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`U.S. Patent 6,671,757 Bestavros Dec. ISO Pet. for Inter Partes Review
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`IN UNITED STATES PATENT AND TRADEMARK OFFICE
`__________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`__________________
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`DROPBOX, INC.
`Petitioner
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`v.
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`SYNCHRONOSS TECHNOLOGIES, INC.
`Patent Owner
`__________________
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`Case Nos. IPR2016-00850 & IPR2016-00851
`__________________
`
`DECLARATION OF AZER BESTAVROS, PH.D. IN SUPPORT OF
`DROPBOX, INC.’S PETITIONS FOR INTER PARTES REVIEW OF
`U.S. PATENT NO. 6,671,757 (CLAIMS 1-29)
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`
`
`Mail Stop: Patent Board
`Patent Trial and Appeal Board
`U.S. Patent and Trademark Office
`P.O. Box 1450
`Alexandria, VA 22313-1450
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`U.S. Patent 6,671,757 Bestavros Dec. ISO Pet. for Inter Partes Review
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`TABLE OF CONTENTS
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` 
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`I. 
`
`II. 
`
`INTRODUCTION ........................................................................................... 1 
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`BACKGROUND AND QUALIFICATIONS ................................................. 2 
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`III.  COMPENSATION AND RELATIONSHIP TO THE PARTIES .................. 8 
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`IV.  LEGAL STANDARDS ................................................................................... 8 
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`A. 
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`Claim Construction ............................................................................... 8 
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`B.  Anticipation ........................................................................................... 9 
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`C.  Obviousness ......................................................................................... 10 
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`D. 
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`Person of Ordinary Skill in the Art ..................................................... 11 
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`V. 
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`THE ’757 PATENT AND THE STATE OF THE ART ............................... 12 
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`A. 
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`Synchronization ................................................................................... 12 
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`B.  Difference Information ........................................................................ 13 
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`C.  Use of an Intermediate Data Store ...................................................... 18 
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`VI.  CLAIM CONSTRUCTION .......................................................................... 19 
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`A. 
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`B. 
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`“Difference Information” .................................................................... 19 
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`“Difference Transaction” .................................................................... 21 
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`VII.  APPLICATION OF THE PRIOR ART TO CLAIMS 1-29 OF THE
`’757 PATENT ................................................................................................ 24 
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`A. 
`
`Claims 1, 3–8, 10, 15–20, 23–25, 27, and 29 Are Anticipated by
`Nichols. ................................................................................................ 24 
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`1. 
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`2. 
`
`Independent Claims 1, 16 and 24. ............................................. 29 
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`Dependent Claims 4–7, 15, 18–19, and 27 ............................... 47 
`ii
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`3. 
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`4. 
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`5. 
`
`Dependent Claims 8, 10, 20 and 25 .......................................... 54 
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`Dependent Claims 3 and 17 ...................................................... 58 
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`Dependent Claims 23 and 29 .................................................... 59 
`
`B. 
`
`C. 
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`Claims 1, 3–8, 10, 15–20, 23–25, 27, and 29 Are Obvious Over
`Nichols In Light of the General Knowledge of a POSA..................... 65 
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`Claims 1, 3–10, 14–21 and 24–28 Are Anticipated by the CVS
`Documentation. ................................................................................... 67 
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`1. 
`
`2. 
`
`3. 
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`4. 
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`5. 
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`6. 
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`Independent Claims 1, 16 and 24. ............................................. 76 
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`Dependent Claims 4–7, 15, 18–19, and 27 ............................... 96 
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`Dependent Claims 8, 9, 10, 20, 21 and 25 .............................. 104 
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`Dependent Claims 3 and 17 .................................................... 110 
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`Dependent Claims 14 and 28. ................................................. 111 
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`Dependent Claim 26. .............................................................. 114 
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`D. 
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`Claims 1–10, 14–21, and 24–28 Are Rendered Obvious by the
`CVS Documentation. ........................................................................ 116 
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`1. 
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`2. 
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`Claims 1, 3–10, 14–21, and 24–28. ........................................ 116 
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`Claim 2. ................................................................................... 118 
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`E. 
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`Claims 1–7, 11–13, 16–19, 22, 24, and 27 Are Obvious over
`Kistler in view of Burns. ................................................................... 120 
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`1. 
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`2. 
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`3. 
`
`Kistler ...................................................................................... 120 
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`Burns ....................................................................................... 125 
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`The POSA Would Have Been Motivated to Combine
`Burns with Kistler and Would Have Expected to Succeed
`in Doing So ............................................................................. 129 
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`4. 
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`5. 
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`6. 
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`7. 
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`8. 
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`9. 
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`Claims 1, 16, 24, and 27 Would Have Been Obvious ............ 132 
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`Claims 2, 3, and 17 Would Have Been Obvious .................... 156 
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`Claim 4 Would Have Been Obvious ....................................... 160 
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`Claims 5 and 18 Would Have Been Obvious ......................... 161 
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`Claims 6, 7, and 19 Would Have Been Obvious .................... 164 
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`Claims 11, 12, and 22 Would Have Been Obvious ................ 167 
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`10.  Claim 13 Would Have Been Obvious ..................................... 172 
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`VIII.  CONCLUSION ............................................................................................ 175 
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`EXHIBIT LIST
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`Ex. 1002
`Ex. 1003
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`Ex. 1004
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`Ex. 1005
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`Ex. 1006
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`Ex. 1007
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`Exhibit
`No.
`Ex. 1001 U.S. Patent No.6,671,757, “Data Transfer and Synchronization
`System” (“the ’757 patent”)
`Declaration of Azer Bestavros, Ph.D.
`David A. Nichols, Pavel Curtis, Michael Dixon, and John Lamping,
`High-Latency, Low-Bandwidth Windowing in the Jupiter
`Collaboration System, USER INTERFACE SOFTWARE AND
`TECHNOLOGY (Nov. 14–17, 1995) (“Nichols”)
`Cvsclient.ps, “CVS Client/Server” (excerpted from cvs-
`1.10.3.tar.gz)
`Cvs.ps, “Version Management with CVS for Version 1.10.3”
`(excerpted from cvs-1.10.3.tar.gz)
`James J. Kistler & M. Satyanarayanan, “Disconnected Operation in
`the Coda File System,” ACM TRANSACTIONS ON COMPUTER
`SYSTEMS vol. 10, no. 1 (1992) (“Kistler”)
`Randal C. Burns & Darrell D.E. Long, “Efficient Distributed
`Backup with Delta Compression,” IOPADS ’97 Proceedings of the
`Fifth Workshop on I/O in Parallel and Distributed Systems (1997)
`(“Burns”)
`Patent Owner’s Response, Inter Partes Reexamination of U.S.
`Patent No. 6,671,757 (Feb. 8, 2013)
`Action Closing Prosecution, Inter Partes Reexamination of U.S.
`Patent No. 6,671,757 (Mar. 15, 2013)
`Response B to Office Action Under 37 C.F.R. § 1.11, U.S. Patent
`No. 6,671,757 (May 1, 2003)
`Philip E. Margolis, Computer & Internet Dictionary, 3d ed.,
`Random House Webster’s (1999)
`Yui-Wah Lee et al., “Operation-Based Update Propagation in a
`Mobile File System,” USENIX (1999)
`Cyclic Software’s Download Site (http://download.cyclic.com/pub/)
`as of Dec. 2, 1998 [https://web.archive.org/web/19981202004350/
`v
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`Ex. 1008
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`Ex. 1009
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`Ex. 1010
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`Ex. 1011
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`Ex. 1012
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`Ex. 1013
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`Ex. 1014
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`Ex. 1015
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`Ex. 1016
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`Ex. 1017
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`Ex. 1018
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`Ex. 1019
`Ex. 1020
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`http://download.cyclic.com/pub/]
`The HTTP Distribution and Replication Protocol,
`http://www.w3.org/TR/NOTE-drp-19970825 (last visited Mar. 21,
`2016)
`Jim Gray et al., Transaction Processing: Concepts and Techniques
`(1993)
`Karl Fogel & Moshe Bar, Open Source Development with CVS, 3d
`ed., Paraglyph Press (2000)
`Russel Sandberg et al., “Design and Implementation of the Sun
`Network Filesystem,” USENIX ASSOCIATION SUMMER
`CONFERENCE PROCEEDINGS, PORTLAND 1985 (June 11-14, 1985)
`Chapter 6 of Brian W. Kernighan & Dennis M. Ritchie, THE C
`PROGRAMMING LANGUAGE (1988)
`“RCSFILES” (excerpted from cvs-1.10.3.tar.gz)
`James W. Hunt and M. Douglas McIlroy, “An Algorithm for
`Differential File Comparison,” Bell Laboratories, Computing
`Science Technical Report 41 (1976)
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`I, Azer Bestavros, hereby state the following:
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`Bestavros Dec. ISO Pet. for Inter Partes Review
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`I.
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`INTRODUCTION
`1.
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`I have been retained by Williams & Connolly LLP to review U.S.
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`Patent No. 6,671,757 (the “’757 patent”) (Ex. 1001) and provide opinions as to
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`whether the claims of the ’757 patent are anticipated by the prior art and/or would
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`have been obvious to a person of ordinary skill in the art. I am working as a
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`private consultant on this matter and the opinions presented here are my own. I am
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`over 21 years of age, and am otherwise competent to make this declaration.
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`2.
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`In this declaration I provide opinions regarding the relevant art to the
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`’757 patent, the level of skill of a person of ordinary skill in that art, and how such
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`a person would understand the disclosures of the ’757 patent. In performing my
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`analysis, I have reviewed the ’757 patent” and the other materials cited herein, and
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`I have relied on these materials as well as my decades of training and experience in
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`the field of computer science.
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`3.
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`This report is based on information currently available to me. I
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`reserve the right to continue my investigation and analysis, which may include a
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`review of documents and information not yet produced. I further reserve the right
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`to expand or otherwise modify my opinions and conclusions as my investigation
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`and study continues, and to supplement my opinions and conclusions in response
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`to any additional information that becomes available to me.
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`II. BACKGROUND AND QUALIFICATIONS
`4.
`I am a Professor of Computer Science at Boston University, whose
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`faculty I joined in 1991. I chaired the Computer Science Department at Boston
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`University from 2000 to 2007, overseeing a period of significant growth,
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`culminating in the Department being ranked seventh in the country by the
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`Chronicle of Higher Education for scholarly productivity.
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`5.
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`I am the Founding Director of the Hariri Institute for Computing at
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`Boston University. The Hariri Institute was formed in 2010 to “create and sustain
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`a community of scholars who believe in the transformative potential of
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`computational perspectives in research and education.” I serve as the co-Chair of
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`the Council on Educational Technology & Learning Innovation, which was set up
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`in 2012 to develop Boston University’s strategy as it relates to leveraging online
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`technology in on-campus, residential programs. I also serve as chair of the Data
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`Science Initiative, which was launched in 2014 to grow and consolidate Boston
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`University’s footprint in data science research and education.
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`6.
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`Throughout my academic career, in addition to my academic
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`responsibilities, I have held several regional and national leadership positions
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`through which I have overseen the development of technology and policy related
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`to networked computer systems. These positions include: serving since 2013 as
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`board member of the Cloud Computing Caucus, a non-profit, non-partisan
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`coalition of industry and key government stakeholders, focused on raising
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`awareness and educating lawmakers and the public on issues associated with cloud
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`computing; serving from 2007 to 2012 as the elected chair of the Institute of
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`Electrical and Electronics Engineers (“IEEE”) Computer Society Technical
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`Committee on the Internet; and serving since 2010 as co-chair for Research,
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`Education, and Outreach of the Massachusetts Green High-Performance
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`Computing Center, a data center run by a consortium of the five major research
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`institutions in the Commonwealth of Massachusetts (Boston University, Harvard
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`University, Massachusetts Institute of Technology, Northeastern University, and
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`the University of Massachusetts).
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`7.
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`I am a senior member of the Association for Computer Machinery
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`(ACM) and a senior member of the Computer Society of IEEE, among other
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`professional societies and organizations. Within these organizations, I have served
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`as general chair, program committee (PC) chair, or PC member of most flagship
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`technical conferences in networking, distributed systems, real-time systems, and
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`databases, such as ACM Principles on Distributed Computing (“PODC”),
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`International Conference on Distributed Computing Systems (“ICDCS”), ACM
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`Cluster, Cloud, and Grid Computing (“CCGRID”), ACM Sigmetrics, IEEE
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`Infocom, IEEE International Conference on Network Protocols (“ICNP”), ACM
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`Mutlimedia Systems (“MMSys”), IEEE HotWeb, IEEE International Conference
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`on Data Engineering (“ICDE”), and International Conference on Very Large Data
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`Bases (“VLDB”). I co-organized formative workshops that led to two major ACM
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`conferences related to embedded systems and Internet communications—ACM
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`SIGPLAN LCTES and ACM SIGCOMM Internet Measurement Conference,
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`respectively. I have also served on the editorial board of several major journals
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`and periodicals, which currently include “Communications of the ACM,” the most
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`read periodical for computer science professionals.
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`8.
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`Prior to joining the faculty at Boston University, from June 1988 to
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`September 1991, I was a Research Fellow, Teaching Fellow, and Research
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`Assistant at Harvard University. From September 1985 to June 1987, I was a
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`Research Assistant, Teaching Assistant, and Instructor at Alexandria University in
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`Alexandria, Egypt.
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`9.
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`In sum, I have studied, taught, practiced, and conducted research in
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`Computer Science and Computer Engineering for more than 30 years. My
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`expertise is in the broad fields of computer networking, distributed systems and
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`real-time computing, with significant experience in Web content caching,
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`replication and distribution systems, scalable Internet services, cloud computing,
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`Internet architecture and networking protocols, among others.
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`10. More specifically, as it relates to the technologies pertinent to this
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`case, I have considerable experience in Web and Internet architecture, protocols,
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`and services related to content caching, distribution, and delivery. My work in the
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`mid-1990s on Web caching generally, and on server-side content distribution in
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`particular, pioneered the “push” content-distribution model adopted years later by
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`content delivery networks, such as those provided by Akamai, Digital Island, and
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`Adero. My work in the late-1990s on scalable web server architectures led to a
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`patent on distributed routing, which was the basis of a startup company named
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`Commonwealth Network Technologies (CNT), which focused on web server load-
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`balancing. Owing to the commercial viability of the distributed-routing techniques
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`I developed, CNT was acquired by WebManage Inc. in 1999. Other related
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`research contributions include: my seminal work on traffic characterization and
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`reference-locality modeling; my work on concurrency-control and synchronization
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`for real-time and streaming databases; my work on various network transport
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`protocols such as TCP, end-system multicast, and streaming media delivery
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`protocols; my work on end-to-end measurement and on inference of wireline and
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`wireless network caricatures; my work on resource management for mobile and
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`ad-hoc networks; my network security work on identifying and on countering
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`adversarial exploits of system and network dynamics; my work on verification of
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`network protocol compositions, including the identification of unsafe arrangements
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`of HTTP agents; my work on virtualization services and programming
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`environments for embedded sensor networks; and my work on economics-inspired
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`approaches to the design of networking and cloud computing applications.
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`11. Funded by over $20 million of government and industry grants, my
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`research work has yielded 18 Ph.D. theses, 6 issued patents, 3 startups, and
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`hundreds of refereed papers that have been cited over 13,000 times. My research
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`contributions include pioneering the Web push content-distribution model
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`described above; seminal work on Internet traffic characterization, web and
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`streaming media caching, prefetching, and replication; novel peer-to-peer and
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`cloud-assisted delivery of live and stored real-time streams; game-theoretic
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`approaches to cloud resource management; and safety certification of networked
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`systems and software. At the Hariri Institute, I am spearheading a number of cloud
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`computing, big-data, and cybersecurity initiatives, most notably the Open Cloud
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`Exchange project which aims to set up a new model for public clouds and for
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`cloud marketplaces.
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`12.
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`I have extensive consulting and industrial research experience,
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`including past and current engagements with a number of technology firms, such
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`as BBN Technologies, Sycamore Networks, NetApp, Microsoft, Verizon Labs,
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`Macromedia, Allaire, Bowne, SUTI Technologies, and AT&T Bell Labs. I have
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`consulted and served on the technical advisory board of many companies, and I
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`have been retained by a number of law firms to provide consultation services on
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`intellectual property issues related to Internet technologies and applications.
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`13. My academic curricular development efforts include developing and
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`teaching the content of the CS-350 course at Boston University. I have taught this
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`course since 1998. Through a rigorous treatment of the invariant concepts
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`underlying computing systems design, CS-350 familiarizes students with canonical
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`problems that reoccur in software systems, including operating systems, networks,
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`databases, and distributed systems, and provides students with a set of classical
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`algorithms and basic performance evaluation techniques for tackling such
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`problems. As is particularly relevant here, the course also includes units on basic
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`concepts of synchronization and consistency semantics. More recently, I have
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`spearheaded a team effort to develop a set of courses for non-majors that can be
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`used to introduce elements of mathematical abstraction, quantitative and
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`methodical thinking, as utilized in mathematics, statistics, and computer science,
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`with an emphasis on their relevance in our daily lives as reflected in widely used
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`Internet and Web technologies and applications. In addition to these courses, I
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`have taught undergraduate courses and graduate seminars on large-scale Internet
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`systems, sensor networks, computer architecture, and real-time systems, and have
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`guest-lectured in Sociology on issues related to Technology, Society and Public
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`Policy.
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`14. Over the years, my contributions in research, teaching, and service
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`have been recognized through a number of awards, including multiple best-paper
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`awards at numerous IEEE and ACM conferences, multiple distinguished ACM and
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`IEEE service awards, and by being selected multiple times as a distinguished
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`speaker of the IEEE Computer Society, with the last such selection occurring in
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`2010. In 2010, I received the United Methodist Scholar Teacher Award in
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`recognition of “outstanding dedication and contributions to the learning arts and to
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`the institution” at Boston University, and the ACM Sigmetrics Inaugural Test of
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`Time Award for research results “whose impact is still felt 10-15 years after its
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`initial publication.”
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`III. COMPENSATION AND RELATIONSHIP TO THE PARTIES
`15.
`I am being compensated at an hourly rate of $650 for my time
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`working in connection with this matter, including studying materials associated
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`with this matter, preparing this or other documents, and providing testimony. I am
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`also being compensated for the reasonable expenses I incur. My compensation
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`does not depend on my testimony, opinions, or the outcome of these petitions.
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`16.
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`It is my understanding that Synchronoss Technologies, Inc.
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`(“Synchronoss”) is the current assignee of the ’757 patent (which was assigned on
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`its face to “fusionOne, Inc.”). Prior to this matter, I have not been employed or
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`retained by Synchronoss, fusionOne, or Dropbox. I own no stock in Synchronoss,
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`fusionOne, or Dropbox, and am aware of no other financial interest I have with
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`those companies.
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`IV. LEGAL STANDARDS
`17. Although I am not an attorney and do not expect to offer any opinions
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`regarding the law, I have been informed of certain legal principles that I relied
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`upon in forming the opinions set forth in this declaration.
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`A. Claim Construction
`18.
`I understand that for purposes of this matter the terms in the claims of
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`the ’757 patent are to be given their broadest reasonable interpretation in light of
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`the specification of the ’757 patent, as understood by a person of ordinary skill in
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`the art (“POSA”) as of the priority date of the ’757 patent.
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`19.
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`I understand that, in interpreting the claims of the patent, the most
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`weight is given to the claims themselves. I also understand that the words of the
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`claims are generally interpreted according to their ordinary and customary
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`meaning. I further understand that the terms of a claim are to be interpreted in
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`light of the patent’s specification. I understand that a patentee may provide a
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`definition for a claim term in the specification that differs from the ordinary and
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`customary meaning it would otherwise have, in which case, the inventor’s
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`definition governs. Further, I understand that the use of a claim term in the
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`specification and prosecution history provides further information about how the
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`term is to be understood in the claims.
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`B. Anticipation
`20.
`I understand that a claimed invention is unpatentable if a single prior
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`art reference “anticipates” the claimed invention, which I understand to mean that
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`the prior art discloses each and every limitation of the claimed invention. I
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`understand that in order to anticipate the claimed invention, the prior art reference
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`must not only disclose all elements of the claim within the reference, but must also
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`disclose those elements arranged as in the claim.
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`C. Obviousness
`21.
`I understand that even if a claim is not anticipated, an invention that
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`would have been obvious to a POSA at the time of the invention is not patentable.
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`I understand that obviousness is determined by considering several factors,
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`including: the state of the art at the time the invention was made; the level of
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`ordinary skill in the art; differences between what is described in the art and the
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`claims at issue; and secondary considerations of nonobviousness (such as
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`commercial success, long-felt but unsolved needs, failure of others, and
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`unexpected results). In order to be relevant to the issue of obviousness, I
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`understand that any secondary considerations must have a connection or nexus to
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`the claimed invention. I further understand that the use of hindsight is not
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`permitted in the obviousness inquiry.
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`22.
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`I understand that multiple references may be combined to render the
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`claimed invention obvious. I further understand that the prior art, knowledge in
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`the field, common sense, practical considerations, and/or design or market
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`incentives may provide a motivation or reason to combine prior art reference to
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`arrive at the claimed invention. I further understand that a showing of obviousness
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`also requires that the POSA would have had a reasonable expectation of success in
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`making or using the claimed invention.
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`D.
`23.
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`Person of Ordinary Skill in the Art
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`I have been informed that the POSA is a hypothetical person who is
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`presumed to have known all of the relevant art at the time of the invention. I have
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`been informed that a POSA may possess the education, skills, and experience of
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`multiple actual people who would work together as a team to solve a problem in
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`the field. I have been informed that factors that may be considered in determining
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`the level of ordinary skill in the art may include: (1) the educational level of the
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`inventor; (2) type of problems encountered in the art; (3) prior art solutions to
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`those problems; (4) rapidity with which innovations are made; (5) sophistication of
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`the technology; and (6) educational level of active workers in the field.
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`24. On the basis of my consideration of these factors as well as my
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`experience with, and research related to, the fields of networking and distributed
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`systems, I have been asked to opine as to the person of ordinary skill in the art to
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`which claims 1–29 of the ’757 patent are directed. In my opinion, such a person of
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`ordinary skill in the art should have at least a bachelor’s degree in Computer
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`Science or equivalent experience. Such a person would have experience working
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`with and programming networked computer systems. Such a person would be
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`familiar with the underlying principles of network synchronization, including data
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`transfer, distributed systems, and content sharing and distribution across networks.
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`Bestavros Dec. ISO Pet. for Inter Partes Review
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`U.S. Patent 6,671,757
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`V. THE ’757 PATENT AND THE STATE OF THE ART
`A.
`Synchronization
`25. The ’757 patent claims systems for synchronizing data between two
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`“systems” or “devices,” over a network, through an intermediate server. Ex. 1001
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`at 46:58–50:9.1 As used here, “synchronizing” data refers simply to copying the
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`data from one place to another, such that if a file is modified on Computer #1 and
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`then “synchronized” to Computer #2, the most recent version of the file
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`(containing any and all modifications) will appear on Computer #2.
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`26. Systems for synchronizing data between and among many connected
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`client computers, mobile devices, and servers were well-known as of the priority
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`date of the patent, which, for purposes of this declaration, I assume to be January
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`1 I note that it was common in the art as of the priority date of the ’757 patent to
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`refer to a computer that accepts incoming connections from other computers and
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`services requests from them as a “server,” and the computers that connect to a
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`server, as “clients.” In this parlance, the multiple individual users’ workstations
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`are “clients” that connect to one or more “servers” that serve as centralized data
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`stores and communicate with one another primarily or exclusively via those
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`servers. I use these terms for convenience. It is important to understand—as
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`would have a POSA at the relevant time—that a client may both send information
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`to and receive information from a server, and vice versa.
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`U.S. Patent 6,671,757
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`26, 2000, i.e. the filing date of the ’757 patent. Such synchronization systems
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`Bestavros Dec. ISO Pet. for Inter Partes Review
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`could be found in a range of networked information systems and distributed
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`environments, and relied upon in a variety of settings that required the
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`transmission of data between client computers, devices, and servers.
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`27. The ’757 patent purports to address two problems with the prior art,
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`namely: (1) previous synchronization systems were inefficient because they
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`transferred the entire contents of files being synchronized over the network; and
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`(2) previous systems only synchronized data through direct connections between
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`the computers or devices being synchronized, and not through an intermediate
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`server. See, e.g., Ex. 1001 at 1:48–54; 2:21–29; 2:45–50; 3:23–31. I provide a
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`brief overview of the ’757 patent’s disclosure relating to both of these alleged
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`improvements over the prior art below.
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`28. As I will discuss further in subsequent sections, the ’757 patent does
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`not disclose improvements over the prior art either in regards to efficient transfer
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`or transfer through an intermediate server. The techniques that underpin the ’757
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`patent can be found in the prior art, and, in fact, had been put together in the prior
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`art in the same way they are claimed in the patent.
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`B. Difference Information
`29. One of the purported improvements over the prior art discussed in the
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`’757 patent is increased efficiency in file transfer. Specifically, the ’757 patent
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`discloses transferring parts of files, instead of whole files, over a network, by
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`U.S. Patent 6,671,757
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`sending what it refers to as “difference information.” See, e.g., Ex. 1001 at 3:32–
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`Bestavros Dec. ISO Pet. for Inter Partes Review
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`45; 6:3–30. This approach was seen as particularly beneficial given that the ’757
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`patent describes performing synchronization over networks such as the Internet
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`and other potentially low-bandwidth connections.
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`30.
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`In the systems disclosed in the ’757 patent, when a file is newly
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`created since the last synchronization, “the difference information Δ will be the
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`entire file.” Ex. 1001 at 6:14–16. However, when a pre-existing file changes and
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`needs to be synchronized with a version stored on another system connected to the
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`network, the “difference information Δ comprises only the differences in such file
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`and where such differences occur.” Ex. 1001 at 6:11––14.
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`31. According to the ’757 patent, sending only changes to files results in
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`“a reduction in the bandwidth utilized to transmit data between two systems.” Ex.
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`1001 at 8:32–33. Because the size of the data that is transmitted is smaller than it
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`would be if entire files were shipped, transmitting only differences between data
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`“increases the speeds at which such transactions,” i.e., synchronizations, “can take
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`place.” Ex. 1001 at 8:34–38.
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`32. The ’757 patent discloses software components that implement the
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`functions of generating and transferring difference information. Each system in
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`the ’757 patent includes a component called a “sync engine,” which is software
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`that interfaces both with data stored locally and on the network. As part of the
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`interfacing capability, the sync engine generates difference information from files
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`U.S. Patent 6,671,757
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`stored on the client. Ex. 1001 at 3:34–36. The sync engine also has the capability
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`Bestavros Dec. ISO Pet. for Inter Partes Review
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`to transmit difference information to the network data store, as well as receive
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`difference information from the network data store. Ex. 1001 at 3:43-45. After the
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`sync engine “receive[s] difference information from the data store,” it is able to
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`interface with data on the system to “update said data . . . with said difference
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`information.” Ex. 1001 at 3:39–42.
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`33. As I will discuss further below, the transmission of difference
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`information in a synchronization system was taught in multiple prior art references
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`that are asserted as invalidity references in this proceeding. But, in fact, these
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`concepts long predate those specific references.
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`34. The “diff” utility was a standard command-line utility included in
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`Unix systems dating back to the 1970s. See James W. Hunt and M. Douglas
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`McIlroy, “An Algorithm for Differential File Comparison,” Bell Laboratories,
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`Computing Science Technical Report 41 (Ex. 1020). The “diff” utili