`
`
`
`EXHIBIT 1003EXHIBIT 1003
`
`
`
`
`
`
`
`Ulllted States Patent
`
`[19]
`
`[11] Patent Number:
`
`5,991,885
`
`Chang et al.
`
`[45] Date of Patent:
`
`Nov. 23, 1999
`
`US005991885A
`
`[54] METHOD AND APPARATUS FOR
`DETECTING THE PRESENCE OF A
`REMOTE DEVICE AND PROVIDING
`
`POWER THERET0
`
`[75]
`
`Inventors: Wen F. Chang, Saratoga; Fang C. Yu,
`Fremont, both of Calif.
`
`[73] Assignee: Clarinet Systems, Inc., San Jose, Calif.
`
`[21] Appl' No’: 08/872977
`[22]
`Ffled;
`Jun_ 11, 1997
`
`6
`
`[51]
`
`...................................................... .. G06F 1/26
`Int. Cl.
`............................................. ..
`U.S. C].
`[58] Field of Search ....................... .. 395/750.01, 750.08,
`395/200; 713/300; 710/62
`
`[56]
`
`References Cited
`Us. PATENT DOCUMENTS
`
`395/750.02
`9/1998 McKaughan et al.
`.
`5,802,305
`
`9/1998 Jung ......................... .. 395/750.01
`5,805,904
`5,845,150 12/1998 Henion ............................. .. 395/750.08
`
`Primary Examiner—Glenn A. Auve
`Assistant Examiner—DaVid A. Wiley
`Attorney, Agent, or Firm—Gray, Cary, Ware & Freidenrich
`
`[57]
`
`ABSTRACT
`
`.
`A network system includes a network that detects the
`presence of a remote terminal connected to a network and
`determines the functional protocol of the remote terminal. If
`the remote terminal is an infrared adapter, the network hub
`provides electrical power to the infrared adapter and con-
`tinually monitors for the presence of the infrared adapter.
`Upgn remgval Of the infrared adapter, the netwgrk remgves
`electrical power that is applied to a user interface connector
`that connects to the infrared adapter. If another protocol is
`detected for the remote terminal, the network hub commu-
`nicates with the remote terminal in that protocol and con-
`Verts the data to the protocol of the network.
`
`5,652,893
`
`7/1997 Ben—Meir et al.
`
`............... .. 395/750.01
`
`18 Claims, 10 Drawing Sheets
`
`300
`'/\/
`
`320
`
`803
`
`322
`
`324
`\
`
`304
`
`/ 301
`325
`
`"'1
`
`.;2;2a;; .
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`205
`204
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`204
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`
`I
`
`205
`
`205
`
`204
`/ I
`
`204
`
`I
`214
`215 /1;‘
`E ‘W’
`BASE-T
`COMPUTER
`
`216
`
`Z
`212—1
`
`5
`212-2
`
`318
`
`RING
`COMPUTER
`
`{-
`919-3
`
`
`
`U.S. Patent
`
`Nov. 23, 1999
`
`Sheet 1 of 10
`
`5,991,885
`
`HIGHER LAYERS
`
`139
`
`LOGICAL LINI< CDNTRDL
`[|_I_[3)
`I38
`
`LAYER 7-3
`
`LAYER 2
`
`
`
`
`
`‘T/“ MEDIA ACCESS CDNTRDL
`IMACI
`I34
`
`LAYER 1
`
`PHYSIE/J|%I_2LAYER
`
`DATA
`TERMINAL
`EDUIRMENT
`[UTE]
`
`MEDIA
`
`ATTACHMENT
`
`UNIT
`[MM
`142
`J
`
`J
`
`DTE
`
`UNTECRATED
`
`MAUI
`
`I30
`
`MEDIUM DERENDANT
`INTERFACE IMDII
`
`
`
`MEDIUM
`
`FIGURE 1
`
`
`
`U.S. Patent
`
`Nov. 23, 1999
`
`Sheet 2 of 10
`
`5,991,885
`
`
`
`
`
`NETWORK
`
`216
`
`10/1 00
`
`BASE—T
`
`212-1
`
`//
`2122
`
`919-3
`
`FIGURE 2
`
`
`
`U.S. Patent
`
`Nov. 23, 1999
`
`Sheet 3 of 10
`
`5,991,885
`
` 2’|B
`
`10/100
`BASE—T
`
`318
`
`TOKEN
`RING
`
`2’|2—’|
`
`/
`
`212-2
`
`212-3
`
`FIGURE 8
`
`
`
`U.S. Patent
`
`Nov. 23, 1999
`
`Sheet 4 of 10
`
`5,991,885
`
`FIGURE 4a
`
`FIGURE 4b
`
`
`
`U.S. Patent
`
`Nov. 23, 1999
`
`Sheet 5 of 10
`
`5,991,885
`
`FILTER AND
`TRANSFORMER
`
`W 45
`
`(5004
`
`500-2
`
`(500-3
`
`(500-4
`
`500-5
`
`/500-8
`
`/500-7
`
`
`
`
`FILTER AND
`TRANSFORMER
`
`
`MODULE
`
`FIGURE 5a
`
`5008
`®\1O’JU'lJ>CA.'Jl'U-‘-
`
`FILTER AND
`R
`TR/IIIgggLIIET
`
`RJ 45
`CONNECTOR
`
`FILTER AND
`
`
`
`
`TRANSFORMER
`MODULE
`
`FIGURE 5b
`
`I
`
`
`
`U.S. Patent
`
`Nov. 23, 1999
`
`Sheet 6 of 10
`
`5,991,885
`
`FILTER AND
`F” 45
`TRAN F RMER
`CONNECTOR
`MSDBLE
`
`
`504-1
`
`
`
`TRANSFORMER
`
`FILTER AND
`
`MODULE CD\|CDU'lJ>-CJJl'\J-—‘-
`
`/5042
`
`/504-3
`
`504-4
`
`/504-5
`
`/5046
`
`504-7
`
`/504-8
`
`FIGURE 53
`
`
`
`U.S. Patent
`
`Nov. 23, 1999
`
`Sheet 7 of 10
`
`5,991,885
`
`Baa
`
`ESQ/28
`
`mmm%m_u_
`
`
`
`
`U.S. Patent
`
`Nov. 23, 1999
`
`Sheet 8 of 10
`
`5,991,885
`
`.Em<m_9DH3292
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`
`
`
`U.S. Patent
`
`Nov. 23, 1999
`
`Sheet 9 of 10
`
`5,991,885
`
`
`
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`
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`
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`
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`
`
`
`U.S. Patent
`
`Nov. 23, 1999
`
`Sheet 10 of 10
`
`5,991,885
`
`702
`
`704
`
`START
`
`CONNECT NETWORKING
`DATA PATH TO
`
`PROTOCOL HANDLER 2, OR
`
`UP—LINK CONNECTOR.
`
`TURN OFF
`POWER SUPPLY
`
`B40.
`
`OUTPUTS TIMING
`
`SIGNAL
`B15
`
`CONNECT NETWORKING
`
`DATA PATH TO
`
`PROTOCOL HANDLER I,
`
` TURN ON
`POWER SUPPLY
`
`Ei40.
`
` OUTPUTS
`GENERAL PURPOSE SIGNAL
`
`E313
`
`
`
`
` INITIAL
`PRESENCE
`'?
`
`
`
`7OS
`
`YES
`
`
`CONTINUOUS
`PRESENCE
`
`
`
`L__,.T/L
`
`DETECTION
`PHASE
`
`CONNECTION
`PHASE
`
`FIGURE 7
`
`
`
`1
`METHOD AND APPARATUS FOR
`DETECTING THE PRESENCE OF A
`REMOTE DEVICE AND PROVIDING
`POWER THERETO
`
`FIELD OF THE INVENTION
`
`This invention relates to networking systems, and more
`particularly, to network hubs and network interface adapters
`for automatically and continuously detecting the presence of
`a remote adapter coupled to a network twisted-pair cable,
`providing electrical power from a network hub to the remote
`adapter via the network twisted-pair cable, creating a multi-
`protocol networking system, and automatically connecting
`the remote adapter to the appropriate network hub.
`BACKGROUND OF THE INVENTION
`
`When personal computers became sufficiently small to
`allow user portability, it became necessary to provide con-
`nections between a portable computer and a computer
`network system. Traditionally, the portable computer uses a
`Personal Computer Memory Card International Association
`(PCMCIA) card for either an Ethernet or Token Ring
`network hard wire connection.
`
`Recently, both portable computers and computer net-
`works include infrared transceivers that allow wireless com-
`
`munication between the portable computer and the computer
`network for
`increased mobility. The computer network
`includes a protocol conversion bridge that converts commu-
`nicated data between an infrared protocol and a protocol of
`the computer network. The protocol conversion bridge is
`coupled to a connector typically near the user’s work station.
`The connector is then coupled to a network hub that is
`centrally located. A dedicated electrical power supply
`located near the bridge and the infrared transceiver provides
`electrical power to the protocol conversion bridge. The
`dedicated electrical power supply increases the system cost
`and requires an AC electrical power outlet.
`Several systems provide both electrical power and signals
`over a common wire. For example, conventional telephone
`systems that use 48V on a telephone wire transmit both
`electrical power and communication signals over a single
`pair of lines. U.S. Pat. No. 5,444,184 describes a system that
`transmits both electrical power and low baud rate signals
`over the same twisted-pair wires. An attachment unit inter-
`face (AUI) in LAN applications uses dedicated wires in a
`cable to provide electrical power from a data terminal
`equipment (DTE) to an external medium attachment unit
`(MAU) which could be 50 meters away from the DTE. All
`of these systems simply provide electrical power over the
`wires. None of these systems checks or confirms the type of
`system connected thereto before supplying the electrical
`power.
`
`Standard network protocols may be described in an Open
`System Interconnection (OSI) interface standard. One stan-
`dard network protocol is the Ethernet which is described in
`IEEE standard 802.3 CSMA/CD,
`the subject matter of
`which is incorporated by reference in its entirety. Another
`standard network protocol is the Token Ring protocol which
`is described in ANSI/IEEE standard 802.5,
`the subject
`matter of which is incorporated by reference in its entirety.
`Both of these IEEE standards describe the media access
`
`control (MAC) layer and the physical layer of the OSI
`interface.
`
`FIG. 1 is a pictorial view of the interface layers of the OSI
`standard. For simplicity, layer 3 through layer 7 of the OSI
`are combined as higher layers 139. Layer 2 of the OSI
`
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`5,991,885
`
`2
`
`interface comprises the data link control (DLC) which
`includes a logical link control (LLC) layer 138 and a media
`access control (MAC) layer 134. Physical layer 1 of the OSI
`interface comprises several sublayers including an attach-
`ment unit interface (AUI). The AUI is specified for a 10
`Mb/s Ethernet but not for a 100 Mb/s Ethernet. A media
`attachment unit (MAU) 142 includes all of the physical
`sublayers other than signaling and coding sublayer. In a
`twisted-pair cable,
`the medium dependent interface MDI
`144 is an RJ45 connector.
`
`Many conventional network systems detect either layer 1
`or 2 that the data terminal equipment 130 supports. This
`detection allows the network systems to share circuitry,
`connectors, and the medium so that the network systems
`may handle multiple protocols. By sharing, the cost of the
`DTE is reduced and the inconvenience or damage is mini-
`mized when misconnection is made to the wrong connector.
`However, all of these conventional systems presume that the
`DTE conforms to the IEEE Standards. Accordingly, these
`detection systems test only systems that comply with the
`IEEE Standards. Depending on the range of the layers that
`these systems want to detect, the systems require a different
`degree of involvement and resources includes central pro-
`cessing units, software codes and flow, system bus, memory,
`protocol handler, and transceivers. The system also is pro-
`tocol dependent and the DTE must run only the protocols
`that
`the system can understand. The systems are not
`intended, nor do they function to detect an electronic system
`which is not in conformance with IEEE Standards.
`
`U.S. Pat. No. 5,497,460 discloses a detection mechanism
`that allows two different media access control layer proto-
`cols (Ethernet and Token Ring) to share the same connector
`and medium in the OSI model of FIG. 1. The detection
`scheme requires a sophisticated processing unit that issues a
`protocol dependent MAC frame and physical signals and
`compares a predefined status in memory to determine which
`one of the two presumed protocols runs on the twisted-pair
`cable. The detection scheme cannot communicate with any
`device which does not conform with Ethernet or Token
`Ring.
`Under the same Ethernet MAC protocol, U.S. Pat. No.
`5,410,535 describes a device that differentiates between
`mediums that the device is connected to so that the con-
`nected devices may share the same connector. The medium
`in this case could be a twisted-pair cable or AUI for other
`medium types. The control flow and logic manufactured in
`silicon are Ethernet physical layer dependent. U.S. Pat. No.
`5,541,957 includes a separate physical layer logic to allow
`two Ethernet connections operating at different transfer rates
`to share the same connector.
`
`U.S. Pat. No. 5,121,482 describes a device that detects the
`connected device independent of networking protocol. But
`its detection mechanism relies on the impedance of the data
`signal lines, its detection circuitry is also coupled directly to
`the data signal line, which may lead to interference or even
`corruption on the communication link when running the
`detection procedure.
`It is desired to have a network system that recognizes
`remote devices connected to a connector of the network
`
`intruding on the normal
`time without
`system in real
`operation, provides appropriate electrical power as required
`without damaging the connected remote device, and auto-
`matically connects the device to a network hub running an
`appropriate protocol.
`SUMMARY OF THE INVENTION
`
`The present invention provides a detection circuit for
`detecting the presence of a remote device, which may or
`may not be a network device.
`
`
`
`5,991,885
`
`3
`The present invention provides a system for controlling
`the application of electrical power to a detected device. The
`system includes a signal generator and a feedback analyzer.
`The signal generator receives a timing signal, a control
`signal, and a select signal. The signal generator provides a
`presence request signal in response to the select signal being
`in a first
`logic state and provides the control signal
`in
`response to the select signal being in a second logic state.
`The feedback analyzer is coupled to the detected device and
`provides a presence signal in response to the presence signal
`detected from the coupled device being of a predetermined
`type and being coupled to the output of the signal generator.
`The feedback analyzer provides the select signal in a second
`logic state when such a device is detected and provides the
`select signal of a first logic state when such a device is not
`detected. The feedback analyzer controls the application of
`electrical power to the coupled device of a predetermined
`type in response to the present signal.
`The present invention provides a method for applying
`electrical power. At a first detection time, a first device is an
`initiator and applies a symmetric bipolar signal to a second
`device. At a second detection time, a feedback signal from
`the second device, based upon the signal supplied by the first
`device at the first detection time, triggers a comparator and
`indicates the successful connection of the second device to
`
`the first device. Alternatively, the second device may pro-
`vide the feedback signal based on another electrical power
`source and not based on the symmetric bipolar signal. At a
`third detection time,
`the first device supplies a current
`limited electrical power to the second device. At a fourth
`detection time, the second device uses the electrical power
`gained from the first device to sustain its own operation also
`use it to derive the feedback signal to replace the original
`signal that is provided by the first device. At a fifth detection
`time, the first device is freed to remove the applied signal
`state in the first detection time, and use the same line for
`other purpose.
`The present invention provides a network system that
`includes a plurality of user interface connectors and first and
`second network hubs. Each of the plurality of user interface
`connectors is adapted for coupling to a remote device. The
`first network hub communicates on a first operational pro-
`tocol. The second network hub is coupled to the plurality of
`user interface connectors for communicating data between
`devices coupled thereto and is coupled to the first network
`hub. The second network hub identifies the operational
`protocol of a coupled device. When the identified opera-
`tional protocol of the coupled device is a first operational
`protocol,
`the second network hub communicates data
`between the first and second network hubs. When the
`
`identified operational protocol of the coupled device is a
`second operational protocol, the second network hub com-
`municates with said coupled device in a second operational
`protocol and identifies the presence of an adapter of a first
`type coupled to at least one of the plurality of user interface
`connectors and continuously provides electrical power to the
`adapter in response to the identified presence of the adapter.
`The second network hub stops providing electrical power to
`the adapter in response to no identified presence of the
`adapter.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a pictorial view illustrating the interface layers
`of the open system interconnection model.
`FIG. 2 is a block diagram illustrating a network system in
`accordance with the present invention.
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`FIG. 3 is a block diagram illustrating a network system in
`accordance with another embodiment of the present inven-
`tion.
`
`FIG. 4a is block diagram illustrating the network hub of
`the network system of FIG. 2 in accordance of the present
`invention.
`
`FIG. 4b is a block diagram illustrating a network hub of
`the network system of FIG. 3 in accordance with another
`embodiment of the present invention.
`FIG. 5a is a schematic diagram illustrating a conventional
`10Base-T twisted-pair cable connection.
`FIG. 5b is a schematic diagram illustrating a conventional
`100Base-TX twisted-pair cable connection.
`FIG. 5c is a schematic diagram illustrating a conventional
`Token Ring twisted-pair cable connection.
`FIG. 6a is a schematic diagram illustrating a device
`presence detector that is coupled to a remote adapter of a
`first type in accordance with the present invention.
`FIG. 6b is a schematic diagram illustrating a device
`presence detector coupled to a remote adapter of a second
`type in accordance with the present invention.
`FIG. 6c is a schematic diagram illustrating a device
`presence detector coupled to a remote adapter of a third type
`in accordance with the present invention.
`FIG. 7 is a flow diagram illustrating the operation of the
`device presence detector of FIGS. 6a—6c in accordance with
`the present invention.
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`
`invention
`The methods and systems of the present
`instantly and continuously detect the connection status dur-
`ing idle or normal operation of the systems. In one embodi-
`ment of the present
`invention,
`the system, without
`the
`presence of a detected network adapter, assumes a connected
`device uses a specific protocol, such as Ethernet or Token
`Ring. In another embodiment of the present invention, the
`network system is configured for an infrared (IR) adapter or
`Ethernet and not Token Ring. In such a system, a user
`connector of the system functions with either an IR adapter
`or an Ethernet adapter. In another embodiment of the present
`invention,
`the network system is configured for an IR
`adapter or Token Ring, and not for Ethernet. In such a
`system, a user connector of the system functions with either
`an IR adapter or a Token Ring adapter. In yet another
`embodiment of the present invention, the network system is
`configured for an IR adapter, Token Ring, and Ethernet.
`More particularly, the network hub 202 (FIG. 2) and the
`network hub 302 (FIG. 3) of the present invention provide
`the electrical power to the detected device when the pres-
`ence of the detected device is confirmed, and does not
`provide electrical power to the connector and the twisted-
`pair cable when either adapters of another type (such as
`Ethernet 10Base-T, 100Base-TX 100Base-T4, and Token
`Ring adapters) are connected or when no adapter is con-
`nected. Since the detected device receives the electrical
`
`power from the detecting device, a separate costly electrical
`power supply is not needed. The systems of the present
`invention reduce cost, and eliminate the massive intercon-
`nection wires and the electrical power plug in the office.
`FIG. 2 is a block diagram illustrating a network system
`200 in accordance with the present invention. The network
`system 200 includes a network 201 and a plurality of
`computers 212. For clarity, only three computers, 212-1
`through 212-3, are shown. The computers 212 may be, for
`
`
`
`5,991,885
`
`5
`example, workstations, portable computers, desktop PCs, or
`personal digital assistants (PDA).
`The network 201 includes a network hub 202, a plurality
`of twisted-pair cables 205, a plurality of user interface
`connectors 204, and an infrared adapter 206. For simplicity
`and clarity, only four twisted-pair cables 205 and four user
`interface connectors 204 are shown. Also, for clarity, only
`one infrared adapter 206 is shown. Of course, the network
`201 may include other numbers of network hubs 202, hub
`user connectors 208, twisted-pair cables 205, user interface
`connectors 204, and infrared adapters 206.
`The network hub 202 includes a plurality of hub user
`connectors 208 and an up-link connector 210. The up-link
`connector 210 allows the network 201 to be connected to
`
`another network (not shown). The computer 212-1 includes
`a first interface 214 which is an infrared transceiver. The
`
`computer 212-1 communicates in a first protocol via the
`infrared transceiver 214 with the infrared adapter 206. In one
`embodiment of the present invention, the first protocol is an
`infrared protocol. The computers 212-2 and 212-3 each
`include a second computer interface 216 that communicates
`in a second protocol. In one embodiment of the present
`invention, the protocol of the computer interface 216 is a
`10Base-T or 100Base-TX protocol. In another embodiment
`of the present
`invention,
`the protocol of the computer
`interface 216 is a Token Ring protocol. In one embodiment
`of the present invention, the user interface connectors 204
`are conventional RJ45 connectors.
`
`The computers 212-2 and 212-3 may be physically con-
`nected to the network 201 via the hub user connectors 208
`
`by physical wire connections, such as twisted-pair wires,
`between the respective second computer interfaces 216 and
`the user interface connectors 204. The twisted-pair cable
`according to one embodiment of the present invention may
`be conventional category 3 or 5 twisted-pair cable. The wire
`may be disconnected at the computer 212-2 or 212-3 to
`allow the user to have portability of the associated computer
`212.
`
`The network 201 communicates with the plurality of
`computers 212 via the user interface connectors 204, using
`the infrared adapter 206 for wireless communication or
`using the computer interfaces 216 for wired communication.
`Specifically,
`the computer 212-1 communicates without
`wire and instead uses an infrared signal 215 communicated
`between the IR adapter 206 and the IR transceiver 214 of the
`computer 212-1 to communicate with the network 201. The
`plurality of computers 212 may communicate with each
`other via the hub user connectors 208 or communicate with
`
`another network via the up-link connector 210.
`The network 201, according to one embodiment of the
`present invention, is a Local Area Network (LAN) and may
`link to other networks.
`
`The network 201 recognizes the protocol of computers
`212 coupled to the network hub 202 and communicates with
`the computer 212 in the appropriate protocol. The network
`201 provides electrical power to an IR adapter 206 when the
`IR adapter 206 is coupled to the network hub 202, but does
`not provide electrical power for other adapter for other
`protocols. If the network 201 determines that another type of
`device other than an IR adapter 206 is coupled to a user
`interface connector 204, the network 201 does not apply
`electrical power. The network system 200 provides wireless
`communication between computers 212 and the network
`201. Although the adapter 206 is described herein as oper-
`ating with infrared, the adapter 206 may provide wireless
`coupling other than infrared, such as radio frequency. In
`
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`6
`such a case, the network system 200 may be modified to
`operate with these other means of wireless coupling or
`combinations thereof.
`
`Specifically, the network hub 202 determines whether a
`remote device is connected to the user interface connectors
`
`204 and determines the type of the remote device. If an
`infrared adapter 206 is connected to a user interface con-
`nector 204, the network hub 202 provides electrical power
`to the IR adapter 206 in response to such detection, and stops
`providing electrical power to the IR adapter 206 in response
`to no detection of the IR adapter 206.
`A user may place a computer 212-1 in the vicinity of the
`IR adapter 206 and communicate with the network 201. The
`IR adapter 206 provides bi-directional communication
`between the network hub 202 and an IR transceiver 214 of
`
`the computer 212-1. The network hub 202 converts data
`from an IR protocol to the protocol of the network and vice
`versa. The network hub 202 also converts data from the
`
`protocol of either of the computers 212-2 or 212-3 into the
`protocol of the network and vice versa. Accordingly, the
`network hub 202 allows communication between any of the
`computers 212 by making the appropriate protocol conver-
`sion.
`
`FIG. 3 is a block diagram illustrating a network system
`300 in accordance with the present invention. The network
`system 300 includes a network 301 and a plurality of
`computers 212. For clarity, only three computers 212-1
`through 212-3 are shown. The computers 212-1 through
`212-3 include respective computer interfaces 214, 216, and
`318. The computer interface 318 communicates in a third
`protocol.
`The network 301 includes a first network hub 302, a
`second network hub 303, an optional third network hub 304,
`a plurality of hub user connectors 204, and first and second
`pluralities of twisted-pair cables 205 and 305, respectively.
`The network 301 may include additional network hubs.
`The network hub 302 includes a plurality of hub user
`connectors 308, a plurality of pass-through connectors 309,
`and an up-link connector 310. The network hub 303 includes
`a plurality of hub user connectors 320 and an up-link
`connector 322. The network hub 304 includes a plurality of
`hub user connectors 324 and an up-link connector 326. The
`twisted-pair cables 305 couple the pass-through connectors
`309 of the network hub 302 to respective hub user connec-
`tors 320 of the network hub 303. Likewise, twisted-pair
`cables 305 couple the pass-through connectors 309 of the
`network hub 302 to respective hub user connectors 324 of
`the network hub 304.
`
`The network 301 communicates with the computers 212
`in a manner similar to that described above in conjunction
`with the network 201 of FIG. 2. However, communications
`within the network 301 differs from communication within
`
`the network 201. Specifically, the network hub 302 pro-
`cesses data in an infrared protocol and passes through data
`in other protocols to the network hubs 303 and 304 for
`processing.
`The first network hub 302 determines whether an infrared
`
`adapter 206 is coupled to a user interface connector 204, and
`if such an IR adapter 206 is detected, the first network hub
`302 converts the data between the protocol of the IR adapter
`206 and the network hub 303 in a manner similar to that of
`
`the network hub 202 of FIG. 2. However, if an IR adapter
`206 is not detected, the first network hub 302 couples the
`corresponding hub connector 308 to the corresponding pass-
`through connector 309 for communication with either the
`second hub 303 or the third hub 304. The network hub 302
`
`
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`does not process the data from the adapter. Hence, the first
`network hub 302 merely passes data communicated between
`the second network hub 303 or the third network hub 304
`
`and the computer 212 without further processing.
`The network hub 302 implements a “pass through” of
`network data to allow the system to use conventional
`network hub 303 and/or 304 to support a standard network
`protocol such as Ethernet and/or Token Ring.
`In one
`embodiment of the present invention, the network 301 is
`coupled only to a computer that is in one of two protocols,
`for example, an infrared protocol and an Ethernet protocol.
`The present
`invention allows a user using an existing
`network hub to establish a multiple protocol network system
`301 for infrared communication, Ethernet and/or Token
`Ring. Multiple networking protocols share the same con-
`nector 204. Reusing existing conventional hubs and sharing
`the same connector reduces the system cost and increases
`the convenience of network access.
`
`FIG. 4a is a block diagram illustrating the network hub
`202 in accordance with the present invention. The network
`hub 202 includes a plurality of hub user connectors 208, an
`up-link connector 210, connection path 402, networking
`data path 404, detection path 406, first and second protocol
`handlers 408 and 410, respectively, networking data path
`411 and 412, a plurality of device presence detectors 414,
`and select signal path 416.
`The networking data path 404 couples the hub user
`connector 208 to a first terminal of the connection path 402.
`The detection path 406 couples the device presence detector
`414 to the hub user connector 208. The first and second
`
`protocol handlers 408 and 410, respectively, are coupled to
`respective second and third terminals of the connection path
`402. The networking data path 411 couples the first and
`second protocol handlers 408 and 410. The networking data
`path 412 couples the second protocol handler 410 to the
`up-link connector 210. The select signal path 416 couples
`the device presence detector 414 to the connection path 402.
`The device presence detector 414 provides a presence
`request signal on the detection path 406 which is applied to
`the hub user connector 208 for determining whether an
`infrared adapter 206 is coupled to the hub user connector
`208. If an infrared adapter 206 is not coupled to the hub user
`connector 208, the device presence detector 414 applies a
`signal to the select signal path 416 that selectively couples
`the hub user connector 208 through the connection path 402
`to the second protocol handler 410 which communicates
`with a computer 212 connected to hub user connector 208 in
`the second protocol. Communication with another network
`(not shown) by the second protocol handler 410 is via the
`up-link connector 210. On the other hand, if the infrared
`adapter 206 is coupled to the hub user connector 208, the
`device presence detector 414 provides a select signal on the
`select signal path 416 to couple the hub user connector 208
`through the connection path 402 to the first protocol handler
`408. The first protocol handler 408 may communicate with
`another network (not shown) via the networking data paths
`411 and 412, and the up-link connector 210.
`The first protocol handler 408 performs the conversion
`between the first protocol and the second protocol, and also
`performs repeater or switching functions of the first protocol
`among the user connectors 208 with IR adapters 206. The
`second protocol handler 410 performs repeater or switching
`functions of the second protocol among up-link connector,
`the first protocol handler 408, and user connectors 208,
`without IR adapters 206. Connection paths 402 provide
`networking paths between the first protocol handler 408 and
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`user connectors 208 with IR adapters 206, and the network-
`ing paths between the second protocol handler and user
`connectors 208 without IR adapters 206. Networking path
`411 allows both protocol handlers 408 and 410 to share the
`components for the up-link path.
`FIG. 4b is a block diagram illustrating the network hub
`302 in accordance with the present invention. The network
`hub 302 includes a plurality of hub user connectors 308, a
`plurality of pass-through connectors 309, an up-link con-
`nector 310, connection path 402, networking data path 404,
`detection path 406, protocol handler 408, a plurality of
`device presence detectors 414, select signal path 416 and
`networking data path 418.
`The networking data path 404 couples the hub user
`connector 308 to a first terminal of the connection path 402.
`The detection path 406 couples the device presence detector
`414 to the hub user connector 308. The protocol handler 408
`is coupled to a second terminal of the connection path 402.
`The networking data path 418 couples the protocol handler
`408 to the up-link connector 310. The pass-through connec-
`tor 309 is coupled to a third terminal of the connection path
`402. The select signal path 416 couples the device presence
`detector 414 to the connection path 402.
`The device presence detector 414 provides a presence
`request signal on the detection path 406 which is applied to
`the hub user connector 308 for determining whether an
`infrared adapter 206 is coupled to the hub user connector
`308. If an infrared adapter 206 is not coupled to the hub user
`connector 308, the device presence detector 414 applies a
`select signal to the select signal path 416 that selectively
`couples the hub user connector 308 through the connection
`path 402 to the pass-through connector 309. This allows
`communication between a network hub 303 or 304 with a
`computer 212 coupled to the hub user interface connector
`308. In this way, the network hub 302 merely passes data
`between the network hub 303 or 304 to the computer 212.
`Such communication is in the protocol of the network hub
`303 or 304. On the other hand, if an infrared adapter 206 is
`coupled to the hub user connector 308, the device presence
`detector 414 provides a select signal on a select signal path
`416 to couple the hub user connector 308 through the
`connection path 402 to the protocol handler 408. Commu-
`nication between the network hub 302 and the computer 212
`is an infrared protocol. The protocol handler 408 may
`communicate with another network (not shown) via the
`up-link connector 310. The protocol handler 408 performs
`the conversion between the IR protocol and the second
`protocol, and also performs repeater or switching functions
`of the IR protocol among user connectors 208 with IR
`adapters 206.
`By way of background, local-area network (LAN) appli-
`cations that include a twisted-pair cable as the media for data
`transfer typically use a standard RJ45 connector between
`components of the system, such as a networking port on PC,
`workstation, hub, bridge, or router. For example, a standard
`RJ45 connector is used with twisted-pair cable in Ethernet
`10Base-T, 100Base-T, and Token Ring systems. The
`twisted-pair cable contains 6 wires (3 pairs) or 8 wires (4
`pairs). The LAN of these systems typic