(12)
`
`United States Patent
`Rogers
`
`(10) Patent N0.:
`(45) Date of Patent:
`
`US 6,556,564 B2
`Apr. 29, 2003
`
`US006556564B2
`
`(54) SCHEDULED INTERNET PROTOCOL
`TELEPHONE INSTRUMENT SYSTEM
`(75) Inventor‘ Steven A Rogers Alton NH (Us)
`'
`'
`’
`’
`
`Primary Examiner—Douglas Olms
`Assistant Examiner—Bob A. Phunkulh
`(74) Attorney, Agent, or Firm—Weingarten, Schurgin,
`Gagnebin & Lebov1c1 LLP
`
`(73) Assignee: 532E323? Networks, Inc., Portsmouth,
`
`(57)
`
`ABSTRACT
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U_S_C_ 154(k)) by 66 days'
`
`(21) APPL NO; 09/780,685
`_
`(22) Flled:
`(65)
`
`Feb‘ 8’ 2001
`Prior Publication Data
`Us 2001/0033565 A1 Oct 25 2001
`'
`’
`Related US Application Data
`(60) Provisional application No. 60/181,099, ?led on Feb. 8,
`2000-
`(51) Int. c1.7 .............................................. .. H04L 12/66
`(52) US. Cl. ..................... .. 370/352; 370/443; 370/498;
`379/88'17
`(58) Field of Search ............................... .. 370/352, 353,
`370/354, 355, 356, 389, 419, 474, 476,
`442, 443, 444, 498; 709/8817
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`6/1996 Henley et al. ........... .. 370/60.1
`5,526,353 A
`3/1997 Doll et al. ................ .. 370/389
`5,610,920 A
`5,825,873 A 10/1998 Duncan et al.
`379/419
`5,832,275 A 11/1998 Olds ................. ..
`395/712
`6,185,184 B1
`2/2001 Mattaway et al. ........ .. 370/230
`
`ALAN telephone which makes Voice telephone Calls ‘We? a
`local area netvvork (LAN) data networli. Acoustic vo1ce
`sounds are digitally encoded and transmitted as data, over
`the LAN. The disclosed telephone simultaneously receives
`LAN data packets and decodes them, translating the data
`into acoustic audio voice sounds. All communications With
`the netWork occur through the use of the LAN, including
`data for call control and for voice signals. The disclosed
`LAN telephone uses a packet scheduling technique to pre
`vent packet collision, delay or loss. The scheduling tech
`nique relies on time of transmission and arrival to sWitch
`Packet& Additionalb? the disclosed LAN telephone is Oper'
`able to receive poWer from a data sWitch, using LAN Wiring.
`The instrument further includes a means for attaching
`Peripheral devices through an electronic interface System’ as
`Well as an internal system for alloWing the telephone to be
`moved’ from one Connection to another’ Without Changing
`the telephone number. The instrument also provides a sys
`tem for automatically changing the internal control softWare
`of the instrument, or of any connected peripheral. A system
`for connecting an external “speaker-phone” system is also
`disclosed, Which gives the instrument’s user the ability to
`place the voice audio source and pickup in a location that is
`convenient to the user and not necessarily co-located With
`the instrument itself.
`
`21 Claims, 14 Drawing Sheets
`
`|<——————— Schedule Interval 40 -——————>l
`
`}
`
`l
`
`a 0 I
`Schedule Assignment
`
`1
`Heartbeat
`Packet
`41
`
`Voice Packet(s)
`
`/ I/ Data A1 42 n n
`
`
`
`Voice Packet(s)
`
`II Data A2 43 \- N
`
`' ' '
`
`H
`Packet
`41
`
`l
`
`Schedule Assignment for First Telephone "A"
`
`Voice Packet(s)
`Data B1 and A1
`46
`
`Voice Packet(s)
`Data B1 and A1
`47
`O I I ———__-_—?
`Schedule Assignment for
`Two Telephones ( "A", and "8") Active
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 1 0f 14
`
`US 6,556,564 B2
`
`Status Display 3
`
`Operator
`Console 7
`
`LAN Cable
`
`Handset 2 /’
`
`Left
`
`A0 C
`W...
`wm C $8
`Cn
`on
`
`4
`
`LAN Telephone
`Base Umt 6
`
`Punch-down Block
`
`/12
`
`CIDDCID
`
`Telephone Handset
`K 10
`
`g 1::
`
`Wall Jack 11
`K 14
`
`/
`18 C
`
`Telephone Handset
`13
`
`WAN Link
`I 17
`
`DUE
`
`t
`
`Statlon Cable 14)
`
`Instrument Cable 18
`
`FIG. 2
`Prior Art
`
`n nun
`
`(PBX
`<Multipair Cable
`
`16
`
`15
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 2 of 14
`
`US 6,556,564 B2
`
`Telephone Handset 21
`
`Telephone Power
`Supply 29
`
`Network Server(s) 26
`E
`
`[:l
`
`DUB
`DDD
`DOD
`
`0
`
`-—__-—-_
`
`29
`
`Telephone Handset 23
`[:Il
`DCICI
`333
`
`Desktop Computer(s) 24
`I
`
`Telephony Server 27
`
`E1
`°
`
`Wide Area
`— Telephone Interface -
`28
`
`\ Telephony Server Link 30
`
`E
`
`l'JCI uuclcpclncr
`soucmurhnuu
`"SDUDEJDEICIC!
`DDI'JCIDEIDDDD
`
`29
`
`Telephone Handset 25
`l:
`CIDD
`DDEI
`DUB
`
`Local Area Network
`Switch 22
`
`FIG. 3
`Prior Art
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 3 of 14
`
`US 6,556,564 B2
`
`l<————————- Schedule Interval 40 --—————>{
`
`If
`
`0 0 0
`Schedule Assignment
`FIG. 4(a)
`
`1
`Heartbeat
`Packet
`41
`
`Voice Packetls)
`/ Data "Al" 42
`
`Voice Packet(s)
`Data "A2" 43
`
`Heartbeat
`Packet
`
`I
`
`
`
`0 0 0 Schedule Assignment for First Telephone "A"
`
`‘
`
`If
`
`Voice Packet(s)
`[ Data "B1" 44
`
`Voice Packet(s)
`Data "B2" 45 \ £41
`_\
`. I Q
`Schedule Assignment for Second Telephone "B"
`FIG. 4(0)
`
`I
`
`r
`
`Voice Packet(s)
`/ Data B1 and A1
`[ 46
`I I I __——____-_—?
`Schedule Assignment for
`Two Telephones ( "A", and "8") Active
`FIG. 4(d)
`
`Voice Packet(s)
`Data B1 and A1
`47
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 4 of 14
`
`US 6,556,564 B2
`
`_
`Right Accessory
`Connector 52
`
`Left Accessory
`Connector 53
`
`Handset
`Connector 72
`
`Handset
`Connector 70
`
`Signal Conditioni®__1
`
`72
`
`Internal Speaker 69
`/ internal Microphone 68
`LAN Connector
`
`/ Dual-Voltage Power
`
`_ _______ _
`
`Conditioning 54 (A V A v
`
`)
`
`“- '_“____ "
`
`r___‘_______ _
`M00
`‘i
`/
`DtoA
`I
`ConverterN
`:
`73
`l
`\_ ___ ___. d"
`Microprocessor 74 D f T t
`
`Serial "USB“
`
`interface
`Circuits 55
`
`67
`
`Power
`
`Circuit
`
`66
`
`+
`DC Power
`LAN Physical
`interface (PHY) 65
`
`Digital Signal
`Processor 75
`
`LAN Media
`Access Controller
`(MAC) 64
`
`‘ Microprocessor
`Text Display
`63
`
`Bus 76
`
`l
`
`l
`
`‘O t tL t h
`u p“ ac 85
`
`62
`
`L
`ll’ldlCGtOl'S 61
`
`T
`
`t
`
`t
`
`T
`
`/'
`input
`Latches
`60
`a (RAM Memory 58
`Flash Memory 57
`ROM Memory 56
`
`>
`Key Switches 59
`
`FIG. 5
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 5 0f 14
`
`US 6,556,564 B2
`
`Transmit 48VDC Pair, ''
`Data
`Power
`_
`
`.
`Pm1-2
`
`Receive 48VDC pairz +
`Data
`Power
`_
`
`Pin 3:6
`
`430:2? 430%: P3573
`
`'
`48 VDC 48VDC Pam +
`
`+
`
`Pin 4, 5
`
`'
`
`Pin 7,8
`
`Power
`
`Power
`
`_
`
`Accessory
`Power
`System
`86
`
`Loxgihzarss
`Network
`s3
`
`CDC/2:3
`onve er
`84
`
`Accessory
`
`48VDC 5VDC Power
`S stem
`In
`Out
`V85
`
`I
`
`l
`
`G
`
`]\
`
`-
`
`\LAN Connector
`80
`
`Surge ATTeStOr
`82
`
`LAN Telephone
`Curcuit Card
`81
`
`FIG. 6
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 6 6f 14
`
`US 6,556,564 B2
`
`Vcc +48
`VDC 90
`
`Cuurent Sense
`Resistors 98
`
`W
`
`48 VDC Power
`Switch 99
`
`, i,_
`
`VCC
`+5 or 48 VDC 100
`
`W
`
`5 VDC 91
`V0“
`W '
`HV Comparato
`J
`92
`
`+
`
`LV Comparator 93
`
`putBuffer 94
`
`NO
`- gel-5 VDC Po er
`0
`Switch 0N7
`NC
`
`D __J
`101
`
`D + J
`102
`
`Pin 1
`
`Pin 2
`
`Pin 3
`
`Pin 4
`
`Microproccessor Bus 95/
`FIG. 7(a)
`
`0t H t h
`u pu a c
`96 Power Gnd corrrgictor
`
`103
`
`105
`To Accessory Downstream
`1 Input Power BUS
`+5 or 48 V\ K Power Circrit
`f\1]8
`_
`l
`\
`1
`Current Limit
`LVcc +5V
`Resistor 110
`116
`
`NC
`
`Pin 1
`
`,
`Pm 2
`
`Pin 3
`
`D - 106
`(
`
`D + 107
`1
`
`5-3.3 DC-DC
`48-5 DC-DC
`Converter 112 _O NO Converter 114 EA
`ccessory
`Power 117
`
`Power Select
`SWHCh 1 13
`\mput
`Buffer 119
`
`48V
`pin 4 K I
`Comparator 111
`K \
`Vottage Level
`Resistor108 Power Gnd 109
`
`‘I'
`
`FIG. 70))
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 7 0f 14
`
`US 6,556,564 B2
`
`Left Accessory
`Connector 121
`
`_
`RlghtACCeSSOW
`
`Connector 120 As
`
`Dual-Voltage Power
`/ Conditioning 122
`
`KeySwitch Matrix
`/ 130
`
`K Indicators 131
`
`$
`
`i
`
`T
`
`1
`
`Output Latches
`132
`
`L
`
`Text
`Dispiay 133
`
`K [ Output Latches
`128
`Microprocessor
`‘2\4
`
`Seriai "use"
`Circuits 129x \
`
`Interface \
`
`$
`
`1
`1
`
`1
`t
`
`11
`
`1
`
`1
`input }
`
`Latches
`129
`Data and Address Bus
`134
`
`( gFlash Memory 126
`{RAM Memory 127
`
`ROM Memory 125
`
`FIG. 8
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 8 0f 14
`
`US 6,556,564 B2
`
`Hard
`Reset @
`
`lnitiallzatlon and Self Test l?
`
`Initial Display 14_2
`
`OK Version 1-1 J
`
`Power lnit Display
`143
`
`ldle State
`E
`
`Fall
`RAM, Power
`
`Fall Display
`146
`J
`
`DHCP Display
`148
`
`DHCP Question Q DHCP? = Y J
`
`Y DHCP?
`H2
`
`N
`
`Instrument lP Entry
`Display 151
`Instrument lP Number= J
`Enter Instrument lP @ 1020122232
`
`Server lP Entry
`Display 153
`
`Enter Server IP E2
`
`Instrument IP Number: __/
`10.201.222.37
`
`End
`lnit 155
`
`FIG. 9(a)
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 9 0f 14
`
`US 6,556,564 B2
`
`Power-On
`Start 1651
`
`initialization and
`Self Test @2
`
`‘
`
`Init Display
`164
`
`Initial Display E oKversion1'1 J
`
`idie State
`155
`
`Y
`
`Access DHCP
`IP 117
`
`‘
`
`Logon
`Display 171
`
`Delay 16-9-
`
`Send LOQOFI
`
`LQgQn J
`
`Logon Fail
`Display 175
`Logan Fail _,/
`
`Ready Display
`177
`
`FIG. 9(b)
`
`Ready 17-5
`
`3/22/2001
`10:55:09 AM J
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 10 0f 14
`
`US
`6,556,564 B2
`
`Screen record for:
`
`Frost, Jack
`
`Instrument Serial Number: 343-547-789-2001-34
`
`Switch:
`
`Switch Slot:
`
`Switch Port:
`
`Physical Location:
`
`instrument Type:
`
`Lakeside 2
`
`7
`
`7/24 39
`
`3-230-4
`
`SES-Z
`
`instrument Description:
`
`Single Executive Station
`
`Extension Number:
`
`6255
`
`User Record for LAN Phone Auto-iD
`
`FIG. 9(c)
`
`Location Record Switch: Lakeside 2
`
`User Record
`
`)180
`
`|__
`
`Slot:
`
`Port:
`
`3
`
`1
`
`2
`
`3
`4
`5
`
`6
`
`3-230-4
`
`Frost, Jack
`
`3-230-3
`
`Conference Room, Smaii
`
`Location
`
`3-231-3
`4-232-1
`5-233-1
`
`Morgon, Anna
`Clayton, Jean
`Brockton, George
`
`6-2344
`
`Unassigned
`
`Record 181
`)
`
`Location Record for LAN Phone Auto-ID
`FIG. 9(a)
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 11 0f 14
`
`US 6,556,564 B2
`
`Update Program
`Display 201
`_/
`
`Update
`
`U date OK Display
`p
`199
`
`OK Version 1.2 J
`
`Send Update
`Fail Message 1_9A
`
`Receive Update
`Command 1_91
`i
`
`Authenticate and Send
`Response 19;
`
`Receive Update 19;
`
`l
`
`Perform Error
`Check gag
`
`N
`
`OK?
`E
`
`Y
`
`Store in Flash
`Memory M
`l
`
`Send Update AcK
`19g
`
`Ready
`M
`
`FIG. 10
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 12 of 14
`
`US 6,556,564 B2
`
`speakerPhorie
`Accessory 210
`
`"On-Off" Indicator
`219
`
`'
`
`Microphone Array
`21 1
`
`mi?fnzdi 2
`p
`, Microphone Array
`/ (Hidden) 214
`
`Mule Button 213 Microphone Array
`/ (Hidden) 214
`
`Mute Indicator
`215
`
`Connector 216
`
`Accessory Cable
`217
`
`FIG. 11
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 13 of 14
`
`US 6,556,564 B2
`
`Upstream Accessory
`Connector 220
`
`2
`
`From
`Microphone Array
`
`235
`
`Signal Conditioning
`234
`Dual-Voltage Power
`Conditioning 221
`
`Top Speaker 237
`/ Top Microphone 238
`
`Rear
`M'cmpggge Array
`
`\r
`
`7 V V V
`
`Serial "USB"
`|nterface
`Circuits 223\
`
`A to D
`D to A
`Accessory
`_P_°W>ef 222 ConverterR
`233
`Microprocessor232 D t
`
`‘
`
`c
`_
`‘
`_
`Digital Signal
`Processor 231
`
`Microprocessor
`Address & Data
`Bus 238
`
`l
`
`A
`
`v
`
`i
`
`l
`
`l
`
`lnput
`Latches
`228
`(
`RAM Memory 226
`Flash Memory 225
`
`ROM Memory 224
`
`Mute, On-Off
`Switches 227
`
`i
`
`i
`
`\ Output Latches 62
`
`L Mute, On-Off
`Switches 230
`
`Internal Block Diagram for Speakerphone Accessory
`FIG. 12
`
`

`

`U.S. Patent
`
`Apr. 29, 2003
`
`Sheet 14 of 14
`
`US 6,556,564 B2
`
`Off Axis Person
`240
`
`a
`
`b
`
`/Speakerphone
`Accesory 246
`
`Rear
`Microphone
`Array 245
`>0 o——//
`c
`
`Front
`Microphone
`Array 241 x d
`“o
`o
`
`C
`d
`> enter; Person
`44
`
`Microphone 242
`
`Speaker 243
`
`FIG. 13
`
`

`

`US 6,556,564 B2
`
`1
`SCHEDULED INTERNET PROTOCOL
`TELEPHONE INSTRUMENT SYSTEM
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`
`This application claims priority under 35 USC §119(e) to
`provisional application serial No. 60/181,099, entitled
`“LOCAL AREA NETWORK (LAN) TELEPHONE
`INSTRUMENT SYSTEM”, and ?led Feb. 8, 2000.
`
`STATEMENT REGARDING FEDERALLY
`SPONSORED RESEARCH OR DEVELOPMENT
`
`N/A
`
`BACKGROUND OF THE INVENTION
`
`The present invention relates generally to telephone
`instruments, and more speci?cally to telephone instruments
`that are directly connected to a data LAN (Local Area
`Network).
`As it is generally knoWn, telephone systems for business
`use normally consist of a central sWitch or Private Branch
`exchange (PBX), illustrated by PBX 16 shoWn in FIG. 2,
`Which connects to telephones throughout the business via a
`tWisted pair Wire 14 and 15. An example of such a system
`con?guration is depicted in FIG. 2. In most cases the PBX
`16 Will use a single tWisted pair cable 14 to connect With the
`telephone instrument 13. During operation of the system
`shoWn in FIG. 2, the PBX 16 sends signals to and receives
`signals from the telephone instruments 10 and 13 via a
`frequency translated modem system.
`Existing PBX systems typically use dedicated Wiring,
`shoWn as multi-pair cables 15 in FIG. 2, connected to the
`PBX 16. The multi-pair cables 15 are connected to punch
`doWn blocks 12. The punch-doWn blocks 12 are normally
`placed in a closet on the ?oor of the of?ce building, near the
`telephone instruments 10 and 13. The individual station
`cables 14 are also connected to the punch-doWn blocks 12.
`The station cables 14 lead to the Wall jacks 11. The telephone
`instruments 10 and 13 are connected to the system via
`instrument cables 18 to the Wall jack 11. The telephones 10
`and 13 are poWered via a DC current that is carried by the
`same pair as that used for signaling. Telephone calls are
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`
`
`made outside the premises via a Wide Area NetWork link 17 connected to the PBX unit 16. The WAN link 17 is
`
`45
`
`2
`phones 21, 23 and 25 can use the same Wiring and data
`sWitches as are used to convey LAN data, thus resulting in
`increased ?exibility and overall loWer cost.
`A signi?cant problem With the LAN -PBX approach illus
`trated in FIG. 3 is that telephony data has different delivery
`requirements than normal computer and server data. Tele
`phony data must be delivered on-time (Within a feW
`milliseconds), and Without delay, on a continuous basis.
`Normal computer data can usually suffer delays of a feW
`hundred milliseconds Without dif?culty. Delays of this mag
`nitude (a feW hundred milliseconds) are common in com
`puter netWorks. They occur because computer data is trans
`mitted at a variable and unpredictable rate. As a result, there
`can be momentary blockages and congestion, even though
`the netWork has adequate bandWidth for the average data
`load.
`Existing LAN -PBX systems attempt to solve this problem
`by giving telephony data priority over computer data. In the
`event of data congestion, such existing systems pass tele
`phony data ahead of computer data. This priority system can
`Work When only one telephone With data to transmit is
`present on a given circuit at a given time. HoWever, When a
`circuit must carry multiple telephone connections, the con
`gestion problem can arise again. This happens because
`multiple packets With equivalent priority give no means for
`arbitration. Consider the Telephony Server Link 30 shoWn in
`FIG. 3. When multiple telephone calls are placed to the
`WAN interface 28 they must all pass through the link 30. In
`that event, multiple telephony data packets, all having
`equivalent priority, may simultaneously require shared tele
`phony server link 30 resource. Apriority mechanism cannot
`distinguish betWeen them, and the packets cannot interfere
`With one another.
`Another problem With the LAN-PBX is that Ethernet
`cables and sWitches make no provision for providing poWer.
`Generally, in an Ethernet-based system as shoWn in FIG. 3,
`poWer is provided by a separate telephone poWer supply 29
`at each station or instrument. As a result, it is dif?cult to
`operate the entire netWork in the event of a poWer outage.
`The user must provide backup poWer at each instrument,
`instead of centrally, as is possible With a typical PBX
`system.
`Additionally, both PBX and LAN-PBX systems have
`dif?culty supporting multiple types of instruments, in a
`?exible manner. Some instruments need many features,
`While others need only basic capabilities. There is no con
`venient Way to extend or modify an instrument’s behavior
`Without complete replacement. That is, accessories to instru
`ments are rarely supported.
`Typical existing PBX systems, such as the one illustrated
`in FIG. 2, suffer from another problem. The telephone
`number of a particular handset is determined by the circuit
`jack to Which it is attached. This is inconvenient, as users
`may need to move a handset from one jack to another, While
`maintaining the same telephone number. Under such
`circumstances, the typical PBX user must recon?gure the
`sWitch.
`Finally, existing LAN telephones are operated by inter
`nally stored control softWare. Such softWare must normally
`be installed separately into each instrument. This procedure
`makes softWare updates and corrections dif?cult, since each
`instrument must be reloaded individually.
`For the reasons stated above, it Would be desirable to have
`a LAN telephone instrument system Which uses the same
`Wiring system as is used to convey data transmission, and
`Which operates Without the delays that may occur in existing
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`often a multi-channel circuit, such as What are commonly
`referred to as “T1” or “PRI” links.
`The typical existing PBX system requires dedicated Wir
`ing. It does not share Wiring With the data LAN that is
`common in most businesses. Thus, tWo Wiring netWorks are
`normally required Within an of?ce building, one for data and
`one for telephones.
`Recently, a technique for creating a “virtual” PBX has
`been employed that is referred to as a “LAN-PBX.” In this
`technique, the telephone instrument uses a common Ethernet
`LAN cable, instead of a single tWisted pair cable, to com
`municate With the PBX. An illustrative LAN -PBX system is
`shoWn in FIG. 3. In this case, the PBX is actually a
`telephony server 27 With sWitch control softWare that is
`connected to the LAN. The telephones 21, 23 and 25 are
`Ethernet LAN devices that also communicate over the LAN.
`Thus the telephony application, consisting of telephones 21,
`23, and 25, and a telephony server 27, attached to a WAN
`interface 28, can utiliZe the same sWitch 22 as the computers
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`24 and netWork data servers 26. The advantage of the
`LAN-PBX architecture shoWn in FIG. 3 is that the tele
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`systems. It Would further be desirable to have a LAN
`telephone instrument system Which a) operates using power
`supplied over Ethernet cables, b) provides for accessory
`attachments, c) can maintain a phone number even When
`moved to a neW jack, and d) enables convenient doWnload
`ing of softWare.
`
`BRIEF SUMMARY OF THE INVENTION
`Consistent With the present invention, a LAN telephone
`instrument is disclosed. The disclosed LAN telephone uses
`a Time-based Routing (TBR) technique to schedule packets
`of voice-telephony data. Through use of the Time-Based
`Routing technique, the problems of multiple LAN telephone
`instruments sending contending or colliding packets is
`avoided. The disclosed LAN telephone operates in connec
`tion With a system for providing poWer to the LAN tele
`phone instrument through an attached LAN cable. This
`alloWs multiple LAN telephone instruments to be centrally
`poWered.
`The disclosed LAN telephone further includes a technique
`for automatically providing a remote sWitch With location of
`the LAN telephone instrument, thus enabling automatic
`direction of calls thereto. Additionally, a system for remote
`con?guration of the control program of a LAN telephone
`instrument is also disclosed, Which employs the LAN itself
`to provide the data connection over Which the control
`program is doWnloaded.
`The present disclosure further includes a system for
`attachment of telephone instrument accessories, Which may
`be used to eXtend the functional capability of the LAN
`telephone instrument. An illustrative accessory, an operator
`console, is described in detail.
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`BRIEF DESCRIPTION OF THE SEVERAL
`VIEWS OF THE DRAWING
`The invention Will be more fully understood by reference
`to the folloWing detailed description of the invention in
`conjunction With the draWings, of Which:
`FIG. 1 shoWs a physical depiction of the LAN telephone,
`With an operator console accessory unit, and an internal
`speakerphone unit;
`FIG. 2 depicts a typical Private Branch EXchange (PBX);
`FIG. 3 depicts a typical LAN-PBX system;
`FIGS. 4a—4d shoW schedule assignment for tWo of the
`disclosed LAN phones sharing the same circuit path;
`FIG. 5 depicts an illustrative internal block diagram for an
`embodiment of the disclosed LAN telephone;
`FIG. 6 depicts an illustrative schematic diagram shoWing
`an eXternal poWer system for an embodiment of the dis
`closed LAN telephone;
`FIGS. 7(a) and 7(b) shoW an illustrative schematic dia
`gram for an accessory poWer system and interface system;
`FIG. 8 shoWs an illustrative block diagram of an operator
`console accessory unit;
`FIGS. 9(a), 9(b), 9(c) and 9(a) shoW softWare ?oWcharts
`and entry ?elds of an automatic identi?cation system for the
`disclosed LAN telephone;
`FIG. 10 shoWs a softWare ?oWchart of the disclosed
`control program change system;
`FIG. 11 shoWs a physical depiction of the disclosed
`external speakerphone accessory;
`FIG. 12 shoWs a block diagram of the disclosed speak
`erphone accessory; and
`FIG. 13 illustrates the beam-steering technique of the
`disclosed speakerphone accessory.
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`DETAILED DESCRIPTION OF THE
`INVENTION
`All disclosures of provisional application serial No.
`60/181,099, entitled “LOCAL AREA NETWORK (LAN)
`TELEPHONE INSTRUMENT SYSTEM”, and ?led Feb. 8,
`2000, are hereby included by reference herein.
`FIG. 1 shoWs a physical representation of an embodiment
`of the disclosed LAN telephone. The embodiment of the
`LAN telephone shoWn in FIG. 1 includes a base unit 6
`containing electronics circuitry necessary to provide the
`functions associated With the base unit 6 as described herein.
`The base unit 6 supports a handset 2, an internal speaker 5
`for speakerphone functions, and a status display 3 for
`displaying user status information. The base unit 6 may be
`connected to a data sWitch via a LAN cable 1, for eXample
`by Way of a conventional data cable infrastructure, such as
`that shoWn in FIG. 3. An accessory connector is provided on
`each side of the base unit 6, as illustrated by left accessory
`connector 4. Using the accessory connectors, it is possible to
`add a variety of accessory devices, including an operator
`console 7 as shoWn in FIG. 1, and/or an external speaker
`phone.
`The internal circuitry of an illustrative embodiment of the
`base unit 6 is shoWn in FIG. 5. The embodiment of the
`disclosed LAN telephone shoWn in FIG. 5 is implemented as
`a microprocessor based system. Speci?cally, a microproces
`sor 74 is shoWn attached to a parallel microprocessor bus 76,
`Which provides an interface to various components via its
`address and data lines. In the embodiment of FIG. 5, the
`microprocessor 74 may, for eXample, be a Reduced Instruc
`tion Set Computer (RISC) processor, using a 16 bit Wide
`data bus. The bus 76 is also connected to a Read Only
`Memory (ROM) 56, Flash Memory 57, and a Read And
`Write Memory (RAM) 58. The bus 76 further connects to
`USB interface circuits 55, as Well as input latches 60 and
`output latches 62. The bus 76 additionally connects to a
`LAN Media Access Controller 64, a teXt display 63 and a
`Digital Signal Processor (DSP) 75.
`The organiZation of the hardWare shoWn in FIG. 5 advan
`tageously permits features of the disclosed LAN telephone
`to be implemented using control softWare. For eXample, the
`microprocessor 74 may use three types of memory to store
`such control softWare: ROM 56, Flash 57 and RAM 58. The
`ROM 56 may be used to store the microprocessor’s basic
`initialiZation program. When the LAN telephone is poWered
`on, usually by attachment to the poWered LAN cable 1, the
`microprocessor 74 ?rst eXecutes a portion of its control code
`that is stored in the ROM 56. The control code program
`stored in the ROM 56 causes the microprocessor 74 to
`initialiZe all hardWare peripherals of the LAN telephone,
`such as the MAC 64 and the output latches 62. The control
`code program stored in the ROM 56 further performs a
`self-test of the LAN telephone. The self test includes check
`ing the microprocessor itself, testing the RAM 58 and
`performing a checksum veri?cation of the contents of ROM
`56 and the Flash memory 57. The ROM 56 also contains
`program code operable to load the Flash memory from the
`MAC 64.
`One of the indicators 61, for eXample a light emitting
`diode (LED), is placed on the bottom of the LAN telephone,
`near the LAN connector. This LED indicator is attached to
`a ?ip-?op register that automatically resets itself on each
`poWer up, thus causing the LED indicator to turn on. As the
`microprocessor 74 ?nishes its self-test, it toggles the “set”
`line on the ?ip-?op register by activating a one bit port on
`the output latches 62. This action causes the LED indicator
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`US 6,556,564 B2
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`to turn off. In this Way, the LAN telephone’s main electron
`ics module can indicate if it is functioning properly. The
`control code instructions stored in the ROM 56 may, in
`addition, also display an “OK” message in the text display
`63. HoWever, in the event that the text display 63
`malfunctions, the LED indicator Will still operate.
`When the microprocessor 74 ?nishes executing the con
`trol program code stored in the ROM 56, it then executes
`control program code stored in the ?ash memory 57. The
`main body of the LAN telephone control program function
`ality is stored in the ?ash memory 57. Flash memory 57 is
`advantageously capable of having its contents updated or
`replaced. Through use of this capability of the ?ash memory
`57, the LAN telephone can be loaded With neW program
`code providing additional or modi?ed functionality.
`Similarly, a fault or bug in the control program can be
`repaired, by storing a neW program into the ?ash memory
`57. If no program code is loaded in the ?ash memory 57, or
`if the program in the ?ash memory 57 does not yield a proper
`error check, then the microprocessor Will enter an idle state.
`In this idle state, the microprocessor aWaits a neW control
`program to be doWnloaded into the LAN phone, for example
`from a LAN sWitch.
`The RAM memory 58 is used for the storage of program
`variables and state information. The RAM 58 may have part
`or all of its memory protected via a “battery backup”. In this
`Way variable values can be maintained across a poWer
`failure.
`During operation, the disclosed LAN telephone may
`communicate With other LAN telephones via the LAN to
`Which it is attached. The LAN telephone uses the LAN MAC
`64 to send and receive packets of data in Ethernet format.
`The LAN MAC 64 is connected to the LAN cable using a
`PHYsical interface (PHY) 65. The PHY 65 provides level
`and impedance translation, as Well as other signal condi
`tioning needed to send packets over a tWisted pair Wire. The
`PHY 65 is connected to the LAN Connector 67. The LAN
`Connector 67 may, for example, be a conventional “RJ”
`style connector (e.g. RJ-45). The PHY 65 uses tWo tWisted
`pair Wires Within the cable bundle attached to the LAN
`Connector 67, one for transmit data and one for receive data.
`In an illustrative embodiment, the disclosed LAN tele
`phone obtains its operating poWer from the LAN cable 1
`shoWn in FIG. 1, through the LAN Connector 67. This
`embodiment makes use of another, normally unused Wire
`pair in the cable bundle to receive poWer, for example from
`a LAN sWitch. The received poWer is conditioned and
`voltage translated via the poWer circuit 66. This poWer
`circuit 66 is further described herein With reference to FIGS.
`6 and 7.
`The LAN telephone base unit 6, as shoWn in FIG. 1,
`includes a number of user buttons, shoWn for purposes of
`illustration as key sWitches 59 in FIG. 5. The key sWitches
`59 may be operated by a user, in order to dial calls, and/or
`to access various features of the LAN telephone. The states
`of the key sWitches 59 are determined by the microprocessor
`74 as it reads the contents of the input latches 60. The input
`latches 60 are connected to the key sWitches 59. In this Way,
`more key sWitches can be accommodated, for a given
`number of input latch ports. The microprocessor 74 reads the
`key sWitches 59 periodically, for example, at times deter
`mined by an internal interrupt. The microprocessor 74
`rejects spurious key transitions, only accepting those that are
`active for at least a minimum time.
`LED indicators on the disclosed LAN telephone may be
`used to display call status. The microprocessor 74 may
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`control the state of such indicators, as needed, via com
`mands to the output latches 62.
`The text display 63 in the embodiment of FIG. 5 may, for
`example, be a tWo-line Liquid Crystal Display (LCD). The
`text display 63 may receive poWer from a circuit card Within
`the LAN telephone. The microprocessor 74 Writes messages
`to the text display 63 to provide assistance to the user.
`Accessories may be connected to the disclosed LAN
`telephone via a modi?ed Universal Serial Bus (USB) inter
`face. In the illustrative embodiment of FIG. 5, this interface
`is provided via USB controllers 55, Which are connected to
`the bus 76. The microprocessor 74 may send and receive
`messages and commands to accessories via this modi?ed
`USB interface. The USB Controllers 55 are connected to the
`left 53 and right 52 accessory connectors via a poWer
`conditioning circuit 54.
`Connection to the handset 2 shoWn in FIG. 1 is made via
`the DSP 75 shoWn in FIG. 5. The DSP 75 is an integrated
`processor that is optimiZed for manipulating analog signals
`that are translated into digital form. The DSP 75 is connected
`to the bus 76. In the embodiment of FIG. 5, the DSP 75
`includes an internal dual-port RAM, Which is connected to
`a DSP core processor and to the bus 76. In this Way, the DSP
`75 may be issued commands and its control program loaded
`by the microprocessor 74, out of the ?ash memory 57, over
`the bus 76. In the embodiment shoWn in FIG. 5, the DSP 75
`also includes an internal ROM, Which can contain a basic
`“Boot” program for the DSP. After initialiZation, the DSP 75
`provides a message, via its dual-port memory, to the micro
`processor 74, indicating that the DSP 75 is ready to accept
`its control program. The control program of the DSP 75 is
`loaded into DSP memory, by the microprocessor 74, prior to
`the LAN telephone entering a “Ready” state. In the Ready
`state, the LAN telephone is ready to accept and place
`telephone calls.
`The DSP 75 is further shoWn connected to the analog
`inputs and outputs via Analog to Digital (A to D) and Digital
`to Analog (D to A) converters 73. The converters 73 translate
`the analog, voltage-based signal into a digital signal. In the
`embodiment shoWn in FIG. 5, the A to D and D to A
`converters 73 are combined into one package, providing
`tWo-Way translation. The handset 2 (FIG. 1), and a headset
`(not shoWn), are connected to the base unit via the handset
`connector 71 and headset connector 70 shoWn in FIG. 5. The
`internal speaker 69 and internal microphone 68 shoWn in
`FIG. 5 are directly connected to the DSP 75 via a signal
`conditioning element 72. The signal conditioning element
`72 also provides an interface to the handset connector 71 and
`the headset connectors 70. The signal conditioning element
`72 provides signal limiting, gain or attenuation, ?ltering, and
`poWer, as needed.
`To initiate or receive telephone calls, the LAN telephone
`receives control messages from a sWitch or telephone server,
`via the LAN to Which it is connected. These messages and
`associated responses are used to initiate telephony sessions.
`For example, When a call is in progress, speech audio is
`received by the microphone of the handset 2, and conveyed
`through signal conditioning element 72 and converter 73 to
`the DSP 75. The speech audio is thus sampled and converted
`into a stream of digital numbers (“samples”) by the A-D
`functionality of the converters 73. Each such number rep
`resents the voltage of the received microphone speech
`signal. The DSP 75 then places these samples in its internal
`RAM and signals the microprocessor 74 When an appropri
`ate number of samples are ready for processing. At this
`point, the microprocessor 74 reads the samples, places them
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`US 6,556,564 B2
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`7
`into a packet format consistent With a LAN protocol and the
`IP (Internet Protocol) protocol, and sends this resulting
`packet to the LAN sWitch, via the MAC 64. The resulting
`packet may, for example, be What is referred to as an “IP
`over Ethernet” format packet. The DSP 75 may also employ
`a “compression” algorithm, Whereby the number of speech
`signal samples conveyed to the sWitch