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, Allen & Oldham LLP, of Houston, Texas, argued for defendants-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 companies 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. Specifically, 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 noninfringement 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 Patent”); 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 “Apparatus 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 Patents 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. Representative claim 1 of the ’758 Patent recites (in this claim and 

the others below, the term at issue on appeal is emphasized): 

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 information for said electronic device to a 

host system, said electronic device connectable 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 identity 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 determining the location of said electronic device. 

’758 Patent col.21 ll.12–27. This claim, therefore, requires 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, comprising: 

a computer having visual and audible user interfaces; 

a telecommunication interface operatively connected to the computer; and 

agent means embedded in the computer for sending signals to the telecommunication interface including signals for contacting a host monitoring 

system without signaling the visual or audible 

user interface, and for providing the host monitoring system with identification indicia of the computer, 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 requires 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 Apparatus for the Remote Verification of the Operation of Electronic 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 without a license. 

Four independent claims of the ’269 Patent are at issue 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 operation surreptitiously of a user of said electrical 

apparatus for transmitting said collected performance data to a central site means for comparing the received collected performance data with 

expected performance data for electrical apparatus of the type in which said remote site performance monitoring system has been added, said 

remote site system comprising: 

* * * * 

transmission means for initiating, at a semirandom 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 “semirandom 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 ownerleased proprietary software residing in at least 

one remote computer surreptitiously of a user of 

said remote computer to detect violations of software 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. surreptitiously 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 remote 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 message 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 Washington 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 relating 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 proceeded 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 Construction (“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 counterclaimant and cross-appellant. For ease of reference and continuity, 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 thengoverning time frame for the filing of objections under 
ABSOLUTE SOFTWARE v. STEALTH SIGNAL 10

lute Software, Inc. v. Stealth Signal, Inc., Case No. 05-CV1416 (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 constructions 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 modified 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 Judgment Decision 

The district court allowed each party to file one motion 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 expressly 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 district court found that neither the “semi-random rate” 

limitation nor the “terms of said usage agreement” limitation 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 calltiming 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 construed, 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 judgment 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 construed must be compared to the accused device or process.” 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 ascertain the scope and meaning of the asserted claims, we 

look to the words of the claims themselves, the specification, 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 portion 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 judgment 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. Although 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 communication 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 “communication 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 construction. 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-argumentrecordings/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 untimely, 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 responsibility 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 disposition 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 procedure. 

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 materially different from the “IP address” construction Absolute 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 objection, 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 recognize 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 master’s construction of “global network communication 

links,” Absolute urged the court to modify the construction “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 arguments 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 procedure the district court established in this case. In addition, 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 noninfringement 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 inappropriate because genuine issues of material fact remain 

as to whether Stealth’s XTool Tracker agent furnishes, 

supplies, or makes available6 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 noninfringement 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 monitored device.” Stealth’s Principal and Response Br. 15 

(emphasis added). This is an overstatement of the expert’s declaration. Mr. Camargo makes only a conclusory 

statement that Stealth does not infringe Absolute’s patents, 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 following undisputed facts: (1) Stealth’s XTool agent provides 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 network 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 inferences may create disputes regarding basic facts or regarding 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 noninfringement of the ’758 and ’863 Patents.7

3. Summary judgment of noninfringement of the ’914 Patent 

Absolute also appeals the district court’s grant of 

summary judgment of non-infringement of the ’914 Patent, which was based on its finding that Stealth’s XTool 

Tracker does not meet the “contacting . . . without signaling” 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, however, 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 occurrence 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 signaling” 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 noninfringement, 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 definition of “contacting” in the patent, the special master 

relied on two dictionaries that define the word “contacting” 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 “getting in touch with or communicating with a host monitoring system without signaling (not necessarily through 

active suppression) the visual or audible user interface.” 

The district court adopted the special master’s construction, 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 Patent. We disagree with that conclusion for two independent 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 intended 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 communicating 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 “communicating 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 reasonable 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, arguing 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 noninfringement 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 formatting means to the central site means of the system surreptitiously 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 Absolute urged, or whether no such time interval limitation 

exists, which Stealth argued. 

The special master agreed with Absolute, recommending 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 “present 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. (emphasis 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 “preferentially 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 arguments persuasive. 

Although we disagree with the special master’s reasoning 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 “semirandom 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 embodiment as “this invention” or the “present invention” can 

serve to limit the scope of the entire invention, particularly where no other intrinsic evidence suggests otherwise. 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 uniform, 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 specification 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) (although portions of the written description referred to the 

term at issue as limiting the claimed invention to a preferred 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 specification does not uniformly refer to a one-call-per-timeperiod limitation as being co-extensive with the entire 

invention. Significantly, under the Description of Operation 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 randomly – the monitored apparatus shouldn’t 

phone home every Monday at 8 A.M. 

* * * * 

4) Program the Remote Site monitored apparatus 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 period, 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, commends 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 preferentially 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 references provide strong support for the district court’s construction 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 detection 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 transmissions 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 “somewhat random” finds no support in the claims or the specification, 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 noninfringement of the ’269 Patent 

Stealth contends that, even if we agree with the district 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, “exactly once at a randomly chosen time during each occurrence 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 district 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 function of initiating a transmission at a semi-random rate 

because of the undisputed evidence that Absolute’s products 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 Internet availability. According to Stealth, the interval between 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 unusual 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 relevant claims of the ’269 Patent require that the transmissions 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 equivalents 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 substantially 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 installed 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 because 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 information agreement” and “terms of said usage 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 agreement.” 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 “information” 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 information 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 construction. 

Stealth argues that the district court’s construction of 

“unique usage agreement information” is inconsistent 

with the preferred embodiment, which refers to the apparatus 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 possibility 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 taking 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 number. We find no error in that interpretation, especially 

because Stealth’s proposed construction would render the 

word “terms” meaningless. See Cat Tech LLC v. TubeMaster, 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 electronic 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 “semirandom rate”; 

(5) affirm the district court’s grant of summary judgment 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 consistent with this opinion. 

AFFIRMED-IN-PART, VACATED-IN-PART, and 

REMANDED 

COSTS

Each party shall bear its own costs.