Absolute Software, Inc. v. Stealth Signal, Inc.

United States Court of Appeals
for the Federal Circuit
__________________________

ABSOLUTE SOFTWARE, INC. AND
ABSOLUTE SOFTWARE CORPORATION,
Plaintiffs-Appellants,
v.
STEALTH SIGNAL, INC. AND
COMPUTER SECURITY PRODUCTS, INC.,
Defendants-Cross Appellants.
__________________________

2010-1503, -1504
__________________________

Appeals from the United States District Court for the
Southern District of Texas in case no. 05-CV-1416, Senior
Judge Ewing Werlein, Jr.
_________________________

Decided: October 11, 2011
_________________________

IRENE Y. LEE, Russ August & Kabat, of Los Angeles,
California, argued for plaintiffs-appellants. With her on
the brief was MARC A. FENSTER.

JEREMY L. DOYLE, Reynolds, Frizzell, Black, Doyle, Al-
len & Oldham LLP, of Houston, Texas, argued for defen-
dants-cross appellants. With him on the brief were J.
CHRISTOPHER REYNOLDS and BILLY BERRYHILL.
__________________________
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 2

Before RADER, Chief Judge, PROST, and O’MALLEY, Circuit
Judges.
O’MALLEY, Circuit Judge.
This is a patent infringement action between compa-
nies that sell competing software products designed to
track lost or stolen laptop computers, which one company
refers to as “LoJack for Laptops.” Each side asserted
claims of patent infringement against the other based on
their respective software products. Following the parties’
cross-motions for summary judgment, the district court
entered summary judgment of non-infringement for each
side. See Absolute Software, Inc. v. Stealth Signal, Inc.,
731 F. Supp. 2d 661 (S.D. Tex. 2010) (“District Court
Decision”). Both sides appeal from this judgment. Spe-
cifically, Absolute Software, Inc. and Absolute Software
Corporation (collectively, “Absolute”) challenge certain of
the district court’s claim constructions and appeal from
the district court’s grant of summary judgment of non-
infringement in favor of Stealth Signal, Inc. (“Stealth
Signal”) and Computer Security Products, Inc. (“CSP”)
(collectively, “Stealth”) with respect to U.S. Patent Nos.
6,244,758 (“the ’758 Patent”); 6,300,863 (“the ’863 Pat-
ent”); and 6,507,914 (“the ’914 Patent”) (collectively, the
“Absolute Patents”). Stealth Signal likewise challenges
certain of the district court’s claim constructions and
cross-appeals from the district court’s grant of summary
judgment of non-infringement in favor of Absolute with
respect to U.S. Patent No. 5,406,269 (“the ’269 Patent”).
For the reasons discussed below, we do not alter any
of the claim constructions challenged on appeal. We also
find that the district court correctly granted summary
judgment of non-infringement to Absolute. We conclude,
however, that issues of fact preclude granting summary
judgment of non-infringement to Stealth. Accordingly, we
3 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

affirm-in-part, vacate-in-part, and remand this matter for
further proceedings.
BACKGROUND
A. The Absolute Patents
The Absolute Patents relate to a method, apparatus,
and system for retrieving lost or stolen electronic devices
such as laptop computers, personal digital assistants
(PDAs), and cell phones, via a global network, such as the
Internet. The patents are respectively entitled “Appara-
tus and Method for Monitoring Electronic Devices via a
Global Network” (’758 Patent); “Method and Apparatus to
Monitor and Locate an Electronic Device Using a Secured
Intelligent Agent via a Global Network” (’863 Patent); and
“Computer Security Monitoring Apparatus and System”
(’914 Patent). Under the ’758 Patent, for example, the
invention requires a software program (the “agent”) that
can be loaded onto an electronic device, such as a laptop
computer. Using a global network (e.g., the Internet), the
agent software program communicates information about
the identity and location of the protected electronic device
to a host system, which the host system uses to track the
whereabouts of the device.
Each of the asserted claims of the ’758 and ’863 Pat-
ents requires a step of the agent “providing said host
system with one or more global network communication
links used to enable transmission between said electronic
devices and said host system . . . .” E.g., ’758 Patent
col.21 ll. 24-27; ’863 Patent col.33 ll.22-25. Representa-
tive claim 1 of the ’758 Patent recites (in this claim and
the others below, the term at issue on appeal is empha-
sized):
1. A method for tracing an electronic device
having an agent, said agent used for pro-
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 4

viding identifying indicia and location in-
formation for said electronic device to a
host system, said electronic device con-
nectable to said host system through a
global network, said method comprising
the steps of:
loading said agent within said electronic
device for initiating communication with
said host system such that said agent
evades detection;
automatically providing said host system
with said identifying indicia through said
global network for determining the iden-
tity of said electronic device; and
providing said host system with one or
more of the global network communication
links used to enable transmission between
said electronic device and said host system,
said communication links used for deter-
mining the location of said electronic de-
vice.
’758 Patent col.21 ll.12–27. This claim, therefore, re-
quires that the agent (e.g., the software program loaded
onto a laptop computer) provide the host system with “one
or more global network communication links” that the
host system can use to track the location of the protected
device. With respect to this limitation, the parties dispute
whether a “communication link” can be a single Internet
Protocol (“IP”) address or whether it must be a connection
between two IP addresses, which by definition requires at
least two IP addresses to identify the connection. As
discussed below, the district court construed the term to
require at least two IP addresses.
5 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

With respect to the final Absolute Patent, the ’914
Patent, the only independent claim asserted is claim 4,
which recites
4. A computer security monitoring system, compris-
ing:
a computer having visual and audible user inter-
faces;
a telecommunication interface operatively con-
nected to the computer; and
agent means embedded in the computer for send-
ing signals to the telecommunication interface in-
cluding signals for contacting a host monitoring
system without signaling the visual or audible
user interface, and for providing the host monitor-
ing system with identification indicia of the com-
puter, whereby the host monitoring system could
identify whether the computer has been reported
lost based on the identifying indicia.
’914 Patent col.627 ll.18-29. The emphasized term re-
quires that the agent “contact” the host without making a
signal that a user can see or hear. According to the
Summary of the Invention, this feature allows the agent
to “evade detection and resist possible attempts to disable
it by an unauthorized user.” Id. col.2 ll.22-24. In other
words, the invention requires that the agent send a signal
without alerting an unauthorized user, such as a thief,
thus preventing the user from becoming aware of the
signal and attempting to obstruct it.
B. Stealth’s ’269 Patent
The ’269 Patent, which issued to inventor David
Baran on April 11, 1995, is entitled “Method and Appara-
tus for the Remote Verification of the Operation of Elec-
tronic Devices by Standard Transmission Mediums.”
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 6

Stealth obtained a license to this patent in response to
Absolute’s assertion of patent infringement. The ’269
Patent generally describes an invention that remotely
monitors electronic devices by imbedding in such devices
an agent that makes surreptitious calls to a central
monitoring site. The invention has two fundamental
purposes: (1) to monitor the performance of an electronic
device remotely, and (2) to detect the misuse of software,
such as when it is installed on multiple computers with-
out a license.
Four independent claims of the ’269 Patent are at is-
sue on appeal: claims 11, 12, 25, and 29. Claims 12 and
25 contain the term “semi-random rate.” Representative
claim 12 recites:
12. A remote site performance monitoring system for
inclusion in an electrical apparatus to monitor
and collect performance data thereof during op-
eration surreptitiously of a user of said electrical
apparatus for transmitting said collected per-
formance data to a central site means for compar-
ing the received collected performance data with
expected performance data for electrical appara-
tus of the type in which said remote site perform-
ance monitoring system has been added, said
remote site system comprising:
* * * *
transmission means for initiating, at a semi-
random rate, the transmission of the message
packet from the formatting means to the central
site means of the system surreptitiously of a user
of said electrical apparatus.
’269 Patent col.9 l.59–col.10. l.12 (emphasis added). This
claim requires that the system have a transmission
7 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

means for sending a message packet to a central site
means, and the transmission must occur at a “semi-
random rate.” The Summary of the Invention of the ’269
Patent states that “[t]he call initiation is preferentially
triggered at a carefully controlled semi-random rate,
perhaps once a week.” Id. col.2 ll.57-59.
Finally, the last two claims at issue on appeal, claims
11 and 29 of the ’269 Patent, contain the terms “unique
usage agreement information” and “said terms of said
usage agreement imbedded in said software.” Claim 11
recites:
11. A method for monitoring software usage of owner-
leased proprietary software residing in at least
one remote computer surreptitiously of a user of
said remote computer to detect violations of soft-
ware usage agreements surreptitiously of a user of
said remote computer at a central site means, said
method comprising the steps of:
a. imbedding unique usage agreement information
that is transparent to the user in each original
copy of said owner-leased proprietary software;
b. each of said at least one remote computers
monitoring the use of said software of step a. sur-
reptitiously of a user of said remote computer;
c. each of said at least one remote computers
automatically, at various times, reporting said
terms of said usage agreement imbedded in said
software and the use of said software by said re-
mote computer monitored in step b. to said central
site means surreptitiously of a user of said remote
computer;
* * * *
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 8

’269 Patent col.9 ll.27-58 (emphasis added). This claim
requires the remote computer to send certain usage
agreement information to a central site, though the
parties dispute whether that information can be just the
serial number of a license agreement, or whether it must
include the actual terms and provisions of the license
agreement.
C. The Parties’ Accused Products
Absolute and Stealth sell competing software products
for tracking lost or stolen laptop computers. Stealth’s
product is the XTool Computer Tracker (“XTool” or “XTool
Tracker”). There are two important features of the XTool
Tracker as it relates to this appeal: (1) the “agent” (i.e.,
the software program) of the XTool Tracker sends mes-
sage packets to the host that, when they arrive, contain
both the IP address of the client computer and the IP
address of the host, and it is undisputed that the agent
furnishes at least the IP address of the client computer;
and (2) to design around the “contacting . . . without
signaling” limitation of Absolute’s ’914 Patent, Stealth
added an audible signal that occurs at the end of every
communication between the agent and the host, just
before the connection ends.
Absolute’s product is called Computrace. Importantly
for this appeal, it is undisputed that the Computrace
product is designed to initiate a call to the monitoring
center 24.5 hours following the completion of its previous
call. It is also undisputed that Absolute’s Computrace
product transmits an electronic serial number relating to
a licensing or usage agreement to the host monitoring
center but does not transmit the actual terms of the
licensing or usage agreement.
9 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

D. Litigation and Claim Construction
In October 2004, Absolute filed a complaint in the
United States District Court for the District of Washing-
ton alleging that Stealth infringed the three Absolute
Patents identified above, as well as other patents that are
not at issue on appeal. Stealth Signal counterclaimed for
infringement of the ’269 Patent and for declarations of
non-infringement, invalidity, and unenforceability relat-
ing to the Absolute Patents. 1 Stealth successfully moved
to transfer the action to the United States District Court
for the Southern District of Texas, where the case pro-
ceeded to final judgment.
For purposes of claim construction, the district court
appointed a special master, Professor David B. Johnson,
Associate Professor of Computer Science and of Electrical
and Computer Engineering at Rice University, pursuant
to Rule 53 of the Federal Rules of Civil Procedure. The
special master conducted hearings on the parties’ claim
construction arguments and, on February 8, 2008, issued
a 130-page Report and Recommendation on Claim Con-
struction (“R&R”).
When it appointed the special master, the district
court entered an order requiring the parties to file any
objections to the special master’s recommended claim
construction within twenty days of the R&R. 2 See Abso-

1 Although Stealth Signal, not CSP, owns a license
to the ’269 patent and asserted the counterclaims in this
action, both the district court and the parties refer to
Stealth Signal and CSP collectively as the counterclaim-
ant and cross-appellant. For ease of reference and conti-
nuity, we do the same. Because the district court did not
enter any adverse judgment against CSP, however, CSP
is not properly a cross-appellant.
2 While this order corresponded to the then-
governing time frame for the filing of objections under
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 10

lute Software, Inc. v. Stealth Signal, Inc., Case No. 05-CV-
1416 (S.D. Tex. Apr. 10, 2007) (Order Vacating Hearing
and Appointing Special Master, ECF 143). On February
28, 2008, Absolute and Stealth submitted their respective
objections to the special master’s claim construction.
While Stealth objected to several aspects of the special
master’s report, in its objections, Absolute “commend[ed]
the Special Master on an extraordinarily thorough and
thoughtful analysis of the claim construction issues,” and
objected to only two portions of the report, neither of
which relate to this appeal: (1) the construction of the
term “automatically” from the Absolute Patents; and (2) a
“narrow legal issue” relating to the construction of a
means-plus-function claim. Joint Appendix (“JA”)
040132.
Following the parties’ objections, the special master
issued an Amendment to the Report and Recommendation
on Claim Construction, which amended the claim con-
structions for three terms, only one of which is at issue on
appeal: “semi-random rate.” On June 17, 2009, the
district court adopted the special master’s R&R as modi-
fied by the Amendment to the Report. The specific claim
constructions relevant to this appeal are discussed where
appropriate below.
E. The District Court’s Summary Judg-
ment Decision
The district court allowed each party to file one mo-
tion for summary judgment, not to exceed thirty-five
pages. Following the parties’ cross-motions, the district
court granted summary judgment of non-infringement for

Rule 53 of the Federal Rules of Civil Procedure, it was
entered as a case-management order and did not ex-
pressly invoke the time limits in the rule.
11 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

both parties on their respective patent infringement
claims.
As it relates to Absolute’s infringement claims, the
district court held that Stealth’s XTool Tracker did not
meet the “providing said host system with one or more of
the global network communication links” limitation of the
’758 and ’863 Patents, finding that Absolute failed to
demonstrate that the XTool agent sends a link (i.e., two
IP addresses) to the host. See District Court Decision, at
671-72. The district court also held that Stealth did not
infringe the ’914 Patent, the asserted claims for which
contain the “contacting . . . without signaling” limitation,
because the XTool Tracker emits an audible signal at the
end of every communication with the host. Id. at 673.
With respect to Stealth’s infringement claim, the dis-
trict court found that neither the “semi-random rate”
limitation nor the “terms of said usage agreement” limita-
tion reads onto Absolute’s Computrace software. As for
the “semi-random rate” limitation, the court found that
Absolute did not literally infringe the ’269 Patent because
the Computrace product’s call-time formula places a call
every 24.5 hours after the end of the previous call and,
thus, does not meet the randomness requirement. Id. at
666-67. It also found that Absolute did not infringe under
the doctrine of equivalents because the “semi-random
rate” limitation of the ’269 Patent and Absolute’s call-
timing formula perform different functions. Id. at 668-69.
Finally, the district court found that Absolute did not
meet the “terms of said usage agreement” limitation
because its software sends only a serial number of a
license to a monitoring center, but the claim, as con-
strued, requires the agent to send actual licensing terms.
Id.
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 12

Accordingly, the district court entered summary
judgment of non-infringement for both Absolute and
Stealth. 3 The parties filed timely notices of appeal. This
court has jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).
STANDARDS OF REVIEW
Applying Fifth Circuit law, we review the district
court’s decision to grant summary judgment de novo,
applying the same standard as the district court. United
States v. Caremark, Inc., 634 F.3d 808, 814 (5th Cir.
2011). Summary judgment is appropriate if, in viewing
the evidence in a light most favorable to the non-moving
party, the court finds that “there is no genuine dispute as
to any material fact and the movant is entitled to judg-
ment as a matter of law.” Fed. R. Civ. P. 56(a).
Determining infringement requires two steps. “First,
the claim must be properly construed to determine its
scope and meaning. Second, the claim as properly con-
strued must be compared to the accused device or proc-
ess.” Carroll Touch, Inc. v. Electro Mech. Sys., Inc., 15
F.3d 1573, 1576 (Fed. Cir. 1993) (citations omitted). The
proper construction of a patent’s claims is an issue of
Federal Circuit law, and we review a district court’s claim
construction de novo. Cybor Corp. v. FAS Techs., Inc., 138
F.3d 1448, 1454–55 (Fed. Cir. 1998) (en banc). To ascer-
tain the scope and meaning of the asserted claims, we
look to the words of the claims themselves, the specifica-
tion, the prosecution history, and any relevant extrinsic
evidence. Phillips v. AWH Corp., 415 F.3d 1303, 1315–17
(Fed. Cir. 2005) (en banc).

3 The district court also held that certain claims of
Stealth’s ’269 Patent were invalid under 35 U.S.C. § 112,
¶ 2, for failure to disclose and clearly link any structure to
the recited function. Stealth has not appealed that por-
tion of the decision.
13 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

Infringement, whether literal or under the doctrine of
equivalents, is a question of fact. Bai v. L & L Wings,
Inc., 160 F.3d 1350, 1353 (Fed. Cir. 1998). On appeal
from a grant of summary judgment of non-infringement,
we determine whether, after resolving reasonable factual
inferences in favor of the patentee, the district court
correctly concluded that no reasonable jury could find
infringement. IMS Tech., Inc. v. Haas Automation, Inc.,
206 F.3d 1422, 1429 (Fed. Cir. 2000).
DISCUSSION
A. Absolute’s Appeal
Absolute raises three issues on appeal, arguing that:
(1) the district court’s claim construction of the term
“global network communication links” is erroneous; 4 (2)
genuine issues of material fact preclude summary judg-
ment of non-infringement of the ’758 and ’863 Patents;
and (3) genuine issues of material fact preclude summary
judgment of non-infringement of the ’914 Patent. Al-
though we find that Absolute waived its right to challenge
the district court’s claim construction by failing to file
timely objections to the special master’s R&R, we agree
that summary judgment of non-infringement as to all
three Absolute Patents was improper. We address each
issue in turn below.

4 The full claim term is “providing said host system
with one or more of the global network communication
links used to enable transmission between said electronic
device and said host system.” For ease of reference, we
refer to the term as “global network communication links”
because those words form the crux of the dispute.
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 14

1. Construction of “global network com-
munication links”
In his February 8, 2008 report, the special master
construed the term “global network communication links”
as “the identification of one or more (perhaps less than
all) of the connections (either direct or indirect) between
two nodes in the Internet (one of the nodes may be the
electronic device itself) used to enable data transmission
between said electronic device and said host system.” JA
040027. The construction therefore defines “communica-
tion links” as the connections between two nodes in the
Internet rather than as the nodes, or IP addresses of
routers, themselves.
On February 28, 2008, Absolute filed timely objections
to the special master’s report, but it challenged only two
portions of the report, neither of which related to the
special master’s recommended construction of “global
network communication links.” JA 040132. On the same
date, Stealth also filed objections, including to the special
master’s construction of “global network communication
links.” Stealth argued that “links” should mean “IP
routers,” a position consistent with its proposed construc-
tion. JA 040132. The special master ultimately amended
its construction of three terms but left the construction of
“communication links” unchanged. The district court
adopted the special master’s amended R&R.
On appeal, Stealth argues that Absolute waived its
right to challenge the district court’s construction of
“global network communication links” by failing to object
to the special master’s recommended construction within
the deadline established both by rule and by court order.
There is no dispute that Absolute failed to challenge the
special master’s proposed recommendation within the
twenty-day period. Indeed, Absolute’s counsel conceded
15 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

this fact at oral argument. See Oral Arg. at 10:3 –11:15,
available at http://www.cafc.uscourts.gov/oral-argument-
recordings/all/absolute.html (“That’s absolutely right, we
did not raise that objection within the twenty-day time
period, and that was a mistake on our part.”)
Despite acknowledging that its objection was un-
timely, Absolute asserts that we should not find waiver
because its argument was “presented to the district court”
in the sense that Absolute offered its position prior to the
special master’s report on claim construction. We do not
find Absolute’s argument persuasive. A primary purpose
of appointing a special master is to narrow the issues
before the district court judge to facilitate an efficient and
timely resolution of complex or highly-technical issues,
such as patent claim construction. See Fed. R. Civ. P. 53
adv. comm. notes (2003 amendments) (“The court’s re-
sponsibility to interpret patent claims, for example, may
be greatly assisted by appointing a master who has expert
knowledge of the field in which the patent operates”; “the
advantages of initial determination by a master may
make the process more effective and timely than disposi-
tion by the judge acting alone”). Both Rule 53(f)(2) of the
Federal Rules of Civil Procedure and the district court’s
order expressly included a mechanism for parties to file
objections and a time limit to do so. It is through these
objections that the district court can determine which
issues remain in dispute and require the court’s attention.
Accepting Absolute’s argument that its challenge to the
special master’s claim construction was “presented to the
district court” simply because it was argued to the special
master would eviscerate the very purpose of this proce-
dure.
Although it is true that Stealth timely objected to the
construction of “global network communication links,”
that is irrelevant because it is Absolute, not Stealth, that
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 16

seeks to raise this issue on appeal. 5 Stealth’s objection to
the special master’s construction differed from that now
urged by Absolute. Indeed, Stealth contended that the
proper construction should be “IP router,” which is mate-
rially different from the “IP address” construction Abso-
lute would have us now employ. See Stealth’s Principal
and Response Br. 54 (“Stealth certainly did not agree that
a ‘communication link’ could be identified using an IP
address of any single node, such as the client’s computer.”
(emphasis in original)). Under these circumstances, we
find that Absolute’s failure to raise this particular objec-
tion, in the face of both Rule 53(f)(2) and a court order
setting a specific deadline for the filing of objections,
results in waiver of the argument on appeal. See Sage
Prods., Inc. v. Devon Indus., Inc., 126 F.3d 1420, 1426
(Fed. Cir. 1997) (“[A]ppellate courts do not consider a
party’s new theories, lodged first on appeal . . . . In short,
this court does not ‘review’ that which was not presented
to the district court.”); see also Interactive Gift Express,
Inc. v. Compuserve Inc., 256 F.3d 1323, 1344 (Fed. Cir.
2001) (citing Sage for the same proposition). We recog-
nize that this court retains discretion to deviate from the

5 Twenty-six days after the objections were due,
Absolute filed a response to Stealth’s objections. While
still not asserting a formal objection to the special mas-
ter’s construction of “global network communication
links,” Absolute urged the court to modify the construc-
tion “slightly” to construe “links” to be IP addresses. We
do not find that this belated and imprecise argument
preserved Absolute’s objection on this issue. Indeed,
Absolute neither cited to nor relied upon this submission
in its briefing to this court, asserting instead, and only,
that its arguments to the special master were sufficient.
In the face of Absolute’s express endorsement of the
special master’s construction of this term, we cannot
agree that Absolute timely presented its current argu-
ments on the issue to the district court.
17 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

general rule of waiver in certain circumstances. See
Interactive Gift, 256 F.3d at 1344. We decline to do so
here, however, given the careful claim construction proce-
dure the district court established in this case. In addi-
tion, we otherwise do not find that any of the reasons we
have enumerated in the past for considering an argument
that was not presented properly below are present in this
case. See L.E.A. Dynatech, Inc. v. Allina, 49 F.3d 1527,
1531 (Fed. Cir. 1995) (“An appellate court will consider an
issue not presented below only if: (i) the issue involves a
pure question of law and refusal to consider it would
result in a miscarriage of justice; (ii) the proper resolution
is beyond any doubt; (iii) the appellant had no opportunity
to raise the objection at the district court level; (iv) the
issue presents significant questions of general impact or
of great public concern; or (v) the interest of substantial
justice is at stake.” (internal quotations and brackets
omitted)).
2. Summary judgment of non-
infringement of the ’758 and ’863 Patents
Absolute argues that, even if we affirm the district
court’s construction of “global network communication
links,” summary judgment of non-infringement is inap-
propriate because genuine issues of material fact remain
as to whether Stealth’s XTool Tracker agent furnishes,
supplies, or makes available 6 one or more connections
between two nodes on the Internet (i.e., two IP addresses)
to the host. The district court found that the XTool
Tracker agent furnishes only one IP address to the host
and, therefore, does not infringe the ’758 and ’863 Patents

6 The term “providing,” which precedes “one or
more global network communication links” in the claim,
was construed to mean “the agent furnishing, supplying,
or making available.” JA 030028. Neither party has
challenged this construction on appeal.
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 18

as a matter of law. Because we conclude that there are
genuine issues of fact as to whether the XTool Tracker
agent also provides a second IP address, and therefore a
“connection,” we conclude that summary judgment of non-
infringement on this issue was improper.
Under the district court’s claim construction, if the
agent provides the IP addresses of both the agent and
host, the agent will satisfy this limitation of the asserted
’758 and ’863 Patent claims. The parties disputed
whether the XTool agent provided two IP addresses, and
both sides submitted expert declarations on this point.
Stealth contended in its briefing that its expert witness,
Stealth President Pedro Camargo, stated that “the
Stealth agent provides only the IP address of the moni-
tored device.” Stealth’s Principal and Response Br. 15
(emphasis added). This is an overstatement of the ex-
pert’s declaration. Mr. Camargo makes only a conclusory
statement that Stealth does not infringe Absolute’s pat-
ents, adding that “the Stealth ‘agent’ provides the IP
address of the device; and, an IP address is not a ‘link,’ or
a ‘connection’; it is, instead, a ‘node.’” Decl. of Pedro
Camargo, JA 090010, ¶ 8. He never explicitly states that
Stealth’s agent does not provide the host IP address, nor
does he explain what other component of the electronic
device supplies it.
The testimony of Absolute’s expert, Gregory Ennis, is
also not directly on point. Mr. Ennis only states that the
packet generated by the Stealth agent, “when received by
the host system, contains both the IP address of the
device and the IP address of the Stealth Control Center.”
Decl. of Gregory B. Ennis, JA 100028, ¶ 18. He never
explicitly states that the agent provides both the agent IP
address and the host IP address. Rather, he finishes his
discussion with the conclusory statement that “[t]he agent
thereby provides the host system with such a [global
19 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

network communication] link.” Id. In sum, both experts
had the opportunity to provide direct evidence regarding
how the host IP address comes to be in the message
packet that ultimately arrives at the host, but neither one
conclusively states whether it is the agent that provides
this address.
Given this gap in the record, we are left with the fol-
lowing undisputed facts: (1) Stealth’s XTool agent pro-
vides a message packet to the host system with at least
the agent’s IP address; and (2) the packet contains the IP
addresses of both the agent and the host when it arrives
at the host system. Absolute argues that, based on these
facts, the next logical inference is that the XTool agent
also provides the host IP address. The district court,
however, granted Stealth’s motion for summary judgment
of non-infringement, finding that “Absolute’s arguments
and evidence . . . fail to demonstrate that the XTool agent,
as opposed to any other component of a client device,
furnishes, supplies, or makes available any ‘global net-
work communication link.’” District Court Decision, at
671 (emphasis in original).
We find the district court’s determination on this
point erroneous. The decision fails to draw a reasonable
inference in favor of Absolute, the non-moving party,
namely that the XTool agent itself provides the host IP
address that appears in the message packet. See Ala.
Farm Bureau Mut. Cas. Co. v. Am. Fid. Life Ins. Co., 606
F.2d 602, 609 (5th Cir. 1979) (inferences most favorable to
the non-moving party must be drawn, and “[s]uch infer-
ences may create disputes regarding basic facts or regard-
ing facts to be inferred from such facts”). On these facts, a
reasonable jury could find that the same component that
provides the agent IP address and sends the packet—the
XTool agent—also provides the host IP address that is in
that packet when it arrives at the host. Because the
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 20

evidence of record creates a genuine issue of material fact,
we vacate the district court’s summary judgment of non-
infringement of the ’758 and ’863 Patents. 7
3. Summary judgment of non-
infringement of the ’914 Patent
Absolute also appeals the district court’s grant of
summary judgment of non-infringement of the ’914 Pat-
ent, which was based on its finding that Stealth’s XTool
Tracker does not meet the “contacting . . . without signal-
ing” limitation found in claim 4, the only independent
claim asserted. It is undisputed that Stealth’s XTool
Tracker agent does not emit an audible signal when it
establishes a connection with the host, but that it does
emit a “beep” “at the end of the contact with the host.”

7 We also reject Stealth’s argument that summary
judgment is appropriate even if the agent provides both
the agent and host IP addresses. Stealth contends that
providing the IP addresses of the two endpoints (i.e., the
agent and the host) is insufficient to satisfy this limitation
because it would not identify a connection “used to enable
data transmission between said electronic device and said
host system,” as required by the district court’s claim
construction. Stealth asserts that the construction of this
term requires the identification of one of the intermediate
connections along the route, not just the endpoints.
Under the plain reading of the claim construction, how-
ever, the connections can be either “direct or indirect” and
do not necessarily need to be between two consecutive
nodes. This reading is confirmed by the special master’s
statement in his report: “Note that such a communication
link may be identified by giving the IP address of each of
the two nodes at either end of the communication link, but
neither of these IP addresses and neither of those nodes is
itself a ‘communication link.’ . . . The connection between
each of these consecutive nodes is a communication link
in the Internet, as is the connection between any other
two Internet nodes.” JA 040025-26 (emphases added).
Accordingly, this argument is without merit.
21 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

Decl. of Pedro Camargo, JA 090011, ¶ 14. Based on these
facts, the district court found that “[t]his claim does not
read on Stealth’s XTool agent because upon the occur-
rence of every communication with the host-monitoring
system the agent triggers an audible signal at the end of
that communication.” District Court Decision, at 673
(emphasis in original). On appeal, Absolute argues that
there are at least issues of fact as to whether the agent’s
silence at the beginning of the connection and during
communication constitutes “contacting . . . without signal-
ing” as that term has been construed by the district court.
As explained below, we agree with Absolute and vacate
the district court’s grant of summary judgment on this
issue.
The district court, in granting judgment of non-
infringement, relied heavily on reasoning in the special
master’s R&R. During claim construction, the parties
disputed whether “contacting” meant only the initiation of
a communication or actually encompassed the entire
communication, with Absolute arguing for the former
interpretation. 8 Finding that there was no clear defini-
tion of “contacting” in the patent, the special master
relied on two dictionaries that define the word “contact-
ing” as “to get in touch with; communicate with” and “to
communicate with.” JA 040044 (citing American Heritage
Dictionary of the English Language 406 (3d ed. 1996) and
Random House Webster’s Unabridged Dictionary 437 (2d
ed. 2001)). He also noted that, “[s]ince there is no clear
indication that the patentee intended to limit the use of
this word to only the initiation of the communication, I
find that the word ‘contacting’ as used in the patent is not
so limited.” JA 040044-45. Accordingly, the special

8 The parties did not ask the court to construe this
term as a means-plus-function limitation under 35 U.S.C.
§ 112, ¶ 6.
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 22

master recommended construing the term to mean “get-
ting in touch with or communicating with a host monitor-
ing system without signaling (not necessarily through
active suppression) the visual or audible user interface.”
The district court adopted the special master’s construc-
tion, and neither party challenges the correctness of this
claim construction on appeal.
Because the district court believed the special master
intended to give “contacting” a broad definition, it rejected
Absolute’s argument that the Stealth XTool Tracker
infringes if it either establishes a connection with the host
without signaling or sends information without signaling.
According to the district court, an audible signal at any
time before the communication terminates is sufficient to
avoid the “without signaling” limitation of the ’914 Pat-
ent. We disagree with that conclusion for two independ-
ent reasons.
First, the district court’s claim construction is “getting
in touch with or communicating with,” such that the
Stealth agent infringes the ’914 Patent if it does either.
Here, Stealth’s own expert admits that the agent does not
emit a sound when it establishes a connection with the
host, thereby confirming that Stealth’s XTool Tracker
meets this limitation. Dep. of Pedro Camargo, 92:19-25,
JA 100098. Although the special master may have in-
tended to provide a broad definition for “contacting,” the
plain terms of the construction do not comport with that
intention. In its response to Absolute’s appeal, Stealth
effectively asks this court to change “or” to “and” in the
construction (to read “getting in touch with and communi-
cating with”), but Stealth neither sought to clarify this
construction before the district court nor challenged it on
appeal. Stealth cannot rewrite a claim construction it
previously endorsed at this late stage of the proceedings.
23 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

Second, even if we agreed with Stealth that the use of
the disjunctive “or” in the construction meant only that
“getting in touch with” was synonymous with “communi-
cating with,” there are issues of material fact as to the
temporal relationship between the communication and
the audible signal the XTool agent emits. For example, if
there is a gap between the communication and the XTool
agent’s audible signal, a fact-finder might reasonably
conclude that the communication is sufficiently removed
from the signal that the communication is accomplished
“without signaling.” Or, as Absolute contends, a reason-
able jury might find that, if the communication with the
host is complete—i.e., that all information to be conveyed
to the host system has been conveyed—before the signal
occurs, the signal does not occur during communication,
regardless of any meaningful temporal gap between the
completion of the communication and the signal. While
Stealth argues that the signal always occurs as part of the
communication, that is a question of fact to be assessed by
the trier of fact. Summary judgment of non-infringement
of the ’914 Patent, therefore, must be vacated.
B. Stealth’s Cross-Appeal
Stealth raises three issues on its cross-appeal, argu-
ing that: (1) the district court’s claim construction of the
term “semi-random rate” is erroneous; (2) genuine issues
of material fact preclude summary judgment of non-
infringement of the ’269 Patent; and (3) the district
court’s construction of the terms “unique usage agreement
information” and “said terms of said usage agreement
imbedded in said software” is erroneous. For the reasons
explained below, we conclude that the district court
correctly construed all the claim terms Stealth challenges,
and we find that summary judgment of non-infringement
is proper.
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 24

1. Construction of “semi-random rate”
The term “semi-random rate” appears in independent
claims 12 and 25 of the ’269 Patent, which require
“transmission means for initiating, at a semi-random rate,
the transmission of the message packet from the format-
ting means to the central site means of the system surrep-
titiously of a user of said electrical apparatus.” The
parties dispute the degree of randomness required for the
message transmission, specifically whether the claim is
limited to a random call within a “predetermined time
interval,” such as once per day, week, or month, as Abso-
lute urged, or whether no such time interval limitation
exists, which Stealth argued.
The special master agreed with Absolute, recommend-
ing that “semi-random rate” be construed as “normally
taking place exactly once at a randomly chosen time
during each occurrence of a repeating predetermined time
interval.” JA 030025-26; JA 020005 (order adopting
construction). 9 In reaching this proposed construction,
the special master placed significant weight on the fact
that the specification refers to an embodiment designed to
make one call during a specified time period as the “pre-
sent invention.” Specifically, the relevant text of the ’269
Patent describes the randomizer of Figure 2 as having
two functions: (1) ensuring that there is “one call per time
period, such as day/week/month”; and (2) making sure
“that call is made randomly at only one time during that

9 This construction is from the special master’s
Amendment to the R&R. The special master originally
construed the term as “occurring once at a random time
within a predetermined time interval,” but amended that
construction following additional briefing. Both the
original and amended construction include the time
interval requirement that forms the crux of the claim
construction dispute.
25 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

period.” ’269 Patent col.4 ll.30-37. That section states
that “[t]he present invention is designed to make one, and
only one, call during the selected period . . . .” Id. (em-
phasis added). The specification also refers to Figure 1 as
“a flow chart of the major functions performed by the
present invention,” and states that Figure 2 is a detailed
flow chart of the randomizer portion of Figure 1. Id. col.3
ll.8-11 (emphasis added). The description of Figure 1,
moreover, describes the preferred embodiment by saying
that “[t]he monitoring system of the present invention is
intended to be secretly included at the time of sale . . . .”
Id. col.3 ll.42-43 (emphasis added). Accordingly, the
special master found that the specification limits the
entire invention to placing one call per time interval, a
construction the district court adopted.
On appeal, Stealth argues that the district court’s
construction of the term “semi-random rate” is erroneous
because it: (1) improperly imports a limitation from a
specific embodiment into a claim based on references to
the “present invention”; (2) ignores that the specification
expressly refers to predetermined time interval calling as
an optional feature; (3) ignores that calls are only “prefer-
entially triggered at a carefully controlled semi-random
rate, perhaps once a week,” ’269 Patent col.2 ll.57-59
(emphasis added); and (4) confuses the misuse detection
purpose of the invention, to which the “semi-random rate”
limitation relates, with the performance-monitoring
purpose of the invention. In support of its own proposed
construction, Stealth argues that “semi-” simply means
“somewhat,” such that the intervals must only vary
“somewhat randomly,” but that there is no predetermined
time interval limitation. We do not find Stealth’s argu-
ments persuasive.
Although we disagree with the special master’s rea-
soning that the references in the specification to the
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 26

“present invention” limit the entire invention to the
preferred embodiment, the asserted claims themselves,
and the specification relating to those claims, otherwise
support the district court’s construction that “semi-
random rate” includes a time interval limitation. It is
true that, in some circumstances, a patentee’s consistent
reference to a certain limitation or a preferred embodi-
ment as “this invention” or the “present invention” can
serve to limit the scope of the entire invention, particu-
larly where no other intrinsic evidence suggests other-
wise. See Verizon Servs. Corp. v. Vonage Holdings Corp.,
503 F.3d 1295, 1308 (Fed. Cir. 2007) (“When a patent thus
describes the features of the ‘present invention’ as a
whole, this description limits the scope of the invention”);
Honeywell Int’l, Inc. v. ITT Indus., Inc., 452 F.3d 1312,
1318 (Fed. Cir. 2006) (noting that, “[o]n at least four
occasions, the written description refers to [only one
particular component] as ‘this invention’ or the ‘present
invention’” and finding that the prosecution history does
not support a broader scope).
On the other hand, we have found that use of the
phrase “present invention” or “this invention” is not
always so limiting, such as where the references to a
certain limitation as being the “invention” are not uni-
form, or where other portions of the intrinsic evidence do
not support applying the limitation to the entire patent.
See Voda v. Cordis Corp., 536 F.3d 1311, 1320-22 (Fed.
Cir. 2008) (although parts of the specification referred to a
certain embodiment as the “present invention,” the speci-
fication did not uniformly refer to the invention as being
so limited, and the prosecution history did not reveal such
a limitation); Praxair, Inc. v. ATMI, Inc., 543 F.3d 1306,
1326 (Fed. Cir. 2008) (references to a specific embodiment
as “the apparatus of this invention” and “a useful feature
of this invention” in the specification “are contradicted by
27 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

a number of express statements in the ’609 specification
clearly indicating that [the feature at issue] is a feature
only of certain embodiments”); Rambus, Inc. v. Infineon
Techs. AG, 318 F.3d 1081, 1094-95 (Fed. Cir. 2003) (al-
though portions of the written description referred to the
term at issue as limiting the claimed invention to a pre-
ferred embodiment, “the remainder of the specification
and the prosecution history shows that Rambus did not
clearly disclaim or disavow such claim scope in this case”).
In this case, the ’269 Patent is more like the patents
at issue in Voda, Praxair, and Rambus, in that the speci-
fication does not uniformly refer to a one-call-per-time-
period limitation as being co-extensive with the entire
invention. Significantly, under the Description of Opera-
tion section, the specification of the ’269 Patent states
that:
Some of the features that can be included in the
present invention to make [a work around] more
difficult are:
* * * *
2) Schedule the transmissions to occur ran-
domly – the monitored apparatus shouldn’t
phone home every Monday at 8 A.M.
* * * *
4) Program the Remote Site monitored appa-
ratus to place exactly one call per time period,
i.e. day, week, or month. Thus, if the Central
Site observes multiple calls from the same
software serial number in the same time pe-
riod, then it can be certain that that copy of
the software has been installed on more than
one system in the field.
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 28

’269 Patent col.6 ll.30-60 (emphases added).
This portion of the specification expressly describes
the features of a predetermined time interval and a
random call during that interval as two optional features
of the “present invention.” Because the specification uses
“present invention” in a way that expressly contradicts
earlier references to “present invention” as requiring both
one call during a time interval and the randomness of
that call, we do not agree that the invention is so limited.
Our conclusion does not change the district court’s
construction, however, because the claim language and
the specification otherwise support that construction.
Notably, the language of claim 27, which depends from
independent claim 25, strongly suggests that the term
“semi-random” includes a time interval component.
Claim 25 recites a method including the steps of sending
messages to the host “at a semi-random rate.” Dependent
claim 27 recites the method of claim 25, with the further
step of “identifying if more than one remote monitoring
means transmits the same unique identification to the
central monitoring means within the same selected time
period as another.” ’269 Patent col.11 ll.60-63. Here, the
“same selected time period” refers to the period in which
messages are sent to the host, which is the “semi-random
rate” of claim 25. This claim language, therefore, com-
mends the interpretation that “semi-random rate,” as
used in these claims, refers to calls within a particular
time period.
The specification further supports a time interval
limitation. The term “semi-random rate” appears only in
the Abstract and in the Summary of the Invention, both
times referring specifically to a time interval of “once per
week.” ’269 Patent Abstract (“The call limitation is pref-
erentially triggered at a carefully controlled semi-random
29 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

rate, perhaps once a week.”); id. col.2 ll.57-59 (same).
There are also repeated references in the specification to
the placement of one call per time period. E.g., ’269
Patent col.4 ll.30-37 (“[T]o insure that one call per time
period, such as day/week/month, is made to the Central
Site.”); id. col.4 ll.48-50 (“Thus the triggering time is
uniformly randomly distributed over the selected time
interval, say one month.”); id. col.6 ll.54-56 (“Program the
Remote Site monitored apparatus to place exactly one call
per time period, i.e., day, week, or month.”). These refer-
ences provide strong support for the district court’s con-
struction that the term “semi-random rate” includes a
one-call-per-time-interval aspect.
Given that the ’269 Patent describes the time interval
limitation as an optional or preferred feature, Stealth
argues that construing “semi-random rate” as requiring
such a limitation is erroneous because it improperly
imports a limitation from the preferred embodiment to
the entire patent. For the reasons explained above, we
agree that this time interval limitation does not apply to
the entire invention solely because of references to the
“present invention,” but that limitation does apply to the
“semi-random rate” term as used in the asserted claims.
We are also not persuaded by Stealth’s argument that
it is error to apply the time interval limitation to the term
“semi-random rate” because it confuses the misuse detec-
tion purpose of the invention (i.e., determining whether a
product is being used beyond the scope of the license) with
the performance monitoring purpose of the invention (i.e.,
determining whether the product is functioning properly).
According to Stealth, claims 12 and 25—the claims at
issue that include the term “semi-random rate”—relate
only to performance monitoring. In contrast, claims 11
and 29 relate to misuse detection and do not include the
term “semi-random rate.” Stealth asserts that, for pur-
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 30

poses of monitoring performance, there is no reason why
calls must occur only once within a given interval.
Stealth’s argument is not supported by the record.
Claims 5, 21, 27, and 28 include the “semi-random rate”
limitation and are directed to detecting software misuse
in addition to monitoring performance. Dependant claim
28, for example, incorporates claim 25’s “semi-random
rate” limitation and recites the step of determining
whether a device is “using an illegal copy” of another
proper device. ’269 Patent col.12 ll.1-4. This claim,
therefore, uses the “semi-random rate” limitation in the
context of detecting misuse based on multiple transmis-
sions of the same unique identification “within the same
selected time period.” Accordingly, the district court did
not err in applying a time interval limitation to those
claims that include the “semi-random rate” limitation.
Finally, Stealth’s position is problematic because its
proposed construction of “semi-random” simply as “some-
what random” finds no support in the claims or the speci-
fication, and provides no guidance as to the parameters of
that term. For these reasons, and in light of the claim
language and portions of the specification identified
above, we agree with the district court’s construction of
“semi-random rate.”
2. Summary judgment of non-
infringement of the ’269 Patent
Stealth contends that, even if we agree with the dis-
trict court’s construction of “semi-random rate,” there are
genuine issues of material fact as to whether Absolute’s
product makes calls at a semi-random rate, that is, “ex-
actly once at a randomly chosen time during each occur-
rence of a repeating predetermined time interval.” JA
020005. Stealth asserts that there is sufficient evidence
of infringement both literally and under the doctrine of
31 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

equivalents. We disagree, and therefore affirm the dis-
trict court’s judgment of non-infringement on these
grounds.
a) Literal infringement
As it relates to literal infringement, the district court
found that Absolute’s products did not perform the func-
tion of initiating a transmission at a semi-random rate
because of the undisputed evidence that Absolute’s prod-
ucts are designed to initiate a call to the monitoring
center 24.5 hours following the completion of the last call.
On appeal, Stealth admits that this fact is undisputed.
Stealth’s Reply Br. 10-11 (“As Absolute pointed out, the
material facts on this issue are generally undisputed.
Absolute’s products are designed to initiate a call to the
monitoring center 24.5 hours following the completion of
the previous call . . . .”). Stealth argues that Absolute’s
product infringes, however, because its call times vary
based on the variances in the end-times of each call
session. To support its argument, Stealth points to a
variety of factors that may cause the length of call times
to vary, including whether Absolute is experiencing a
significant load on its system or because of lack of Inter-
net availability. According to Stealth, the interval be-
tween calls made by Absolute’s product can become so
varied as to become “random” as that term is construed.
Stealth’s arguments are without merit. Although the
exact timing of future calls made by Absolute’s product
cannot be predicted with certainty, the fact remains that,
when a call finishes, the next call will be initiated exactly
24.5 hours later. As the district court correctly found, the
’269 Patent’s randomness requirement is not satisfied by
mere unpredictability. See District Court Decision, at
666-67. For example, “when calls are made [by Absolute’s
product] on consecutive days, the second call will always
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 32

be at a later time in the day than the first call,” such that
the calls are not “uniformly randomly distributed over the
selected time interval.” Id. In Absolute’s product, the
time of the next call will always occur exactly 24.5 hours
after the end of the last call. Stealth’s reliance on un-
usual circumstances such as lack of Internet availability
to demonstrate a variety of call times does not make
Absolute’s calls random within the meaning of the ’269
Patent, which requires only that the call “normally” take
place once during a time interval. Ultimately, the rele-
vant claims of the ’269 Patent require that the transmis-
sions occur “at a randomly chosen time,” and exactly 24.5
hours from the last call does not meet that limitation as a
matter of law.
b) Infringement under the doctrine of
equivalents
Stealth also challenges the district court’s finding that
Absolute’s products did not infringe under the doctrine of
equivalents. “Infringement under the doctrine of equiva-
lents requires that the accused product contain each
limitation of the claim or its equivalent.” AquaTex Indus.,
Inc. v. Techniche Solutions, 419 F.3d 1374, 1382 (Fed. Cir.
2005) (citing Warner-Jenkinson Co., Inc. v. Hilton Davis
Chem. Co., 520 U.S. 17, 40 (1997)). An element of an
accused product is equivalent to a claim limitation if the
differences between the two are insubstantial, a question
that turns on whether the element of the accused product
“performs substantially the same function in substan-
tially the same way to obtain the same result” as the
claim limitation. Id. (quoting Graver Tank & Mfg. Co. v.
Linde Air Prods. Co., 339 U.S. 605, 608 (1950)).
Two of the functions of Stealth’s “semi-random rate”
limitation are to detect piracy of software on the devices
on which its software is installed and prevent users from
33 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

detecting when the agent will make the next call to the
central site. In contrast, the 24.5 hour interval built into
Absolute’s products is designed to reduce the load on its
servers so that the devices on which its software is in-
stalled are not all scheduled to call in at the same time, a
fact that Stealth concedes. Stealth, however, also argues
that Absolute touts the secrecy and undetectability of its
product in marketing materials. As the district court
correctly found, there is no evidence that the statements
Stealth cites are related to call timing as opposed to other
features, such as contacting the host without alerting the
user by signaling the audible or visual interface. Indeed,
a user of Absolute’s products can determine precisely
when the software will next contact the host center be-
cause it occurs 24.5 hours after the last communication,
which is not a feature conducive to preventing users from
predicting and preventing the next call. Accordingly, the
district court correctly found that Absolute’s products also
do not infringe under the doctrine of equivalents.
3. Construction of “unique usage infor-
mation agreement” and “terms of said us-
age agreement imbedded in said software”
Finally, Stealth challenges the construction of the
terms “unique usage information agreement” and “terms
of said usage agreement imbedded in said software,”
which appear in claims 11 and 29 of the ’269 Patent.
According to Stealth, Absolute would infringe under a
proper construction of these terms because its software
sends an identifying serial number to the host, but it does
not challenge the finding of non-infringement based on
the current construction.
The district court construed the limitation “unique
usage agreement information” as “information describing
the unique usage agreement for this copy of the software,
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 34

including a statement of the terms of that usage agree-
ment.” In arriving at this proposed construction, the
special master found that the words “said terms” in step c.
of claim 11 inform the meaning of “information” in step
a.—i.e., the word “terms” refers to the type of the “infor-
mation” required. The district court construed “terms of
said usage agreement imbedded in said software” as
“parameters detailing what is granted by the license
agreement for the software, such as the duration or
expiration date, number of authorized installation/seats,
number of authorized users, or restrictions relating to
backup copies of the software.” Importantly for this
appeal, that construction requires that the terms include
more than just a serial number or other identifying in-
formation for a license agreement. It is undisputed that
Absolute’s Computrace product transmits an electronic
serial number to the host monitoring center but does not
transmit the actual terms of the licensing or usage
agreement itself. As a result, its product does not infringe
Stealth’s ’269 Patent under the district court’s construc-
tion.
Stealth argues that the district court’s construction of
“unique usage agreement information” is inconsistent
with the preferred embodiment, which refers to the appa-
ratus sending “the serial number of the apparatus or the
software it is running” to the monitoring means. ’269
Patent col.3 ll.54-55. The embodiment indicates, however,
that this is just one piece of information the apparatus is
programmed to send, and it does not exclude the possibil-
ity that it also sends the terms of the usage agreement.
Id. (“That information would include, for example, the
serial number . . . .”) (emphasis added)). Thus, the district
court’s construction is not inconsistent with the preferred
embodiment.
35 ABSOLUTE SOFTWARE v. STEALTH SIGNAL

Stealth also cites the Description of Operation of the
’269 Patent, which states that “[b]y imbedding a unique
serial number in the software shipped with each system,
it becomes possible to track the current whereabouts of
each copy of the software that has been shipped.” ’269
Patent col.6 ll.17-21. Again, this does not mean that the
serial number is the only information imbedded in the
software, and it leaves open the possibility that the terms
are also imbedded.
Finally, Stealth faults the special master for not tak-
ing into account the word “said” in “said terms of said
usage agreement.” According to Stealth, “said” refers
back to “unique usage agreement information,” which it
contends means “serial number.” Stealth’s argument
fails, however, because the special master did, in fact,
take into account the word “said” when he found that
“said terms” informed the meaning of “information,” such
that “information” includes more than only a serial num-
ber. We find no error in that interpretation, especially
because Stealth’s proposed construction would render the
word “terms” meaningless. See Cat Tech LLC v. Tube-
Master, Inc., 528 F.3d 871, 885 (Fed. Cir. 2008) (refusing
to adopt a claim construction that would render a claim
limitation meaningless). We, therefore, agree with the
district court’s construction of this claim term.
CONCLUSION
For the foregoing reasons, we
(1) affirm the district court’s construction of “one or
more of the global network communication links
used to enable transmission between said elec-
tronic device and said host system”;
(2) vacate the district court’s grant of summary
judgment of non-infringement by Stealth of the
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 36

’758 and the ’863 Patents;
(3) vacate the district court’s grant of summary
judgment of non-infringement by Stealth of the
’914 Patent;
(4) affirm the district court’s construction of “semi-
random rate”;
(5) affirm the district court’s grant of summary judg-
ment of non-infringement of the ’269 Patent; and
(6) affirm the district court’s construction of “unique
usage information agreement” and “terms of said
usage agreement imbedded in said software.”
This case is remanded for further proceedings consis-
tent with this opinion.
AFFIRMED-IN-PART, VACATED-IN-PART, and
REMANDED
COSTS
Each party shall bear its own costs.