ 102(g)(2) may inform my analysis under pre-amendment § 102(g) . Post-amendment § 102(g)( 1) controls priority
of invention in interference proceedings and is not applicable here.

15

The parties agree that a computer simulation may prove actual reduction to practice under
certain circumstances. (Oral Argument at 65: 15-18 ("[A] computer simulation can be a
reduction to practice if, in fact, you're performing all the steps of the claim.")). TC Tech argues,
however, that such reduction to practice is inappropriate here because the '488 patent claims
cannot be performed without a physical system. Thus, an allegedly anticipating invention cannot
be reduced to practice without a physical system. (Id. at 9). It is undisputed that Dr. Jacobsen
did not construct a physical system but performed simulations using software on a single
computer. (D.I. 268, Ex. 4 at 135:21-136:24; D.I. 288 at 1-2; Oral Argument at 70:18-71:6).
TC Tech cites to this Court's opinion in L-3 Communications Corp. v. Sony Corp., 2013
WL 5942521 (D. Del. Oct. 16, 2013). In L-3, the Court held that a computer simulation was

insufficient to show actual reduction to practice because it was not "a physical embodiment" as
required by Cooper v. Goldfarb , 154 F.3d 1321 (Fed. Cir. 1998). Id. at *1. Cooper addressed
reduction to practice in the context of an interference proceeding. 154 F.3d at 1326. The Federal
Circuit found no actual reduction to practice through laboratory experiments, in part because the
party failed to show "the physical embodiment relied upon as an actual reduction to practice
[included] every limitation of the [interference] count." Id. at 1327-28.
Sprint relies on Huawei Technologies, Co. v. Samsung Electronics Co. , 340 F. Supp. 3d
934 (N.D. Cal. 2018). In Huawei, the court found a computer simulation sufficient to show the
alleged prior invention was reduced to practice and thus qualified as § 102(g) prior art. Id. at 986
(applying post-amendment § 102(g)(2)). The court did not provide any independent analysis,
however, but merely followed Mosaid Technologies Inc. v. Samsung Electronics Co., 362 F.
Supp. 2d 526 (D.N.J. 2005). The court in Mosaid denied summary judgment of no reduction to
practice based on a computer simulation. Id. at 548. The court in Mosaid explained, "[I]n this

16

technologically advanced society of ours, there are areas of science where a successfully run
simulation represents the end of the inventive process and the construction of the physical
embodiment is but a matter of mere routine and mechanical application. In that case, and only in
that case, it seems appropriate that a simulation should be a valid reduction to practice." Id.
This Court has declined to follow Mosaid in light of the Federal Circuit decision in Cooper. L-3,
2013 WL 5942521 at *2.
I again decline to follow Mosaid. I think actual reduction to practice should be addressed
under the Federal Circuit' s well-established framework set forth in Steed.
Under the first Steed requirement, the relevant question is whether Dr. Jacobsen's
computer simulations "performed a process that met all the limitations of the [asserted]
claim[s]." See In re Steed, 802 F.3d at 1318. TC Tech argues that they did not because the
simulations were done on a single computer and the asserted claims require transmission of data
from one location to another. (D.I. 267 at 9; Oral Argument at 66:6-23). Sprint argues that no
such transmission is required. (D.I. 288 at 10).
I do not find Sprint's arguments persuasive. Although the asserted claims do not have a
"transmitting" limitation, they clearly involve the movement of data from a "remote location" to
a "central location." Both claims require "at each remote location, utilizing a modulator to
modulate .. . time domain data onto a carrier signal for transmission to [a] central location," and
"receiving at said central location from one or more of said remote locations ... time domain
data modulated on . . . carrier signals." '488 patent at 10:63-65, 11:1 -3, 12:1-3, 12:7-9. Sprint
offers no explanation for how a single computer could "receiv[ e]" data at a "central location"
from "remote locations." (See Oral Argument at 70: 18-71 :6).

17

Therefore, as Dr. Jacobsen's computer simulations could not meet all the limitations of
the asserted claims, they are insufficient to show actual reduction to practice as required by §
102(g). I do not need to consider Steed' s second requirement.

2. Patent Applications
For the following reasons, TC Tech's motion is DENIED with respect to constructive
reduction to practice by filing patent applications.
TC Tech asserts that a U.S. patent is prior art as of its filing date under 35 U.S.C. §
102(e) and not as of its date of conception under§ 102(g). Therefore, TC Tech argues that
Sprint cannot use the filing of patent applications for Cioffi ' 651 , Bingham ' 573 , or Bingham
'612 to show constructive reduction to practice of Dr. Jacobsen' s prior invention under§ 102(g).
(D.I. 267 at 9-10).
TC Tech is correct that§ 102(e) governs the use of patents as prior art. The Federal
Circuit has held, "When patents are not in interference, the effective date of a reference United
States patent as prior art is its filing date in the United States, as stated in § 102(e ), not the date
of conception or actual reduction to practice of the invention claimed or the subject matter
disclosed in the reference patent." Sun Studs, Inc. v. ATA Equip. Leasing, Inc. , 872 F.2d 978,
983 (Fed. Cir. 1989), overruled on other grounds by A. C. Aukerman Co. v. R.L. Chaides Constr.

Co., 960 F.2d 1020 (Fed. Cir. 1992). I think there is a difference, however, between asserting a
patent as prior art, and relying on the filing of a patent application as constructive reduction to
practice of a prior invention that is asserted as prior art. I do not think Sun Studs controls the
latter situation.4

4
Section 102(e) applies to patents and patent applications filed in the U.S. without regard for where the
invention occurred. Section 102(g) applies to inventions made in the U.S. without regard for whether a related
patent or patent application is filed. I see no reason why the subsections must be mutually exclusive- both may
apply if a U.S. patent or patent application is filed on an invention made in the U.S.

18

TC Tech also relies on this Court's decision in Sanos, Inc. v. D&M Holdings Inc., 2017
WL 4969330 (D. Del. Nov. 1, 2017). In Sanos, the Court followed Sun Studs to find that a
patent ("the Rietschel patent") could not be asserted as § 102(g) prior art. Id. at *7 (applying
post-amendment § 102(g)(2)). The Rietschel patent was filed too late to be prior art under §
102(e). Instead, D&M argued that its product ("the Exstreamer") was a prior invention
invalidating the asserted patents under § 102(g). But D&M could not prove that the Exstreamer
reflected a reduction to practice of the inventions claimed in the asserted patents. Therefore,
D&M argued that the Exstreamer was an embodiment of the Rietschel patent and the disclosures
of the Rietschel patent could be asserted as prior art under§ 102(g). Id.

Sanos does not help TC Tech. D&M was attempting to use § 102(g) to circumvent §
102(e). Under D&M's theory, the Rietschel patent could be backdated under§ 102(g) to qualify
as prior art despite not being prior art under§ 102(e). The Court rejected that theory as
improperly distorting the § 102(g) analysis-the proper inquiry was "not whether the Exstreamer
is an embodiment of the Rietschel patent, but whether the Exstreamer itself invalidates the
[asserted] patents." Sanos, 2017 WL 4969330, at *6-7. Unlike D&M, Sprint is not using§
102(g) to backdate patents that are not otherwise prior art. The patents Sprint seeks to rely on for
reduction to practice under § 102(g) are also independently asserted as prior art under § 102(e ).
TC Tech does not dispute that the patents qualify as prior art under§ 102(e). (D.I. 288 at 11;
D.I. 306 at 2-4; D.I. 352 at 3; Oral Argument at 76:15-18). Further, while I agree with Sanos
that the proper inquiry under§ 102(g) is "whether the [Jacobsen invention] itself invalidates the
['488 patent]," that does not address the present issue-whether filing a patent application can be
constructive reduction to practice under§ 102(g). See 2017 WL 4969330, at *6-7.

19

In Solvay S. A. v. Honeywell International, Inc., the Federal Circuit addressed reduction to
practice in the context of proving a prior invention under§ 102(g). 622 F.3d 1367 (Fed. Cir.
2010) ("Solvay I") (applying post-amendment § 102(g)(2)). The court stated, "Actual reduction
to practice requires that the claimed invention work for its intended purpose, while constructive
reduction to practice occurs when a patent application on the claimed invention is filed." Id. at
1376 (citing Hybritech Inc. v. Monoclonal Antibodies, Inc., 802 F.2d 1367, 1376 (Fed. Cir.
1986)).5 Thus, I find filing a patent application may constitute constructive reduction to practice
under § 102(g).
Therefore, TC Tech has failed to show that Sprint' s § 102(g) defense fails as a matter of
law, because the filing of the Cioffi ' 651 , Bingham ' 573 , or Bingham ' 612 patent applications
can qualify as constructive reduction to practice of the Jacobsen invention.
B. Anticipation

TC Tech moves for summary judgment of no anticipation by eight different references(1) "the ICC Paper" (D.I. 268, Ex. 5), (2) "the NCTA Paper" (id. , Ex. 6), (3) "the Amati
Contribution" (id. , Ex. 7), (4) "the CCTA Paper" (id. , Ex. 8), (5) Cioffi ' 651 (id. , Ex. 9), (6)
Bingham '573 (id. , Ex. 10), (7) Bingham ' 61 2 (id. , Ex. 11 ), and (8) "the Jacobsen Dissertation"
(id. , Ex. 12) (collectively, "the Asserted References"). (D.I. 267 at 6). First, TC Tech argues

that none of the Asserted References discloses the use of complex signals as required by claim 2
of the '488 patent. (Id. at 12-16). Second, TC Tech argues that three of the eight references-

5 TC Tech argues that Solvay I should not control because the court only mentions constructive reduction to
practice " in dicta and never applies it in any context." (D.I. 306 at 3-4). Although that may be true, TC Tech has
not pointed to any Federal Circuit decisions indicating a contrary view. At minimum, Solvay I is persuasive
authority.

20

the ICC Paper, the NCT A Paper, and the Amati Contribution-fail to disclose modulation onto a
carrier signal as required by both claims 1 and 2 of the '488 patent. (Id. at 16-18).
1. Use of Complex Signals (Claim 2)

For the following reasons, TC Tech's motion is DENIED with respect to no anticipation
for failure to disclose the use of complex signals.
The term "complex signal" does not appear in the claims. TC Tech argues that the
limitation arises from the use of "in-phase" and "quadrature" signals, which together make up a
complex signal. (D.I. 267 at 4; D.I. 268, Ex. 3 ~ 63). The relevant portion of claim 2 states,
Using a demodulator, multiplying .. . time domain data with in-phase and
quadrature carrier signals to obtain in-phase and quadrature baseband signals,
converting said in-phase and quadrature baseband signals to digital form, and .
. . performing .. . orthogonal transform using said in-phase and quadrature
baseband signals as real and imaginary values, respectively, to demodulate ...
time domain data from the carrier frequency signal . ...
'488 patent at 12:11-19. TC Tech argues that in-phase signals represent real values, while
quadrature signals represent imaginary values. (D.I. 267 at 4; D.I. 268, Ex. 3 ~ 83). Thus, the
Asserted References cannot anticipate claim 2 because they only disclose the use of real signals.
(Id. at 13-14).

TC Tech' s theory is based on a disputed material fact. The parties' experts clearly
disagree over how the claimed in-phase and quadrature signals operate. TC Tech asserts that a
quadrature signal is not a real signal and thus not disclosed by the Asserted References. (D.I.
267 at 13-15; D.I. 268, Ex. 3 ~~ 63 , 83). Sprint asserts that both in-phase and quadrature signals
are real signals and thus disclosed by the Asserted References. (D.I. 288 at 16; D.I. 289
This is a factual dispute that cannot be resolved at summary judgment.

21

~~

8-12).

2. Modulation onto a Carrier (Claims 1 and 2)
For the following reasons, TC Tech' s motion is GRANTED with respect to no
anticipation for failure to disclose modulation onto a carrier.
Both claims of the '488 patent require "utilizing a modulator to modulate . .. time
domain data onto a carrier signal for transmission to [the] central location." '488 patent at
10:63-65 , 12:1-3. Sprint' s expert, Dr. Jacobsen, argues that the ICC Paper, the NCTA Paper, and
the Amati Contribution each inherently discloses the required modulation onto a carrier through
disclosure of simulated systems that transmit signals in a bandwidth from 30-36 MHz. Dr.
Jacobsen explains, " [A] skilled artisan would not have understood there to be any other way,
other than by modulation onto a carrier, for the [disclosed signals] to reside between 30 and 36
MHz." (D.I. 289, Ex. 1 ,r 290 (discussing the ICC Paper); see also id.

,r,r 328, 400).

TC Tech argues, based on Mr. Bates' expert testimony, that Dr. Jacobsen' s theory fails
because there are multiple ways to transmit a signal in the 30-36 MHz range that do not require
modulating onto a carrier. (D.I. 267 at 17; D.I. 268, Ex. B ,r,r 283-285 , 355-357, 435-437).
Further, the fact that modulation onto a carrier would allegedly "be more cost-effective, simpler,
easier to implement, and would consume less power" is insufficient to show that the references
inherently disclose the limitation. (Id. at 17-18 (quoting Dr. Jacobsen' s Reply Report (D.I. 269,
Ex. 14 ,r 202)). In support, TC Tech relies on HTC Corp. v. Cellular Communications
Equipment, LLC, 877 F.3d 1361 (Fed. Cir. 2017).

" [A]nticipation by inherent disclosure is appropriate only when the reference discloses
prior art that must necessarily include the unstated limitation." Monsanto Te ch. LLC v. E.I du
Pont de Nemours & Co., 878 F.3d 1336, 1343 (Fed. Cir. 2018). "Whether a claim limitation is

inherent in a prior art reference is a question of fact. " Telemac Cellular Corp. v. Topp Telecom,

22

Inc., 247 F.3d 1316, 1328 (Fed. Cir. 2011). " [R]ecourse to extrinsic evidence is proper to
determine whether a feature, while not explicitly discussed, is necessarily present in a reference.
The evidence must make clear that the missing feature is necessarily present, and that it would be
so recognized by persons of ordinary skill in the relevant art." Id. (citations omitted).

HTC is on point. In HTC, the Federal Circuit agreed with the PTAB ' s finding that the
disputed claim limitation was not inherently disclosed by the prior art. 877 F.3d at 1368-69.
HTC had only shown that it was "possible" for the disclosed subject matter to correspond to the
claim limitation. The Federal Circuit held that that possibility alone was not enough to find the
prior art "necessarily discloses" the claim limitation. Id. at 1369.
Here, Dr. Jacobsen admits that Mr. Bates identifies another approach to transmit signals
in the 30-36 MHz range without modulation onto a carrier. She opines, however, "A skilled
artisan would have recognized the approach suggested by Mr. Bates as unnecessarily complex,
expensive, and wasteful." (D.I. 269, Ex. 14 ,i 145). She further notes that a textbook in the
relevant field "characterizes the technical requirements of Mr. Bates' s approach as ' ridiculous. "'

(Id. ,i 146). 6 Like in HTC, Dr. Jacobsen acknowledges that the claim limitation-modulation
onto a carrier-is only one of a plurality of approaches corresponding to the disclosed subject
matter-transmission in the 30-36 MHz range. See 877 F.3d at 1369. Therefore, based on Dr.
Jacobsen's testimony, modulation onto a carrier cannot be "necessarily present" in the ICC
Paper, the NCT A Paper, or the Amati Contribution. I do not think it is relevant, for inherent
anticipation, that a person of ordinary skill in the art would have found modulation onto a carrier
substantially more desirable than Mr. Bates' alternative approach.

6

TC Tech argues that Dr. Jacobsen 's reliance on the textbook (" Couch") is " factually unsupported." (D.I.
306 at 8). This appears to be based on the attorneys' understanding of the technology described in the textbook.
(Id.) . I do not find such argument persuasive.

23

C. License and Patent Exhaustion
For the following reasons, TC Tech's motion is GRANTED with respect to no license
and patent exhaustion.
Sprint's license and patent exhaustion theories are based on a set of agreements between
CableLabs, the original owner of the ' 488 patent, and several of Sprint' s vendors ("the
CableLabs Agreements"). (E.g., D.I. 269, Ex. 19; see also D.I. 267 at 20; D.I. 288 at 19). The
CableLabs Agreements created a pool of intellectual property associated with Data Over Cable
Services Interface Specifications ("DOCSIS"), which "define interface requirements for
equipment involved in the delivery of data over coax and hybrid fiber/coax networks and to
sublicense such rights on a royalty-free basis." (D.I. 269, Ex. 19 at 1). I assume the CableLabs
Agreements are substantively identical as the parties focus on just one agreement. (D.I. 267 at
20-23; D.I. 288 at 19-22 (referring to the agreement between CableLabs and ZTE USA Inc. (D.I.
269, Ex. 19)). The CableLabs Agreements, in relevant part, provide:
CableLabs hereby grants to Licensor and its Affiliates a nontransferable,
worldwide, nonexclusive, royalty-free license under CableLabs' patents and
copyrights which are essential for compliance with the Specifications and a
nontransferable, worldwide, nonexclusive, royalty-free sublicense under all
patents and copyrights to which CableLabs may have or hereafter acquires the
right to sublicense, through other [DOCSIS] Licenses Agreements, which are
essential for compliance with the Specifications to make, have made, use, offer
to sell, sell and import products which conform to the Specifications.
(DJ. 269, Ex. 19 § 2.3 (emphasis added)). "Specifications" means "any and all specifications
designated by CableLabs ... as part of the [DOCSIS] ... ." (Id. § 1.5).
Sprint argues that the '488 patent was a CableLabs patent "essential for compliance with
[DOCSIS] ," and thus, its vendors had a license to the patent through the CableLabs Agreements.
(DJ. 288 at 19). TC Tech argues that Sprint has failed to provide any evidence that (1) the '488

24

patent was an "essential" patent, and (2) the CableLabs Agreements covered use of the licensed
patents for LTE cellular products or services. (D.1. 267 at 20).
To support its view that the ' 488 patent is "essential" and thus licensed by the CableLabs
Agreements, Sprint argues that DOC SIS requires the use of orthogonal frequency-division
multiple access ("OFDMA"), which is the same technology allegedly covered by the ' 488 patent.
(D.1. 288 at 19 (citing DOCSIS (D.I. 290, Ex. 5 § 7.3.2))). Sprint asserts that this was confirmed
by Thomas Williams, a named inventor of the '488 patent, and Judson Cary, a VP and Deputy
General Counsel of CableLabs. (Id. at 20).
Mr. Williams stated during deposition that the term "OFDMA" post-dated the ' 488

patent. (D.I. 290, Ex. 6 at 220:23-24). However, he agreed that DOCSIS requires use of
OFDMA (id. at 220:13-16), and that he believed " [e]lements in OFDMA . .. are included in the
488 Patent" (id. at 221:1-2; see also id. at 51:21-52:14).
Mr. Cary stated, in a pre-suit email while preparing to sell CableLabs patents, that he had

"tentatively identified 5 of the patents for sale/license, mostly in the DOC SIS area." (D.I. 290,
Ex. 13 at IAG000191). He listed the ' 488 patent as one of the five but added that CableLabs
would "need to noodle over how to make potential buyer/licensees aware of the exclusions
[CableLabs would] need for [its] members and licensees (e.g. , under the DOCSIS patent pool,
but limited to that use for DOCSIS)." (Id. ). During deposition, Mr. Cary clarified that he meant
(1) whoever bought the patents would need to grant a reciprocal license back to CableLabs and
its members, and (2) any patents "essential" to DOCSIS would be licensed pursuant to an
existing agreement. (D.I. 269, Ex. 18 at 37:6-24). Notably, he added that CableLabs has "never
made any determination whether any of [the identified patents] are essential." (Id. at 37:24-

25

38:1). Sprint also asserts, and TC Tech does not dispute, that Mr. Cary provided a list of licenses
to the patent broker including the CableLabs Agreements. (D.1. 288 at 20; D.I. 306 at 9).
I do not think Sprint has provided sufficient evidence to support a finding that the '488
patent is "essential" to DOCSIS and thus covered by the CableLabs Agreements. At most, Mr.
Williams and Mr. Cary have indicated that they believe the ' 488 patent has some overlapping
elements with DOCSIS. First, I do not think having some overlapping elements is equivalent to
being "essential." 7 Second, both Mr. Williams and Mr. Cary made conclusory statementsneither articulated why the ' 488 patent should be considered "essential" to DOCSIS. Mr. Cary
admitted that CableLabs never conducted an analysis. (D.I. 269, Ex. 18 at 37:24-38 :1). Mr.
Williams based his testimony on OFDMA yet was unable to define the term. (D.I. 290, Ex. 6 at
52:3-10 ("[W]hat even does OFDMA constitute? . .. [A] lot of questions that need to be
answered.").
Therefore, TC Tech has met its burden on summary judgment of showing that there is no
dispute of material fact concerning the defenses of license and patent exhaustion based on the
CableLabs Agreements. Because I find Sprint cannot show the '488 patent was licensed under
the CableLabs Agreement, I do not reach TC Tech's second argument that even licensed patents
cannot be used for LTE products and services.

D. Prosecution History Estoppel and Disclaimer
For the following reasons, TC Tech's motion is GRANTED with respect to Sprint's
prosecution history estoppel defense. I also find that Sprint' s related prosecution disclaimer
arguments fail as a matter of law.

7

I would think that for a patent to be "essential," DOCSIS must require practicing the claimed invention.
Sprint has not provided any evidence comparing DOCSIS with the '488 patent claims.

26

TC Tech only moves for summary judgment on prosecution history estoppel, but I
believe the parties ' arguments may be better suited for prosecution disclaimer. (D.I. 288 at 2223; D .I. 3 06 at 10-11 ). The Federal Circuit explained the distinction:
Prosecution history estoppel applies as part of an infringement analysis to
prevent a patentee from using the doctrine of equivalents to recapture subject
matter surrendered from the literal scope of a claim during prosecution.
Prosecution disclaimer, on the other hand, affects claim construction and
applies where an applicant' s actions during prosecution prospectively narrow
the literal scope of an otherwise more expansive claim limitation. Though
distinct, both doctrines serve to constrain the enforceable scope of patent
claims commensurate with any subject matter surrendered during prosecution
to obtain the patent, and a single action during prosecution can engender both a
prosecution disclaimer and prosecution history estoppel.

Trading Techs. Int'l, Inc. v. Open E Cry, LLC, 728 F.3d 1309, 1322 (Fed. Cir. 2013) (internal
citations omitted).
Sprint raises two arguments based on TC Tech' s preliminary response in the inter partes

review (" IPR") of the ' 488 patent. (D.I. 288 at 23-24; D.I. 290, Ex. 8). First, the claimed
"central location" must refer to Sprint's LTE network base station. (D.I. 288 at 23). Second, the
claimed "remote locations" must use the same carrier frequency, which Sprint's "remote
locations" do not do. (Id. at 24).
1. Prosecution History Estoppel

Prosecution history estoppel is a multi-step inquiry. First, a court must find "an
amendment filed in the [USPTO] has narrowed the literal scope of a claim." Festa v. Shoketsu

Kinzoku Kogyo Kabushiki, 344 F.3d 1359, 1366 (Fed. Cir. 2003). Second, the reason for that
narrowing amendment must be "a substantial one relating to patentability." Id. at 1366-67.
Third, the subject matter surrendered by the narrowing amendment must include the particular
equivalent in question. Id. at 1367.

27

Sprint has failed to identify a narrowing amendment, let alone a particular equivalent
surrendered by that narrowing amendment. In fact, the only evidence that Sprint relies on are TC
Tech's IPR statements, which are unrelated to any claim amendment. (D.I. 288 at 23-24). Those
statements, if relevant, go towards prosecution disclaimer, not prosecution history estoppel.
2. Prosecution Disclaimer
Prosecution disclaimer requires that "the alleged disavowing actions or statements made
during prosecution be both clear and unmistakable." Omega Eng 'g, Inc. v. Raytek Corp., 334
F.3d 1314, 1325-26 (Fed. Cir. 2003). Statements made during an IPR proceeding, before or after
an institution decision, can support a finding of prosecution disclaimer. Aylus Networks, Inc. v.
Apple Inc., 856 F.3d 1353, 1359, 1362 (Fed. Cir. 2017).
First, Sprint argues that TC Tech has disclaimed any construction of "central location"
that excludes Sprint's LTE network base station, because TC Tech has indicated that a base
station may be a "central location." (D.I. 288 at 23). Sprint points to TC Tech' s IPR response
describing the '488 patented invention as a method "for multiple remote units (such as cellular
phones) to communicate with a central unit (such as a base station)" (D.I. 290, Ex. 8 at 1),
"providing an efficient multiple access-scheme to transfer data from multiple remotes to a single
base station" (id.), and addressing "signaling sent from multiple remote locations (e.g., cellular
phones) towards a central location (e .g., cellular base stations)" (id. at 5). Therefore, Sprint
argues that TC Tech cannot now assert infringement based on a "central location" being an
individual sector in Sprint' s LTE base station, as opposed to the entire base station. (D.I. 288 at
23 -24).
As discussed regarding Sprint's motion for summary judgment, whether an individual
sector in Sprint' s LTE base station can be considered a "central location" is a disputed question

28

of fact. See supra§ III.A.I. Although TC Tech indicated in its IPR response that a generic
"base station" may be a "central location," that does not necessarily mean that Sprint' s particular
LTE network base station is also a "central location." Prosecution disclaimer thus does not apply
to limit "central location." Therefore, TC Tech is not barred from asserting its infringement
theory based on Sprint's individual base station sectors.
Second, Sprint argues that prosecution disclaimer bars TC Tech from asserting that
Sprint' s LTE network meets the "same carrier frequency" limitation in the '488 patent. (D.I. 288
at 24). Sprint relies on TC Tech' s IPR argument that the prior art did not teach the "same carrier
frequency" limitation because the disclosed technology "could transmit on different carriers at
the same time." (Id. (quoting D.I. 290, Ex. 8 at 21-22)). Sprint argues that it is undisputed that
the remote locations in Sprint' s LTE network "could transmit [and do transmit] on different
carriers at the same time," and thus do not meet the "same carrier frequency" limitation. (Id.).
Sprint makes a noninfringement argument under the guise of prosecution disclaimer. 8
The cited portion of TC Tech' s IPR response merely indicates that the claimed invention requires
transmission on the "same carrier frequency," which is not disputed. (See D.I. 290, Ex. 8 at 21 22). Therefore, as prosecution disclaimer does not apply, TC Tech is not barred from asserting
that Sprint's LTE network meets the "same carrier frequency" limitation.

V.

CONCLUSION
A separate order will be entered.

8

I already addressed the noninfringement argument in relation to Sprint's motion for summary judgment.
See supra§ III.B .

29