`
`
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`
`
`
`D-Link Systems, Inc.,
`
`Petitioners
`
`v.
`
`ChriMar Systems, Inc.,
`
`Patent Owner
`
`
`
`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 8,942,107
`
`Case No. Unassigned
`
`
`
`
`Mail Stop Patent Board
`Patent Trial and Appeal Board
`U.S. Patent and Trademark Office
`P.O. Box 1450
`Alexandria, VA 22313-1450
`
`
`
`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
`
`TABLE OF CONTENTS
`I. Mandatory Notices (37 C.F.R. § 42.8) ............................. 1
`II.
`Relevant Background on the ’107 Patent ......................... 2
`A. Description of the Alleged Invention of the
`’107 Patent ........................................................................ 2
`Level of Ordinary Skill ..................................................... 5
`B.
`III. Claim Construction ........................................................... 5
`IV.
`Identification of Challenge (37 C.F.R. § 42.104(b))
` and Reasonable Likelihood That the Challenged
`Claims Are Unpatentable .................................................. 6
`A. Ground 1: The Challenged Claims Are Obvious
`Based on Hunter in View of Bulan. .................................. 7
`Overview of Hunter in View of Bulan ............................. 8
`Reasons to Combine Hunter and Bulan .......................... 10
`The Combined System of Hunter and Bulan .................. 14
`Operation of Bulan's Current Control Apparatus ........... 15
`Hunter in View of Bulan: Step-by-Step ......................... 21
`Application of Hunter in View of Bulan ........................ 24
`Independent Claim 1 ....................................................... 24
`Dependent Claim 5 ......................................................... 33
`Dependent Claim 31 ....................................................... 33
`Dependent Claim 43 ....................................................... 35
`Dependent Claim 70 ....................................................... 36
`Dependent Claim 72 ....................................................... 38
`Dependent Claim 74 ....................................................... 38
`
`1.
`a)
`b)
`c)
`d)
`1.
`a)
`b)
`c)
`d)
`e)
`f)
`g)
`
`i
`
`
`
`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
`
`h)
`i)
`j)
`
`Dependent Claim 75 ....................................................... 39
`Dependent Claim 83 ....................................................... 39
`Dependent Claim 103 (across 1, 5, 31, 43, 70, 72,
`and 75) ............................................................................ 39
`Independent Claim 104 ................................................... 41
`k)
`Dependent Claim 111 ..................................................... 42
`l)
`m) Dependent Claim 123 ..................................................... 42
`n)
`Dependent Claim 125 (across 104, 111, and 123) ......... 42
`B. Ground 2: The Challenged Claims are obvious
`based on Bloch in view of Huizinga and IEEE
`802.3. .............................................................................. 42
`Overview of Bloch in View of Huizinga and
`IEEE 802.3 ...................................................................... 43
`Overview of Bloch .......................................................... 43
`Overview of Huizinga .................................................... 48
`Overview of IEEE 802.3 (IEEE-93 and IEEE-95) ......... 49
`The Combined System of Bloch, Huizinga,
`and IEEE 802.3 (-93 & -95) ........................................... 51
`Reasons for Combinability ............................................. 52
`Application of Bloch in View of Huizinga and
`IEEE 802.3 ...................................................................... 54
`Independent Claim 1 ....................................................... 54
`Dependent Claim 5 ......................................................... 59
`Dependent Claim 31 ....................................................... 60
`Dependent Claim 43 ....................................................... 60
`Dependent Claim 70 ....................................................... 61
`
`a)
`b)
`c)
`d)
`e)
`
`1.
`
`a)
`b)
`c)
`d)
`
`e)
`2.
`
`ii
`
`
`
`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
`
`f)
`g)
`h)
`i)
`j)
`
`Dependent Claim 72 ....................................................... 62
`Dependent Claim 74 ....................................................... 63
`Dependent Claim 75 ....................................................... 63
`Dependent Claim 83 ....................................................... 63
`Dependent Claim 103
`(across 1, 5, 31, 43, 70, 72, and 75) ................................ 64
`Independent Claim 104 ................................................... 65
`k)
`Dependent Claim 111 ..................................................... 66
`l)
`m) Dependent Claim 123 ..................................................... 66
`n)
`Dependent Claim 125
`(across 104, 111, and 123) .............................................. 66
`Conclusion .................................................................................................... 67
`V.
`Certificate of Service .................................................................................... 68
`VI.
`VII. Certificate of Compliance with 37 C.F.R. § 42.24 ....................................... 69
`
`
`
`iii
`
`
`
`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
`
`Short Name
`’107 patent, or ’107
`Crayford
`Hunter
`Bulan
`Bloch
`IEEE-1993
`
`LIST OF EXHIBITS
`Description
`U.S. Patent 8,942,107 to Austerman, III et al.
`Declaration of Ian Crayford
`WO 96/23377 to Hunter
`U.S. Patent 5,089,927 to Bulan et al.
`U.S. Patent 4,173,714 to Bloch et al.
`IEEE International Standard ISO/IEC 8802-3:
`1993
`IEEE Standard 802.3u-1995
`
`IEEE-1995 (part 1)
`
`IEEE-1995 (part 2)
`Huizinga
`Blacharski
`
`Number
`1001
`1002
`1003
`1004
`1005
`1006
`
`10071
`
`1008
`1009
`1010
`
`IEEE Standard 802.3u-1995
`U.S. Patent 4,046,972 to Huizinga et al.
`Dan Blacharski, “Maximum Bandwith: A
`Serious Guide to High-Speed Networking,”
`Que Corporation (1997)
`Randy H. Katz, “High Performance Network
`and Channel-Based Storage,” Report
`UCB/CSD 91/650, September 1991
`List of Pending Cases Involving U.S. Patent
`8,942,107
`Resume of Ian Crayford
`
`1011
`
`Katz
`
`1012
`
`Related Matters
`
`1013
`
`Crayford C.V.
`
`
`1
`IEEE Standard 802.3u-1995 has been separated into Exhibits 1007 and 1008
`
`to comply with file size limitations for Exhibits. Exhibits 1007 and 1008 are
`
`continuously paginated, from 1-200, and 201-415, respectively.
`
`iv
`
`
`
`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
`
`
`
`Number
`1014
`
`
`Short Name
`IEEE Press Release
`
`
`1015
`
`Complaint
`
`1016
`1017
`1018
`
`’058 patent
`’152 patent
`Complaint
`
`Description
`IEEE Standards Association News & Events:
`Press Releases “IEEE 802.3 Standard for
`Ethernet Marks 30 Years of Innovation and
`Global Market Growth”
`Chrimar Systems, Inc. et al. v. Juniper
`Networks, Inc., Case No. 6:15-cv-00630 (N.D.
`Cal.), Dkt. No. 1.
`U.S. Patent No. 6,247,058 to Miller et al.
`U.S. Patent No. 6,865,152 to Luhmann
`Chrimar Systems Inc., et al. v. D-Link
`Systems., Case No 6:15-cv-653 (E.D. Tex.)
`filed on July 2, 2015.
`
`v
`
`
`
`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
`
`D-Link Systems, Inc. (“D-Link Systems” or “Petitioner”) requests inter partes
`
`review (“IPR”) of claims 1, 5, 31, 43, 70, 72, 74, 75, 83, 103, 104, 111, 123, and 125
`
`(“the Challenged Claims”) of U.S. Patent No. 8,942,107 (“the ’107 patent”), which
`
`is attached to this Petition as Exhibit 1001.
`
`I. Mandatory Notices (37 C.F.R. § 42.8)
`Real Party-in-Interest (§ 42.8(b)(1)): D-Link Systems, Inc. D-Link
`
`System’s Parent – D-Link Corporation – is also disclosed to the PTAB in the interest
`
`of completeness. D-Link Corporation had no involvement in or control over the
`
`preparation of this IPR Petition and it is not involved in the pending matters between
`
`D-Link Systems and Patent Owner set forth below.
`
`Related Matters (§ 42.8(b)(2)): The ’107 patent is the subject of 51 civil
`
`actions filed in the Eastern District of Michigan, Eastern District of Texas, and
`
`Northern District of California. Attached as Exhibit 1012 is a list identifying each
`
`of these civil actions, which includes Chrimar Systems Inc., et al. v. D-Link
`
`Systems., Case No 6:15-cv-653 (E.D. Tex.) filed on July 2, 2015. Ex.1018. The
`
`’107 patent is also the subject of pending IPR2016-01391 and terminated IPR2016-
`
`00569. IPR2016-01757 and IPR2017-00718 also involve the ’107 patent. IPRs have
`
`also been filed on related U.S. Patent Nos. 8,902,760, 8,115,012, and 8,019,838.
`
`IPR2016-01389, IPR2016-01397, IPR2016-01399 and IPR2016-01425. These
`
`cases may affect, or be affected by, decisions in this proceeding.
`
`1
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`
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
`
`Standing (§ 4.104(a)): D-Link Systems certifies that this patent is eligible
`
`for inter partes review and that it is not barred or estopped from requesting inter
`
`partes review of the Challenged Claims on the grounds identified herein.
`
`Designation of Lead and Back-Up Counsel and Service Information (§§
`
`42.8(b)(3)-(4)):
`
`Back-Up Counsel
`To be Assigned
`
`
`Lead Counsel
`David Hoffman (Reg. No. 54,174)
`Fish & Richardson P.C.
`3200 RBC Plaza
`60 South Sixth Street
`Minneapolis, MN 55402
`Tel: (512) 472-8154
`Fax: (202) 783-2331
`Hoffman@fr.com
`
`
`Pursuant to 37 C.F.R. § 42.10(b), Powers of Attorney accompany this
`
`
`
`Petition. Please address all correspondence to lead and back-up counsel.
`
`Petitioner also consents
`
`to electronic service by email at
`
`IPR40492-
`
`0004IP1@fr.com.
`
`Fee for Inter Partes Review (37 C.F.R. § 42.103): The undersigned
`
`authorizes the PTO to charge the required fees to Deposit Account No. 06-1050,
`
`referencing Docket No. 40492-0004IP1.
`
`II. Relevant Background on the ’107 Patent
` Description of the Alleged Invention of the ’107 Patent
`The ’107 patent issued from Application No. 13/370,918 which was filed on
`
`2
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`
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`Feb. 10, 2012. The ’ 107 patent claims the benefit of Provisional Patent
`
`Application No. 60/081,279, filed Apr. 10, 1998. Ex. 1002 (“Crayford”) ¶ 42.
`
`The ’ 107 patent explains that it is directed to equipment networked over
`
`“pre-existing wiring or cables that connect pieces of networked computer
`
`equipment to a network.” ’107 3:23-27, 4:62-66. The ’107 patent acknowledges
`
`that at the time of the alleged invention, “existing Ethernet communications” and
`
`equivalents thereof were known. ’107 3:40-42, 5:20-24 (“Ethernet, Token Ring, or
`
`ATM”). The ’ 107 patent provides examples of networked equipment including
`
`personal computers and telephones connected to a hub in a network. ’107 4:66-5:3.
`
`The equipment would be connected over “conventional multi-wire cables that
`
`include a plurality of transmit and receive data communication links.”2 ’107 5:12-
`
`19, 5:26-31 (“a pair of transmit wires”; “a pair of receive wires”). Crayford ¶ 44.
`
`The specification discloses a central module on the network that has a DC
`
`power supply where the voltage provided by the power supply is modulated to
`
`provide “both status information and power” across the transmit and/or receive lines
`
`to a remote module on the network. ’107 5:64-67. The specification discloses that
`
`a remote module can send information to the central module by altering the total
`
`current draw by the remote module. ’107 6:16-19. Crayford ¶ 46.
`
`
`2 Emphasis added to quotes unless otherwise indicated.
`
`3
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`
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`The specification discloses embodiments that purport to provide an improved
`
`system for “asset tracking and management,” including monitoring and identifying
`
`“asset movement” and “theft.” ’107 1:20-3:14. Patent Owner, however, is
`
`attempting to apply the claims of the ’107 patent as covering scope beyond asset
`
`tracking and management and the disclosed embodiments. For instance, Patent
`
`Owner has taken the position that the claims of the ’107 patent read on the 802.3af
`
`Power over Ethernet (“PoE standard”). See Ex. 1015 ¶¶ 17- 18; Ex. 1012. Patent
`
`Owner has filed various lawsuits—including against Petitioner—interpreting the
`
`Challenged Claims of the ’107 Patent to broadly cover network switches that deliver
`
`power to a remote device over Ethernet. Id. Crayford ¶ 47.
`
`As will be shown in this Petition, the basic concepts of supplying power
`
`from a DC power supply over the same conductors over which data is
`
`communicated, known as “phantom” powering, was well known decades before
`
`the alleged invention of the ’107 patent. See Ground 2 (discussing Bloch patent,
`
`issued in 1979). And by the time of the alleged invention, providing DC power in
`
`this manner over the same conductors used for Ethernet communication was also
`
`well known. See Ground 2 (discussing Hunter International Patent application,
`
`published in 1996, and IEEE specifications from 1993 and 1995). It was also
`
`well known at the time of the alleged invention to convey information from one
`
`piece of equipment to another by modulating the voltage provided by the DC
`
`4
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`power supply or by modulating the current drawn from the power supply over the
`
`same conductors used for normal network communication, such as Ethernet. See
`
`Ground 1 (Hunter and Bulan references), Ground 2 (Bloch patent). Crayford ¶ 48.
`
`Level of Ordinary Skill
`
`A person of ordinary skill in the art at the time of the alleged invention
`
`would have had at least a B.S. degree in electrical engineering or computer
`
`science, or the equivalent, and at least three years of experience in the design of
`
`network communication products. Crayford ¶ 49-51
`
`III. Claim Construction
`A claim in IPR is given the broadest reasonable interpretation (“BRI”) in
`
`light of the specification to a person having ordinary skill in the art. Cuozzo Speed
`
`Tech., LLC v. Lee, 2016 U.S. Lexis 3927 (2016).
`
`“powered off”; “powered-off Ethernet terminal equipment”; “powered-
`
`off end device” (’107 Patent, Claims 103, 104, 111, 123, 125): The BRI of this
`
`term is “without operating power” because claim 104 recites “the powered-off
`
`end device to draw different magnitudes of DC current flow” indicating that
`
`“powered-off” does not mean entirely removed from the application of power.
`
`Crayford ¶ 52-55.
`
`“BaseT” (claim 5): Claim 5 recites “BaseT Ethernet communication
`
`signals.” “BaseT” should be construed as “10BASE-T and 100BASE-T.” The ’107
`
`5
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`
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`patent consistently uses the term “BaseT” as part of the larger phrase “10BASE-
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`T.” ’107 12:19-29. The ’107 patent references “existing Ethernet communications”
`
`and equivalents thereof, which would include 100BASE-T at the time of the
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`purported invention. ’107 3:40-42, Ex. 1007 (IEEE-95) at 2 (“Type 100BASE-T”).
`
`Crayford ¶ 54.
`
`Petitioner notes that claim construction in inter partes review is broader
`
`than in litigation. Thus, nothing in this Petition should be taken as an assertion
`
`regarding how the claims should be construed in litigation. Moreover, nothing
`
`should be construed as expressing any position as to whether the claims constitute
`
`patentable subject matter under 35 U.S.C. § 101, or whether they satisfy the
`
`definiteness, enablement, best mode, or written description requirements of 35
`
`U.S.C. § 112.
`
`IV.
`Identification of Challenge (37 C.F.R. § 42.104(b)) and Reasonable
`Likelihood That the Challenged Claims Are Unpatentable
`Petitioner requests institution of an IPR and cancellation of the Challenged
`
`Claims of the '107 patent based on the following grounds:
`
`•
`
`Ground 1: Under
`
`35 U.S.C. § 103(a), the Challenged Claims are
`
`obvious based on WO 96/23377 (“Hunter”) (Ex. 1003) in view of U.S.
`
`Patent No. 5,089,927 (“Bulan”) (Ex. 1004).
`
`•
`
`Ground 2: Under 35 U.S.C. § 103(a), the Challenged Claims are obvious
`
`based on U.S. Patent No. 4,173,714 (“Bloch”) (Ex. 1005) in view of
`
`6
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`U.S. Patent 4,046,972 (“Huizinga”) (Ex. 1009) and IEEE 802.3 (1993
`
`and 1995) (Exs. 1006-1008).
`
`Ground 1 is not redundant to Ground 2. In Ground 1, Hunter (1996)
`
`discloses phantom power over an Ethernet network, which when combined with
`
`the current control apparatus of Bulan satisfies the claim limitations. In Ground 2,
`
`the Bloch (1979) reference, teaches a system that closely tracks the preferred
`
`embodiment of the ’107 patent, including the current modulation technique
`
`discussed above in Section II.A. It does so, however, in a telephone network
`
`rather than Ethernet (which was developed four years later, in 1983). When
`
`combined with the teachings of the Ethernet specifications (1993 and 1995), it
`
`reads on the embodiment of the specification of the ’107 patent. Crayford ¶ 62.
`
` Ground 1: The Challenged Claims Are Obvious Based on Hunter
`in View of Bulan.
`The Challenged Claims are obvious over Hunter in view of Bulan for the
`
`reasons below. Crayford ¶ 63. Hunter and Bulan are prior art because their filing
`
`dates (January 26, 1996 and October 12, 1989, respectively) predate the earliest
`
`7
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`
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`possible priority date of the '107 patent. Hunter is cited on the face of the
`
`'107 patent but not was not discussed during prosecution. Bulan does not appear
`
`to have been cited or discussed during prosecution.
`
`1. Overview of Hunter in View of Bulan
`Hunter discloses a system for supplying DC “phantom power” over an
`
`Ethernet cable from a central piece of networking equipment (hereafter “Hub”) to a
`
`remote piece of terminal equipment (hereafter “TE”). Hunter Abstract, 37:20-28
`
`(“10Base-T” Ethernet), 51 (“Ethernet®”; “100Base-T” Ethernet; “isoEthernet®”).
`
`The phantom power is supplied over the same twisted-pair conductors in the
`
`Ethernet cable that are used to carry data between the Hub and the TE. Hunter
`
`37:20-28. The Hub includes a “protective device 213” (such as “a thermistor or
`
`polyfuse”) to protect against “overcurrents” in the DC current flow from the Hub
`
`to the TE. Hunter 38:12-19. Crayford ¶ 64.
`
`8
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`
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`
`
`PETITION FIGURE 1
`
`
`
`Hunter Fig. 2 (markings added), 31:9-11(“phantom powering subsystem”),
`
`32:5- 15 (“hubs”). Crayford ¶ 65.
`
`Bulan discloses an improved protective device (“current control apparatus”)
`
`for use in phantom-powered network systems like Hunter, and this device would
`
`replace the existing protective device of Hunter. Bulan 1:65-2:26, Abstract
`
`(“effective overcurrent protection”), 4:2-10 (“well known phantom power feed
`
`arrangement”). Crayford ¶ 66.
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`9
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`
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`
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`PETITION FIGURE 2
`
`
`
`Bulan Fig. 2 (“current control apparatus”), 4:20-42 (circuit).
`
`Reasons to Combine Hunter and Bulan
`
`Bulan is directed to systems for phantom powering network terminal
`
`equipment, and Hunter discloses such a system. Hunter Abstract (“[P]ower
`
`subsytem and method for providing phantom power … via a computer network
`
`bus”), 36:12-15 (“[P]ositive and negative outputs … of the power supply ... are
`
`coupled to the center taps 224, 234 of the windings ... of the first and second
`
`transformers”), Fig. 2; Bulan 4:7-10 (“Power terminals ... are connected to centre
`
`taps 16 and 17 of the transformer windings 11 in a well known phantom power
`
`feed arrangement.”),3 Fig. 1. Hunter and Bulan disclose similar terminal
`
`equipment that could be phantom powered, and similar levels of DC voltage.
`
`Hunter 23:19-21 (TE may be “an Integrated Services Terminal Equipment ('ISTE')
`
`
`3 Emphasis added to quotes here and below unless otherwise indicated.
`
`10
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`device” that is “compatible with ISDN standards”), 23:9 (“power is supplied at
`
`about 48V”); Bulan Abstract (“Integrated Services Digital Network (ISDN)
`
`terminal equipments (TEs)”), 1:49-50 (“power source, at a potential of about 50
`
`volts”). Crayford ¶ 67.
`
`Bulan is intended to provide a superior replacement for the “typical current
`
`limiting circuit” in such phantom powering systems, and Hunter employs just such a
`
`current limiting circuit: i.e., its “protective device 213.” Bulan 1:65-2:14; Hunter
`
`38:12-15. Hunter's protective device 213 is “preferably a thermistor or polyfuse”
`
`that protects from “overcurrents that may damage” the “power supply 210 and the
`
`bus.” Hunter 38:15-19. Crayford ¶ 68.
`
`Bulan criticizes the “typical current limiting circuit” as “inappropriate for
`
`operation throughout the whole current load regime” because it fails to distinguish
`
`between two conditions: (1) overcurrents resulting from “unintended operational
`
`faults, for example ... short circuits”; and (2) “a normal power up event in a TE”
`
`that contains a “DC to DC converter” (hereafter “DC-DC”). Bulan 1:26-31, 1:52-
`
`2:1. To “initiate operation of the typical DC to DC converter” in a TE, a “surge of
`
`current” is required that “may exceed an ampere for as much as ten milliseconds,”
`
`and this normal surge of current may “mimic” an operational fault. See Bulan
`
`1:52-65, Abstract. Crayford ¶ 69.
`
`Because the “typical current limiting circuit” applies the same current limit
`
`11
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`to both conditions, it either sets the limit so low that “there will be insufficient
`
`current for start up of the DC to DC converter,” or sets the limit so high that “a
`
`fault may be permitted to draw current for a period of time sufficient to seriously
`
`jeopardize the operations of ... the line power source circuits [in the Hub]”). Bulan
`
`1:66-2:8. Crayford ¶ 70.
`
`Hunter’s protective device 213 suffers from this same deficiency, because a
`
`“thermistor or polyfuse” cannot respond differently to the two conditions. See
`
`Hunter 38:12-19; Crayford ¶ 71.
`
`Bulan's “current control apparatus” solves this dilemma in the typical current
`
`limiting circuit (such as Hunter's) by distinguishing between operational faults and
`
`DC-DC startups. Bulan 1:28-29, 1:57-2:23. When the Bulan apparatus detects an
`
`overcurrent condition, it switches a high impedance resistor into the path to protect
`
`the circuitry: this forces the current down to a safe “trickle” level. Bulan 4:20-25
`
`(“current sensor 26”; “current path switch 25”), 4:35-40, 4:63-68 (“small trickle
`
`of current”). If the overcurrent was caused by an operational fault, current will
`
`continue to be drawn at this “trickle” level indefinitely until the fault is resolved—
`
`and the high impedance will continue to remain in place to protect the circuitry.
`
`See Bulan 6:44-46. If, however, the overcurrent was caused by a DC-DC trying
`
`and failing to start up, the resulting “open circuit” condition will be detected by the
`
`absence of “trickle” current. Bulan 6:43-51. Hence the Bulan apparatus can
`
`12
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`Petition for Inter Partes Review of U.S. Patent No. 8,942,107
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`detect the failure of the DC-DC to start up, and it switches the high impedance
`
`resistor out of the path so the TE's DC-DC can resume starting up. Bulan 6:47-
`
`58, 7:7-13. The operation of Bulan's current control apparatus is discussed in
`
`greater detail below. See Overview(c-d)4; Crayford ¶ 72.
`
`A PHOSITA would recognize that the Hunter system could be used to
`
`supply phantom power to TE's containing DC-DC's, and would conclude the
`
`Bulan current control apparatus would be a superior alternative to Hunter's
`
`protective device 213. Bulan 1:52-65 (“A typical TE includes a ... DC to DC
`
`converter” which requires a “surge of current” to “initiate operation”); Hunter
`
`39:5-8 (similarly indicating the presence of a DC-DC in the TE: “DC-DC
`
`converters … readily commercially available.”). Crayford ¶ 73.
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`Replacement of Hunter's protective device 213 with Bulan's “current control
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`apparatus” would be a particularly straightforward task for a PHOSITA with a
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`more than reasonable expectation of success, since the Bulan appartus is intended
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`to simply replace prior art current limiting circuits without further modification. See
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`Bulan 2:23-26 (“The current control apparatus is for connection in series between
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`the power source and the transmission line”); Hunter Fig. 2 (protective device
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`213 in series between phantom power source 210 and transmission
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`line);
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`4 Citations to "Overview" in Ground 1 are to § IV.A.1.
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`Crayford ¶ 74. Both Hunter and Bulan assume there is a separate protective
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`device in the Hub to regulate the current to each separate TE, making the
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`combination a simple one-for-one replacement. Hunter Fig. 2 (protective device
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`213 in series to single remote “ISTE”); Bulan Fig. 1 (each “NT1” in Hub
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`connected to a single remote TE device), 4:17-25 (“Each of the NT1s includes a
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`line interface circuit” that includes the current control apparatus of the invention).
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`Replacing protective device 213 in Hunter with Bulan's apparatus is the
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`simple substitution of one known element with another to yield a predictable
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`result (a Hub equipped with a protective device that can distinguish between faults
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`and DC-DC startups). Moreover, this replacement is merely the use of a known
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`technique (Bulan's current control technique) to improve a similar device ready
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`for improvement (Hub supplying phantom power to network terminal equipment)
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`to yield a predictable result (Hub with more intelligent current limiting system).
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`Crayford ¶ 75. See also MPEP 2143 (exemplary obviousness rationales based on
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`KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421 (2007)).
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`The Combined System of Hunter and Bulan
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`In the combined system, Bulan's current control apparatus simply replaces
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`the existing “protective device 213” of Hunter, and DC current and power continue
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`to flow through the phantom power circuit unchanged, as shown below:
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`PETITION FIGURE 3
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`
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`Hunter Fig. 2 (modified to substitute current control apparatus in Fig. 2 of
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`Bulan for Hunter's existing protective device 213, annotations added); Crayford ¶ 77.
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` Operation of Bulan's Current Control Apparatus
`The operation of Bulan's “current control apparatus” is detailed here. Bulan
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`teaches that the current control apparatus (depicted in Bulan Fig. 2) includes a
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`“current sensor 26” that continuously monitors the level of DC current in the
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`path that loops from the positive terminal of the Hub's phantom power supply to
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`the TE and back to the negative terminal of the power supply. Petition Figure 2
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`(current sensor 26); Bulan 2:26-28 (“means for generating a magnitude signal
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`being representative of an amount of said energizing direct current flow”), 4:20-33
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`(“current sensor 26”), 4:49-50 (“current sensing device”). Crayford ¶ 78.
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`Bulan generates two current level signals internally for use with the current
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`sensor; these “control signals” are references against which the current level
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`sensed by the current sensor can be compared:
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`(1) A “static control signal” (also referred to herein as “static signal”
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`or “static limit”) is generated by “static reference generator 23.” Bulan 3:5-6, 4:25-
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`26, 5:16-31 (internal circuitry), Fig. 5 (circuit diagram). This static signal is
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`unchanging, and it defines the “maximum limit of load current” which should
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`normally be drawn by the TE. Bulan 3:5-6, 2:2, 7:6 (“normal operating current”),
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`5:16-18 (“static reference generator ... is used to provide a stable voltage supply –
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`V1 and a reference voltage V REF-”). When the current level sensed by the
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`current sensor rises above this “static” level, an overcurrent condition of some
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`kind is indicated. See Bulan 2:24-36, 3:5-12; Crayford ¶ 80.
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`(2) A “dynamic control signal” (also referred to herein as “dynamic
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`signal” or “dynamic limit”) is generated by “dynamic reference generator 24.” Bulan
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`3:7- 12, 4:27, 5:6-15 (internal circuitry), Fig. 4 (circuit diagram). The dynamic
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`signal is normally set at the unchanging static level, but when the sensed current
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`exceeds the static limit indicating an overcurrent condition, the dynamic signal is
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`temporarily boosted to define a higher “maximum limit of the inrush current.”
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`Bulan 3:7-12, 5:33-44 (“in an event where the sense voltage (50) becomes greater
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`than the potential of [static] V REF- ....”), 5:66-6:2 (“control signal at the output
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`60 is therefore a static level as determined by the potential at junction 60t, unless
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`the potential is over-ridden by the dynamic level switched ... to the output 60”);
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`Crayford ¶ 81.
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`Once boosted (because sensed current exceeded the static limit), the
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`dynamic signal does not remain indefinitely at the higher level; rather it
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`“decay[s]” over time in a manner defined by the “RC value” of the dynamic
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`reference generator's resistor/capacitor (R/C) circuit. Bulan 5:44-46; Crayford
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`¶ 82. This decay is shown in the following figure from Bulan.
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`PETITION FIGURE 4
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`
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`Bulan Fig. 6, 6:59-60, 6:65-7:1 (“Assuming an inrush of current ... , the
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`
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`maximum permissible limit [dynamic signal] rises abruptly to a peak whereafter
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`the limit is reduced exponentially in accordance with the RC time constant”). And
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`“if at any time during the decay portion the [current] sense signal becomes less
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`than the potential of [static] V REF-,” the decaying control signal is “terminate[d]”
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`(and the dynamic signal resets to the static level). Bulan 5:52-55, 7:2-7; Crayford ¶
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`83.
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`Bulan's dynamic signal imposes a decaying inrush current maximum in this
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`manner because if the inrush current is merely the result of a DC-DC startup, then
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`the current drawn should be expected to decline over time as the DC-DC completes
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`its startup. See Bulan 1:57-62 (“momentary surge of current” is “that which is
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`required to initiate operation of the typical DC to DC converter”). On the other hand,
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`if the inrush is caused by an “unintended operational fault[]” such as a “short
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`circuit[],” then the overcurrent condition will continue indefinitely until resolved,
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`and hence it would be certain to violate the decaying dynamic limit eventually
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`(as intended). See Bulan 1:27-30, 6:44-47; Crayford ¶ 84.
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`When the current detected by current sensor 26 exceeds the dynamic limit, a
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`“current path switch 25” in the Bulan apparatus switches a high impedance
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`(resistor 48 in Bulan Fig. 3) into the current path. Petition Figure 2; Bulan 4:24-
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`25, 4:35-40 (“The current path switch is required to provide a current path which
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`at any one time is of a very low impedance, or alternately is of a much higher
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`impedance”), 6:36-44 (“if the sensed current exceeds the [dynamic] control signal
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`permissible level ….. FET 41 [is] locked OFF”). The addition of this high
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`impedance to the path forces the current down to a safe “trickle” level, thereby
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`protecting the power supply in the Hub from the overcurrent condition. See Bulan
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`4:62-66, 6:43-44 (“the trickle current is conducted via the current path 9d.”), Fig. 3
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`(circuit diagram including trickle path 9d), 1:28-31 (“limiting current flow in the
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`interest of preventing catastrophic failure”); Crayford ¶ 85.
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`Bulan teaches that “[t]his [high impedance path] condition is maintained
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`until an effective external open condition is established.” Bulan 6:44-47, 4:62-68.
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`If the overcurrent was caused by a genuine “unintended operational fault[]” such
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`as a “short circuit[],” there will not be an open circuit and the TE will continue to
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`draw trickle current indefinitely until the fault is resolved—and the high
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`impedance will therefore remain in the path. See Bulan 1:28-29, 6:44-47, 4:62-67.
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`If, on the other hand, the