UNITED STATES PATENT AND TRADEMARK OFFICE
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`
`Ruckus Wireless, Inc., Brocade Communication
`Systems, Inc. and Netgear, Inc.,
`Petitioners
`v.
`ChriMar Systems, Inc.,
`Patent Owner
`
`
`PETITION FOR INTER PARTES REVIEW
`OF U.S. PATENT NO. 8,902,760
`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
`
`
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`
`Ruckus Wireless, Inc., Brocade Communication
`Systems, Inc. and Netgear, Inc.,
`Petitioners
`v.
`ChriMar Systems, Inc.,
`Patent Owner
`
`
`PETITION FOR INTER PARTES REVIEW
`OF U.S. PATENT NO. 8,902,760
`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
`
`
`
`
`
`TABLE OF CONTENTS
`
`I.
`II.
`
`Page
`Mandatory Notices (37 C.F.R. § 42.8) ............................................................ 1
`Relevant Background on the ’760 Patent ........................................................ 3
`A. Description of the Alleged Invention of the ’760 Patent ...................... 3
`B.
`Level of Ordinary Skill ......................................................................... 5
`III. Claim Construction .......................................................................................... 6
`IV.
`Identification of Challenge (37 C.F.R. § 42.104(b)) and Reasonable
`Likelihood That the Challenged Claims Are Unpatentable ............................ 7
`A. Ground 1: The Challenged Claims Are Obvious Based on
`Hunter in View of Bulan. ...................................................................... 8
`1.
`Overview of Hunter in View of Bulan ........................................ 8
`a.
`Reasons to Combine Hunter and Bulan .......................... 10
`b.
`The Combined System of Hunter and Bulan .................. 15
`c.
`Operation of Bulan’s Current Control Apparatus .......... 16
`d.
`Hunter in View of Bulan: Step-by-Step ........................ 22
`Application of Hunter in View of Bulan .................................. 24
`a.
`Independent Claim 1 ....................................................... 24
`b.
`Dependent Claim 31 ....................................................... 34
`c.
`Dependent Claim 37 ....................................................... 35
`d.
`Dependent Claim 59 ....................................................... 37
`e.
`Dependent Claim 69 ....................................................... 37
`f.
`Dependent Claim 72 ....................................................... 39
`g.
`Independent Claim 73 ..................................................... 41
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`2.
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`B.
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`V.
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`e.
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`2.
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`Dependent Claims 106, 112, 134, 142, and 145 ............. 41
`h.
`Ground 2: The Challenged Claims Are Obvious Based on
`Bloch in View of Huizinga and IEEE 802.3. ...................................... 41
`1.
`Overview of Bloch in View of Huizinga and IEEE 802.3 ....... 42
`a.
`Overview of Bloch .......................................................... 42
`b.
`Overview of Huizinga .................................................... 47
`c.
`Overview of IEEE 802.3 (IEEE-93 and IEEE-95) ......... 48
`d.
`The Combined System of Bloch, Huizinga, and
`IEEE 802.3 ...................................................................... 50
`Reasons to Combine Bloch, Huizinga and IEEE
`802.3 ............................................................................... 51
`Application of Bloch in View of Huizinga and IEEE 802.3 .... 53
`a.
`Independent Claim 1 ....................................................... 53
`b.
`Dependent Claim 31 ....................................................... 60
`c.
`Dependent Claim 37 ....................................................... 61
`d.
`Dependent Claim 59 ....................................................... 61
`e.
`Dependent Claim 69 ....................................................... 62
`f.
`Dependent Claim 72 ....................................................... 63
`g.
`Independent Claim 73 ..................................................... 64
`h.
`Dependent Claims 106, 112, 134, 142, and 145 ............. 65
`Conclusion ..................................................................................................... 65
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`ii
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`Petition for Inter Partes Review of U.S. Patent No. 8,902,760
`
`Number
`1001
`
`1002
`1003
`1004
`1005
`1006
`
`10071
`1008
`1009
`1010
`
`Short Name
`’760 patent, or ’760
`
`Crayford
`Hunter
`Bulan
`Bloch
`IEEE-1993
`
`IEEE-1995 (part 1)
`IEEE-1995 (part 2)
`Huizinga
`Blacharski
`
`LIST OF EXHIBITS
`Description
`U.S. Patent 8,902,760 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 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
`8,902,760
`Resume of Ian Crayford
`
`1011
`
`Katz
`
`1012
`
`1013
`
`Related Matters
`
`Crayford CV
`
`
`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.
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`Petition for Inter Partes Review of U.S. Patent No. 8,902,760
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`Number
`1014
`
`Short Name
`IEEE Press Release
`
`1015
`
`Complaint
`
`1016
`1017
`1018
`
`’058 patent
`’152 patent
`Complaint
`
`Description
`Shuang Yu, IEEE 802.3 “Standard for
`Ethernet” Marks 30 Years of Innovation
`and Global Market Growth, IEEE Press
`Release, June 24, 2013
`Chrimar Systems, Inc. et al. v. Ruckus
`Wireless, Inc., Case No. 3:16-cv-00186-SI
`(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. Netgear,
`Inc., Case No. 3:16-cv-00624-SI (N.D.
`Cal.), Dkt. No. 1.
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`Petition for Inter Partes Review of U.S. Patent No. 8,902,760
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`Ruckus Wireless, Inc., Brocade Communication Systems, Inc. and Netgear,
`
`Inc. (“Petitioners”) request inter partes review (“IPR”) of claims 1, 31, 37, 59, 69,
`
`72, 73, 106, 112, 134, 142, and 145 of U.S. Patent No. 8,902,760 (“the ’760 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)): Petitioners are the real parties-in-
`
`interest. No unnamed entity is funding, controlling, or otherwise has an opportunity
`
`to control or direct this Petition or Petitioners’ participation in any resulting IPR.
`
`Related Matters (§ 42.8(b)(2)): The ’760 patent is the subject of 46 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. Ruckus Wireless,
`
`Inc., Case No 3:16-cv-00186-SI (N.D. Cal.) and Chrimar Systems Inc., et al. v.
`
`Netgear, Inc., Case No 3:16-cv-00624-SI (N.D. Cal.). The ’760 patent is also the
`
`subject of instituted IPR2016-00574 and -01399 and pending in IPR2016-01759.
`
`IPRs have also been filed on related U.S. Patent Nos. 8,942,107, 8,115,012, and
`
`8,019,838. IPR2016-00569, -00983, -01151, -01389, -01397, -01425, -01426, -
`
`1757, and -01758. These cases may affect, or be affected by, decisions in this
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`proceeding.
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`Petition for Inter Partes Review of U.S. Patent No. 8,902,760
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`Concurrent with the filing of this Petition, Petitioners are also filing a Petition
`
`for the related ‘107 Patent and ‘838 Patent.
`
`Standing (§ 4.104(a)): Petitioners certify that this patent is eligible for inter
`
`partes review and that none of them are barred or estopped from requesting inter
`
`partes review of the Challenged Claims on the grounds identified herein because
`
`this petition is accompanied by a motion for joinder. The one-year time bar of 35
`
`U.S.C. §315(b) does not apply to a request for joinder. 35 U.S.C. § 315(b) (final
`
`sentence) (“[t]he time limitation set forth in the preceding sentence shall not apply
`
`to a request for joinder under subsection (c)”); 37 C.F.R. § 42.122(b).
`
`Designation of Lead and Back-Up Counsel and Service Information
`
`(§§ 42.8(b)(3)-(4)):
`
`Lead Counsel
`Joseph Powers (Reg. No. 47,006)
`Duane Morris LLP
`30 South 17th Street
`Philadelphia PA 19103-4196
`Tel: 215-979-1842
`Fax: 215-689-3797
`JAPowers@duanemorris.com
`
`Back-up Counsel
`Christopher Tyson (Reg. No. 63,850)
`Duane Morris LLP
`505 9th St. NW, Ste 1000
`Washington DC 20004
`Tel: 202-776-7851
`Fax: 202-776-7801
`CJTyson@duanemorris.com2
`
`
`2 Petitioners request authorization to file a motion for Matthew Yungwirth to
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`appear pro hac vice, as Mr. Yungwirth is an experienced attorney who is counsel for
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`Petitioners Ruckus Wireless, Inc. and Netgear, Inc. in the concurrent litigation and
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`has established familiarity with the subject matter at issue.
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`Petition for Inter Partes Review of U.S. Patent No. 8,902,760
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`Pursuant to 37 C.F.R. § 42.10(b), a Power of Attorney accompanies this
`
`Petition. Please address all correspondence to lead and back-up counsel. Petitioners
`
`also consent to electronic service by email to lead and back-up counsel.
`
`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. 04-1679,
`
`referencing Docket No. G1543-00002 (’760 IPR).
`
`II. Relevant Background on the ’760 Patent
`A. Description of the Alleged Invention of the ’760 Patent
`The ’760 patent issued from Application No. 13/615,755 (“the ’755
`
`application”), which was filed on Sept. 26, 2008. The ’760 patent claims the benefit
`
`of Provisional Patent Application No. 60/081,279, filed Apr. 10, 1998. Ex. 1002
`
`(“Crayford”) ¶ 44.
`
`The ’760 patent explains that it is directed to equipment networked over “pre-
`
`existing wiring or cables that connect pieces of networked computer equipment to a
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`network.” ’760 3:23-27, 4:62-66. The ’760 patent acknowledges that at the time of
`
`the alleged invention, “existing Ethernet communications” and equivalents thereof
`
`were known. ’760 3:40-42, 5:20-24 (“Ethernet, Token Ring, or ATM”). The ’760
`
`patent provides examples of networked equipment including personal computers and
`
`telephones connected to a hub in a network. ’760 4:66-5:3. The equipment would
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`be connected over “conventional multi-wire cables that include a plurality of
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`transmit and receive data communication links.”3 ’760 5:12-19, 5:26-30 (“a pair of
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`transmit wires”; “a pair of receive wires”). Crayford ¶ 45.
`
`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
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`to a remote module on the network. ’760 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. ’760 6:16-19. Crayford ¶ 46.
`
`The specification discloses embodiments that purport to provide an improved
`
`system for “asset tracking and management,” including monitoring and identifying
`
`“asset movement” and “theft.” ’760 1:20-3:14 (Background). Patent Owner,
`
`however, is attempting to apply the claims of the ’760 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 ’760 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 two of the
`
`Petitioners—interpreting the challenged claims of the ’760 Patent to broadly cover
`
`
`3 Unless stated otherwise, emphasis to quotations have been added.
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`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,
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`known as “phantom” powering, was well known decades before the alleged
`
`invention of the ’760 patent. See Ground 2 (discussing Bloch patent, issued in 1979).
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`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
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`IEEE specifications from 1993 and 1995). It was also well known at the time of the
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`alleged invention to convey information from one piece of equipment to another by
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`modulating the voltage provided by the DC power supply or by modulating the
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`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.
`
`B.
`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
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`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.,
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`LLC v. Lee, 2016 U.S. Lexis 3927 (2016).
`
`“powered off” (’760 Patent, Claims 72, 145): The BRI of this term is
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`“without operating power” because claims 72, depending from 1, recites that the
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`“powered-off piece of BaseT Ethernet equipment” is to “draw different magnitudes
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`of current flow from the at least one DC supply” and this indicates that “powered-
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`off” does not mean entirely removed from the application of power. Crayford ¶ 54.
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`“BaseT” (’760, challenged claims): The challenged claims recites “BaseT
`
`Ethernet” to describe the recited elements such as a system, central equipment,
`
`terminal equipment, and communication signals. “BaseT” should be construed as
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`“10BASE-T and 100BASE-T.” The ’760 patent consistently uses the term “BaseT”
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`as part of the larger phrase “10BASE-T. ’760 12:22-26. The ’760 patent references
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`“existing Ethernet communications” and equivalents thereof, which would include
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`100BASE-T at the time of the purported invention. ’760 3:41-43, Ex. 1007 (IEEE-
`
`95) at 2 (“Type 100BASE-T”). Crayford ¶ 55.
`
`Petitioners note 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
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`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
`Petitioners request institution of an IPR and cancellation of the challenged
`
`claims of the ’760 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
`
`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 ’760 patent, including the current modulation technique discussed above in
`
`§ 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
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`Ethernet specifications (1993 and 1995), it reads on the embodiment of the
`
`specification of the ’760 patent. Crayford ¶ 63.
`
`A. 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 ¶¶ 64-134. Hunter and Bulan are prior art because their
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`filing dates (January 26, 1996 and October 12, 1989, respectively) predate the
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`earliest possible priority date of the ’760 patent. Hunter is cited on the face of the
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`’760 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
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`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
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`(“10Base-T” Ethernet), 51 (“Ethernet®”; “100Base-T” Ethernet; “isoEthernet®”).
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`The phantom power is supplied over the same twisted-pair conductors in the
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`Ethernet cable that are used to carry data between the Hub and the TE. Hunter 37:20-
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`28. The Hub includes a “protective device 213” (such as “a thermistor or polyfuse”)
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`to protect against “overcurrents” in the DC current flow from the Hub to the TE.
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`Hunter 38:12-19.
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`PETITION FIGURE 1
`
`
`Hunter Fig. 2 (markings added), 31:9-11 (Fig. 2 illustrates “phantom powering
`
`subsystem”), 32:5-15 (“hubs”). Crayford ¶¶ 65-66.
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`Bulan discloses an improved protective device (“current control apparatus”)
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`intended for use in phantom-powered network systems such as Hunter, and this
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`improved device would simply replace the existing protective device 213 of Hunter.
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`Bulan 1:65-2:26, Abstract (“effective overcurrent protection”), 4:2-10 (“well known
`
`phantom power feed arrangement,” where power supplied over same wire pairs used
`
`to send data). Crayford ¶ 67.
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`PETITION FIGURE 2
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`
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`Bulan Fig. 2 (“current control apparatus”), 4:20-42 (circuit).
`
`a.
`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 (“A power
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`subsytem and method for providing phantom power... via a computer network bus”),
`
`36:12-15 (“The positive 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.”),4
`
`Fig. 1. Hunter and Bulan disclose similar examples of terminal equipment that could
`
`be phantom powered, and similar levels of DC voltage. Hunter 23:19-21 (TE may
`
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`4 Emphasis added to quotes unless otherwise indicated.
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`be “an Integrated Services Terminal Equipment (‘ISTE’) device” that is “compatible
`
`with ISDN standards”), 23:9 (“power is supplied at about 48V”); Bulan Abstract
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`(“Integrated Services Digital Network (ISDN) terminal equipments (TEs)”), 1:50
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`(“about 50 volts”). Crayford ¶ 68.
`
`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 ¶ 69.
`
`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 that result 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 (“mimic”).
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`Petition for Inter Partes Review of U.S. Patent No. 8,902,760
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`Because the “typical current limiting circuit” must blindly apply the same
`
`current limit to both conditions, it must either set 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.
`
`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 ¶¶ 70-72.
`
`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 resistor 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
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`absence of “trickle” current. Bulan 6:43-51. Hence the Bulan apparatus can detect
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`the failure of the DC-DC to start up, and it switches the high impedance resistor out
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`of the path so the TE’s DC-DC can resume starting up. Bulan 6:47-58, 7:7-13. The
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`operation of Bulan’s current control apparatus is discussed in greater detail below.
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`See Overview(c-d)5.
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`A PHOSITA would recognize that the Hunter system could be used to supply
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`phantom power to TE’s containing DC-DC’s, and would therefore conclude the
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`Bulan current control apparatus would be a superior alternative to Hunter’s existing
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`protective device 213. Bulan 1:52-65 (“A typical TE includes a... DC to DC
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`converter” which requires a “surge of current” to “initiate operation”); Hunter 39:5-
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`8 (similarly indicating presence of a DC-DC in the TE: “DC-DC converters to
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`convert 48V [supplied by Hunter’s phantom power] to transistor-to-transistor logic
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`(‘TTL’) voltage levels (i.e. 3V or 5V) are also readily commercially available.”).
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`Crayford ¶ 74.
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`Equipped with the Bulan apparatus instead of Hunter’s existing protective
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`device 213, Hunter would no be longer be faced with the dilemma of setting a current
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`limit that was either too low to allow a DC-DC to start up, or too high to prevent
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`damage from faults. Bulan 2:1-8, 2:9-14 (“object of the invention” to “provid[e] an
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`5 Citations to “Overview” in Ground 1 are to § IV.A.1.
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`over current protection feature which is effective across the entire load current
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`regime of the terminal equipment”); Crayford ¶ 75.
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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 more
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`than reasonable expectation of success, since the Bulan apparatus is intended to
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`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 (showing protective
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`device 213 in series between phantom power source 210 and transmission line).
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`Both Hunter and Bulan assume there is a separate protective device in the Hub to
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`regulate the current to each separate TE, making the combination a simple one-for-
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`one replacement. Hunter Fig. 2 (protective device 213 in series to single remote
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`“ISTE”); Bulan Fig. 1 (each “NT1” in Hub connected to a single remote TE device),
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`4:17-25 (“Each of the NT1s includes a line interface circuit” that includes the current
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`control apparatus of the invention). Crayford ¶ 76.
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`Replacing protective device 213 in Hunter with the Bulan apparatus is the
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`simple substitution of one known element (Hunter’s protective device) with another
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`(Bulan’s current control apparatus) to yield a predictable result (a Hub equipped with
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`a protective device that can intelligently distinguish between faults and DC-DC
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`startups). Moreover, this replacement is the use of a known technique (Bulan’s
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`current control technique) to improve a similar device ready for improvement
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`(another Hub supplying phantom power to network terminal equipment) to yield a
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`predictable result (a Hub with a more intelligent current limiting system). Crayford
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`¶ 77. See also MPEP 2143 (obviousness rationales based on KSR Int’l Co. v. Teleflex
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`Inc., 550 U.S. 398, 415-421 (2007)).
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`b.
`The Combined System of Hunter and Bulan
`In the combined system, Bulan’s current control apparatus simply replaces the
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`existing “protective device 213” of Hunter, and DC current and power continue to
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`flow through the phantom power circuit unchanged, as shown below:
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`PETITION FIGURE 3
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`Hunter Fig. 2 (modified to substitute current control apparatus in Fig. 2 of Bulan for
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`Hunter’s existing protective device 213, annotations added in red and blue);
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`Crayford ¶¶ 78-79.
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`c.
`Operation of Bulan’s Current Control Apparatus
`The operation of Bulan’s “current control apparatus” is detailed below.
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`Crayford ¶¶ 80-88. This apparatus includes a “current sensor 26” that continuously
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`monitors the level of DC current in the path that loops from the positive terminal of
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`the Hub’s phantom power supply to the TE and back to the negative terminal of the
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`power supply. Petition Figure 2 (current sensor 26); Bulan 2:26-28 (“means for
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`generating a magnitude signal being representative of an amount of said energizing
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`direct current flow”), 4:20-33 (“current sensor 26”), 4:49-50 (“current sensing
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`device”).
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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 sensed
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`by the current sensor can be compared:
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`(1) A “static control signal” (also referred to herein as “static signal” or
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`“static limit”) is generated by “static reference generator 23.” Bulan 3:5-6, 4:25-26,
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`5:16-31 (internal circuitry), Fig. 5 (circuit diagram). This static signal is unchanging,
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`and it defines the “maximum limit of load current” which should normally be drawn
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`by the TE. Bulan 3:5-6, 2:2, 7:6 (“normal operating current”), 5:16-18 (“static
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`reference generator... is used to provide a stable voltage supply – V1 and a reference
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`voltage V REF-”). When the current level sensed by the current sensor rises above
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`this “static” level, an overcurrent condition of some kind is indicated. See Bulan
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`2:24-36, 3:5-12.
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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.”
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`Bulan 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.” Bulan
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`3:7-12, 5:33-44 (“in an event where the sense voltage (50) becomes greater than the
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`potential of [static] V REF- ....”), 5:66-6:2 (“control signal at the output 60 is
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`therefore a static level as determined by the potential at junction 60t, unless the
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`potential is over-ridden by the dynamic level switched... to the output 60”).
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`Once boosted (because sensed current exceeded the static limit), the dynamic
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`signal does not remain indefinitely at the higher level; rather it “decay[s]” over time
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`in a manner defined by the “RC value” of the dynamic reference generator’s
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`resistor/capacitor (R/C) circuit. Bulan 5:44-46; Crayford ¶ 84. This decay is shown
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`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 maximum
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`permissible limit [dynamic signal] rises abruptly to a peak whereafter the limit is
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`reduced exponentially in accordance with the RC time constant”). And “if at any
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`time during the decay portion the [current] sense signal becomes less than the
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`potential of [static] V REF-,” the decaying control signal is “terminate[d]” (and the
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`dynamic signal resets to the static level). Bulan 5:52-55, 7:2-7.
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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 (as
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`intended). See Bulan 1:27-30, 6:44-47.
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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 4:24-25,
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`4:35-40 (“The current path switch is required to provide a current path which at any
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`one time is of a very low impedance, or alternately is of a much higher impedance”),
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`6:36-44 (“if the sensed current exceeds the [dynamic] control signal permissible
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`level…. FET 41 [is] locked OFF”). The addition of this high impedance to the path
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`forces the current down to a safe “trickle” level, thereby protecting the power supply
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`in the Hub from the overcurrent condition. See Bulan 4:62-66, 6:43-44 (“the trickle
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`current is conducted via the current path 9d.”), Fig. 3 (circuit diagram including
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`trickle path 9d), 1:28-31 (“limiting current flow in the interest of preventing
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`catastrophic
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