`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`———————
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`———————
`
`
`
`Cisco Systems, Inc.,
`Petitioner
`
`vs.
`
`TQ Delta, LLC
`Patent Owner
`
`
`———————
`
`
`
`PETITION FOR INTER PARTES REVIEW
`
`OF
`
`U.S. PATENT NO. 7,835,430
`
`
`
`
`
`
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`TABLE OF CONTENTS
`
`PETITIONER’S EXHIBIT LIST ......................................................................... iv
`
`I.  MANDATORY NOTICES ............................................................................... 1 
`
`A.  Real Party-in-Interest ................................................................................. 1 
`
`B.  Related Matters .......................................................................................... 1 
`
`C.  Lead and Back-up Counsel and Service Information ............................... 2 
`
`II.  GROUNDS FOR STANDING .......................................................................... 2 
`
`III.  REQUESTED RELIEF ..................................................................................... 3 
`
`IV.  REASONS FOR THE REQUESTED RELIEF ................................................ 3 
`
`A.  Summary of the ’430 Patent ...................................................................... 3 
`
`B.  Prosecution History ................................................................................... 5 
`
`C.  Priority Date .............................................................................................. 6 
`
`D.  Summary of the Petition ............................................................................ 7 
`
`V. 
`
`IDENTIFICATION OF CHALLENGES AND CLAIM
`CONSTRUCTION ............................................................................................ 7 
`
`A.  Challenged Claims ..................................................................................... 7 
`
`B.  Claim Construction .................................................................................... 8 
`
`C.  Statutory Grounds for Challenges ........................................................... 10 
`
`D.  Level of Ordinary Skill in the Art ........................................................... 10 
`
`E.  Note Regarding Page Citations ............................................................... 11 
`
`VI.  IDENTIFICATION OF HOW THE CONSTRUED CLAIMS ARE
`UNPATENTABLE .......................................................................................... 11 
`
`ii
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`A.  Summary of the Prior Art ........................................................................ 11 
`
`1. 
`
`2. 
`
`3. 
`
`4. 
`
`Summary of Milbrandt .................................................................... 11 
`
`Summary of Chang ......................................................................... 12 
`
`Summary of Hwang ........................................................................ 13 
`
`Summary of ANSI T1.413 .............................................................. 13 
`
`B.  Reasons to Combine ................................................................................ 14 
`
`1.  Reasons to Combine Milbrandt with Chang ................................... 14 
`
`2.  Reasons to Combine Milbrandt/Chang with Hwang ...................... 20 
`
`3.  Reasons to Combine Milbrandt/Chang/Hwang with ANSI
`T1.413 ............................................................................................. 22 
`
`C.  Challenge #1: Claims 1-6 are rendered obvious under 35 U.S.C.
`§ 103 by Milbrandt in view of Chang, Hwang, and ANSI T1.413 ......... 24 
`
`i. 
`
`Claim 1 ............................................................................................ 24 
`
`ii.  Claim 2 ............................................................................................ 34 
`
`iii.  Claim 3 ............................................................................................ 39 
`
`iv.  Claim 4 ............................................................................................ 42 
`
`v.  Claim 5 ............................................................................................ 44 
`
`vi.  Claim 6 ............................................................................................ 46 
`
`VII.  CONCLUSION ................................................................................................ 49 
`
`VIII. Certificate of Word Count ............................................................................... 50 
`
`
`
`
`
`iii
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`PETITIONER’S EXHIBIT LIST
`
`May 6, 2016
`
`1001 U.S. Patent No. 7,835,430 to Krinsky et al.
`
`1002 Prosecution File History of U.S. 8,432,956
`
`1003 Prosecution File History of U.S. 8,238,412
`
`1004 Prosecution File History of U.S. 7,835,430
`
`1005 Prosecution File History of U.S. 7,570,686
`
`1006 Prosecution File History of U.S. 6,658,052
`
`1007 U.S. Provisional Application No. 60/224,308
`
`1008 U.S. Provisional Application No. 60/174,865
`
`1009 Declaration of Dr. Sayfe Kiaei Under 37 C.F.R. § 1.68
`
`1010 Curriculum Vitae of Dr. Sayfe Kiaei
`
`1011 U.S. Patent No. 6,636,603 to Milbrandt
`
`1012 U.S. Patent No. 6,891,803 to Chang et al.
`
`1013 U.S. Patent No. 6,590,893 to Hwang et al.
`
`1014 ANSI T1.413-1995 Standard
`
`1015 Charles K. Summers, ADSL STANDARDS, IMPLEMENTATION, AND
`ARCHITECTURE (CRC Press 1999) (selected pages)
`
`1016 Walter Goralski, ADSL AND DSL TECHNOLOGIES (McGraw-Hill 1998)
`(selected pages)
`1017 Harry Newton, NEWTON’S TELECOM DICTIONARY, 16th Ed. (2000)
`(selected pages)
`
`iv
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`1018 Valerie Illingworth and John Daintith, THE FACTS ON FILE
`DICTIONARY OF COMPUTER SCIENCE (Market House Books 2001)
`(selected pages)
`
`1019 Thomas Starr, John M. Cioffi, Peter J. Silverman, UNDERSTANDING
`DIGITAL SUBSCRIBER LINE TECHNOLOGY, (Prentice Hall 1999)
`(selected pages)
`
`1020 Andrew S. Tanenbaum, COMPUTER NETWORKS (Prentice Hall 1996)
`(selected pages)
`
`1021 B. P. Lathi, Modern Digital and Analog Communication Systems
`(Oxford University Press 1998) (selected pages)
`
`1022 Behzad Razavi, RF MICROELECTRONICS (Prentice Hall 1997) (selected
`pages)
`
`1023 Declaration of David Bader
`
`
`v
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`I. MANDATORY NOTICES
`
`A. Real Party-in-Interest
`
`The Petitioner and real party in interest is Cisco Systems, Inc.
`
`B. Related Matters
`
`To the best knowledge of the Petitioner, U.S. Patent No. 7,835,430 (“the
`
`’430 Patent”) is involved in the following litigations:
`
`Number
`1-15-cv-00611
`
`Name
`TQ Delta LLC v. Comcast Cable
`Communications LLC
`TQ Delta LLC v. CoxCom
`TQ Delta LLC v. DIRECTV
`TQ Delta LLC v. DISH
`TQ Delta LLC v. Time Warner Cable
`TQ Delta LLC v Verizon
`Communications, Inc.
`Adtran Inc v. TQ Delta LLC
`TQ Delta LLC v. ADTRAN
`ADTRAN v. TQ Delta, LLC
`TQ Delta, LLC v. ZyXEL
`Communications Corp.
`TQ Delta, LLC v. Pace Americas, LLC 1-13-cv-01835
`TQ Delta LLC v. Zhone Techs. Inc.
`1-13-cv-01836
`
`
`1-15-cv-00612
`1-15-cv-00613
`1-15-cv-00614
`1-15-cv-00615
`1-15-cv-00616
`
`1-15-cv-00121
`1-14-cv-00954
`5-14-cv-01381
`1-13-cv-02013
`
`Court Filed
`DED
`Jul. 17, 2015
`
`DED
`DED
`DED
`DED
`DED
`
`Jul. 17, 2015
`Jul. 17, 2015
`Jul. 17, 2015
`Jul. 17, 2015
`Jul. 17, 2015
`
`Feb. 3, 2015
`DED
`Jul. 17, 2014
`DED
`ALND Jul. 17, 2014
`DED Dec. 9, 2013
`
`DED Nov. 4, 2013
`DED Nov. 4, 2013
`
`The ’430 Patent and related U.S. Patent Nos. 8,432,956 (“the ’956 Patent”)
`
`and 8,238,412 (“the ’412 Patent”) are involved in the following related matters:
`
`Name
`Petition for Inter Partes Review of the
`’430 Patent by ARRIS Group, Inc.
`
`Court Filed
`Number
`IPR2016-00428 PTAB
`Jan. 2, 2016
`
`1
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`Petition for Inter Partes Review of the
`’956 Patent by ARRIS Group, Inc.
`Petition for Inter Partes Review of the
`’430 Patent by ARRIS Group, Inc.
`
`
`IPR2016-00429 PTAB
`
`Jan. 3, 2016
`
`IPR2016-00430 PTAB
`
`Jan. 3, 2016
`
`Also, concurrent with the filing of the present Petition for IPR of the ’430
`
`Patent, Petitioner is filing Petitions for IPRs of the related ’956 and ’412 Patents.
`
`C. Lead and Back-up Counsel and Service Information
`
`Lead Counsel
`David L. McCombs
`HAYNES AND BOONE, LLP
`2323 Victory Ave. Suite 700
`Dallas, TX 75219
`Back-up Counsel
`Theodore M. Foster
`HAYNES AND BOONE, LLP
`2323 Victory Ave. Suite 700
`Dallas, TX 75219
`
`Gregory P. Huh
`HAYNES AND BOONE, LLP
`2323 Victory Ave. Suite 700
`Dallas, TX 75219
`
`
`
`214-651-5533
`Phone:
`214-200-0853
`Fax:
`
`david.mccombs.ipr@haynesboone.com
`USPTO Reg. No. 32,271
`
`972-739-8649
`Phone:
`972-692-9156
`Fax:
`
`ipr.theo.foster@haynesboone.com
`USPTO Reg. No. 57,456
`
`972-739-6939
`Phone:
`972-692-9156
`Fax:
`
`gregory.huh.ipr@haynesboone.com
`USPTO Reg. No. 70,480
`
`II. GROUNDS FOR STANDING
`
`Petitioner certifies that the ’430 Patent is available for inter partes review
`
`and that Petitioner is not barred or estopped from requesting inter partes review
`
`challenging the patent claims on the grounds identified in this Petition.
`
`2
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`III. REQUESTED RELIEF
`
`Petitioner asks that the Board review the accompanying prior art and
`
`analysis, institute a trial for inter partes review of claims 1-6 of the ’430 Patent,
`
`and cancel those claims as unpatentable.
`
`IV. REASONS FOR THE REQUESTED RELIEF
`
`As explained below and in the declaration of Cisco Systems’ expert, Dr.
`
`Sayfe Kiaei, the concepts described and claimed in the ’430 Patent were not novel.
`
`This Petition and Dr. Kiaei’s declaration explain where each element is found in
`
`the prior art and why the claims would have been obvious to a person of ordinary
`
`skill in the art prior to the earliest effective priority date.
`
`A. Summary of the ’430 Patent
`
`The ’430 Patent describes exchanging diagnostic and test information
`
`between transceivers over a digital subscriber line. Ex. 1001, 1:44-47. The
`
`diagnostic and test information are exchanged using multiple carriers with a higher
`
`order quadrature amplitude modulation scheme with more than 1 bit per carrier.
`
`Id., 3:38-41. The information exchanged includes idle channel noise information.
`
`Id., 5:59-67; Ex. 1009, p. 12-15.
`
`Fig. 1 of the ’430 Patent illustrates a functional block diagram of an
`
`exemplary communication system capable of the claimed techniques.
`
`3
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`Ex. 1001 Fig. 1.
`
`Claims 1-6 are each independent claims. Claims 1, 3, and 5 relate to a
`
`transmitter and a method of transmitting a message, while claims 2, 4, and 6 relate
`
`to a receiver and a method of receiving such a message. Claim 1 is generally
`
`
`
`representative:
`
`1. A transceiver capable of transmitting test information over a
`communication
`channel using multicarrier modulation
`comprising:
`a transmitter portion capable of transmitting a message, wherein the
`message comprises one or more data variables that represent the
`test information, wherein bits in the message are modulated
`onto DMT symbols using Quadrature Amplitude Modulation
`(QAM) with more than 1 bit per subchannel and wherein at
`least one data variable of the one or more data variables
`comprises an array representing frequency domain received idle
`channel noise information.
`Ex. 1001, 8:33-44.
`
`4
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`B. Prosecution History
`
`The ’430 Patent was filed as U.S. Patent Application No. 12/477,742 (“the
`
`’742 application”) on June 3, 2009. The ’742 application was filed with a
`
`preliminary amendment cancelling the original claims and presenting new claims
`
`47-52. Ex. 1004 at 286.
`
`In the first Office action, claim 52 was rejected as unpatentable under 35
`
`U.S.C. §101 and claims 47-51 were indicated as allowable. Id. at 274-275. The
`
`applicants then amended claim 52 to recite “non-transitory” computer-readable
`
`information storage media. Id. at 260. The Examiner then rejected claims 44-50
`
`under nonstatutory double patenting over U.S. Patent No. 7,570,686. Id. at 123-
`
`126. In response, applicants then submitted a terminal disclaimer. Id. 113. The
`
`Examiner then issued a Notice of Allowance indicating that claims 44-52 have
`
`been allowed and providing a statement of reasons for allowance that emphasized
`
`features of the “message” recited in each of the independent claims:
`
`The instant Application is directed to a transceiver capable of
`transmitting and receiving, a non-transitory computer readable
`information storage media having stored thereon instructions that, if
`executed, cause a transceiver to perform a method of transmitting and
`receiving a combination of uniquely distinct features “the message
`comprises one or more data variables that represent the test
`information wherein bits in the message are modulated onto DMT
`svmbols using Quadrature Amplitude Modulation (QAM) with more
`
`5
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`than 1 bit per subchannel and wherein at least one data variable of
`the one or more data variables comprises an array representing
`frequency domain received idle channel noise information”.
`
`Id. at 68-71 (emphasis original). The ’430 Patent issued on November 16, 2010.
`
`C. Priority Date
`
`The ’430 Patent claims priority to two provisional applications, but the
`
`claims are not entitled to the benefit of either provisional filing date.
`
`Provisional Application No. 60/224,308 was filed on August 10, 2000. The
`
`’308 Provisional Application names as inventors Murat Belge, Michael A Tzannes,
`
`and Halil Padir. Ex. 1007 at 1, 3. None of these individuals is named as an inventor
`
`on the ’430 Patent. Because there is no overlap of inventorship, the ’430 Patent is
`
`not entitled to the benefit of the filing date of the ’308 Provisional Application. 35
`
`U.S.C. § 119(e)(1); MPEP 211.01(a).
`
`Provisional Application No. 60/174,865 was filed on January 7, 2000. The
`
`’865 Provisional Application describes “bits that are modulated by using 1 bit per
`
`DMT symbol modulation.” Ex. 1008 at 5. The application does not describe using
`
`Quadrature Amplitude Modulation (QAM) with more than 1 bit per subchannel, as
`
`required by every claim of the ’430 Patent. The application also does not describe
`
`an array representing frequency domain received idle channel noise information, as
`
`required by every claim of the ’430 Patent. Accordingly, the ’430 Patent is not
`
`entitled to the benefit of the filing date of the ’865 Provisional Application. 35
`
`6
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`U.S.C. § 119(e)(1); MPEP 211.05.
`
`D. Summary of the Petition
`
`Testing a communication line for its ability to support digital subscriber line
`
`(DSL) services, and exchanging test information, were not new as of the ’430
`
`Patent’s effective filing date in 2001. Specifically, the prior art recognized that a
`
`DSL communication link needed to measure the transmission characteristics of the
`
`telephone line over which it operates. Since DSL is a multicarrier communication
`
`technology, and since the transmission characteristics can vary significantly over
`
`the different carrier frequencies available, the prior art also recognized that the
`
`measurements should include separately measuring the noise and power of each
`
`carrier frequency. DSL standards had also adopted the transmission of data using
`
`quadrature amplitude modulation (QAM) with more than 1 bit per subchannel.
`
`Because the ’430 Patent’s claims use the prior-art communication technology to
`
`exchange information gathered using prior-art line measurements, the claims are
`
`unpatentable and should be canceled.
`
`V. IDENTIFICATION OF CHALLENGES AND CLAIM
`CONSTRUCTION
`
`A. Challenged Claims
`
`Claims 1-6 of the ’430 Patent are challenged in this Petition.
`
`7
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`B. Claim Construction1
`
`This Petition analyzes the claims consistent with the broadest reasonable
`
`interpretation in light of the specification. See 37 C.F.R. § 42.100(b). All claim
`
`terms not discussed below are to be given their broadest reasonable interpretation,
`
`as understood by one of ordinary skill in the art consistent with the disclosure. In
`
`re Translogic Tech., Inc., 504 F.3d 1249, 1257 (Fed. Cir. 2007).
`
`“frequency domain received idle channel noise information” (claims 1-6):
`
`The ’430 Patent specification does not use this term, but does discuss an “average
`
`idle channel noise.” Ex. 1001, 4:7. The specification also mentions a “frequency
`
`domain received idle channel” as part of a bulk enumeration of kinds of test
`
`information. Id., 5:59-6:2. A person of ordinary skill in the art would have
`
`understood that “frequency domain” generally refers to analysis of a signal on a
`
`frequency basis. See, e.g., Ex. 1017, p.377; Ex. 1009, p. 17-19. A person of
`
`ordinary skill in the art would have understood that “idle channel noise” refer to
`
`noise that exists in a communication path when no signals are present. Ex. 1017,
`
`p.438; Ex. 1009, p. 19-20. This same concept is sometimes also referred to as
`
`“background noise.” See Ex. 1017, p.97; Ex. 1009, p. 20. Consistent with the
`
`specification’s description and for the purposes of this proceeding, a POSITA
`
`1 It is noted that there are other relevant terms that are discussed by Dr. Kiaei in his
`
`declaration. See Ex. 1009 at 22-26.
`
`8
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`would have understood that the broadest reasonable interpretation of this phrase
`
`includes “information about the background noise present in each of a plurality of
`
`frequency subchannels when the subchannels are not in use.” Ex. 1009 at 20.
`
`“array” (claims 1-6): The ’430 Patent does not provide an express definition
`
`for this term, but rather uses this term in accordance to its ordinary meaning. Ex.
`
`1001, 4:30-35. Contemporary dictionaries define array to mean an “ordered
`
`collection of identical structures” (Ex. 1017, p.71) or a “collection of data items …
`
`[that are] arranged in a particular order or pattern and are all of the same type” (Ex.
`
`1018, p.9). Consistent with the specification’s description and for the purposes of
`
`this proceeding, a POSITA would have understood that the broadest reasonable
`
`interpretation of “array” to include “an ordered collection of multiple data items of
`
`the same type.” Ex. 1009 at 20-21.
`
`“transceiver” (claims 1-6): The word “transceiver” is a combination of the
`
`words transmitter and receiver. Ex. 1009, p. 22. The ’430 Patent “refer[s] to the
`
`transceivers generically as modems.” Ex. 1001, 1:48-62. Consistent with the ’430
`
`specification, and for the purposes of this proceeding, a POSITA would have
`
`understood that the broadest reasonable interpretation of “transceiver” includes a
`
`“device, such as a modem, with a transmitter and receiver.” Ex. 1009 at 22-23; Ex.
`
`1017, p.913.
`
`9
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`C. Statutory Grounds for Challenges
`
`Challenge #1: Claims 1-6 are obvious under 35 U.S.C. § 103(a) over U.S.
`
`Patent No. 6,636,603 to Milbrandt (“Milbrandt”) (Ex. 1011) in view of U.S. Patent
`
`No. 6,891,803 to Chang et al. (“Chang”) (Ex. 1012), and U.S. Patent No.
`
`6,590,893 to Hwang et al. (“Hwang”) (Ex. 1013), and further in view of American
`
`National Standards Institute (ANSI) T1.413-1995 Standard, entitled “Network and
`
`Customer Installation Interfaces – Asymmetric Digital Subscriber Line (ADSL)
`
`Metallic Interface,” (“ANSI T1.413”) (Ex. 1014). Ex. 1009, p. 32, 43.
`
`Milbrandt was filed on July 30, 1999, Chang was filed December 18, 1998,
`
`and Hwang was filed on April 7, 1999. All three references are prior art at least
`
`under § 102(e). ANSI T1.413 was approved on August 18, 1995, published shortly
`
`thereafter, and is prior art under § 102(b). Ex. 1009, p. 31-32; Ex. 1023 ¶ 2. Also,
`
`the additional evidentiary references relied upon by Dr. Kiaei in his declaration
`
`were also publicly available. Ex. 1023 ¶¶ 3-9.
`
`D. Level of Ordinary Skill in the Art
`
`The level of ordinary skill in the art may be reflected by the prior art of
`
`record. See Okajima v. Bourdeau, 261 F.3d 1350, 1355 (Fed. Cir. 2001); In re
`
`GPAC Inc., 57 F.3d 1573, 1579 (Fed. Cir. 1995). Here, the person of ordinary skill
`
`in the art is someone knowledgeable concerning multicarrier communications.
`
`That person would have (i) a Master’s degree in Electrical and/or Computer
`
`10
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`Engineering, or equivalent training, and (ii) approximately five years of experience
`
`working in digital telecommunications. Ex. 1009, p. 15-17. Lack of work
`
`experience can be remedied by additional education, and vice versa. Id. at 16.
`
`E. Note Regarding Page Citations
`
`For exhibits that include suitable page numbers in their original publication,
`
`Petitioner’s citations are to those original page numbers and not to the page
`
`numbers added for compliance with 37 CFR 42.63(d)(2)(ii).
`
`VI. IDENTIFICATION OF HOW THE CONSTRUED CLAIMS ARE
`UNPATENTABLE
`
`A. Summary of the Prior Art
`
`Claims 1-6 of the ’430 Patent are rendered obvious under 35 U.S.C. § 103(a)
`
`over Milbrandt in view of Chang, Hwang, and ANSI T1.413. Ex. 1009, p. 32.
`
`1. Summary of Milbrandt
`
`Milbrandt describes technology that allows a digital subscriber line (DSL)
`
`service provider to test the telephone lines used to deliver service to its customers.
`
`Milbrandt’s system collects measurements of “line noise” and other characteristics
`
`using devices located at the customers’ premises. Ex. 1011, Abstract. The noise
`
`measurements and other information are transmitted from the customers’ premises
`
`to the service provider’s central office over the same telephone lines used to
`
`provide DSL service. Id., 11:38-53. Milbrandt describes using the collected
`
`measurements for various purposes, including determining a transmit power level
`
`11
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`for the modems providing DSL services and estimating the data rate capacity of the
`
`subscriber lines. Id., Abstract, 3:17-24, 10:18-24; Ex. 1009, p. 28-29.
`
`Milbrandt further describes how DSL services can provide for high speed
`
`data transmission and Internet access. Id., 1:30-39. The communication
`
`components in Milbrandt’s network use “ADSL [asymmetric DSL] techniques that
`
`comply with ANSI Standard T1.413, such as discrete multi tone (DMT)
`
`modulation” to transmit and receive messages. Id., 9:33-34; Ex. 1009, p. 28-29.
`
`2. Summary of Chang
`
`Like Milbrandt, Chang is directed testing digital telecommunications
`
`networks. Ex. 1012, 2:54-55. In particular, Chang describes measuring
`
`“background noise” across a frequency spectrum by terminating the line with a
`
`characteristic impedance, thereby ensuring that no signals are being transmitted.
`
`Id., 2:59-60, 12:61-65. Further, in this context, Chang describes that it was well
`
`known to use memory such as “ROM” “PROM” “EPROM” and “FLASH” for
`
`storing executable instructions to cause an ADSL modem to perform various steps
`
`during operation. Id., 7:31-56, 7:55-56. Thus, Chang discloses a way to measure
`
`background noise and also provides additional details about memory and
`
`executable software that can be utilized in ADSL modems, such as the ADSL
`
`modems described in Milbrandt. Ex. 1009, p. 29-30.
`
`12
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 7,835,430
`
`3. Summary of Hwang
`
`Hwang similarly describes a “network using discrete multi-tone (DMT)
`
`technology.” Ex. 1013, 4:58-59. More specifically, Hwang describes “higher-rate
`
`digital subscriber line communication schemes capable of utilizing twisted pair
`
`wiring from an office or other terminal node of a telephone network to the
`
`subscriber premises.” Id., 2:23-27. Like Milbrandt, Hwang employs ADSL
`
`techniques, and Hwang explains that ADSL uses discrete multi-tone (DMT)
`
`technology to divide the available frequency range into 256 distinct carriers, or
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`tones. Id., 3:3-5; Ex. 1011, 9:31-34. Within each carrier, data is encoded using
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`quadrature amplitude modulation (QAM) signals. Ex. 1013, 3:1-3. These
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`techniques provide “effective high-speed data communications over twisted pair
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`wiring between customer premises and corresponding network-side units, for
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`example located at a central office of the telephone network.” Id., 3:15-19. Thus,
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`Hwang provides additional details about the same standards-based ADSL
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`communication technology described in Milbrandt. Ex. 1009, p. 30-31.
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`4. Summary of ANSI T1.413
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`ANSI T1.413 is a standards specification defining the electrical
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`characteristics and signals used in Asymmetric Digital Subscriber Line (ADSL)
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`communications. Ex. 1014, Abstract. The standard specifies the minimum
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`requirements for equipment implementing ADSL. Id.; Ex. 1009, p. 32.
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`Among the features of ADSL is the encoding to data into discrete multitone
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`(DMT) symbols. Ex. 1014, pp. 23-34. Within each DMT subchannel, an ADSL
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`transmitter encodes a variable number of bits of data using a constellation encoder.
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`Id., 43-45. Those of skill in the art would have recognized the constellation
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`encoder of ANSI T1.413 as performing quadrature amplitude modulation. Ex.
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`1009, p. 31-32; Ex. 1016 at 188.
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`B. Reasons to Combine
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`1. Reasons to Combine Milbrandt with Chang
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`Milbrandt describes techniques for measuring operational characteristics,
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`such as noise information via digital subscriber line (DSL), including
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`Asymmetrical Digital Subscriber Line (ADSL). Ex. 1011, 8:53-65, 9:31-34.
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`Milbrandt describes collecting noise information during operation. Id., 12:58-62.
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`Specifically, Milbrandt teaches sampling a time domain signal communicated by
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`the central office to a modem at the subscriber premises. Ex. 1011, 12:58-13:3; Ex.
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`1009, p. 33.
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`Those of skill in the art would have recognized, however, that it is also
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`important to measure and evaluate the noise present on the subscriber when the
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`subchannel is not in operation, since these measurements represent system noise
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`not associated with signals transmitted on the channel. Ex. 1009, p. 33. Skilled
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`artisans understood that “noise” in a communication system generally refers to any
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`unwanted signals introduced into the telephone line. Ex. 1017, p. 613. System
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`noise can come from a variety of sources. Examples include thermal noise, which
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`is caused by the random motion of electrons in the wires that make up the
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`subscriber line. Ex. 1020, p. 109. Cross talk is the inductive coupling of signals
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`between adjacent wires. Id. Impulse noise is a power spike and can be caused by
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`events such as making or breaking electrical connections to the line. Id. Those of
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`skill in the art would recognize that all of these common noise sources are
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`independent of the data signals transmitted on a subscriber line, and therefore, they
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`are most readily and directly measured when there are no data signals on the line.
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`Ex. 1009, p. 33-34.
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`Chang is similarly directed toward evaluating DSL communications,
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`including determining operational characteristics such as noise information, and
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`more specifically “background noise” when no data is being transmitted. Ex. 1011,
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`1:6-8, 2:59-61. As Chang explains, “Background noise measures the noise
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`characteristics on the wire pair over a frequency band of interest . . . for
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`background noise measurement, slave test set 200b terminates the far end wire pair
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`with the characteristic impedance of the wire pair 720. Master test set 200a then
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`performs measurement of the extraneous signals at the near end.” Id., 12:59-66.
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`A person of ordinary skill in the art working with Milbrandt’s system would
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`have recognized the advantages of measuring background noise using Chang’s
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`technique for assessing interactions. Ex. 1009, p. 34. For example, when the
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`system of Milbrandt updates the transmit power level for a device on one telephone
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`line, the impact on adjacent idle telephone lines within a binder group can be
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`monitored using Chang’s approach. Id., pp. 34-35. Those of skill in the art would
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`have understood that raising the transmit power level on a telephone line can
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`improve service quality by delivering a stronger signal to the far end. Id., p. 35.
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`With a stronger signal, a denser modulation scheme can be employed, allowing
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`more bits to be encoded onto the DMT subcarriers, and thus faster data
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`communication speeds to be provided. Id.
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`It would have been obvious to a person of ordinary skill in the art at the time
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`to combine the teachings of Chang with those of Milbrandt, for the purpose of
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`assessing interactions from other sources, including thermal effect, inductive
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`coupling, and power spikes. Ex. 1009, p. 35-36. A person of ordinary skill would
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`have understood that assessing the background noise would allow for taking
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`appropriate remedial measures to minimize system interactions. Id. For example,
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`taking remedial measures could include adjusting the gains for a particular
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`communications channel to minimize inductive coupling and including devices to
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`dampen power spikes. Id. A person of ordinary skill would have understood that
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`taking appropriate remedial measures to address system noise would maximize
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`throughput and reliability, improve service to customers, and also make the system
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`as whole commercially desirable in the marketplace. Id.
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`In short, the combination of Milbrandt and Chang is nothing more than
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`applying the Chang’s known technique (i.e., measuring background noise in a DSL
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`system) to the DSL system of Milbrandt, to yield predictable results (e.g.,
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`assessing system interactions, taking remedial measures, maximizing throughput
`
`and reliability, improving service to customers, and also making the system as
`
`whole commercially desirable in the marketplace.) Ex. 1009, p. 36.
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`Further, the combination of Milbrandt and Chang is nothing more than
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`combining prior art elements (i.e., Chang’s background noise test circuitry and
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`measurement approach to Milbrandt’s system) according to known methods to
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`yield predictable results (e.g., assessing system interactions, taking remedial
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`measures, maximizing throughput and reliability, improving service to customers,
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`and also making the system as whole commercially desirable in the marketplace).
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`Ex. 1009, p. 36-37.
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`Chang also provides additional details about ADSL services, beyond those
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`expressly disclosed in Milbrandt, by explaining that the modem can be
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`implemented with a processor and memory, such “as RAM, a ROM, a PROM, an
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`EPROM, a FLASH, registers or other similar devices. Memory 412 can be used to
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`store the program codes of data or both.” Id., 7:31-46; Ex. 1009, p. 37.
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` A person of ordinary skill in the art working with the technology of
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`Milbrandt would have found it obvious to look Chang, which describes additional
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`modem hardware/software implementation details for the purpose of obtaining a
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`more complete understanding. Ex. 1009, p. 37-38. In doing so, it would have been
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`obvious to a person of ordinary skill in the art at the time to combine the teachings
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`of Chang with those of Milbrandt, for the purpose of allowing Milbrandt’s modems
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`to include executable instructions on non-transitory memory to perform various
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`communication protocol steps during operation. Id. Utilizing non-transitory
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`memory such, as ROM, PROM, EPROM, and FLASH for storing executable
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`instructions (as Chang teaches), is well suited and desirable for use in Milbrandt’s
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`modems because the information in the non-transitory memory is retained when
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`the modem is powered down thus obviating the need to reload the memory with
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`the executable instructions on power up, thereby expediting the time to power up.
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`Id. Indeed, it was commonplace and well known to use any one of ROM, PROM,
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`EPROM, and FLASH for storing executable instructions in production modems.
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`Id., p. 38.
`
`In short, th