Commonwealth Scientific & Industrial Research Organisation v. Buffalo Technology (USA), Inc.

United States Court of Appeals for the Federal Circuit

2007-1449

COMMONWEALTH SCIENTIFIC AND
INDUSTRIAL RESEARCH ORGANISATION,

Plaintiff-Appellee,

v.

BUFFALO TECHNOLOGY (USA), INC.
and BUFFALO, INC.,

Defendants-Appellants.

Daniel J. Furniss, Townsend and Townsend and Crew LLP, of Palo Alto, California,
argued for plaintiff-appellee. With him on the brief were Gary H. Ritchey and Nancy L.
Tompkins.

Richard D. Kelly, Oblon, Spivak, McClelland, Maier & Neustadt, P.C., of Alexandria,
Virginia, argued for defendants-appellants. With him on the brief were Robert C. Mattson,
Frank J. West, Takahiro Miura, and Robert C. Nissen. Of counsel were Joanna H. Kim
and Richard J. Codding, Akin, Gump, Strauss, Hauer & Feld, LLP, of Los Angeles,
California.

Richard C. Vasquez, Morgan Miller Blair, a Law Corporation, of Walnut Creek,
California, for amici curiae Accton Technology Corporation (Taiwan). With him on the brief
were Jeffrey T. Lindgren, Kevin R. Brodehl, and Eric W. Benisek.

Ruffin B. Cordell, Fish & Richardson P.C., of Washington, DC, for amicus curiae
Microsoft Corporation. With him on the brief was Barry K. Shelton, of Austin, Texas.

Theodore B. Olson, Gibson, Dunn & Crutcher LLP, of Washington, DC, for amici
curiae Atheros Communications, Inc., et al. With him on the brief were Matthew D. McGill,
Amir C. Tayrani, and Thomas A. Burns.

Roy T. Englert, Jr., Robbins, Russell, Englert, Orseck, Untereiner & Sauber LLP, of
Washington, DC, for amici curiae Battelle Memorial Institute, et al. With him on the brief
was Mark T. Stancil.

Kathleen M. Sullivan, Quinn Emanuel Urquhart Oliver & Hedges, LLP, of Redwood
Shores, California, for amici curiae Nokia Corporation, et al. With her on the brief were
Brian C. Cannon and Tun-Jen Chiang. Of counsel on the brief were Ronald A. Antush and
David L. Cohen, Nokia Corporation and Nokia Inc., of Irving, Texas.
 Richard W. Clary, Cravath, Swaine & Moore LLP, of New York, New York, for
amicus curiae Qualcomm Incorporated.

Steffen N. Johnson, Winston & Strawn LLP, of Washington, DC, for amicus curiae
Technology Properties Limited. With him on the brief were Gene C. Schaerr, Andrew C.
Nichols, and James F. Hurst, of Chicago, Illinois.

Robert A. Cote, McKool Smith, P.C., of New York, New York, for amicus curiae Wi-
LAN, Inc. With him on the brief were Robert E. Goodfriend and Jason Blackstone, of
Dallas, Texas, Rodney R. Sweetland, III, of Washington, DC, and Gretchen K. Harting
and Seth R. Hasenour, of Austin, Texas.

Appealed from: United States District Court for the Eastern District of Texas

Judge Leonard Davis
 United States Court of Appeals for the Federal Circuit

2007-1449

COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION,

Plaintiff-Appellee,

v.

BUFFALO TECHNOLOGY (USA), INC.
and BUFFALO, INC.,

Defendants-Appellants.

Appeal from the United States District Court for the Eastern District of Texas
in case no. 2:05-CV-53, Judge Leonard Davis.
___________________________

DECIDED: September 19, 2008
___________________________

Before LOURIE, RADER, and BRYSON, Circuit Judges.

Opinion for the court filed by Circuit Judge BRYSON. Opinion concurring in the result
filed by Circuit Judge LOURIE.

BRYSON, Circuit Judge.

Commonwealth Scientific and Industrial Research Organisation (“CSIRO”) is

Australia’s national science agency. It engages in a range of basic and applied

scientific research in diverse fields. One of its research projects has been directed to

solving problems presented by indoor wireless local area networks (“WLANs”). WLANs

usually have a network topology consisting of one or more access points with a wired

connection to a local area network. They feature wireless connections to one or more

transceivers that reside on remote devices such as laptop computers. The remote
devices communicate with the network access points by way of radio wave

transmissions.

One of the difficulties encountered by those who sought to develop WLAN

systems was the problem of multiple, echoed signals traveling from transmitters to

receivers. The multiple, echoed signals are caused by the “bouncing” of transmitted

radio waves off objects within a room or building, causing the echoed signals to reach

the receiver at different times subsequent to the receipt of the main signal. The “echo

effect” caused by the bouncing signals creates what is known as the “multiple path

propagation” or “multipath” problem. When the multipath problem is present, a single

signal sent from a transmitter will be received multiple times by the receiver over a short

period of time. When that happens, the echoes from a first transmission may mask

subsequent transmissions.

One means of dealing with the multipath problem is to delay the transmission of

subsequent signals sufficiently to avoid the masking effect. Delaying the transmission

of subsequent signals, however, reduces the maximum data rate the network can

achieve and thereby renders the wireless transmission system less useful for many

applications.

In order to combat the multipath problem without reducing the data transmission

rate of the system, CSIRO invented a solution that was ultimately described and

claimed in U.S. Patent No. 5,487,069 (“the ’069 patent”). The proposed solution was to

transmit different portions of a series of signals containing the data to be transmitted

over a number of different frequency channels. By transmitting data on many different

frequencies, the system would ensure that none of the signals in the series (or their

2007-1449 2
echoes) would interfere with other signals transmitted on different channels. And by

transmitting a number of signals on different frequencies simultaneously, the WLAN

system could achieve a high overall transmission rate while still allowing sufficient

temporal separation between each signal transmitted on each frequency to avoid inter-

symbol interference.

In a patent infringement action filed in the United States District Court for the

Eastern District of Texas, CSIRO accused Buffalo Technology (USA), Inc., and Buffalo,

Inc., (collectively, “Buffalo”) of infringing various claims of the ’069 patent. After

construing the disputed claim terms of the ’069 patent, the district court addressed the

parties’ cross-motions for summary judgment. In its order on those motions, the court

granted summary judgment in favor of CSIRO on the contested issues of patent validity

and infringement.

Independent claim 42 is one of the claims that the district court found to be

infringed. That claim provides as follows:

A transceiver for operation in a confined multipath transmission
environment, said transceiver comprising antenna means coupled to
transmission signal processing means and to reception signal processing
means, said transmission signal processing means in turn coupled to an
input data channel, said transceiver being operable to transmit and
receive data at radio frequencies, said transmission signal processing
means comprising modulation means for modulating input data of said
input data channel into a plurality of sub-channels comprised of a
sequence of data symbols such that the period of a subchannel symbol is
longer than a predetermined period representative of the time delay of
significant ones of non-direct transmission paths, means to apply data
reliability enhancement to said data passed to said modulation means and
means, interposed between said data reliability enhancement means and
said modulation means, for interleaving blocks of said data.

Independent claim 56, which the court also found to be infringed, is similar to claim 42,

but it claims a transmitter instead of a transceiver. Independent claim 68, also found to

2007-1449 3
be infringed, contains many of the elements of claim 42, but instead of claiming an

apparatus, it claims a method of transmitting data in a confined multipath environment

of radio frequencies.

Following the district court’s entry of summary judgment of infringement, CSIRO

moved for the entry of a permanent injunction. After a hearing, the court entered an

injunction against Buffalo, as requested.

On appeal, we affirm the district court’s summary judgment rulings in all but one

respect. With respect to the issue of validity, we uphold the court’s entry of summary

judgment that the ’069 patent was not anticipated. We also uphold the district court’s

entry of summary judgment that the ’069 patent was not invalid because of the addition

of new matter to the application or because the asserted claims lacked a sufficient

written description in the original specification. With respect to the issue of

obviousness, however, we conclude that the district court erred by entering summary

judgment against Buffalo because we hold that there was a disputed issue of material

fact as to whether the prior art references that were before the district court were

combinable in a manner that would have rendered the asserted claims of the ’069

patent obvious. Although we vacate the summary judgment of obviousness, we have

nonetheless addressed the issue of infringement, on which the district court entered

summary judgment against Buffalo, because that issue will continue to be important to

the ultimate disposition of the case unless the claims are held to be invalid for

obviousness. As to that issue, we uphold the district court’s summary judgment of

infringement.

2007-1449 4
 I

The summary judgment proceedings in this case were unusual in that the parties

stipulated that the district court could make findings of fact with respect to disputed

factual issues in the course of deciding the cross-motions for summary judgment. At

the summary judgment hearing on August 15, 2006, the trial judge asked the parties to

confirm “with respect to the issue of infringement and with respect to the issue of validity

that both sides agree that the Court has before it all of the record that it needs to

determine both of these issues, whichever way it might ultimately determine to go.”

Both parties agreed. For further clarification, the court then asked the parties, “[I]f the

Court gets into anything where there is a factual issue that needs to be determined, are

you both stipulating that you have before the Court the record and are agreeing that the

Court can make that factual determination?” Again, both parties agreed. Buffalo’s

counsel later stated that the stipulation permitting the court to decide any fact issues

that might arise applied only to those issues on which Buffalo had moved for summary

judgment. Those issues included infringement, anticipation, and invalidity because of a

written description violation based on the alleged introduction of new matter. But with

respect to obviousness, as to which Buffalo did not file a cross-motion for summary

judgment, Buffalo’s counsel stated that “any factual issues that came up in the context

of obviousness would be reserved for later adjudication.” After a brief colloquy between

the court and counsel, it was agreed that the court would not make findings of fact on

obviousness, but instead would decide on summary judgment whether Buffalo had met

its burden of “presenting enough evidence to raise a fact issue sufficient to get to a jury

on the question of obviousness.”

2007-1449 5
 On appeal, Buffalo acknowledges that the parties agreed to allow the court to

decide factual issues at the summary judgment stage, but it argues that with respect to

anticipation the stipulation was limited to claims 68-72. The record on that point is

somewhat unclear. Buffalo’s counsel stated at one point that the stipulation was

intended to permit the court to decide any factual issues that arose in connection with

any matters as to which the parties had filed cross-motions for summary judgment, “to

the extent that those cross-motions really overlap.” Buffalo now contends that with

respect to anticipation the stipulation was limited to claims 68-72 because even though

CSIRO moved for summary judgment of no anticipation as to all the asserted claims,

Buffalo moved for summary judgment of anticipation only as to claims 68-72.

While the record is not as clear as it could be on this point, the district court

interpreted the stipulation to grant it the authority to decide any factual issues relating to

anticipation. Given that the district court is in the best position to understand the

position of the parties as expressed through their series of exchanges with the court at

the summary judgment hearing, we sustain the court’s interpretation of the stipulation.

Accordingly, we will apply the same standard on appeal that applies to the decisions of

a district court after a bench trial with respect to the court’s rulings on (1) anticipation,

(2) invalidity because of new matter and written description violations, and (3)

infringement of the asserted claims. With respect to the issue of obviousness, we will

review the trial court’s rulings under the conventional summary judgment standard.

II

Buffalo’s principal argument on anticipation is based on an article by J.C. Rault

and others entitled “The Coded Orthogonal Frequency Division Multiplexing (COFDM)

2007-1449 6
Technique, and its Application to Digital Radio Broadcasting Towards Mobile

Receivers.” That article, which was published by the Institute of Electrical and

Electronics Engineers (“IEEE”) in 1989, describes the problems presented by

transmitting signals to mobile receiving stations (such as moving vehicles) in a dense

urban area. In particular, the article addresses the dual problems of (1) frequency

variation in signals received by moving vehicles due to the Doppler effect and (2)

multipath propagation of signals “due to multiple reflections by buildings and other

scattering structures around the vehicle.” According to the Rault article, those problems

could both be addressed by the use of coded orthogonal frequency division mulitiplexing

(“COFDM”). That is, the data could be transmitted by interleaving a sequence of short

symbol transmissions over multiple channels of different frequencies so that the

transmission rate for each symbol could be slow enough to avoid interference from

signal reflections, while the transmission rate for the entire multiplexed transmission

would still be high enough to be useful for high-speed applications. At the same time,

the spacing of the multiplexed sub-channels could be large enough to compensate for

the frequency variations caused by the Doppler effect.

The trial court found that Rault disclosed several of the limitations of independent

claims 42, 56, and 68—the modulation means, the data reliability enhancement means,

and the interleaving means. The district court did not find that Rault anticipated any of

the claims, however, because the court found that Rault failed to disclose the limitation,

found in the preamble of each of the independent claims, that referred to the use of the

invention “in a confined multipath transmission environment.” The trial court construed

2007-1449 7
the words “in a confined multipath transmission environment” to mean “in an indoor

environment.”

On appeal, Buffalo first argues that Rault anticipates the relevant claims of the

’069 patent because the district court improperly construed the preamble language to

constitute a limitation of each of the claims. CSIRO responds that Buffalo waived that

argument by not raising it below. In response to the claim of waiver, Buffalo contends

that it preserved the “preamble” argument because, in the course of the parties’

arguments over claim construction, it argued that the phrase “confined multipath

transmission environment” should not be limited to an indoor environment. Instead,

Buffalo argued, that term should embrace both indoor and outdoor environments that

have defined or confined multipath transmission environments.

That argument, which was made by Buffalo in the district court with respect to

claim construction, is quite different from the argument it now makes with respect to

anticipation, i.e., that the recitation of “confined multipath transmission environment” in

the preambles of the asserted independent claims is not a claim limitation that should

be considered for purposes of anticipation. Before the district court, Buffalo could have

argued both (1) that the phrase “confined multipath transmission environment” does not

mean “indoor environment,” and (2) that, in any event, the environment of use defined in

the preamble should not be treated as a separate limitation. But Buffalo made only the

first argument. It has therefore waived the argument that the relevant language in the

preamble does not limit the claims.

In the alternative, Buffalo argues that Rault anticipates the asserted claims even

if the language in the preamble is treated as a limitation, because Rault discloses the

2007-1449 8
use of the invention in an indoor environment. In support of that argument, Buffalo first

quotes language from Rault indicating that outdoor urban environments can be “hostile”

and can pose multipath problems. Buffalo then notes that the ’069 patent deals with

multipath problems and concludes that “Rault disclosed communication techniques

applicable to both indoor and outdoor environments.” The trial court considered that

issue, however, and found as a factual matter that Rault’s discussion of outdoor

environments did not anticipate the use of the patented technique in an indoor

environment. Buffalo’s cursory assertion that the trial court was incorrect as to that

ruling is not enough to overcome the “clear error” standard that applies to the factual

finding that Rault does not disclose an indoor environment and therefore does not

anticipate. Accordingly, we affirm the decision of the district court on that aspect of

Buffalo’s anticipation argument.

III

Buffalo next contends that the asserted claims are anticipated based on the

combination of two articles. One is an article by T.A. Wilkinson and S.K. Burton entitled

“Spread Spectrum for Radio LANs,” which was published in May 1992 in an IEEE

Colloquium on Radio LANs. The other is an article by J.A.C. Bingham entitled

“Multicarrier Modulation for Data Transmission: An Idea Whose Time Has Come,” which

was published in May 1990 in the IEEE’s Communications Magazine. Buffalo

acknowledges that in the district court it did not argue obviousness based on the

combination of those two references. For that reason, it has not argued in this court

that the asserted claims would have been obvious based on the combination of those

references. Instead, Buffalo argues anticipation based on those references; it contends

2007-1449 9
that the two references serve as the single reference that is required for anticipation,

see Scripps Clinic & Research Found. v. Genentech, Inc., 927 F.2d 1565, 1576 (Fed.

Cir. 1991), because Bingham is incorporated by reference in Wilkinson.

To support its contention that Bingham is incorporated by reference, Buffalo cites

Advanced Display Systems v. Kent State University, 212 F.3d 1272 (Fed. Cir. 2000).

That case sets forth the rule as to when a document will be deemed incorporated by

reference in another document for purposes of validity analysis. The Advanced Display

Systems case states the following with respect to that issue:

Incorporation by reference provides a method for integrating material from
various documents into a host document—a patent or printed publication
in an anticipation determination—by citing such material in a manner that
makes clear that the material is effectively part of the host document as if
it were explicitly contained therein. To incorporate material by reference,
the host document must identify with detailed particularity what specific
material it incorporates and clearly indicate where that material is found in
the various documents.

212 F.3d at 1282 (internal citations omitted). The court’s role in such cases is to decide

“what material in addition to the host document constitutes the single reference” needed

to serve as the basis for a finding of anticipation. Id. at 1283.

In pertinent part, Wilkinson describes “parallel [frequency hopping] . . . where

multiple frequency slots are used simultaneously or COFDM could be used to achieve

increased information rates.” At the point that Wilkinson refers to COFDM, it contains a

footnote citation, without comment, to Bingham. The footnote citation in Wilkinson could

provide a justification for combining the references for obviousness purposes, but there

is nothing about the reference to Bingham that appears to constitute an incorporation of

any or all of the information from the Bingham reference under the standard set forth in

Advanced Display Systems. In particular, the reference to Bingham does not “identify

2007-1449 10
with detailed particularity what specific material it incorporates and clearly indicate

where that material is found in the various documents.” Advanced Display Systems,

212 F.3d at 1282; see also Zenon Envtl., Inc. v. U.S. Filter Corp., 506 F.3d 1370, 1378

(Fed. Cir. 2007). Because Wilkinson does not incorporate Bingham by reference, we

affirm the district court’s ruling that the combination of Wilkinson and Bingham does not

anticipate the asserted claims of the ’069 reference. We do not reach the merits of the

question whether each limitation of each asserted claim is disclosed by the combination

of the two references.

IV

Buffalo next contends that the district court improperly granted summary

judgment that the asserted claims of the ’069 patent are not invalid for obviousness.

A

Before the district court, Buffalo relied on a number of different combinations of

references. On appeal, Buffalo focuses on two of them: the combination of the Rault

article and the article by Wilkinson; and the combination of the Rault article and a U.S.

patent to Fattouche entitled “Method and Apparatus for Multiple Access Between

Transceivers in Wireless Communications Using OFDM Spread Spectrum.” In arguing

that it introduced sufficient evidence on the issue of obviousness to avoid summary

judgment, Buffalo relies principally on the declaration and report of its expert, David

Bagby.

With respect to the combination of Rault and Fattouche, the district court faulted

the Bagby declaration and report for offering “only conclusions” that those references

disclose all of the elements of each of the claims and that all of the claims would have

2007-1449 11
been obvious. The court stated that “[t]here is no delineation as to what elements of the

claims are absent from any particular one of the references that are supplied by the

other reference in the combination of Fattouche and Rault.”

That criticism of Buffalo’s evidence is misplaced. Mr. Bagby’s report contains a

limitation-by-limitation analysis of each of the claims and sets forth where each limitation

of the claims is found in the various prior art references. Moreover, as the district court

elsewhere acknowledged, CSIRO’s expert admitted that Rault discloses the modulation

means, the data reliability enhancement means, and the interleaving means recited in

independent claims 42, 56, and 68. The only limitation of the asserted independent

claims that the district court found not to be disclosed in Rault was the “in a confined

multipath transmission environment” (i.e., indoor environment) limitation. As to that

limitation, however, CSIRO conceded, as the district court noted, that “Fattouche does

disclose a system for use indoors.”

With respect to the combination of the two IEEE publications authored by Rault

and by Wilkinson, the district court criticized Mr. Bagby’s analysis as “cursory.” The

court stated that the evidence of motivation to combine the references was limited to the

“common desire to deal with multiple propagation effects” and Mr. Bagby’s conclusion

that it would be natural for one of skill in the art to combine the references because

IEEE publications are primary sources of technical information. Invoking the so-called

“teaching, suggestion, and motivation” (“TSM”) test, the district court held that the

evidence was insufficient to show a sufficient teaching, suggestion, or motivation to

combine those references. The court based its conclusion on the ground that there is

“an important distinction between the general motivation to address a problem and the

2007-1449 12
motivation to create a particular solution to the problem.” According to the court, Buffalo

did not “proffer[] specific evidence as to the source of a teaching, suggestion, or

motivation to combine the prior art references.” What the court found lacking in

Buffalo’s submission was “identification of any specific evidence in the combination of

references (or anywhere else in the record) that suggests combining them in a manner

that results in the claimed subject matter.”

B

Buffalo argues that the district court’s analysis of the evidence submitted on

summary judgment and its reliance on the absence of any specific teaching, suggestion,

or motivation to combine the prior art references was erroneous, particularly in light of

the Supreme Court’s recent decision in KSR International Co. v. Teleflex Inc., 127 S. Ct.

1727 (2007). In KSR, which was decided after the district court entered its summary

judgment order in this case, the Supreme Court criticized this court’s application of the

TSM test for being unduly rigid. The KSR case involved the same kind of problem that

is presented here—the question of obviousness as applied to an invention that consists

of a combination of elements, all of which are found in prior art references. In that

setting, the Court stated, a “combination of familiar elements according to known

methods is likely to be obvious when it does no more than yield predictable results.” Id.

at 1739.

In addressing the TSM test, the Supreme Court acknowledged that “it can be

important to identify a reason that would have prompted a person of ordinary skill in the

relevant field to combine the elements in the way the claimed new invention does,” but

the Court warned against converting that inquiry into a “rigid and mandatory formula[].”

2007-1449 13
KSR, 127 S. Ct. at 1741. The Court criticized this court’s application of the TSM test as

focusing only on the precise problem the patentee was trying to solve. Under the

correct analysis, the Court wrote, “any need or problem known in the field of endeavor

at the time of invention and addressed by the patent can provide a reason for combining

the elements in the manner claimed.” Id. at 1742.

The Court further criticized this court for “its assumption that a person of ordinary

skill attempting to solve a problem will be led only to those elements of prior art

designed to solve the same problem.” 127 S. Ct. at 1742. To the contrary, the Court

explained, “familiar items may have obvious uses beyond their primary purposes, and in

many cases a person of ordinary skill will be able to fit the teachings of multiple patents

together like pieces of a puzzle. . . . A person of ordinary skill is also a person of

ordinary creativity, not an automaton.” Id.

In light of the analytical framework set forth by the Supreme Court in KSR, the

district court’s analysis of the summary judgment dispute was flawed. As noted, the trial

court found (and CSIRO’s expert acknowledged) that Rault teaches all of the limitations

of the independent claims except for use in an indoor environment. Moreover, Buffalo

points out that Rault and Wilkinson both address the multipath problem, and that

Wilkinson and Fattouche address solutions to that problem in an indoor environment.

As Mr. Bagby explained in his report, although Wilkinson is principally directed to other

methods of dealing with the multipath problem, it refers to dealing with that problem in

“an indoor environment,” and it specifically refers to the use of COFDM “to achieve

increased information rates” in a radio frequency LAN where it is necessary to “combat

severe multipath.” Like Rault and Wilkinson, Fattouche addresses the multipath

2007-1449 14
problem, and like Wilkinson, it discloses the use of OFDM in a wireless LAN. Moreover,

Fattouche expressly states that its system “can be used indoors as well as outdoors

using the same transceivers.”

Buffalo argues that the suggestion to combine Rault with Wilkinson or Fattouche

derives from the fact that all three references address the same problem: solving the

multipath problem that affects wireless radio communications in hostile environments.

In his declaration, Mr. Bagby pointed out that the common thread in each of those

references “is the express focus[] on the specific area of multipath reflection problems in

wireless communications,” which is “precisely the same problem that the ’069 Patent

purports to solve.” Moreover, Mr. Bagby stated that Rault prescribes the use of

“frequency division multiplexing, coding and/or interleaving to specifically mitigate the

multipath problem” in the context of a wireless radio frequency communication.

Accordingly, Mr. Bagby concluded, “it would be natural for one skilled in the art to

combine these references.” Furthermore, Mr. Bagby stated that “multipath is an

inherent aspect of radio signal propagation, whether indoor or outdoor.” Therefore, he

concluded, the prior art solutions for mobile radio communications were equally

applicable to indoor radio communications.

In defense of the district court’s summary judgment order, CSIRO argues that Mr.

Bagby did not proffer sufficient specific evidence as to the source of a teaching,

suggestion, or motivation to combine the cited references. CSIRO cites the declaration

of its expert, Dr. Bantz, who stated that in his work on wireless LANs at IBM, the use of

OFDM “was almost immediately dismissed . . . as unsuitable for an indoor wireless

environment.” CSIRO further asserts that “the propagation of radio waves indoors is

2007-1449 15
very different than propagation out-of-doors, and was poorly understood” at the time of

the invention. Because relatively low-speed outdoor radio applications were regarded

as presenting a very different problem from indoor LANs requiring a high data rate,

CSIRO contends that there would have been no reason to combine Rault with either

Wilkinson or Fattouche. Accordingly, CSIRO argues, this is not a case “where there

could have been a simple substitution of one known element for another or the mere

application of a known technique to a piece of prior art ready for the improvement.”

CSIRO’s argument is highly factual and underscores the factual nature of the

dispute that is at the core of the obviousness issue presented in this case. While the

ultimate question of patent validity is a question of law, the proper resolution of that

ultimate question typically turns on underlying factual inquiries, including the scope and

content of the prior art and the differences between the prior art and the claims at issue.

See Graham v. John Deere Co., 383 U.S. 1, 17 (1966). CSIRO’s contention that the

prior art deals with a problem that is not directly analogous to the problem facing the

inventors of the ’069 patent is a factual question that has been put into issue by Mr.

Bagby’s declaration and report and cannot be resolved on summary judgment.

CSIRO’s argument also fails to take sufficient account of the Supreme Court’s

ruling in KSR that “any need or problem known in the field of endeavor at the time of

invention and addressed by the patent can provide a reason for combining the elements

in the manner claimed.” 127 S. Ct. at 1742. Buffalo introduced evidence that all of the

references on which it relied were directed to solving the same problem—the multipath

problem for wireless communication using radio frequencies. It also offered evidence

that a person of ordinary skill in the art, seeking to solve that well-known problem, would

2007-1449 16
be motivated to look to references of the sort that Buffalo cited to the district court,

including Rault, Wilkinson, and Fattouche. While CSIRO offered evidence to counter

Mr. Bagby’s declaration and report, the facts set forth in the competing expert

presentations in this case cannot be resolved on summary judgment on the grounds

invoked by the district court.

Even before KSR, this court had made clear that the motivation to combine

particular references could be found in the nature of the problem to be solved. In re

Gartside, 203 F.3d 1305, 1320-21 (Fed. Cir. 2000); Pro-Mold Tool Co. v. Great Lakes

Plastics, Inc., 75 F.3d 1568, 1573 (Fed. Cir. 1996) (motivation to combine “may also

come from the nature of a problem to be solved, leading inventors to look to references

relating to possible solutions to that problem”). In that regard, this court’s decision in

Cross Medical Products v. Medtronic Sofamor Danek, Inc., 424 F.3d 1293 (Fed. Cir.

2005), is instructive. In that case, as in this one, the district court granted summary

judgment of nonobviousness over the accused infringer’s objections. This court

reversed the summary judgment, holding that there was sufficient evidence to create a

triable issue of fact as to whether a person of ordinary skill in the art would have been

motivated by the nature of the problem to combine references that offered ways to solve

it. The problem in Cross Medical was that a particular surgical device used in back

surgery was widely recognized as presenting difficulties to surgeons. That problem, the

court held, “provided sufficient motivation to navigate the prior art in the spinal implant

field in search of a teaching on how one might modify the [prior art] device” in the

manner achieved in the patent. 424 F.3d at 1322. In the course of its discussion, the

Cross Medical court rejected the argument that the problem addressed by the patent

2007-1449 17
differed somewhat from the problem encountered by surgeons who used the prior art

device. “One of ordinary skill in the art,” the court wrote, “need not see the identical

problem addressed in a prior art reference to be motivated to apply its teachings.” Id. at

1323.

In this case, the problem addressed by Rault, Wilkinson, and Fattouche was the

same, or at least quite similar—the multipath problem encountered by systems of radio

frequency communications in hostile environments. All of the references addressed the

problem and suggested the use of an OFDM-based system to solve the problem.

Wilkinson involved indoor applications and suggested the use of COFDM to achieve

high rate communications in a very hostile environment; Fattouche suggested the use of

OFDM for indoor wireless communications between transceivers, and Rault suggested

the combination of COFDM and the other elements of the invention in a hostile urban

environment. As in Cross Medical, the problems addressed by the references are

sufficiently similar to the problem presented by high-speed indoor wireless LANs that

there is a factual question whether a person of skill in the art would have looked to the

teaching of those references in seeking to solve the multipath problem for a wireless

indoor LAN. See In re Translogic Tech., Inc., 504 F.3d 124, 1262 (Fed. Cir. 2007)

(“court can take account of the inferences and creative steps that a person of ordinary

skill in the art would employ”; a person of ordinary skill in the art “would have solved this

design need by pursuing known options within his or her technical grasp”); In re Dillon,

919 F.2d 688, 694 (Fed. Cir. 1990) (en banc) (a reference is not from non-analogous art

if “the reference is reasonably pertinent to the particular problem with which the inventor

was involved”). Thus, as in Cross Medical, there is a factual issue as to the motivation

2007-1449 18
to combine prior art references that requires that we vacate the district court’s order of

summary judgment with respect to obviousness.

C

CSIRO makes several alternative arguments in support of summary judgment,

arguments that the district court did not address. First, CSIRO argues that the

secondary considerations addressed in its experts’ declarations show that the claims of

the ’069 patent would not have been obvious. In Graham, the Supreme Court held that

secondary considerations such as “commercial success, long felt but unsolved needs,

failure of others, etc., might be utilized to give light to the circumstances surrounding the

origin of the subject matter sought to be patented” and “may have relevancy” as indicia

of obviousness or nonobviousness. 383 U.S. at 17-18.

In his declaration, CSIRO expert David Bantz stated that while he was with IBM

in 1988, he worked on the problem of an indoor wireless connection for computers and

that neither his group nor others working in the field came up with the solution that

CSIRO invented. He added that he was surprised that CSIRO had “approach[ed] the

problem through the use of OFDM, an approach rejected by IBM and by every other

company of which I was aware,” and he concluded that CSIRO had “hit on the solution

that so many others, including IBM, had tried but failed to find.” A second CSIRO

expert, Allen Levesque, summarized several approaches that had been tried in the field

of wireless LANs by the early 1990s and concluded that there had been “considerable,

but ultimately unsuccessful efforts expended by leading technical organizations

attempting to meet the need for an effective wireless alternative to traditional cabled

LANs.”

2007-1449 19
 The secondary consideration evidence offered by CSIRO’s experts would be

useful to a trier of fact in determining whether the invention of the ’069 patent would

have been obvious to a person of ordinary skill at the time of the invention, as we have

recognized that such evidence “constitutes independent evidence of nonobviousness.”

Ortho-McNeil Pharm., Inc. v. Mylan Labs., 520 F.3d 1358, 1365 (Fed. Cir. 2008); see

also Gambro Lundia AB v. Baxter Healthcare Corp., 110 F.3d 1573, 1579 (Fed. Cir.

1997). But it does not justify the entry of summary judgment in CSIRO’s favor in light of

the evidence Buffalo introduced as to the primary considerations bearing on

obviousness. That is particularly true in light of the fact that Buffalo offered evidence

explaining why those seeking to devise high-speed wireless LANs in the early 1990s did

not succeed. Buffalo’s expert stated that those working on such projects were

constrained by market considerations requiring, for example, that wireless LAN

adaptors be usable with personal computers and thus be relatively inexpensive.

Because of the state of the art of silicon process development, Buffalo’s expert stated

that LANs operating at high frequencies were not commercially attractive at that time.

Moreover, he explained that in the United States in the early 1990s, limitations on the

use of desirable portions of the radio spectrum discouraged the development of wireless

LAN systems. The secondary consideration evidence, like the evidence with regard to

the primary considerations, thus presents factual issues for a trier of fact.

CSIRO also argues that Buffalo failed to show that the prior art references

disclosed the elements of the asserted claims in the same order that they appeared in

the claims and that the references failed to disclose the particular structures

corresponding to the means-plus-function limitations in the asserted claims. While the

2007-1449 20
district court did not address that issue, we note that Rault on its face appears to

contemplate a structure having the disclosed elements in the same order as in the

asserted claims. In Rault’s diagram of a receiver according to the described structure,

Rault depicts a demodulator, a deinterleaver, and data reliability enhancement

mechanisms, in that order. The reverse sequence of structures in the corresponding

transmitter would be lined up in exactly the order recited in the asserted claims of the

’069 patent.

Next, CSIRO argues that Buffalo’s references do not “show structure

corresponding to the structure found for the means-plus-function elements of the

patent.” CSIRO is apparently referring to the structures disclosed in the specification of

the ’069 patent that correspond to the modulation means, the data reliability means, and

the interleaving means. One of the inventors testified, however, that interleaving, multi-

level modulation, and data reliability enhancement in the form of forward error correction

were all well known in the art at the time of the invention. He added that the elements

that performed those functions in the system of the invention were also known in the art.

In its brief to the district court, CSIRO made the same admission, acknowledging that

“[t]he Wireless LAN system disclosed in the ’069 patent is comprised of a variety of

elements, all of which were known in the prior art.” Furthermore, Mr. Bagby stated that

the structures disclosed in Rault corresponded to the structures described in the ’069

patent, and CSIRO offered no contrary evidence on that issue. Finally, CSIRO’s

argument is seemingly at odds with the representation of its own expert, Peter Molsen,

who characterized each of those limitations as having been disclosed in Rault. The

summary judgment therefore cannot be sustained on this ground.

2007-1449 21
 CSIRO’s last contention is that even if Buffalo has shown that the independent

claims would have been obvious, it has not made that showing in the case of the

dependent claims. Mr. Bagby presented a limitation-by-limitation analysis of the

dependent claims as well as the independent claims. CSIRO’s showing in the district

court with respect to the dependent claims consisted principally of a claim chart in which

its expert asserted, without elaboration, that various limitations of the independent and

dependent claims were not found in particular references. The district court did not

address the dependent claims at all in connection with the obviousness summary

judgment order. In light of the absence of any discussion of the dependent claims by

the district court and in light of the conflicting expert evidence as to the dependent

claims, we are not prepared to hold that the record at this point supports a summary

judgment of nonobviousness as to those claims.

In sum, we conclude that the evidence offered by Buffalo created a genuine

issue of material fact as to whether there was a motivation to combine prior art

references dealing with the multipath problem and whether the combination of those

prior art references disclosed all of the limitations of the independent claims of the ’069

patent. We therefore vacate the district court’s summary judgment of nonobviousness

and remand for further proceedings on that issue.

V

Buffalo next argues that the applicant for the ’069 patent impermissibly added

new matter to the application, in violation of 35 U.S.C. § 132, when the applicant

amended the application on July 3, 1995, and that the asserted claims of the ’069

patent, all of which were first added to the application at that time, are invalid under the

2007-1449 22
prohibition against adding new matter, which this court enforces under 35 U.S.C. § 112,

¶ 1, because the claims are not supported by the disclosure in the original application.

As originally filed, the application identified the invention as relating to a wireless

LAN “in which the devices communicate by way of radio transmissions.” Several

statements in the specification, however, referred to radio transmissions at frequencies

“in excess of 10 GHz,” and the claims were limited to transmissions in that frequency

range.

The 1995 amendment to the application replaced several of the references to

frequencies in excess of 10 GHz with the words “radio frequencies.” The effect of the

change was to increase the range of frequencies specifically referenced by the affected

passages from radio frequencies in excess of 10 GHz to frequencies ranging from 3

KHz to 300 GHz, which the parties agree is the conventional understanding of the range

of “radio frequencies.” The same amendment added new claims, including the claims

asserted in this case, that did not contain references to frequencies in excess of 10

GHz. Instead, the new claims referred to transmissions at “radio frequencies.”

Buffalo argues that the effect of those changes was to broaden the disclosure of

the patent, thereby improperly adding new matter to the application, in violation of

section 132. As a consequence, Buffalo contends that the new claims that were

introduced at that time are invalid in light of the written description requirement of

section 112, paragraph 1.

The question presented by this issue is whether the specification of the original

application contained a written description of the invention sufficient to allow persons of

ordinary skill in the art to recognize that the inventor invented the subject matter that is

2007-1449 23
claimed in the asserted claims. Johnson Worldwide Assocs., Inc. v. Zebco Corp., 175

F.3d 985, 993 (Fed. Cir. 1999). 1 If it did not, the legal consequences would be that the

1995 amendment would be considered to have added new matter to the application,

and the newly added claims would not be supported by the original specification.

While Buffalo has asserted both “new matter” and “written description” violations,

the two issues turn on a single question in this case: whether the 1995 amendment to

the specification broadened the disclosure of what the inventors invented. As Buffalo

acknowledges, “Whether you call this a written description issue or a new matter issue,

you end up at the end of the day at the same point. And it is really the same analysis as

to what happened.” Because the first question in the inquiry is whether the amendment

to the specification added new matter to the application, and because the disposition of

the written description issue turns on the answer to that question, we address Buffalo’s

argument under the rubric of new matter.

The question whether new matter has been added to an application is a question

of fact. Brooktree Corp. v. Advanced Micro Devices, Inc., 977 F.2d 1555, 1574 (Fed.

Cir. 1992). As noted above, the trial court was authorized by the parties to act as the

finder of fact with regard to any disputed facts relating to the section 132 validity issue.

1
Quoting from the district court’s opinion, Buffalo argues that the court applied
the wrong standard to this issue, requiring Buffalo to show that the disclosure contained
a clear statement restricting the scope of the invention. While it is true that the district
court at one point employed language suggesting the use of that more restrictive
standard, other references throughout the court’s lengthy treatment of the issue
demonstrate that the court understood and applied the correct standard. At the outset
of its discussion of the issue, for example, the court correctly stated that “[i]n order to
satisfy the written description requirement, the disclosure of the application for the ’069
patent must reasonably convey to one skilled in the art that the inventors were in
possession of the claimed subject matter to the extent of the scope of the asserted
claims.”

2007-1449 24
The district court made a reference to the absence of any genuine issue of material fact,

which calls into question whether the court regarded the issue as presented to it as fact-

finder or presented as a summary judgment issue. Immediately after that reference,

however, the court made the following statement: “Buffalo has failed to demonstrate by

clear and convincing evidence that the written description of the Australian application

could not or does not reasonably convey to one of skill in the art that the inventors were

in possession of the claimed subject matter of the asserted claims.” In light of that

statement, we interpret the court’s action as constituting a ruling on the section 132

issue on both legal and factual grounds, including making findings of fact based on the

evidence submitted to the court, as the court was permitted to do by the parties’

stipulations. We therefore review the district court’s new matter ruling under the clear

error standard.

Moreover, in the context of a validity challenge based on new matter, the fact that

the United States Patent and Trademark Office (“PTO”) has allowed an amendment

without objection “is entitled to an especially weighty presumption of correctness” in a

subsequent validity challenge based on the alleged introduction of new matter.

Brooktree, 977 F.2d at 1574-75 (citations omitted). Buffalo therefore not only must

overcome the clear error standard, but it must do so in the face of a presumption of

validity based on the PTO’s issuance of the patent despite the amendments.

Viewed in isolation, the substitution of the references to “radio frequencies” in

place of the references to the minimum transmission frequency of 10 GHz in the original

application is suggestive of a broadening of the disclosure. Reviewing the application

as a whole, however, we conclude that there is enough material in the original

2007-1449 25
disclosure to support the district court’s finding that the invention was in fact broader

than systems operating only in the frequency range “in excess of 10 GHz.”

At the outset, it is important to note that no one has suggested that the 10-GHz

minimum reflects a distinction that has any technical significance. Nor has Buffalo

sought to show that transmissions above 10 GHz and transmissions below 10 GHz are

distinct in any way relevant to patentability. To the contrary, it is apparent from the

original application itself that the references to the 10-GHz minimum transmission

frequencies were presented as useful embodiments of the invention, not as limitations

to the invention as a whole. For example, the reference in the abstract to a “wireless

transceiver and method of transmitting data, all of which are capable of operating at

frequencies in excess of 10 GHz” (emphasis added) suggests a system that has the

capacity to operate at those frequencies, not one that is limited to that frequency range.

Similarly, each of the references to transmission of radio frequencies “in excess of 10

GHz” in the portion of the specification that was amended were in the context of

descriptions of particular embodiments of the invention. Those passages do not make

express reference to lower transmission rates, but they also do not express a limitation

on the scope of the invention.

Importantly, even in the original specification the references to frequency range

were not limited to frequencies in excess of 10 GHz. There is one explicit reference in

the original specification to a transmission rate of less than 10 GHz. The application

refers to the need to “have a relatively high transmission rate and therefore transmit on

a relatively high frequency, of the order of 1 GHz or higher.” That reference provides

explicit support for a lower transmission rate, at least down to the order of 1 GHz. That

2007-1449 26
reference also makes clear that the choice of high frequency is simply a preference, in

light of the higher transmission speeds available at that frequency, not a requirement

driven by some limitation on the capacity of the invention.

A more subtle allusion to a different frequency range is found in Figure 6 of the

’069 patent, which was present in the original application. That figure contains a

reference to an output of 2-3 GHz, which is then combined with a carrier wave having a

frequency of 58 GHz to produce a broadcast frequency of 60-61 GHz for external

transmission. Figure 6 does not directly disclose a sub-10-GHz transmission system,

but it would appear to be clear to a person of ordinary skill in the art that the step up in

frequency from 2-3 GHz to 60-61 GHz is an optional step that is separate from and not

essential to the operation of the invention. That is, Figure 6 can be viewed as disclosing

two discrete pieces of equipment, the first operating at 2-3 GHz and the second

consisting of a standard frequency step-up device that operates at a higher frequency.

Viewed in that manner, Figure 6 supports CSIRO’s argument that the invention

described in the original application was not confined to a frequency range in excess of

10 GHz.

The testimony of Buffalo’s expert, Mr. Bagby, provides additional support for

concluding that the district court did not commit clear error in its resolution of the new

matter issue. Mr. Bagby admitted that Figure 6 discloses to a person of ordinary skill in

the art that one would not need to step up the transmission rate to 61 GHz, but instead

could transmit at much lower rates, as long as the carrier frequency stayed at or above

2-3 GHz, which is the output of the transmitter that is at the heart of the invention. In

fact, Mr. Bagby admitted that one skilled in the art “would understand from [Figure 6]

2007-1449 27
that if you wanted to you wouldn’t have to step it up at all and you could simply transmit

at 2 to 3 GHz if sufficient bandwidth were available to do that.” In response to a

question whether one could transmit at the 2.4 GHz ISM band by using Figure 6 “and

simply eliminating the step-up/step-down oscillator,” he stated, “It’s a possibility.” And in

response to the ultimate question whether Figure 6 “disclose[s] the fact that this

invention can be used at less than 10 GHz,” Mr. Bagby responded, “If there is sufficient

bandwidth, then this is a possibility.”

It is true that Mr. Bagby later stated that he believed the originally filed application

was “intended to be 10 GHz and up,” but that later statement merely refers to the

express contents of the original application; it does not undermine Mr. Bagby’s earlier

testimony that one of ordinary skill in the art would understand from the original

application that it discloses an invention that is operable at lower frequencies.

Moreover, that is the way the trial court understood and characterized Mr. Bagby’s

statement. The court observed that Mr. Bagby’s statement “does not address the

question as to what the statement in the [original] application would mean to one skilled

in the art in regard to whether the inventors were in possession of the subject matter of

the asserted claims” and that Mr. Bagby’s statement “does not indicate that one skilled

in the art would necessarily understand the statement in the Australian application and

the teaching to use OFDM as a solution to multipath to mean that the inventors were

addressing a problem that only occurs at frequencies in excess of 10 GHz.” In its

capacity as fact-finder, the trial court was justified in relying in part on Mr. Bagby’s

admissions to conclude that the original application disclosed an invention that could

operate below 10 GHz.

2007-1449 28
 Significantly, CSIRO’s expert, Dr. Andrews, testified that one of skill in the art

would understand from the original specification that the inventors of the ’069 patent

had invented, were in possession of, and had described a digital communication

technique “that could be operated successfully over the radio spectrum, including

frequencies over 10 GHz and frequencies down below even 1 GHz.” Dr. Andrews

explained that the techniques described in the patent were frequency independent and

therefore that there is no reason a person of skill in the art would expect them to

operate differently at frequencies above 10 GHz than at lower frequencies within the

radio portion of the electromagnetic spectrum.

Finally, as additional support for its finding on the new matter issue, the district

court relied on the testimony and publications of the inventors to find that they were in

possession of and had described an invention that was not limited to operation at

frequency levels above 10 GHz. Inventor O’Sullivan testified that in the work that led up

to the patent application the inventors had “proposed experimentation at 40 [GHz]” and

“demonstrated measurements at 2.4 GHz,” and that “the testbed developed actually

operated initially at 2.4 [GHz].” The court also referenced a publication co-authored by

two of the inventors that discussed choosing 60 GHz as the transmission frequency

because “[n]one of the bands below 60 GHz has more than 100 MHz available and are

in congested parts of the spectrum where expansion is not possible. Therefore, these

are not likely candidates for use in a high-speed WLAN system.” The court found that

the “inventors’ testimony is clear [with respect to the references to 10 GHz] that they

were only attempting to identify an area of the radio frequency spectrum where there

was sufficient bandwidth available for the higher data rates sought. The inventors’

2007-1449 29
testimony does not compel a conclusion that they were in possession of an invention

that only worked at frequencies in excess of 10 GHz.” Thus, acting as finder of fact, the

district court concluded that the inventors were in possession of and had described an

invention that was not limited to operation above 10 GHz and that a person of ordinary

skill would not interpret the original application to be so limited.

For the reasons given above, we uphold the district court’s ruling refusing to

invalidate the asserted claims based on the alleged improper addition of new matter to

the application. Buffalo has not offered a sufficient basis for us to conclude that the

district court’s finding on that issue was clearly erroneous and thus has failed to

overcome the demanding burden imposed on it by the applicable standard of review.

VI

Buffalo next challenges the district court’s finding that it infringed claims 42-48,

56-60, and 68-72 of the ’069 patent. In so doing, Buffalo focuses on the means-plus-

function limitations that recite “means to apply data reliability enhancement” and “means

for interleaving blocks of said data.” Those limitations are found in independent claims

42 and 56 as well as in their dependent claims. Claim 68 and its dependent claims are

method claims and do not contain means-plus-function limitations, although they each

contain limitations closely analogous to the means-plus-function limitations at issue.

A

Under section 112, paragraph 6, of the Patent Act, 35 U.S.C. § 112, ¶ 6, a

patentee may express an element in a claim as a means for performing a specified

function without reciting the particular structure that performs the recited function. In

such a case, the “means-plus-function” limitation “must be construed to cover the

2007-1449 30
corresponding structure, material, or acts described in the specification and equivalents

thereof. Literal infringement of a section 112, paragraph 6, limitation requires that the

relevant structure in the accused device perform the identical function recited in the

claim and be identical or equivalent to the corresponding structure in the specification.”

Odetics, Inc. v. Storage Tech. Corp., 185 F.3d 1259, 1266-67 (Fed. Cir. 1999) (internal

citations and quotations omitted).

The district court construed one of the means-plus-function limitations of the

asserted independent claims—the “means to apply data reliability enhancement”

limitation—as corresponding to the “[r]ate ½ TCM (trellis coded modulation) encoder

described in block 42 of Figure 7 and references at 6:32-46” of the ’069 patent. Buffalo

does not dispute that its accused devices perform the function recited in that limitation.

Thus, the question for infringement purposes is whether the devices have a structure

that is identical or equivalent to the structure disclosed in the specification. Buffalo

argues that its devices contain “convolutional encoders,” which are not the same as, or

equivalent to, the structure identified in the specification of the ’069 patent.

As noted by Buffalo’s own expert, Mr. Lanning, the rate ½ TCM encoder

discussed in the ’069 patent has two sub-components, each of which performs a distinct

function. The first is a convolutional encoder, which the parties agree performs the data

reliability enhancement function of the means-plus-function limitation. The second

subcomponent performs what the parties have referred to as signal mapping. Buffalo

argues that the functions of the two subcomponents of the rate ½ TCM encoder are

inseparable and therefore if its accused products do not perform both functions of the

encoder as a whole, then the devices do not infringe the claims. Mr. Lanning, however,

2007-1449 31
conceded that the subcomponents and their functions are distinct. He explained that

after generating the convolutional encoder output, “[t]hen you have to generate the TCM

output. [Convolution encoding] is only the first step in the process . . . only the start.

The TCM encoding then takes place on the output of the Convolution Encoder, as well

as considering other input bits that have not come from the Convolution Encoder.”

Because the second subcomponent of the rate ½ TCM encoder receives output from

the first subcomponent and then processes that input, the two subcomponents are

properly viewed as separable and distinct, even though the patent describes them as

performed by a single device. Therefore, Buffalo is essentially arguing that its products

do not infringe because its convolutional encoders are not coupled to a second

subcomponent that performs signal mapping.

Buffalo does not avoid infringement simply because the device disclosed in the

patent subsequently performs a function distinct from that required by the data reliability

enhancement means limitation. With respect to that function, Buffalo has not offered

any reason to conclude that the convolutional encoder in its products is not identical or

equivalent to the convolutional encoder that is part of the data reliability enhancement

means described in the patent. Although the trial court stated that the rate ½ TCM

encoder corresponds to the data reliability enhancement means, it is clear from the

court’s discussion of the issue that it was comparing the separable convolutional

encoding subcomponent of the disclosed rate ½ TCM encoder to the accused devices.

As part of its argument, Buffalo points out that, in an embodiment disclosed in the

’069 patent, the output of the rate ½ TCM encoder is sent to a quadrature phase-shift

keying encoder by way of an interleaver. ’069 patent, col. 2, ll. 38-41, Figure 7. Buffalo

2007-1449 32
then points to the testimony of Mr. Lanning to argue that the patented device would not

work properly if Buffalo’s convolutional encoder were used in place of the rate ½ TCM

encoder, which includes the signal mapper. That argument, however, simply restates

the point that Buffalo’s convolutional encoder differs from the rate ½ TCM encoder in

that the latter contains both a convolutional encoder and a signal mapper. Buffalo does

not argue that there is any relevant difference between its convolutional encoder and

the convolutional encoding subcomponent of the TCM encoder. Nor does Buffalo

dispute that if one were to add a signal mapper to its device connected serially to its

convolutional encoder, it would provide an appropriate output to the interleaver and the

quadrature phase-shift keying encoder. The district court therefore properly concluded

that the accused devices contain structure that performs the data reliability

enhancement function of that means-plus-function limitation and that the structure that

performs that function in the accused devices is identical or equivalent to the structure

described in the ’069 specification.

B

Buffalo’s second non-infringement argument is that its devices do not have

structure that performs the “means . . . for interleaving blocks of said data” as required

by the asserted claims. Buffalo concedes that its products perform bit-by-bit

interleaving. It contends, however, that the trial court erred in construing “blocks of

data” to mean “blocks of data having one or more bits.” Buffalo contends that under the

normal meaning of the term “block,” a “block of data” consists of two or more bits and

that to construe a block of data as consisting of one or more bits impermissibly reads

the term “block” out of the claims. We disagree. There is no suggestion in the use of

2007-1449 33
the term “block of data” that the data must be contained in a plurality of subparts or

components. While in ordinary parlance, a “block” is generally considered to be a group

acting or treated as a unit, even in that context there is no requirement that every

“block” or group contain multiple members (for example, the independent block in the

U.S. Senate currently consists of one Senator). In the context of computer engineering,

the term “block of data” typically refers to any unit of data that is the subject of some

operation; it is irrelevant to the definition of “block” whether it consists of a single bit or

many. For example, the IBM Dictionary of Computing (10th ed. 1993), defines the term

“block” to include “one or more records” or “one or more logical records.” Id. at 67.

Therefore, in this context, a block of data is most reasonably understood to consist of

one or more bits. Nor does the fact that the patent describes a di-bit interleaver and the

interleaving of data in two-bit blocks mean that the claims must be limited to devices

that interleave blocks consisting of at least two bits. 2 See Ventana Med. Sys. v.

Biogenex Labs., Inc., 473 F.3d 1173, 1181 (Fed. Cir. 2006) (“[A]lthough the

specification often describes very specific embodiments of the invention, we have

repeatedly warned against confining the claims to those embodiments.”).

In any event, CSIRO points out that the ’069 patent discloses an embodiment

employing binary phase shift keying (“BPSK”), which it contends requires single-bit

interleaving. ’069 patent, col. 9, line 29, through col. 10, line 2. Buffalo’s expert

conceded that BPSK requires single bit interleaving. In its reply brief, Buffalo appears

to agree that the BPSK embodiment requires single-bit interleaving: “Although the

2
Buffalo does not contend that the ’069 patent is limited to the described
embodiment using pairs of bits. For example, Buffalo seems to agree that a device
interleaving blocks of four bits would infringe the claims.

2007-1449 34
BPSK embodiment described in the dependent claims would be combined with a single-

bit interleaver, the dependent claims cannot broaden the corresponding structure for the

‘means . . . for interleaving blocks of data.’” Because the evidence indicates that a

BPSK embodiment discloses a single bit interleaver (and thus single-bit blocks), we

conclude that the specification supports the district court’s construction of the term

“blocks of data” to refer to data packets consisting of one or more bits of data. We

therefore sustain the trial court’s decision construing the term “blocks of data” to refer to

data consisting of one or more bits.

Buffalo next argues that its products do not infringe because they use single-bit

interleavers, which are not the structural equivalents of the di-bit interleavers disclosed

in the specification. In response to that argument, the district court referred to what

appears to be uncontroverted evidence from the declaration of CSIRO’s expert, Dr.

Monsen, that “interleavers that handle different block sizes are insubstantially different.”

Instead of arguing that the di-bit and single-bit interleavers are somehow significantly

different devices, Buffalo instead argues that the type of interleaving performed is

different. In doing so, however, Buffalo is simply returning to its argument about the

appropriate construction for the term block size. The proper inquiry is whether there are

insubstantial differences in the way that the interleavers operate on data and the result

that is obtained. Based on the uncontroverted evidence, the district court permissibly

concluded that the accused device and the structure in the patent interleave data in

substantially similar manners and produce the same result: interleaved blocks of data.

We therefore uphold the trial court’s finding of infringement.

VII

2007-1449 35
 Buffalo challenges the district court’s decision to enter a permanent injunction in

this case, and several amici have filed briefs supporting and opposing the issuance of

injunctive relief rather than remitting CSIRO to its legal remedy of an award of damages.

Because we are remanding this case to the district court for further proceedings on the

issue of obviousness, we do not reach the question whether the entry of a permanent

injunction constituted an abuse of discretion.

Each party shall bear its own costs for this appeal.

AFFIRMED IN PART, VACATED IN PART, and REMANDED.

2007-1449 36
 United States Court of Appeals for the Federal Circuit
2007-1449

COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION,

Plaintiff-Appellee,

v.

BUFFALO TECHNOLOGY (USA), INC.
and BUFFALO, INC.,

Defendants-Appellants.

Appeal from the United States District Court for the Eastern District of Texas
in case no. 2:05-CV-53, Judge Leonard Davis.

LOURIE, Circuit Judge, concurring.

I join the court’s opinion and concur in its judgment on the basis of the thorough

analysis by Judge Bryson and the standard of review by which we review district court

decisions. However, the case is very close and there is a sound basis for an alternative

conclusion, viz., that the patent is invalid for violation of the prohibition against

introduction of new matter. I believe it is worthwhile to briefly note that alternative basis.

The written description of the patent states that the radio transmissions at which

the claimed wireless LAN operates are at > 10 GHz. Figure 6 does not disclose

otherwise, and testimony indicated that it was a mere “possibility” that the invention

could be used at less than 10 GHz. However, by amendment, applicants cancelled

portions of the specification that stated that the transmissions of the invention occur

at > 10 GHz, leaving only one such reference and substituting other paragraphs stating

that the invention operates “at radio frequencies.” The granted patent eventually

contained claims reciting “at radio frequencies,” not limited to “in excess of 10 GHz.”
The patentees have now asserted such broader claims against transceivers that

apparently would not infringe the original, more limited claims.

The new matter statute, 35 U.S.C. § 132, provides that “[n]o amendment shall

introduce new matter into the disclosure of the invention.” In my view, given the total

record in the case, it would be reasonable to conclude that applicants changed the

nature of the specification by amendment from one describing their invention as being

one operating at > 10 GHz to one lacking that limitation. Such a change could well be

viewed as the introduction of new matter that invalidates the patent.

Notwithstanding the above, given the fact that the district court found otherwise,

and the court’s persuasive analysis, I join the court, having noted what I believe is a

reasonable alternative view.

2007-1449 2