Network-1 Technologies, Inc. v. Hewlett-Packard Company

Case: 18-2338 Document: 81 Page: 1 Filed: 11/20/2020

United States Court of Appeals
for the Federal Circuit
______________________

NETWORK-1 TECHNOLOGIES, INC.,
Plaintiff-Appellant

v.

HEWLETT-PACKARD COMPANY, HEWLETT
PACKARD ENTERPRISE COMPANY,
Defendants-Cross-Appellants
______________________

2018-2338, 2018-2339, 2018-2395, 2018-2396
______________________

Appeals from the United States District Court for the
Eastern District of Texas in Nos. 6:11-cv-00492-RWS, 6:13-
cv-00072-RWS, Judge Robert Schroeder, III.
______________________

OPINION ISSUED: September 24, 2020
OPINION MODIFIED: November 20, 2020 *
______________________

GREGORY S. DOVEL, Dovel & Luner, LLP, Santa Mon-
ica, CA, argued for plaintiff-appellant. Also represented by
SEAN LUNER, RICHARD ELGAR LYON, III; JEFFREY A.
LAMKEN, MoloLamken LLP, Washington, DC.

MARK ANDREW PERRY, Gibson, Dunn & Crutcher LLP,

* This opinion has been modified and reissued fol-
lowing a petition for panel rehearing filed by Appellant.
Case: 18-2338 Document: 81 Page: 2 Filed: 11/20/2020

2 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

Washington, DC, argued for defendants-cross-appellants.
Also represented by OMAR FAROOQ AMIN; HERSH H. MEHTA,
Morgan, Lewis & Bockius LLP, Chicago, IL; NATALIE A.
BENNETT, Washington, DC.

ANDREW M. MASON, Klarquist Sparkman, LLP, Port-
land, OR, for amicus curiae T-Mobile USA, Inc. Also rep-
resented by SARAH ELISABETH JELSEMA, JOHN D.
VANDENBERG; SARAH J. KALEMERIS, Winston & Strawn
LLP, Chicago, IL.
______________________

Before PROST, Chief Judge, NEWMAN and BRYSON,
Circuit Judges.
PROST, Chief Judge.
Network-1 Technologies, Inc. (“Network-1”) appeals a
final judgment of the United States District Court for the
Eastern District of Texas. Network-1 sued Hewlett-Pack-
ard (“HP”), alleging infringement of U.S. Patent
No. 6,218,930 (“the ’930 patent”). HP argued in response
that the ’930 patent is invalid, and that HP did not in-
fringe. The jury found the patent not infringed and invalid.
Following post-trial motions, the district court denied Net-
work-1’s request for a new trial on infringement but
granted Network-1’s motion for judgment as a matter of
law (“JMOL”) on validity.
Network-1 appeals the district court’s final judgment
that HP does not infringe the ’930 patent, arguing the dis-
trict court erred in its claim construction. HP cross-ap-
peals the district court’s determination that HP was
estopped from raising certain validity challenges under
35 U.S.C. § 315(e)(2) based on HP’s joinder to an inter
partes review (“IPR”) before the Patent Trial and Appeal
Board (“Board”). On cross-appeal, HP also argues that
Network-1 improperly broadened claim 6 of the ’930 patent
during reexamination.
Case: 18-2338 Document: 81 Page: 3 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 3
COMPANY

For the reasons explained below, we affirm-in-part, re-
verse-in-part, vacate, and remand. Specifically, as to Net-
work-1’s appeal, we affirm-in-part and reverse-in-part the
district court’s claim construction and remand to the dis-
trict court. As to HP’s cross-appeal, we vacate the district
court’s JMOL on validity and remand. And finally, we af-
firm the district court’s decision with respect to improper
claim broadening.
FACTUAL BACKGROUND
I. The ’930 Patent
The ’930 patent is titled “Apparatus and Method for Re-
motely Powering Access Equipment over a 10/100 Switched
Ethernet Network.” It discloses an apparatus and methods
for allowing electronic devices to automatically determine
if remote equipment is capable of accepting remote power
over Ethernet. See ’930 patent col. 1 ll. 13–17. According
to the patented method, a “low level current” is delivered
over a data signaling pair to an access device (also called
remote equipment or remote access equipment). Id. at
col. 2 ll. 8–10. After the low level current is sent, a network
switch senses the resulting “voltage level” on the data sig-
naling pair. Id. at col. 1 l. 65–col. 2 l. 14. If the device can
accept remote power, the sensed voltage level will match a
“preselected condition” of the voltage, such as a particular
“varying voltage” level. Id. at col. 2 ll. 10–14, col. 3 ll. 2–
17. Upon detecting the preselected condition, the network
switch will increase the current from the low level to a
higher level sufficient to allow the “remote equipment [to]
become[] active.” Id. at col. 3 ll. 17–22. If the preselected
condition of the voltage is not detected, the network switch
will determine that the device cannot accept remote power
and will not transmit a higher current. Id. at col. 3 ll. 3–
11.
The ’930 patent issued in April 2001 with 9 claims, in-
cluding two independent claims: claims 1 and 6. Claim 6
is representative of the issues on appeal. Claim 6 recites:
Case: 18-2338 Document: 81 Page: 4 Filed: 11/20/2020

4 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

6. Method for remotely powering access equipment
in a data network, comprising,
providing a data node adapted for data switching,
an access device adapted for data transmission, at
least one data signaling pair connected between
the data node and the access device and arranged
to transmit data therebetween, a main power
source connected to supply power to the data node,
and a secondary power source arranged to supply
power from the data node via said data signaling
pair to the access device,
delivering a low level current from said main
power source to the access device over said data sig-
naling pair,
sensing a voltage level on the data signaling pair in
response to the low level current, and
controlling power supplied by said secondary
power source to said access device in response to
a preselected condition of said voltage level.
’930 patent claim 6 (emphases added to terms challenged
on appeal).
On appeal, Network-1 contends that the district court
erroneously construed the claim terms “main power
source” and “low level current.” On cross-appeal, HP con-
tends that Network-1 improperly broadened the term “sec-
ondary power source” during reexamination.
II. The Reexamination Proceedings
After it issued, and concurrent with the underlying dis-
trict court action, the ’930 patent was reexamined twice be-
fore the U.S. Patent and Trademark Office. The first
reexamination, No. 90/012,401 (“the ’401 reexamination”),
concluded in October 2014. See J.A. 333–35. It confirmed
the patentability of claims 6, 8, and 9, and resulted in the
issuance of claims 10–23. Relevant to HP’s cross-appeal,
Case: 18-2338 Document: 81 Page: 5 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 5
COMPANY

claims 15 and 16 were added depending from original
claim 6.
Claim 15 recites: “Method according to claim 6,
wherein said secondary power source is the same source
of power as said main power source.” ’930 patent, Ex Parte
Reexamination Certificate, col. 1 ll. 39–41 (emphasis
added).
Claim 16 recites: “Method according to claim 6,
wherein said secondary power source is the same physi-
cal device as the main power source.” Id. at col. 1 ll. 42–44
(emphasis added).
The second reexamination, No. 90/013,444, concluded
in November 2015. It confirmed the patentability of claims
6 and 8–23. See J.A. 336–37.
PROCEDURAL BACKGROUND
This case has a long and complicated history, which be-
gan in 2011 when Network-1 sued a number of defendants,
including HP, for infringement of the ’930 patent in the
U.S. District Court for the Eastern District of Texas. After
several stays, the district court finally reached the under-
lying final judgment in 2018. We discuss the relevant
background here.
I. The Avaya IPR

After Network-1 filed its complaint in the district court,
another defendant, Avaya Inc. (“Avaya”), petitioned for
IPR of the ’930 patent. The district court stayed its pro-
ceedings pending IPR. The Board partially instituted
Avaya’s petition. See Avaya Inc. v. Network-1 Sec. Sols.,
Inc., No. IPR2013-00071, Paper 18, 2013 WL 8595554
(P.T.A.B. May 24, 2013) (“the Avaya IPR”). Specifically,
the Board instituted review of claims 6 and 9 of the ’930
patent based on two grounds: (1) anticipation under
Case: 18-2338 Document: 81 Page: 6 Filed: 11/20/2020

6 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

35 U.S.C. § 102(b) by Matsuno 1; and (2) obviousness under
35 U.S.C. § 103(a) by De Nicolo 2 and Matsuno. Id. at *16.
Following institution, HP, together with other petition-
ers, filed an IPR petition and motion to join the Avaya IPR.
HP’s petition included grounds different from those that
had already been instituted. The Board denied HP’s re-
quest. HP, with others, thereafter filed a second IPR peti-
tion and motion to join the Avaya IPR, this time including
only the grounds already instituted. The Board granted
HP’s request, and HP was joined as a party to the Avaya
IPR. At the time that HP filed its second IPR petition,
more than one year had passed since the district court com-
plaint had been served, and therefore, HP was time-barred
under 35 U.S.C. § 315(b) from having its own petition in-
stituted. But because § 315(b) creates an exception from
the time bar for joinder under 35 U.S.C. § 315(c), HP was
nonetheless able to join.
In its final written decision, the Board held that nei-
ther claim 6 nor claim 9 was unpatentable over the insti-
tuted grounds. We affirmed. See Avaya Inc. v. Network-1
Techs., Inc., 612 F. App’x 613 (Fed. Cir. 2015).
II. The District Court Action
After more stays, Network-1 continued its suit in the
district court. In 2017, the district court issued its con-
struction of disputed claim terms, including “low level cur-
rent” and “main power source.” See Network-1 Techs., Inc.
v. Alcatel-Lucent USA, Inc., ET, No. 6:11-cv-492, Report
and Recommendation of the Magistrate Judge, D.I. 693,
at 12 (E.D. Tex. Nov. 4, 2016) (J.A. 24–48); see also Net-
work-1 Techs., Inc. v. Alcatel-Lucent USA, Inc., ET, No.

1 Japanese Unexamined Patent Application Publica-
tion No. H10-13576, published Jan. 16, 1998 (“Matsuno”).
2 U.S. Patent No. 6,115,468, filed Mar. 26, 1998,
issued Sept. 5, 2000 (“De Nicolo”).
Case: 18-2338 Document: 81 Page: 7 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 7
COMPANY

6:11-cv-492, Order Adopting Report and Recommendation
of U.S. Magistrate Judge, D.I. 860, at 1, 5–7 (E.D. Tex.
May 2, 2017) (J.A. 49–68). Together with its claim con-
struction, in relevant part, the district court denied HP’s
summary judgment motion that argued claim 6 was imper-
missibly broadened through the ’401 reexamination.
J.A. 40–42, 57–59.
This case finally proceeded to trial in November 2017.
At trial, Network-1 argued that HP infringed claims 6, 13,
14, 17, 20, and 22 of the ’930 patent (“the asserted claims”)
by selling particular Power over Ethernet (“PoE”) switches.
HP argued that each of the asserted claims was rendered
obvious by both public use of “the Fisher system,” which
was a PoE system developed by David Fisher, and by the
patents and printed publications referred to as “the Fisher
patents,” 3 Woodmas, 4 and Chang. 5 See J.A. 78.
Using a general verdict form, the jury found that HP
did not infringe any asserted claim of the ’930 patent.
J.A. 70. The jury also found that HP had shown that all
asserted claims of the ’930 patent are invalid. J.A. 71.
Following the jury’s verdict, Network-1 filed, in rele-
vant part, a motion for a new trial related to infringement,
and a motion for JMOL and motion for a new trial related

3 U.S. Patent No. 5,994,998, filed May 29, 1997, is-
sued Nov. 20, 1999; U.S. Patent No. 6,710,704, filed Oct.
28, 2002, issued Mar. 23, 2004; International Publication
No. WO 98/54843, published Dec. 3, 1998 (collectively, “the
Fisher patents”).
4 U.S. Patent No. 5,345,592, filed Apr. 8, 1992, is-
sued Sept. 6, 1994 (“Woodmas”).
5 U.S. Patent No. 5,991,885, filed June 11, 1997, is-
sued Nov. 23, 1999; International Publication
No. WO 98/57248, published Dec. 17, 1998 (collectively,
“Chang”).
Case: 18-2338 Document: 81 Page: 8 Filed: 11/20/2020

8 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

to validity. The district court denied the motion for a new
trial on infringement. Applying its construction of the
claim terms “low level current” and “main power source,”
the district court concluded that the jury’s verdict was not
against the great weight of the evidence that HP’s accused
devices did not meet either limitation. See J.A. 92–97.
As to the ’930 patent’s validity, however, the district
court granted Network-1’s motion for JMOL. The district
court concluded that because of HP’s joinder to the Avaya
IPR, HP should have been estopped under 35 U.S.C.
§ 315(e) from raising the remaining obviousness chal-
lenges, which it determined “reasonably could have been
raised” in the Avaya IPR. J.A. 91. 6 The district court did
not conditionally rule on HP’s motion for a new trial with
respect to validity.
Network-1 appealed. HP cross-appealed. We have ju-
risdiction under 28 U.S.C. § 1295(a)(1).
DISCUSSION
On appeal, Network-1 challenges the district court’s
denial of a new trial on infringement based on its argument
that the district court erred in its claim construction.
On cross-appeal, HP challenges the district court’s
JMOL on validity, arguing that the district court erred in
concluding that HP is estopped from raising its obvious-
ness challenges because it joined the Avaya IPR. HP fur-
ther challenges the district court’s denial of summary

6 With respect to the Fisher system, the district
court concluded that HP failed to show that the Fisher sys-
tem constitutes prior art. See J.A. 79–87. On cross-appeal,
HP does not challenge the district court’s conclusion that
the Fisher system does not constitute prior art. Appellee’s
Br. 62 n.2.
Case: 18-2338 Document: 81 Page: 9 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 9
COMPANY

judgment, arguing that the asserted claims of the ’930 pa-
tent were improperly broadened during reexamination.
We address these issues in turn.
I. Claim Construction
Network-1 argues that the district court incorrectly
construed the claim terms “low level current” and “main
power source,” and that this error entitles it to a new trial
on infringement. HP argues in response that the district
court’s claim construction should be affirmed, but that even
if it is not, Network-1 was not prejudiced by the erroneous
claim construction.
For the below-described reasons, we conclude that the
district court correctly construed “low level current” but
erred in its construction of “main power source,” and as a
result of that error, Network-1 is entitled to a new trial on
infringement. We therefore vacate the district court’s judg-
ment of non-infringement and remand for a new trial to
determine whether HP infringes the asserted claims based
on the correct construction of “main power source.”
A
We review the district court’s ultimate construction of
the claim language de novo. Teva Pharms. USA, Inc. v.
Sandoz, Inc., 574 U.S. 318, 331 (2015). “[W]hen the district
court reviews only evidence intrinsic to the patent (the pa-
tent claims and specifications, along with the patent’s pros-
ecution history), the judge’s determination will amount
solely to a determination of law, and [we] will review that
construction de novo.” Id. To the extent that subsidiary
factfinding is required for claim construction analysis, we
review such factfinding for clear error. Id. at 332.
Claim terms “are generally given their ordinary and
customary meaning,” which is “the meaning that the term
would have to a person of ordinary skill in the art in ques-
tion at the time of the invention.” Phillips v. AWH Corp.,
Case: 18-2338 Document: 81 Page: 10 Filed: 11/20/2020

10 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

415 F.3d 1303, 1312–13 (Fed. Cir. 2005) (en banc) (internal
quotation marks and citations omitted). “[T]he claims
themselves provide substantial guidance as to the meaning
of particular claim terms” and “the specification is the sin-
gle best guide to the meaning of a disputed term.” Id.
at 1314–15 (internal quotation marks and citations omit-
ted).
As the party seeking to disturb the non-infringement
judgment, Network-1 “must establish that [the challenged
jury] instructions were legally erroneous, and that the er-
rors had prejudicial effect.” SSL Servs., LLC v. Citrix Sys.,
769 F.3d 1073, 1085 (Fed. Cir. 2014) (quoting Ecolab Inc.
v. Paraclipse, Inc., 285 F.3d 1362, 1373 (Fed. Cir. 2002)).
“It is well established that when an incorrect jury in-
struction—such as an incorrect claim construction—re-
moves from the jury a basis on which the jury could
reasonably have reached a different verdict, the verdict
should not stand.” Cardiac Pacemakers, Inc. v. St. Jude
Med., Inc., 381 F.3d 1371, 1383 (Fed. Cir. 2004); see also
Avid Tech., Inc. v. Harmonic, Inc., 812 F.3d 1040, 1042
(Fed. Cir. 2016). An erroneous claim construction on one
element is harmless “only if a reasonable jury would have
been required by the evidence to find non-infringement
even without the error.” Avid, 812 F.3d at 1047.
B
The district court construed “low level current” as “a
non-data-signal current that is sufficient to begin start up
of the access device but that is not sufficient to sustain the
start up.” J.A. 35; see also J.A. 53–55. The district court
explained that it was construing the disputed phrase to
give meaning to the constituent term “low.” See J.A. 34. It
stated that while the current must be sufficient to “begin
start up,” the current need not “cause start up,” and thus
it construed the term to eliminate “any implication that the
current must be sufficient to result in a completed start-
up.” J.A. 34 (citing ’930 patent col. 3 ll. 12–17).
Case: 18-2338 Document: 81 Page: 11 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 11
COMPANY

On appeal, Network-1 argues that the district court
erred by construing the phrase “low level current” to have
a lower bound. Network-1 agrees that, in the context of the
’930 patent, the phrase “low level current” describes cur-
rent that cannot “sustain start up” but argues that it was
error for the district court to additionally require that the
current be sufficient to begin start up. See Appellant’s
Br. 27. Relying on extrinsic evidence related to the word
“low,” including dictionary definitions, grammar refer-
ences, and claim constructions adopted for unrelated pa-
tents, Network-1 argues that the term points in one
direction and should be construed to have a single refer-
ence point. Network-1 asserts that the correct reference
point with respect to the ’930 patent is the upper boundary
requiring that the current not exceed the level needed to
operate the device. We disagree.
We conclude that the district court correctly construed
“low level current.” As an initial matter, there is no dispute
that the word “low” in the claim phrase “low level current”
operates to limit the upper boundary of the current level.
See Appellant’s Br. 26–29; Appellee’s Br. 36–37. Indeed,
the ’930 patent explicitly describes a low level current with
an upper boundary that is “unable to sustain start up.” See
’930 patent col. 3 ll. 14–16; see also id. at col. 3 ll. 2–13. But
the claim phrase is not limited to the word “low,” and the
claim construction analysis should not end just because one
reference point has been identified. To be sure, the claim
phrase “low level current” does not preclude a lower bound
by use of the word “low.” Rather, in the same way the
phrase should be construed to give meaning to the term
“low,” the phrase must also be construed to give meaning
to the term “current.”
The intrinsic record of the ’930 patent confirms that the
district court correctly construed the phrase to require a
lower boundary of current. See Phillips, 415 F.3d at 1315.
Claim 6 recites “delivering a low level current” to an access
device to detect whether the device can accept remote
Case: 18-2338 Document: 81 Page: 12 Filed: 11/20/2020

12 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

power. ’930 patent col. 4 ll. 49–67 (emphasis added); see
also id. at col. 2 ll. 8–14. The express language of the claim
thus requires that at least some level of current be deliv-
ered. Even Network-1 admits that the term “current” nec-
essarily requires some flow of electric charge because “[i]f
there is no flow, there is no ‘current.’” See Appellant’s Br.
33–34.
The specification of the ’930 patent discloses the lower
boundary of current. It explains that an access device ca-
pable of accepting remote power will signal a varying volt-
age level and teaches “[t]he varying level is created by the
remote power supply beginning to start up but the low cur-
rent level is unable to sustain the start up.” ’930 patent
col. 3 ll. 14–16 (emphasis added); see also id. at col. 3 ll. 2–
13. Thus, consistent with the district court’s construction,
the ’930 patent teaches that the delivered “low level cur-
rent” is current that is sufficient to begin start-up.
Accordingly, we conclude that the district court did not
err in its construction of “low level current.”
C
The district court construed “main power source” as “a
DC power source,” and thereby excluded AC power sources
from its construction. J.A. 50–51. 7 In reaching its decision,
the court relied on HP’s expert testimony that a network
device would either fail to function or would be damaged if
it received AC power. J.A. 50–51. The court therefore con-
cluded that embodiments using AC power are inoperable
and construed “main power source” to exclude such embod-
iments. J.A. 50–51 (“A construction that renders the
claimed invention inoperable should be viewed with ex-
treme skepticism.” (quoting Talbert Fuel Sys. Pats. Co. v.

7 “DC” refers to direct current and “AC” refers to al-
ternating current.
Case: 18-2338 Document: 81 Page: 13 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 13
COMPANY

Unocal Corp., 275 F.3d 1371, 1376 (Fed. Cir. 2002))); see
also J.A. 30–31.
On appeal, Network-1 argues that the claim phrase
“main power source” should be construed consistent with
the ordinary meaning of “power source” to include both AC
and DC power sources. See Appellant’s Br. 46. Network-1
acknowledges that certain embodiments with AC power
sources require power from the main power source to be
converted to DC power before being received by the net-
work device, but Network-1 argues that nothing in the
’930 patent precludes such embodiments. To the contrary,
Network-1 asserts that the intrinsic record supports a con-
struction that includes both types of power sources. We
agree and reverse the district court’s construction of main
power source.
We conclude that the correct construction of “main
power source” includes both AC and DC power sources.
There is no dispute that the ordinary meaning of “power
source” includes both AC and DC power sources. Appel-
lant’s Br. 45–49; see Appellee’s Br. 47. And neither the
claims nor the specification of the ’930 patent require a de-
parture from this ordinary meaning. Starhome GmbH v.
AT & T Mobility LLC, 743 F.3d 849, 857 (Fed. Cir. 2014)
(“In the absence of an express intent to impart a novel
meaning to claim terms, an inventor’s claim terms take on
their ordinary meaning.”).
Claim 6 recites a “main power source” that is “con-
nected to supply power to the data node” and that “de-
liver[s] a low level current . . . to the access device.”
’930 patent col. 4 ll. 56–57, ll. 60–61; see also id. at col. 1
ll. 64–65, col. 2 ll. 8–9. Nowhere do the claims suggest that
the “main power source” should be limited to DC power
sources.
The specification likewise never expresses a preference
for DC power sources, much less a suggestion that DC
power is an “essential” feature of the main power source.
Case: 18-2338 Document: 81 Page: 14 Filed: 11/20/2020

14 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

See GE Lighting Sols., LLC v. AgiLight, Inc., 750 F.3d
1304, 1309–10 (Fed. Cir. 2014). Indeed, far from limiting
the plain language of the claims to a DC power source, the
specification states that the power source may be a “con-
ventional main power supply,” which according to the ordi-
nary meaning would include both AC and DC power
sources. ’930 patent col. 2 ll. 52–53. This reading of the
specification is further confirmed by the ’930 patent’s dis-
closure of a preferred embodiment, which is shown in Fig-
ures 1 and 3. See MBO Labs., Inc. v. Becton, Dickinson &
Co., 474 F.3d 1323, 1333 (Fed. Cir. 2007) (“A claim inter-
pretation that excludes a preferred embodiment from the
scope of the claim is rarely, if ever, correct.” (internal cita-
tion omitted)). In Figure 1, power source 16 is identified as
a “conventional” power supply, and in Figure 3, main power
supply 70 is specifically depicted as a traditional AC power
outlet. ’930 patent col. 2 ll. 52–53, Fig. 3.
Despite the express disclosures of the ’930 patent, the
district court construed “main power source” to exclude AC
power sources on the basis of expert testimony that receipt
of AC power by a network device would render it inopera-
ble. J.A. 30–31, 50–51. This is error for two reasons. First,
even though the network device cannot receive AC power,
the record establishes that “data nodes” or network
switches were commonly used to convert AC power to DC
power as needed to power the network device. Indeed, we
need not look beyond the specification of the ’930 patent.
In the preferred embodiment, as shown in Figure 1, a data
node exists between main power source 16 and the remote
equipment. And in Figure 3, an 8-port switch is shown con-
nected to the AC power outlet such that the AC power is
converted to DC power before reaching the network device.
’930 patent col. 2 l. 29, col. 3 ll. 59–60, Figs. 1 & 3. Even
HP’s expert Dr. Neikirk explained that Figure 3 illustrates
“‘the main power supply 70’ receiving power from a typical
AC wall socket, and in turn suppl[ying] operational power
via the ‘Main Power Distribution Bus’ to the data
Case: 18-2338 Document: 81 Page: 15 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 15
COMPANY

switches.” J.A. 1049 ¶ 35. Nothing in the claims of the
’930 patent precludes the conversion of AC power to DC
power, and it was error for the district court to add such a
limitation.
Second, the district court erred by adding a limitation
to the claims to carve out certain inoperable embodiments.
To be sure, we have stated that we skeptically view a con-
struction that renders all embodiments inoperable, but we
have instructed that it is nonetheless improper to add lim-
itations to constructions to exclude only certain inoperable
embodiments. Cordis Corp. v. Medtronic AVE, Inc.,
511 F.3d 1157, 1174 (Fed. Cir. 2008). In this case, the dis-
trict court’s construction not only excluded inoperable em-
bodiments that do not convert AC to DC power, but also
excluded operable embodiments, like the preferred embod-
iment. See MBO Labs., 474 F.3d at 1333.
Accordingly, we conclude that the district court erred
in its construction of “main power source.”
D
We now consider the effect of the district court’s erro-
neous construction of “main power source” on the jury’s ver-
dict of non-infringement. Network-1 argues that if the
district court erred in its construction of either claim term,
that error was prejudicial, and it is entitled to a new trial
on infringement. HP argues in response that to the extent
either term was misconstrued, such error was harmless
and the judgment of non-infringement should not be dis-
turbed. We conclude that Network-1 established that it
was prejudiced by the district court’s erroneous claim con-
struction of “main power source” and is entitled to a new
trial on infringement.
At trial, HP contested infringement based on the ele-
ments “low level current” and “main power source.” With
respect to “main power source,” the record shows that the
jury was instructed to apply the erroneous construction,
Case: 18-2338 Document: 81 Page: 16 Filed: 11/20/2020

16 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

that Network-1 elicited testimony showing that the main
power source for certain HP products originates at an AC
input, J.A. 2291, 2056, and that HP relied on evidence of
non-infringement, at least in part, based on the fact that
these products are not within the scope of the ’930 patent
because they use an AC input, J.A. 2056–57, 2065–66. The
jury found that HP did not infringe the asserted claims of
the ’930 patent. Because the general verdict form does not
indicate the basis for the jury’s decision, where the evi-
dence shows that HP relied on the district court’s erroneous
construction for its argument that it does not infringe the
asserted claims, we conclude that Network-1 has estab-
lished that it was prejudiced by the claim construction.
J.A. 69–70.
HP argues that the erroneous claim construction was
harmless because HP presented conclusive evidence that
no accused product meets the claim limitation “delivering
a low level current from said main power source.” Appel-
lee’s Br. 25–26 (emphases in original). More particularly,
HP argues that the record shows that its products deliver
detection current from a PoE chip, not an AC or DC power
source. But HP’s argument relies on an element that is not
in the claims—namely, that current be delivered directly
from the main power source to the access device. Indeed,
the district court expressly rejected HP’s attempt to import
such a limitation during claim construction. See J.A 39–40.
And in any case, Network-1 presented evidence at trial
showing that HP’s products practice this claim limitation.
See, e.g., J.A. 1790–95, 2480–81, 2724. We therefore reject
HP’s argument that the non-infringement verdict may be
affirmed on appeal.
Accordingly, we affirm the district court’s construction
of “low level current,” reverse the district court’s construc-
tion of “main power source,” and remand to the district
court for proceedings consistent with this opinion.
Case: 18-2338 Document: 81 Page: 17 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 17
COMPANY

II. Statutory Estoppel
We now turn to HP’s cross-appeal. HP argues that the
district court erroneously granted JMOL with respect to
the ’930 patent’s validity based on its determination that
HP was estopped under 35 U.S.C. § 315(e) from presenting
obviousness challenges as a consequence of its joinder to
the Avaya IPR. We agree that HP is not estopped. We
therefore vacate the district court’s judgment and remand
to the district court for proceedings consistent with this
opinion.
A
We review “decisions on motions for JMOL, motions for
a new trial, and evidentiary rulings under the law of the
regional circuit.” SSL Servs., 769 F.3d at 1082. The Fifth
Circuit reviews decisions on motions for JMOL “de novo,
reapplying the JMOL standard.” Summit 6, LLC v. Sam-
sung Elecs. Co., 802 F.3d 1283, 1293 (Fed. Cir. 2015) (citing
Ford v. Cimarron Ins. Co., 230 F.3d 828, 830 (5th Cir.
2000)). In the Fifth Circuit, a jury verdict may only be re-
versed by JMOL if substantial evidence does not support
the verdict. Versata Software, Inc. v. SAP Am., Inc.,
717 F.3d 1255, 1261 (Fed. Cir. 2013). “Thus, a JMOL may
only be granted when, ‘viewing the evidence in the light
most favorable to the verdict, the evidence points so
strongly and overwhelmingly in favor of one party that the
court believes that reasonable jurors could not arrive at
any contrary conclusion.’” Id. (quoting Dresser–Rand Co.
v. Virtual Automation, Inc., 361 F.3d 831, 838 (5th Cir.
2004)).
B
Following trial, the district court granted Network-1’s
motion for JMOL on validity of the ’930 patent. The district
court concluded that as a result of HP’s joinder to the
Avaya IPR, HP was estopped under 35 U.S.C. § 315(e) from
raising obviousness challenges not based on the Fisher
Case: 18-2338 Document: 81 Page: 18 Filed: 11/20/2020

18 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

system. J.A. 91. According to the district court, in contrast
to the Fisher system, which was not a patent or printed
publication that HP “reasonably could have raised” in the
IPR, HP could have reasonably raised its remaining inva-
lidity arguments during the IPR—i.e., the Fisher patents,
Woodmas, and Chang. J.A. 88–89, 91 (quoting 35 U.S.C.
§ 315(e)(2)). In reaching this conclusion, the district court
specifically rejected HP’s argument that it could not have
raised new grounds in the Avaya IPR because it was a
joined party. The district court stated that “the fact that
HP sought joinder with Avaya’s IPR does not mean that HP
could not have reasonably raised different grounds from
those raised by Avaya.” J.A. 91. The district court further
stated that allowing HP to raise arguments “that it elected
not to raise during the IPR would give it a second bite at
the apple and allow it to reap the benefits of the IPR with-
out the downside of meaningful estoppel.” J.A. 91 (internal
quotations omitted). The district court therefore granted
JMOL on validity without considering the merits of HP’s
invalidity arguments. J.A. 91 & n.6.
HP argues that, in granting Network-1’s motion for
JMOL on invalidity, the district court misapplied the es-
toppel provision under 35 U.S.C. § 315(e)(2). Specifically,
HP argues that no validity ground that it raised at trial
“reasonably could have [been] raised” through its joinder to
the Avaya IPR. See J.A. 88–91. We agree with HP. HP’s
joinder to the Avaya IPR and the estoppel consequences of
that joinder are governed by the America Invents Act
(“AIA”), which established IPR proceedings. According to
the AIA, under 35 U.S.C. § 315(c), HP was permitted to join
the Avaya IPR “as a party” even though HP was time-
barred under § 315(b) from bringing its own petition. But,
as we held in Facebook, Inc. v. Windy City Innovations,
LLC, the joinder provision does not permit a joining party
to bring into the proceeding new grounds that were not al-
ready instituted. Facebook, Inc. v. Windy City Innovations,
LLC, __ F.3d __, No. 18-1400, 2020 WL 5267975, at *9–10
Case: 18-2338 Document: 81 Page: 19 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 19
COMPANY

(Fed. Cir. Sept. 4, 2020). Rather, it may only join the al-
ready-instituted proceeding as a party. Id.
Following a final written decision in an IPR, the AIA
provides for statutory estoppel under 35 U.S.C. § 315(e) to
limit the invalidity challenges that an IPR petitioner may
bring in a separate action involving the same patent
claims. With respect to district court actions, § 315(e)(2)
states:
CIVIL ACTIONS AND OTHER PROCEEDINGS.—The peti-
tioner in an inter partes review of a claim in a pa-
tent under this chapter that results in a final
written decision under section 318(a) . . . may not
assert in . . . a civil action arising in whole or in
part under section 1338 of title 28 . . . that the
claim is invalid on any ground that the petitioner
raised or reasonably could have raised during that
inter partes review.
35 U.S.C. § 315(e)(2) (emphases added). Thus, according to
the statute, a party is only estopped from challenging
claims in the final written decision based on grounds that
it “raised or reasonably could have raised” during the IPR.
Because a joining party cannot bring with it grounds other
than those already instituted, that party is not statutorily
estopped from raising other invalidity grounds.
In this case, the Board instituted two grounds in the
Avaya IPR, which challenged claims 6 and 9 of the ’930 pa-
tent based on Matsuno and De Nicolo. HP did not timely
petition for IPR but relied on the joinder exception to the
time bar under § 315(b). HP first filed a motion to join the
Avaya IPR with a petition requesting review based on
grounds not already instituted. The Board correctly denied
HP’s request. The Board, however, granted HP’s second
joinder request, which petitioned for only the two grounds
already instituted. When the Board reached a final written
decision in the Avaya IPR, because HP was a petitioner in
that proceeding, HP was statutorily estopped from raising
Case: 18-2338 Document: 81 Page: 20 Filed: 11/20/2020

20 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

invalidity grounds based on Matsuno and De Nicolo
against claims 6 and 9 in a district court action. HP, how-
ever, was not estopped from raising other invalidity chal-
lenges against those claims because, as a joining party, HP
could not have raised with its joinder any additional inva-
lidity challenges. Thus, contrary to the district court’s sug-
gestion, permitting HP to challenge the asserted claims of
the ’930 patent as obvious over the Fisher patents, Wood-
mas, and Chang does not give HP a “second bite at the ap-
ple” to challenge the ’930 patent, J.A. 91, because HP could
not have raised such a challenge in the Avaya IPR.
Accordingly, we conclude that HP was not statutorily
estopped under § 315(e) from challenging the asserted
claims of the ’930 patent based on the Fisher patents,
Woodmas, and Chang, which were not raised in the Avaya
IPR and which could not have reasonably been raised by
HP. We therefore vacate the district court’s JMOL decision
on validity with respect to estoppel.

C
Because we conclude that the district court erred in
granting JMOL of validity for Network-1 on the basis that
HP was statutorily estopped from raising certain invalidity
challenges, we vacate that decision.
HP argues that if we vacate the district court’s JMOL
on validity, substantial evidence supports the jury’s verdict
of invalidity, and thus the jury’s verdict should be rein-
stated. In response, Network-1 argues that even if we re-
verse on estoppel, we might affirm the JMOL on
alternative grounds relating to substantive validity argu-
ments in Network-1’s JMOL motion that the district court
did not reach. Network-1 also argues that there is an out-
standing new-trial motion that must be ruled upon. In-
deed, the district court failed to conditionally rule on
Network-1’s motion for a new trial on validity even though
Case: 18-2338 Document: 81 Page: 21 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 21
COMPANY

it was required to do so by Federal Rule of Civil Procedure
50(c). See J.A. 78–91, 9260–65. We will not consider either
Network-1’s alternative grounds for JMOL or its new-trial
motion in the first instance. We therefore remand to the
district court for further proceedings consistent with this
opinion, which include ruling in the first instance on Net-
work-1’s entitlement to JMOL (notwithstanding this
court’s holding on estoppel) and its new-trial motion.
III. Claim Broadening
On cross-appeal, HP also argues that claim 6 and the
other asserted claims are invalid under 35 U.S.C. § 305 be-
cause Network-1 improperly broadened claim 6 through
the addition of claim 15 and 16 in the ’401 reexamination.
We disagree and affirm the district court’s judgment that
the asserted claims were not improperly broadened.
A
A patentee is not permitted to enlarge the scope of a
patent claim during reexamination. 35 U.S.C. § 305. The
broadening inquiry under § 305 involves two steps: (1) “an-
alyz[ing] the scope of the claim prior to reexamination” and
(2) “compar[ing] it with the scope of the claim subsequent
to reexamination.” Creo Prods., Inc. v. Presstek, Inc., 305
F.3d 1337, 1344 (Fed. Cir. 2002). A claim “is broader in
scope than the original claims if it contains within its scope
any conceivable apparatus or process which would not have
infringed the original patent.” See Predicate Logic, Inc. v.
Distributive Software, Inc., 544 F.3d 1298, 1303 (Fed. Cir.
2008).
“Whether amendments made during reexamination
enlarge the scope of a claim is a matter of claim construc-
tion,” Creo Prods., 305 F.3d at 1344, which we review de
novo, while giving deference to subsidiary factual determi-
nations, Teva Pharms., 574 U.S. at 331.
Case: 18-2338 Document: 81 Page: 22 Filed: 11/20/2020

22 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

B
HP argues that dependent claims 15 and 16 added dur-
ing the ’401 reexamination resulted in improper claim
broadening of claim 6 and asserted dependent claims. In
relevant part, prior to reexamination, claim 6 of the
’930 patent was construed in two separate district court ac-
tions to require the “secondary power source” to be physi-
cally separate from the “main power source.” See J.A. 59–
62; see also J.A. 40–42. Subsequently, during the ’401 reex-
amination, Network-1 added claims 15 and 16, which de-
pended from claim 6 and respectively added the limitations
that the secondary power source “is the same source of
power” and “is the same physical device” as the main power
source. ’930 patent, Ex Parte Reexamination Certificate,
col. 1 ll. 39–44.
After claims 15 and 16 issued at the conclusion of the
’401 reexamination, HP moved in the underlying district
court action for summary judgment of invalidity under
35 U.S.C. § 305 for improper claim broadening. Network-1
subsequently filed a statutory disclaimer under 35 U.S.C.
§ 253 of claims 15 and 16. See J.A. 5075. Ultimately, the
district court denied HP’s motion, finding that claim 6 had
not been improperly broadened. J.A. 59–62; see also
J.A. 40–42. In the same order, the district court also con-
strued the claim term “secondary power source” consistent
with the earlier district court actions to require that the
“secondary power source be physically separate from the
driving points of the main power source.” J.A. 52–53; see
also J.A. 32–33.
We do not agree that claim 6 is invalid for improper
broadening based on the addition of claims 15 and 16. Our
broadening inquiry begins and ends with claim 6. Claim 6
was not itself amended during the ’401 reexamination.
And as HP admits, “[t]he district court’s construction [after
reexamination] is consistent with how the [earlier district]
courts construed this term [pre-reexamination].”
Case: 18-2338 Document: 81 Page: 23 Filed: 11/20/2020

NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD 23
COMPANY

Appellee’s Br. 15. Neither party appeals that construction.
There can be no dispute, therefore, that the scope of claim 6
was not changed as a result of the ’401 reexamination.
Where the scope of claim 6 has not changed, there has not
been improper claim broadening, and HP’s argument fails.
See Creo Prods., 305 F.3d at 1344.
Furthermore, our precedent is clear that “dependent
claims cannot broaden an independent claim from which
they depend.” Enzo Biochem Inc. v. Applera Corp., 780
F.3d 1149, 1156–57 (Fed. Cir. 2017). Thus, even were de-
pendent claims 15 and 16 broader than unamended, inde-
pendent claim 6, the remedy would not be to find claim 6
invalid as broadened, but to invalidate added claims 15 and
16. See MBO Labs., Inc. v. Becton, Dickinson & Co., 602
F.3d 1306, 1319 (Fed. Cir. 2010). We need not determine
whether claims 15 and 16 are invalid because they are not
asserted and because those claims have already been can-
celed through Network-1’s statutory disclaimer.
Despite the clarity of our caselaw, HP principally relies
on ArcelorMittal France v. AK Steel Corp., 786 F.3d 885
(Fed. Cir. 2015), to argue that claim 6 was improperly
broadened and should be invalidated. In that case, we con-
cluded that the patentee had improperly broadened inde-
pendent claim 1 through reissue by adding a number of
dependent claims. See ArcelorMittal, 786 F.3d at 890. HP
quotes our explanation that one of the new dependent
claims had “the practical effect of expanding the scope of
claim 1 to cover claim scope expressly rejected by a previ-
ous claim construction ruling.” Appellee’s Br. 70 (quoting
ArcelorMittal, 786 F.3d at 890). HP also emphasizes that
in ArcelorMittal, we held invalid for improper broadening
under 35 U.S.C. § 251 not only the newly added claims but
also claim 1 itself. Appellee’s Br. 70. HP argues that the
facts in ArcelorMittal are “nearly identical” to this case,
and that claim 6 is invalid because claims 15 and 16 have
“the practical effect of expanding” the scope of claim 6. Id.
HP is wrong.
Case: 18-2338 Document: 81 Page: 24 Filed: 11/20/2020

24 NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
COMPANY

ArcelorMittal is inapposite. In that case, the patentee
had stipulated that all reissued claims, including claim 1,
were broader than the original claims. ArcelorMittal, 786
F.3d at 890. Thus, in ArcelorMittal, there was no dispute
that the claims had been broadened. Furthermore, we did
not hold, as HP suggests, see Appellee’s Br. 70–71, that a
dependent claim added during reissue (or reexamination)
may broaden and therefore invalidate an unamended, in-
dependent claim. To the contrary, we rejected “the argu-
ment that a defective reissue application invalidates . . .
[the] original claims carried over from the original applica-
tion.” ArcelorMittal, 786 F.3d at 891 (quoting Hewlett–
Packard Co. v. Bausch & Lomb, Inc., 882 F.2d 1556, 1566
(Fed. Cir. 1989)).
Accordingly, we affirm the district court’s conclusion
that claim 6 and the other asserted claims are not invalid
due to improper claim broadening.
CONCLUSION
We have considered the parties’ remaining arguments
and find them unpersuasive. For the reasons described
above, we affirm-in-part, reverse-in-part, vacate, and re-
mand.
AFFIRMED-IN-PART, REVERSED-IN-PART,
VACATED, AND REMANDED
COSTS
The parties shall bear their own costs.