Case: 19-2191 Document: 47 Page: 1 Filed: 05/14/2020
NOTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
BUSHNELL HAWTHORNE, LLC,
Plaintiff-Appellant
v.
CISCO SYSTEMS, INC.,
Defendant-Appellee
______________________
2019-2191
______________________
Appeal from the United States District Court for the
Eastern District of Virginia in No. 1:18-cv-00760-TSE-
MSN, Judge T. S. Ellis, III.
______________________
Decided: May 14, 2020
______________________
BRIAN SHERWOOD SEAL, Butzel Long, PC, Washington,
DC, for plaintiff-appellant. Also represented by MITCHELL
ZAJAC, Detroit, MI.
ELIZABETH BRANNEN, Stris & Maher LLP, Los Angeles,
CA, for defendant-appellee. Also represented by DOUGLAS
D. GEYSER, JOHN STOKES, PETER K. STRIS.
______________________
Case: 19-2191 Document: 47 Page: 2 Filed: 05/14/2020
2 BUSHNELL HAWTHORNE, LLC v. CISCO SYSTEMS, INC.
Before O’MALLEY, BRYSON, and CHEN, Circuit Judges.
O’MALLEY, Circuit Judge.
Bushnell Hawthorne, LLC (“Bushnell”) appeals a deci-
sion of the United States District Court for the Eastern Dis-
trict of Virginia holding all asserted claims of
U.S. Patent
No. 7,933,951 (“’951 patent”) invalid as indefinite pursuant
to
35 U.S.C. § 112(b). Bushnell Hawthorne, LLC v. Cisco
Sys., Inc., No. 1:18-CV-760,
2019 WL 2745735 (E.D. Va.
July 1, 2019). For the reasons discussed below, we affirm.
I. BACKGROUND
A. The ’951 Patent
The ’951 patent, titled “Systems and Methods for Dis-
cerning and Controlling Communication Traffic,” relates
“to identifying various types of communication traffic and
controlling movement of that traffic within a communica-
tions network.” ’951 patent, col. 1, ll. 1–3, 18–20. The in-
vention “permit[s] redirection of only certain types of
communication traffic of interest[,] for example HTTP traf-
fic, while permitting other types of communication, for ex-
ample SMTP traffic, to pass without redirection.”
Id. at
Abstract. This invention is useful for redirecting internet
traffic to generate advertising revenue.
Id.
Claim 1, the only independent claim in the ’951 patent,
is representative of the claims at issue on appeal:
1. A computer system for redirecting Internet com-
munications, said system comprising:
a first processor that receives information
from a computer at a point of origin;
a second processor that analyzes the infor-
mation for one or more pre-defined bit
strings or character sets;
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BUSHNELL HAWTHORNE, LLC v. CISCO SYSTEMS, INC. 3
a third processor that receives return infor-
mation from a computer that communi-
cates with other computers on the Internet;
a fourth processor that analyzes the return
information for said one or more pre-de-
fined bit strings or character sets;
a fifth processor that
a) supplies one or more IP Ad-
dresses for the information re-
quested if one or more of the pre-
defined bit strings or character sets
are not encountered,
b) supplies one or more second IP
Addresses for the information re-
quested if one or more different bit
strings or character sets are en-
countered,
c) supplies one or more third IP Ad-
dresses if one or more of the pre-de-
fined bit strings or character sets
are encountered and a higher level
protocol can be inferred, and/or
d) allows the traffic to flow thru un-
modified; and
a sixth processor that analyzes a request
submitted to said different IP Address for
one or more alternative bit strings or char-
acter sets,
wherein the alternative bit strings or char-
acter sets are indicative of a particular
higher level Internet communication proto-
col, and
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4 BUSHNELL HAWTHORNE, LLC v. CISCO SYSTEMS, INC.
wherein the system further comprises main-
taining a list of bit strings or character sets
for which a different IP Address should not
be supplied, wherein the list is updated one
or more times after creation of the list, and
wherein the list is updated based on moni-
toring of requests for: originating IP Ad-
dress, requested hostname, size of a DNS
query, frequency of a single hostname or
domain name, port number, date, and/or
time.
’951 patent, col. 21, ll. 9–45 (emphases added). Dependent
claims 8, 13, and 15 contain additional limitations relevant
to this appeal. Claim 8 requires “a seventh processor that
receives a request to connect to a computer at said IP Ad-
dress.”
Id. at col. 22, ll. 7–8 (emphasis added). Claim 13
provides “a tenth processor at the different IP Address.”
Id.
at col. 22, l. 24 (emphasis added). And claim 15 adds “items
for the list are generated by the sixth processor that ana-
lyzes a request submitted to said different IP Address.”
Id.
at col. 22, ll. 28–30 (emphasis added).
With respect to the claim term “said different IP Ad-
dress,” the specification provides:
[T]he present invention provides a computer sys-
tem for redirecting Internet communications,
where the system comprises . . . a processor that
analyzes a request submitted to the different IP Ad-
dress for one or more alternative bit strings or char-
acter sets, wherein the alternative bit strings or
character sets are indicative of a particular higher
level Internet communication protocol.
Id. at col 13, ll. 3–25 (emphasis added). It also states:
[T]he system may comprise maintaining a list of bit
strings or character sets for which a different IP
Address should not be supplied, for example
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BUSHNELL HAWTHORNE, LLC v. CISCO SYSTEMS, INC. 5
wherein items for the list are generated by the pro-
cessor that analyzes a request submitted to said
different IP Address. The list can be maintained by
a processor that transparently passes DNS re-
sponses if one or more conditions or pre-defined bit
strings or character sets are not encountered, and
that supplies a different IP Address if one or more
of the conditions or pre-defined bit strings or char-
acter sets are encountered. . . . In embodiments, a
list is maintained on a computer that analyzes one
or more requests submitted to the different IP Ad-
dress and a list is maintained on a computer that
analyzes the request(s) submitted to the different
IP Address, where the two lists are compared to
identify entries in common or not in common.
Id. at col. 13, l. 47–col. 14, l. 1 (emphases added). Finally,
the specification explains that:
[I]n embodiments, the system can comprise means
for . . . returning to the submitter of the request an
IP Address that is different from that requested. In
embodiments, the system further comprises means
for receiving a request for the different IP Address;
means for analyzing the request for the different IP
Address for pre-defined bit strings or character sets
indicative of a particular Internet protocol . . . .
Id. at col. 17, ll. 42–57 (emphases added).
B. District Court Proceedings
Bushnell filed suit against Cisco Systems, Inc. (“Cisco”)
in June 2018, alleging infringement of nineteen claims of
the ’951 patent. The case proceeded to claim construction.
In its claim construction briefing, Cisco argued that all
claims of the ’951 patent were invalid as indefinite. Specif-
ically, Cisco argued that “said different IP Address,” and
related terms, are indefinite. Cisco further alleged that the
claims are indefinite because they mix statutory classes of
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6 BUSHNELL HAWTHORNE, LLC v. CISCO SYSTEMS, INC.
claims. Bushnell argued that all of the disputed terms
carry their plain meaning. It contended that the plain
meaning of the “different IP Address” terms is “an IP ad-
dress supplied by the fifth processor that is different from
the IP address for the information requested by the user or
computer at the point of origin.” Bushnell Hawthorne,
LLC,
2019 WL 2745735, at *2.
Following a Markman hearing, the district court ruled
in favor of Cisco, finding independent claim 1 indefinite on
three separate grounds: (1) “said different IP Address”
lacks antecedent basis and does not have a reasonably cer-
tain meaning to a person of ordinary skill in the art
(“POSA”); (2) “a different IP Address” does not have a rea-
sonably certain meaning to a POSA; and (3) the final limi-
tation, providing that “the system further comprises
maintaining a list,” improperly mixes classes of statutory
subject matter such that it is not clear if the claim is in-
fringed by building or using the system.
Id. at *2–9.
First, the district court explained that the antecedent
basis for “said different IP Address” is unclear—possibly
referring to any of three types of IP addresses that claim 1’s
fifth processor might supply: “one or more IP Addresses,”
“one or more second IP Addresses,” or “one or more third
IP Addresses.”
Id. at *3. Because the IP addresses men-
tioned in the fifth processor limitation are the first in-
stances of the term “IP Addresses” in the claim, the district
court presumed one of those was likely “said different IP
Address.”
Id. The fact that the fifth processor limitation
claims three separate classes of IP addresses, however, led
the district court to conclude that it was not possible to dis-
cern which of the three addresses was referenced by the
disputed limitation.
Id. The district court further ex-
plained that the confusion caused by the claim language is
enhanced by the singular/plural mismatch between the
fifth processor limitation’s potential to produce multiple IP
addresses and the claimed singular “said different IP Ad-
dress.”
Id. at *4.
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BUSHNELL HAWTHORNE, LLC v. CISCO SYSTEMS, INC. 7
Beyond the claim language, the district court found
that the specification provides no clarification on the mean-
ing of the term because most of the specification suffers
from the same lack of antecedent basis problem.
Id. And,
although the specification describes a “means for returning
to the submitter of the request an IP Address that is differ-
ent from that requested,” the remainder of the specification
is ambiguous and makes what appear to be inconsistent
uses of the term.
Id. (quoting ’951 patent, col. 17, ll. 51–
53). In some instances, the district court noted, the speci-
fication refers to a requested IP address as “the different IP
Address.”
Id. (citing, inter alia, ’951 patent, col. 13, l. 22).
Based on this intrinsic record, the district court found that
a POSA would be unable to discern, with reasonable cer-
tainty, whether a particular IP address was “said different
IP Address” within the meaning of the claim.
Id. at *5. It
therefore held the claim indefinite.
Id.
Second, the district court found the claim term “a dif-
ferent IP Address” indefinite. It explained,
[l]ike the term “said different IP address,” the
claim term “a different IP address” appears to al-
lude to another IP address from which “a different
IP address” is different. But the claim language
and specification neither explain how or from what
other IP address “a different IP address” differs nor
otherwise clarify what constitutes “a different IP
address.”
Id. at *6.
Third, the district court held claim 1 indefinite for im-
properly combining the structural elements of a “computer
system” with a method element, “maintaining a list.”
Id.
at *7–9. The district court further held dependent claims
8, 13, and 15 indefinite based on the lack of clarity as to the
meaning of the “IP Address” terms.
Id. at *2–5, 6–7.
Case: 19-2191 Document: 47 Page: 8 Filed: 05/14/2020
8 BUSHNELL HAWTHORNE, LLC v. CISCO SYSTEMS, INC.
Having found all asserted claims indefinite, the district
court entered judgment for Cisco. J.A. 21. Bushnell ap-
peals. We have jurisdiction pursuant to
28 U.S.C. § 1295.
II
“[A] patent is invalid for indefiniteness if its claims,
read in light of the specification delineating the patent, and
the prosecution history, fail to inform, with reasonable cer-
tainty, those skilled in the art about the scope of the inven-
tion.” Nautilus, Inc. v. Biosig Instruments, Inc.,
572 U.S.
898, 901 (2014). We review a district court’s determination
that a claim is indefinite de novo and subsidiary factual
findings, if any, for clear error. Sonix Tech. Co. v. Publ’ns
Int’l, Ltd.,
844 F.3d 1370, 1376 (Fed. Cir. 2017).
Bushnell argues that the district court erred in holding
that “said different IP address,” and related terms, are in-
definite. Appellant’s Br. 12–18. It contends that “said dif-
ferent IP Address” clearly refers to an IP address to which
the user has been redirected.
Id. at 12. Its argument is
unavailing.
Claim 1 of the ’951 patent is, on its face, entirely un-
clear as to the meaning of “said different IP Address.” As
an initial matter, “said different IP Address” appears in the
claim without antecedent basis. Prior to that point, the
claim recites certain IP addresses, but never a “different”
one. See ’951 patent, claim 1. The lack of antecedent basis
signals a potential indefiniteness problem but does not end
the inquiry. See Energizer Holdings, Inc. v. Int’l Trade
Comm’n,
435 F.3d 1366, 1370 (Fed. Cir. 2006) (“Whether
[a] claim, despite lack of explicit antecedent basis . . . none-
theless has a reasonably ascertainable meaning must be
decided in context.”).
Moving to the broader context of the claim, however,
only compounds the problem. Claim 1 describes three clas-
ses of IP addresses prior to the “said different IP Address”
limitation: “one or more IP Addresses,” “one or more second
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BUSHNELL HAWTHORNE, LLC v. CISCO SYSTEMS, INC. 9
IP Addresses,” or “one or more third IP Addresses.” ’951
patent, claim 1. Each of those terms is presumed to have a
separate meaning and, therefore, presumed to refer to dif-
ferent classes of IP addresses. See Bd. of Regents v. BENQ
Am. Corp.,
533 F.3d 1362, 1371 (Fed. Cir. 2008). With
three different IP addresses to choose from, a POSA faced
with the “said different IP Address” limitation is left to
wonder which of the different IP addresses is “said” differ-
ent one.
Further, the mismatch between the various plural IP
addresses provided earlier in the claim and the singular
“said different IP Address” suggests a term that is entirely
untethered from the words around it. It is true that, as a
general rule, a singular noun encompasses the plural for
claim construction purposes. 01 Communique Lab., Inc. v.
LogMeIn, Inc.,
687 F.3d 1292, 1297 (Fed. Cir. 2012). This
claim construction principle, however, does not render the
mismatch irrelevant. Where, as here, a singular/plural
mismatch further confuses an already confused claim, it is
proper to consider the mismatch in discerning whether a
POSA could understand the claim with reasonable cer-
tainty.
The specification does not clarify the meaning of “said
different IP Address.” Much of the specification uses “the
different IP Address” or “said different IP Address” in the
same way as the claim—without explanation or antecedent
basis. At one point, the specification appears to indicate,
contrary to Bushnell’s contention, that the “different” IP
address the patent refers to is the one which was re-
quested. See ’951 patent, col. 13, ll. 21–22 (“a processor
that analyzes a request submitted to the different IP Ad-
dress”). At another, the specification provides comparing
one list of requests submitted to “the different IP Address”
to another list of requests submitted to “the different IP
Address”—reasonably indicating that those two uses of
“different IP Address” are not, even in the same sentence,
referring to identical data sets.
Id. at col. 13, l. 63–col.14,
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10 BUSHNELL HAWTHORNE, LLC v. CISCO SYSTEMS, INC.
l. 1. Given this backdrop, the single sentence in the speci-
fication that potentially supports Bushnell’s interpretation
is insufficient to save the claim. See
id. at col. 17, ll. 51–53
(“means for returning to the submitter of the request an IP
Address that is different from that requested”).
The meaning of “said different IP Address” is entirely
unclear on the record before us. A POSA, faced with the
claims and the specification, 1 could not, with reasonable
certainty, discern the meaning of the claim term. See Nau-
tilus, Inc., 572 U.S. at 901. We thus hold claim 1, and all
claims depending therefrom, indefinite.
III
Because we affirm the district court as to the “said dif-
ferent IP Address” limitation and hold all asserted claims
indefinite, we do not address the remaining issues raised
on appeal. For the reasons discussed above, we affirm the
district court’s decision.
AFFIRMED
1 Neither party argues that the prosecution history
sheds light on the meaning of “said different IP Address.”
Accordingly, we do not consider it here.
