`Tel: 571-272-7822
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`Paper 73
`Entered: February 19, 2014
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`UNITED STATES PATENT AND TRADEMARK OFFICE
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`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
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`
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`MICROSOFT CORPORATION
`Petitioner
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`v.
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`PROXYCONN, INC.
`Patent Owner
`
`Case IPR2012-00026
`Case IPR2013-00109
`Patent 6,757,717
`
`
`
`
`
`Before SALLY C. MEDLEY, THOMAS L. GIANNETTI, and
`MITCHELL G. WEATHERLY Administrative Patent Judges.
`
`WEATHERLY, Administrative Patent Judge.
`
`FINAL WRITTEN DECISION
`35 U.S.C. § 318(a) and 37 C.F.R. § 42.73
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`
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`Cases IPR2012-00026 and IPR2013-00109
`Patent 6,757,717
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`I.
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`BACKGROUND
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`A. Introduction
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`On September 18, 2012, Microsoft Corporation (“Microsoft”), filed a
`petition under 35 U.S.C. §§ 311-319 for inter partes review of claims 1, 3,
`10–12, 14, and 22–24 of U.S. Patent No. 6,757,717 (“the ’717 Patent”).
`IPR2012-00026, Paper 6 (“the ’026 Petition”). We granted the ’026 Petition
`as to certain challenges to the patentability of claims 1, 3, 10, and 22–24,
`and denied the ’026 Petition as to all challenges to the patentability of claims
`11, 12, and 14 on December 21, 2012. IPR2012-00026, Paper 17 (“the ’026
`Decision”).
`Soon afterward, on January 11, 2013, Microsoft filed a second
`petition for inter partes review, this time challenging the patentability of
`claims 6, 7, 9, 11, 12, and 14 of the ’717 Patent. IPR2013-00109, Paper 1
`(“the ’109 Petition”). Microsoft concurrently filed a motion to join
`IPR2013-00109 with IPR2012-00026. IPR2013-00109, Paper 7. We
`granted the ’109 Petition as to certain challenges to patentability of claims 6,
`7, 9, 11, 12, and 14 of the ’717 Patent. IPR2013-00109, Paper 14 (“the ’109
`Decision”). We also granted Microsoft’s motion for joinder and joined
`IPR2013-00109 with IPR2012-00026. IPR2013-00109, Paper 15.
`After institution and joinder of both trials, Proxyconn, Inc.
`(“Proxyconn”) filed its Corrected Patent Owner’s Response (“Resp.”).
`Paper 45.1 Proxyconn also filed Patent Owner’s Corrected Motion to
`Amend (“Mot. Amend”) in which Proxyconn moved to substitute claims 35–
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`1 This reference to “Paper” and all other references to “Paper” from this
`point forward in this Final Written Decision are to papers filed in the joined
`proceeding, which is captioned as IPR2012-00026 and IPR2013-00109.
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`41 for claims 1, 3, 6, 10, 11, 22, and 23, respectively, if the Board were to
`cancel any of those challenged claims as unpatentable. Paper 44.2 This
`Final Written Decision addresses challenges to the patentability of claims 1,
`3, 6, 7, 9–12, 14, and 22–24. Because claims 1, 3, 6, 10, 11, 22, and 23 are
`found unpatentable, this Decision also addresses the patentability of
`proposed substitute claims 35–41.
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`B. The ’717 Patent
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`The ʼ717 Patent describes a system for data access in a packet
`switched network. Ex. 1002, Abstract. The system has a sender/computer
`including an operating unit, a first memory, a permanent storage memory,
`and a processor. The system also has a remote receiver/computer including
`an operating unit, a first memory, a permanent storage memory, and a
`processor. The sender/computer and receiver/computer communicate
`through the network. Id. The sender/computer further includes a device for
`calculating digital digests on data; the receiver/computer further includes a
`network cache memory and a device for calculating digital digests on data in
`the network cache memory; and the receiver/computer and/or the
`sender/computer includes a device for comparison between digital digests.
`Id.
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`As described in the ’026 Petition, the ʼ717 Patent provides a way to
`reduce the amount of redundant data transmitted over a network. ’026
`Petition, 4. The processes described in the ’717 Patent check for the identity
`
`2 Proxyconn filed Patent Owner’s Motion to Amend under 37 C.F.R.
`§ 42.121 on May 21, 2013. Paper 37. In an Order entered June 20, 2013,
`Proxyconn was granted permission to file its Corrected Motion to Amend to
`address typographical errors and file corrected exhibits. Paper 43.
`Proxyconn filed its Corrected Motion to Amend later that same day.
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`between two sets of data by comparing respective digital fingerprints of that
`data. Id. As described in the Summary of the Invention:
`If a sender/computer in the network is required to send
`data to another receiver/computer, and the receiver/computer
`has data with the same digital digest as that of the data to be
`sent, it can be assumed with sufficient probability for most
`practical applications that the receiver/computer has data which
`is exactly the same as the data being sent. Then, the
`receiver/computer can use the data immediately without its
`actual transfer through the network. In the present invention,
`this idea is used in a variety of ways.
`
`Ex. 1002, col. 2, ll. 16-24.
`The patent discloses several embodiments. In one, a sender/computer
`required to send data to a receiver/computer initially sends a digital digest of
`the data. If the receiver/computer already has data with the same digital
`digest, it uses this data as if it were actually transmitted from the
`sender/computer. Id. at col. 2, ll. 26-31. This embodiment is illustrated in
`Figures 5-7. Figure 5 is reproduced below:
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`g the illustratingesentation imatic repreFigure 55 is a schem
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`interaction between a sender//computer
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`and a receeiver/compputer
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`accordinng to the teeachings off one emboodiment of f the ʼ717
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`Patent. IId. at col. 55, ll. 49-511.
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`In this emmbodimennt, the receiver/compuuter receivves a digitaal digest
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`fromm a sender/ccomputer aand searchhes its netwwork cache
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`memory ffor data
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`withh the same digest. If tthe receiveer/computeer finds succh data, it uuses that
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`data as if the data were reeceived froom the sen
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`der/compuuter and isssues a
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`posittive indicaation signall to the sennder/compuuter. Othe
`nds a
`rwise it sen
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`negaative indicaation signaal to the sennder/compputer. Id. aat col. 7, ll.
` 51–60.
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`can bbe sent toggether withh the princiipal digest.. If the recceiver/commputer
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`cannnot find datta having tthe principaal digest, iit searches
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`for data wwith one of
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`the aauxiliary diigests. If ssuch data is found, thhe sender/ccomputer iss required
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`In anothher embodimment, auxiiliary digitaal digests ffor other ddata objectss
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`to seend only thhe differencce betweenn the requeested data oobject and
`the data
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`object correspoonding to tthe auxiliarry digest. IId. at col. 22, ll. 31-377. The
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`exprression in the Specificcation “diffference beetween the
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`first data oor data
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`object and the second datta or data oobject” meeans any biit sequencee that
`bit
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`enabbles the resstoration off the first ddata, given
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`the secondd data, the
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`sequuence, and the methodd employed in calcullating the ddifference.
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`col. 2, ll. 38–422. This emmbodimentt is illustratted in Figuures 8-10.
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`reprooduced bellow:
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`Figure 8 iss
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`Figure 88 is a schemmatic repreesentation iillustratingg the
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`interaction between a sender//computer
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`accordinng to the teeachings off another emmbodimennt of the
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`invention. Id. at cool. 5, ll. 599-61.
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`and a receeiver/compputer
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`In this embodiment the sender/computer sends the principal and
`auxiliary (e.g., of a previous version of the data requested) digests to the
`receiver/computer. Upon receiving a message with these digital digests
`from the sender/computer, the receiver/computer searches its network cache
`memory for data having the same principal digest. If such data is found, the
`receiver/computer uses the data as if the data were received from the
`sender/computer and issues a positive indication signal to the
`sender/computer. Otherwise, the receiver/computer searches its network
`cache memory for data with the auxiliary digests. If it finds data with a
`digital digest substantially equal to one of the auxiliary digests, it issues a
`partial indication signal to the sender/computer, along with a reference to the
`digest. Otherwise it issues a negative indication signal to the
`sender/computer. Id. at col. 8, ll. 11-39.
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`C. Exemplary Claims
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`Claims 1, 6, 10, 11, and 22 are the independent claims among the
`challenged claims of the ’717 Patent. Claims 1, 6, and 10 are directed to
`systems, and claims 11 and 22 are directed to methods. The independent
`challenged claims, which are illustrative of the claims at issue in this inter
`partes review, recite:
`1. A system for data access in a packet-switched
`network, comprising:
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`a sender/computer including an operating unit, a first
`memory, a permanent storage memory and a processor and a
`remote receiver/computer including an operating unit, a first
`memory, a permanent storage memory and a processor, said
`sender/computer and said receiver/computer communicating
`through said network;
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`said sender/computer further including means for
`creating digital digests on data;
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`said receiver/computer further including a network cache
`memory and means for creating digital digests on data in said
`network cache memory; and
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`said receiver/computer including means for comparison
`between digital digests.
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`6. A system for data access in a packet-switched
`network, comprising:
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`a gateway including an operating unit, a memory and a
`processor connected to said packet-switched network in such a
`way that network packets sent between at least two other
`computers pass through it;
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`a caching computer connected to said gateway through a
`fast local network, wherein said caching computer includes an
`operating unit, a first memory, a permanent storage memory
`and a processor;
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`said caching computer further including a network cache
`memory in its permanent storage memory, means for
`calculating a digital digest and means for comparison between a
`digital digest on data in its network cache memory and a digital
`digest received from said packet-switched network through said
`gateway.
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`10. A system for data access in a packet-switched
`network, comprising:
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`a sender/computer including an operating unit, a first
`memory, a permanent storage memory and a processor and a
`remote receiver/computer including an operating unit, a first
`memory, a permanent storage memory and a processor, said
`sender/computer and said receiver/computer communicating
`through a network;
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`said sender/computer further including means for
`creating digital digests on data, and
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`said receiver/computer further including a network cache
`memory, means for storing a digital digest received from said
`network in its permanent storage memory and means for
`comparison between digital digests.
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`11. A method performed by a sender/computer in a
`packet-switched network for increasing data access, said
`sender/computer including an operating unit, a first memory, a
`permanent storage memory and a processor and said
`sender/computer being operative to transmit data to a
`receiver/computer, the method comprising the steps of:
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`creating and transmitting a digital digest of said data
`from said sender/computer to said receiver/computer;
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`receiving a response signal from said receiver/computer
`at said sender/computer, said response signal containing a
`positive, partial or negative indication signal for said digital
`digest, and
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`if a negative indication signal is received, transmitting
`said data from said sender/computer to said receiver/computer.
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`22. A method for increased data access performed by a
`receiver/computer in a packet-switched network, said
`receiver/computer including an operating unit, a first memory, a
`permanent storage memory, a processor and a network cache
`memory, said method comprising the steps of:
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`receiving a message containing a digital digest from said
`network;
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`searching for data with the same digital digest in said
`network cache memory,
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`if data having the same digital digest as the digital digest
`received is not uncovered, forming a negative indication signal
`and transmitting it back through said network; and
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`creating a digital digest for data received from said
`network cache memory.
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`Ex. 1002, col. 10, l. 31 to col. 12, l. 45.
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`D. Remaining Challenges to the Patentability of Claims
`
`We instituted this inter partes review in connection with the following
`challenges to the patentability of claims in the ’717 Patent:3
`1. Anticipation by Perlman: claims 1, 3, and 22-24;
`2. Anticipation by Yohe: claims 1, 3, 6, 7, 10, 22, and 23;
`3. Anticipation by Santos: claims 1, 3, 10, 22, and 23;
`4. Anticipation by DRP: claims 6, 7, 9, 11, 12, and 14;
`5. Obviousness over the combination of Perlman and Yohe: claims 1, 3,
`10, and 22-24; and
`6. Obviousness over the combination of Mattis and DRP: claims 6, 7, 9,
`11, 12, and 14.
`’026 Decision 25–26; ’109 Decision 20.
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`II. ANALYSIS
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`A. Claim Interpretation
`
`We interpret patent claim language in an inter partes review by
`ascribing to that language its broadest reasonable meaning in light of the
`specification of the patent. 37 C.F.R. § 42.100(b); Office Patent Trial
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`3 The challenges to patentability are based upon five prior art references: US
`5,742,820, issued Apr. 21, 1998 (Ex. 1003) (“Perlman”); US 5,835,943,
`issued Nov. 10, 1998 (Ex. 1005) (“Yohe”); Santos and Wetherall,
`INCREASING EFFECTIVE LINK BANDWIDTH BY SUPPRESSING REPLICATED
`DATA (June 1998) (Ex. 1004 ) (“Santos”); THE HTTP DISTRIBUTION AND
`REPLICATION PROTOCOL, W3C Note (August 25, 1997), retrieved from
`http://www.www3.org/TR/NOTE-drp-19970825 (IPR2013-00109,
`Ex. 1003) (“DRP”); US 6,292,880 B1, issued Sep. 18, 2001 (IPR2013-
`00109, Ex. 1004) (“Mattis”).
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`Practice Guide, 77 Fed. Reg. 48,756, 48,766 (Aug. 14, 2012). We also
`interpret claim language according to its ordinary and customary meaning to
`one of ordinary skill in the art in the context of the entire disclosure. In re
`Translogic Tech., Inc., 504 F.3d 1249, 1257 (Fed. Cir. 2007).
`We expressly interpret below only those claim terms that require
`analysis to resolve arguments related to the patentability of the challenged
`claims. Except as otherwise stated, we interpret the remaining claim terms
`as set forth in the ’026 Decision and the ’109 Decision.
`
`1. Data Access
`
`Each contested claim recites “data access.” Ex. 1002, col. 10, l. 31
`(claims 1, 3), col. 10, l. 64 (claims 6, 7, and 9), col. 11, l. 20 (claim 10),
`col. 11, l. 35 (claims 11, 12, and 14), col. 12, l. 30 (claims 22–24).
`Proxyconn urges that “data access” means “obtaining data . . . on a remote
`computer on a network, in response to a request from a client.” Resp. 11
`(citing Ex. 1002, col. 1, ll. 18–26; id. at col. 7, ll. 65–67). In support,
`Proxyconn cites portions of the Specification of the ’717 Patent that describe
`exemplary data transmission sessions in which a network client “requests”
`data from a server. The first cited portion describes such interactions
`between a client and server as “prior art.” Ex. 1002, col. 1, ll. 18–26. The
`second cited portion states: “This transaction begins with a
`receiver/computer sending a request to the sender/computer.” Id. at col. 7,
`ll. 65–67. The phrase “[t]his transaction” refers to the interaction between
`the receiver/computer and the sender computer depicted in Figures 5–7 of
`the ’717 Patent. Id. at col. 7, ll. 51–67.
`By contrast, Microsoft contends that “data access” means “data
`acquisition.” Microsoft Corporation’s Reply to Patent Owner’s Corrected
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`Response (“MS Reply”), 2 (Paper 46). Microsoft dismisses the portions of
`the Specification that Proxyconn cites as neither mentioning “data access”
`nor narrowly defining “data access.” Id. Microsoft argues that other
`portions of the Specification imply that the step of the receiver/computer
`requesting data is merely optional. Id. (citing Ex. 1002, 8:37–39).
`Proxyconn’s expert, Dr. Konchitsky, testified that the Specification
`describes scenarios in which a sender transmits data to a receiver without a
`request from the receiver. See Ex. 1024, 69:1–24, 71:8–22 (describing the
`data communication method illustrated in Figure 8 of the ’717 Patent).
`Microsoft also points out that claim 32, which is not challenged, explicitly
`recites a method in which a client sends a request for data to a server. Paper
`72, Final Hearing Transcript 10:9-12, 79:22–80:9 (“Tr.”).
`Both parties’ interpretations of “data access” are too narrow. Neither
`the challenged claims nor the Specification expressly limits “data access” to
`require a “request from the client” as proposed by Proxyconn. The claims
`merely recite “data access.” Even though the Specification describes
`examples in which the client requests data from a server, the Specification
`does not require that the client request data in all described embodiments of
`the claimed systems and methods. For example, the Specification expressly
`describes an embodiment in which “a sender/computer required to send data
`to a receiver/computer . . . initially sends a digital digest of the data.”
`Ex. 1002, col. 2, ll. 26–28. “[L]imitations are not to be read into the claims
`from the specification.” In re Van Geuns, 988 F.2d 1181, 1184 (Fed. Cir.
`1993) (citing In re Zletz, 893 F.2d 319, 321(Fed. Cir. 1989)). We decline to
`do so here.
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`Microsoft’s position is similarly unsupported by the claims
`themselves or the Specification. None of the challenged independent claims
`affirmatively recites that the receiver/computer acquires data from the
`sender/computer. Microsoft cites no portion of the Specification, and we
`find no support for the proposition that the Specification equates “data
`access” with “data acquisition.”
`We determine that the plain meaning of “data access” is clear.
`Independent challenged claims 1, 6, 10, 11, and 22 recite “access” as a noun
`modified by “data.” Ex. 1002, col. 10, l. 31 (claims 1, 3), col. 10, l. 64
`(claims 6, 7, and 9), col. 11, l. 20 (claim 10), col. 11, l. 35 (claims 11, 12,
`and 14), col. 12, l. 30 (claims 22–24). “Access” plainly means the “freedom
`or ability to obtain or make use of.” MERRIAM WEBSTER’S COLLEGIATE
`DICTIONARY 6 (10th ed. 1999). We conclude, therefore, that the claimed
`systems and methods recite “data access” to refer to the freedom or ability to
`obtain or use data. Although obtaining or acquiring data requires access to
`that data, access to the data need not involve acquisition of that data.
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`2. Permanent Storage Memory
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`Claims 1, 3, 6, 7, 9, 10, and 22–24 recite “permanent storage
`memory.” Ex. 1002, col. 10, l. 31 – col. 13, l. 8. Proxyconn argues that
`“permanent storage memory” means non-volatile memory that can be used
`for writing and reading data and does not refer to read-only memory
`(“ROM”). Resp. 12. The Specification states “an example of a permanent
`storage memory may be a disk drive, a flash RAM or a bubble memory.”
`Ex. 1002, col. 7, ll. 38–40. In support of its proffered definition of
`“permanent storage memory,” Proxyconn also cites Yohe’s statement that
`“‘[p]ermanent storage memory,’ as used herein, includes but is not limited
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`to, disk drive, flash RAM or bubble memory, for example.” Resp. 12
`(quoting Ex. 1005, col. 3, ll. 5–7).
`Microsoft counters that “permanent storage memory” is not restricted
`to non-volatile memory that permits multiple write operations, but may also
`include storage that is write-once, read-many (“WORM”) memory. MS
`Reply 2. Microsoft contends that a CD optical storage disc, a type of non-
`volatile WORM memory, would constitute permanent storage memory. See
`id. (citing Ex. 1024, 88:7–89:12). Thus, the dispute centers on whether
`“permanent storage memory” encompasses ROM and other types of WORM
`types of non-volatile memory.
`The testimony of both experts persuades us that a skilled artisan
`would interpret “permanent storage memory” to cover non-volatile memory
`that supports multiple write operations. Dr. Long equated the “permanent
`storage” described in the ’717 Patent with a “disk” or “flash” memory.
`Ex. 1026, 97:15–98:10. Dr. Konchitsky testified that a skilled artisan would
`have considered “permanent storage memory,” which enables writing or
`storing of information, to differ from “permanent memory,” which can only
`be read after being written one time “in factory.” Ex. 2002 ¶ 21. The ability
`to write data many times to permanent storage memory is consistent with the
`way that “permanent storage memory” is used in the context of at least claim
`6. Claim 6 recites a “caching computer further including a network cache
`memory in its permanent storage memory.” The presence of cache memory,
`which is likely to be written many times, in the “permanent storage
`memory” implies a capability to write data many times to the claimed
`“permanent storage memory.” Because claim terms are normally used
`consistently throughout the patent, the usage of a term in one claim may
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`illuminate the meaning of the same term in other claims. Phillips v. AWH
`Corp., 415 F.3d 1303, 1314 (Fed. Cir. 2005). Therefore, we interpret
`“permanent storage memory” to mean any non-volatile memory that
`supports multiple write operations.
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`3. Sender/Computer and Receiver/Computer
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`Challenged claims 1, 3, 10, 11, 12, 14, and 22–24 recite either a
`“sender/computer” or “receiver/computer” or both. Ex. 1002, col. 10, l. 31 –
`col. 13, l. 8. Previously, we interpreted “sender/computer” to mean a
`computer that sends data and “receiver/computer” to mean a computer that
`receives data. ’026 Decision 14. We also concluded that each of these
`respective computers can encompass multiple devices including
`intermediaries. Id.
`Proxyconn argues that our interpretation is “inconsistent with the ’717
`Patent, is not the broadest reasonable interpretation of the claim terms, and
`should be revised to exclude separate intermediate computers such as
`gateways, proxies, routers, and caching computers.” Resp. 13. Proxyconn
`contends that the Specification consistently refers to the sender and receiver
`computers as separate devices.
`Microsoft contends that we correctly interpreted the computers to
`encompass multiple devices including intermediate devices. The
`Specification represents the receiver and sender computers (46, 42
`respectively) in decidedly schematic form, as shown in Figures 4, 11, and
`14, reproduced below.
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`14, reprodduced fromm top to botttom abovee,
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`Figures 4, 11, and
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`schemattically illusstrate the claimed recceiver/commputer and
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`sender/ccomputer inn various nnetwork coonfigurationns as
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`functionnal block diiagrams.
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`Figure 4 illustrates receiver/computer 46 as a collection of functionally
`defined subsystems 48, 52, and 54, which are described as follows: “[T]he
`receiver/computer has calculating means 52 for calculating a digital digest
`on data stored in its network cache memory 48. The receiver/computer also
`has comparison means 54 for comparing between such a calculated digital
`digest and a digital digest received from the network.” Ex. 1002, col. 7,
`ll. 32–37.
`The Specification appears to have one instance in which a computer is
`described as being separate from or integral with another computer. The
`Specification implies that gateway 60 and caching computer 62 may be
`separate devices, but only by noting that “gateway computer 60 may be
`integrally formed with the caching computer.” Ex. 1002, col. 9, ll. 6–8. The
`Specification, along with the above figures, conveys to a skilled artisan that
`the described computers, including the receiver/computer and the
`sender/computer, may or may not be located in separate housings.
`Accordingly, Proxyconn has not persuaded us to modify the original
`interpretation of “receiver/computer” and “sender/computer.”
`
`4. Gateway . . . Between at Least Two Other Computers
`
`Independent claims 6 recites a “gateway . . . connected to said packet-
`switched network in such a way that network packets sent between at least
`two other computers pass through it.” Ex. 1002, col. 10, l. 66 – col. 11, l. 2.
`Claims 7 and 9, which depend upon claim 6, also include the “gateway” and
`“two other computers.” Id. at col. 11, ll. 13–20. Proxyconn asserts that
`“two other computers” refers to “the sender/computer and the
`receiver/computer.” Resp. 15 (citing Ex. 1002, col. 2, ll. 44–47). The cited
`portion of the Specification, however, merely recites verbatim the language
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`of claim 6 relating to the gateway and two other computers. Therefore, the
`cited portion has not been shown to support Proxyconn’s contention.
`Microsoft contends that no such limitation exists on the “two other
`computers” and that these computers may be any two other computers
`connected on the network to the gateway. See ’109 Petition 13–14,
`Appendix A 5–6.
`We agree with Microsoft. Claim 6 plainly and unambiguously recites
`“two other computers” as a limitation on the manner in which the “gateway”
`is “connected to said packet switched network.” That is, the gateway is
`connected to the network so that “network packets sent between at least two
`other computers pass through it [i.e., the gateway].” Applying the broadest
`reasonable interpretation, we conclude that claim 6 does not limit which
`computers may constitute the “two other computers” between which the
`gateway is connected.
`
`5. Means for comparison between digital digests
`a. Claims 1 and 3
`
`Claim 1 recites “means for comparison between digital digests.”
`Resolution of the parties’ arguments relating to whether Yohe anticipates
`claims 1, 3, and 10 requires that we interpret “digital digests” as recited in
`the comparison means. We interpret “digital digests” by reading claim 1 in
`its entirety. Claim 1 recites that both the sender and receiver include “means
`for creating digital digests on data.” We conclude that the “digital digests”
`recited in the means for comparison refers to the “digital digests on data”
`that are recited earlier in claim 1 in the “means for creating.”
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`b. Claim 10
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`Claim 10, like claim 1, recites that the receiver includes “means for
`comparison between digital digests.” Also like claim 1, claim 10 recites that
`the sender includes a “means for creating digital digests on data.” By
`contrast to claim 1, claim 10 does not recite a “means for creating” in the
`receiver. Ex. 1002, col. 11, ll. 20–33. Instead, the receiver includes a
`“means for storing a digital digest received from said network.” Id. at
`col. 11, ll. 31–32 (emphasis added). The reference to “a digital digest”
`rather than “the digital digest on data” in the storing means implies that the
`receiver can store any type of digital digest received from the network.
`Therefore, the “digests” that are compared in the “means for
`comparison” recited in claim 10 need not be the two digests on data created
`by the sender and receiver. Instead, the “means for comparison between
`digital digests” recited in claim 10 refers to structure that can compare any
`digital digest received from the network with any other digital digest.
`
`6. Searching for Data with the Same Digital Digest
`
`Claims 22–24 recite a step of “searching for data with the same digital
`digest.” Proxyconn argues that the “searching” step requires the capability
`to identify particular data “with the same digital digest” from among a set of
`data that potentially contains multiple items. See Resp. 6, 20–21 (attempting
`to distinguish claims 22–24 from Perlman), 27–28 (attempting to distinguish
`claims 22 and 23 from Yohe), 35–36 (attempting to distinguish claim 23
`from Santos). Microsoft contends that the ’717 Patent equates “search” with
`“check for” and that the Specification never describes any “search” method
`other than “comparing two digest values for a match.” MS Reply 4.
`Microsoft asserts that the recited step of “searching for data with the same
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`digital digest,” merely requires comparing a digest for a data object received
`from the network with a digest of the receiver’s copy of that data object. Id.
`at 5.
`
`The Specification never expressly defines “search.” Nonetheless, the
`plain meaning of “search” is: “to look into or over carefully or thoroughly in
`an effort to find or discover something.” MERRIAM WEBSTER’S COLLEGIATE
`DICTIONARY 1053 (10th ed. 1999). Two dictionaries in the relevant field of
`computing technology define “search” as it would be understood by a skilled
`artisan as follows:
`1. “To scan one or more data elements of a set in order to find elements
`that have a certain property,” IBM DICTIONARY OF COMPUTING 600
`(10th ed. 1993); and
`2. “(information processing). To examine a set of items for those that
`have a desired property,” IEEE STANDARD DICTIONARY OF
`ELECTRICAL AND ELECTRONICS TERMS 808 (3d ed. 1984).
`These dictionary definitions reflect that a skilled artisan would have
`understood “search” to involve analyzing a set of items to identify one
`particular item from among a set of items. A “set” refers to “a number of
`things of the same kind that belong or are used together,” MERRIAM
`WEBSTER’S COLLEGIATE DICTIONARY 1071 (10th ed. 1999), or “[a] finite or
`infinite number of objects of any kind, of entities, or of concepts that have a
`given property or properties in common,” IBM DICTIONARY OF
`COMPUTING 618 (10th ed. 1993). While a set can contain one item, a
`“search” for a desired member of a “set” requires a capability to examine
`more than one item to identify a particular item within that set. Therefore,
`we conclude that “searching for data with the same digital digest in said
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`r data a particularo identify arequires ann ability to
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`netwwork cache
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`memory”
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`object with thee same digiital digest ffrom a set
`data
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`of potentiaally many
`obje
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`cts stored iin the netwwork cachee memory.
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`B. The PPrior Art
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`1.
` Perlman
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`n across a nformationzation of inrelates to Perlmann generally synchroniz
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`1, ll. 6–8. 1003, col. 1work. Ex. 1compputer netw
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`Perlman’ss Figure 2
` to which
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`(reprroduced beelow) is a bblock diagrram of twoo computerr networks
`6, and a
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`multtiple nodess, which include routeers R1–R66, source noodes S1–S
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`destiination nodde D, are cconnected.
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`Perlmann’s Figure 22 is a blockk diagram
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`of two commputer
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`networkks to whichh multiple nnodes are cconnected.
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`Perlmman states that the “nnodes are ttypically geeneral-purprpose compputers” andd
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`that “[e]ach noode typicallly comprisses a . . . mmemory uniit 204” whiich may
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`include “storage locations typically composed of random access memory
`(RAM) devices.” Id. at col. 5, ll. 40–47.
`Packetized data is transmitted across the network with each packet
`having the address of its final destination and the address of the next node to
`which it will travel along the route to the final destination. Id. at col. 5, l. 65
`– col. 6., l. 1. The final destination address remains constant, but the “next
`destination” address changes as the packet moves from node to node in the
`network. Id. at col. 6, ll. 1–4. Upon arrival of a packet to a