United States Patent 5
`Gillig et al.
`
`4,989,230
`[11] Patent Number:
`[45] Date of Patent:
`Jan, 29, 1991
`
`[54] CELLULAR CORDLESS TELEPHONE
`Steven F, Gillig, Roselle; Glen E.
`Pederson, St. Charles, both ofIll.
`
`Inventors:
`
`{75]
`
`Motorola, Inc., Schaumburg,Iil.
`[73] Assignee:
`{21} Appl. No: 249,041
`[22] Filed:
`Sep. 23, 1988
`[51] Unt, CLS oo ccccssceseseceeees HO4B 1/40; H04Q 7/04
`
`[SQ] WS. Che eccccsesssssssssccsssssssateeneseeee 379/59; 379/61
`[58] Field of Search «0.0... 455/89, 73; 379/63,
`379/58, 59, 61
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`saves 455/89
`3,955,140 5/1976 Stephensetal.......
`
`. 379/61
`4,481,382 11/1984 Villa-Real.....
`. 455/32
`4,491,966
`1/1985 Morcerfet al.
`
`woe 455/11
`4,627,107 12/1986 Hohlfeld etal.
`
`379/61 X
`4,659,878
`4/1987 Dinkins.........
`
`eee 379/61
`4,677,655
`6/1987 Hashimoto
`379/62
`4,682,351
`7/1987 Makino..
`
`379/61
`4,700,375 10/1987 Reed......
`. 379/61
`4,706,274 11/1987 Bakeret al.
`
`379/61
`4,741,019 4/1988 Takahashi .
`379/58
`
`4,745,632
`5/1988 Duffy ............
`. 379/61
`4,879,740 11/1989 Nagashimaetal. ..
`FOREIGN PATENT DOCUMENTS
`
`wre 379/61
`58-204640 11/1983 Japan ccccesssessceesees
`. 379/61
`63-181534 7/1988 Japan «neces
`
`379/59
`W089/04569 5/1989 PCT Int'l Appi.
`1/1986 United Kingdom ........... 379/59
`2162404
`OTHER PUBLICATIONS
`
`“Britain Offers Digital Cordless Phone Service”, by
`
`Roger Woolnough, Electronic Engineering Times,
`Dec. 14, 1987, p. 25.
`“Cordlessphone Model No. KX-T3000 EASA--
`PHONE”, published by Panasonic Company Exhibit
`D.
`“DYNATACCellular Mobile Telephone” published
`by Motorola,
`Inc.
`Instruction Manual
`No.
`68P81049E55.
`
`Primary Examiner—Keith E. George
`Attorney, Agent, or Firm—Rolland R. Hackbart
`
`ABSTRACT
`[57]
`A cellular cordless telephone (10) operates with both a
`cordless base station (180) and a cellular base station
`(190) and cellular control terminal (196). In one embodi-
`ment (FIG. 2), a cellular cordless telephone (100) in-
`cludes a cellular transceiver (120), antenna (128), key-.
`board (140), a display (180), handset (160), and mi-
`crocomputer (130) together with a cordless transceiver
`(110) and antenna (118), ali of which maybein a single
`housing. In another embodiment (FIG. 3), a cellular
`cordless telephone (200) includes a cellular telephone
`(220) and a cordless telephone transceiver (210) which
`may be a plugable module. Whenevercellular cordless
`telephone (10) is within range of cordless base station
`(180), telephone calls may be made overthe cordless
`radio channel or transferred from the cellular radio
`channels to the cordless radio channel. If the cellular
`cordless telephone (10) thereafter movesout of range of
`the cordless base station (180), telephone calls may be
`made over the cellular radio. channels or transferred
`from the cordless radio channel to one of the celluiar
`telephone channels.
`:
`
`20 Claims, 7 Drawing Sheets
`
` 198
`
`192
`
`CELLULAR
`BASE
`STATION
`
`CONTROL
`TERMINAL
`
`SAMSUNG 1045
`
`
`
`
`CORDLESS
`BASE
`STATION
`
`
`
`
`CELLULAR
`
`CORDLESS
`
`TELEPHONE
`
`
`
`COMMUNITY
`
`
`CORDLESS
`
`
`188
`BASE STATION
`
`
`
`1
`
`SAMSUNG 1045
`
`

`

`U.S. Patent
`
`Sheet 1 of 7
`
`4,989,230
`
`Jan. 29, 1991
`FIG.7
`
`181
`
`192
`
`CELLULAR
`BASE
`STATION
`
`82
`
`CORDLESS
`BASE
`STATION
`
` 128
`
`
`CELLULAR
`CORDLESS
`
`TELEPHONE
`
`
`
`
`COMMUNITY
`CORDLESS
`
`
`BASE STATION |.
`
`194
`
`
`2
`
`

`

`U.S. Patent
`
`Jan. 29, 1991
`
`Sheet 2 of 7
`
`4,989,230
`
`BL
`
`cal
`
`3sVdMOT
`
`wald-
`
`SSVdHOIH
`
`yall
`
`ZBL
`
`olan Xu
`
`tlOlt
`
`olany|MSLUNSNVYL
`SS31dY09
`
`AMLINOUID
`
`SSITGYOI
`
`YSAIZ03y
`
`3009 “05S XY yl
`
`JTGYNG XY
`
`Lvl
`
`YALNdNODOUDIN
`
`Y3AIZ03u
`
`wVINTD
`
`YALLINSNVYL
`
`AMLINDUID
`
`
`
`olany4ZL
`
`9Zl
`
`tel
`
`noo
`
`000
`
`ooo
`
`000
`
`3
`
`
`
`
`
`
`

`

`Jan, 29, 1991
`
`Sheet 3 of 7
`
`4,989,230
`
`U.S. Patent
`
`SS310Y09
`
`YALLINSNVEL
`
`4
`
`

`

`U.S. Patent
`
`Jan, 29, 1991
`
`Sheet 4 of 7
`
`4,989,230
`
`SSTICUODSVoze
`TID19aNNOO
`
`ONY100SILVALLOY
`
`
`
`ALNIEVINAYAVIdSId
`
`5
`
`
`

`

`Sheet 5 of 7
`
`4,989,230
`FIGC.6
`
`IGNORE CELLULAR PAGE -|IGNORE CORDLESS PAGE
`
`AND WAIT FOR CALL TO
`AND WATT FOR CALL TO
`BE RECEIVED
`BE RECEIVED
`ON CORDLESS
`
`U.S. Patent
`
`Jan. 29, 1991
`
`ON CELLULAR
`
`6
`
`

`

`U.S, Patent
`
`Jan. 29,1991
`
`Sheet 6 of 7
`
`4,989,230
`
`ACTIVATE CCT
`
`600
`
`ONE CALL IN PROCESS
`ON CELLULAR
`OR CORDLESS
`
`602
`
`606
`CALL
`CALL
`
`
`
`RECENED
`ORIGINATED
`
`ON OPPOSITE
`ON OPPOSITE
`
`
`SYSTEM
`. SYSYEM
`
`
`USER SELECTED
`DUAL—MODE
`
`
`
`DOES
`-
`
`USER ACK
`
`
`
` HAS
`PEATURE
`
` ALERT USER OF —
`ALTERNATE SYSTEM CALL
`
`
`SECOND CALL
`
`
`
`
`614
`
`
`
`NO
`
`HAS
`USER SELECTED
`
`
`
`3 WAY UNKING
`
`
`YES
`ENABLE 3 WAY LINKING
`CIRCUIT PROCESSING
`
`616
`
`
`
`PROCESS BOTH CALLS
`SIMULTANEOUS WITH
`SELECTION BETWEEN
`
`THEM MADE BY USER
`
`
`
` 618
`
`7
`
`

`

`U.S. Patent
`
`Jan, 29, 1991
`
`Sheet 7 of 7
`
`4,989,230
`
`FIGC.8
`
`CALL IN PROCESS
`
`700
`
`
`
`MAINTAIN CELLULAR
`CALL AS LONG AS
`
`* POSSIBLE
`
`
`
`
`
`MAINTAIN CALL AS
`LONG AS POSSIBLE
`
`4
`
`718
`
`TRANSFER CORDLESS
`CALL TO CELLULAR
`
`TRANSFER CELLULAR
`CALL TO CORDLESS
`
`8
`
`

`

`1
`
`4,989,230
`
`CELLULAR CORDLESS TELEPHONE
`
`BACKGROUNDOF THE INVENTION
`
`The present invention is generally related to cellular
`telephones and moreparticularly to an improved cellu-
`lar cordless telephone for providing both cellular and
`cordless telephone services.
`In the prior art, cordless telephones typically are used
`in the hometo allow the user to place and receivetele-
`phonecalls at any point throughout the house. Such
`cordless telephones are connected to the user’s tele-
`phone landline. However, due to their limited range,
`such cordless telephonesare notsuitable for use in vehi-
`cles. Vehicular communications are typically achieved
`by meansof radio telephone systems, the most prevalent
`being cellular telephone systems. A cellular telephone
`allows the user to place and receive telephone calls at
`any point throughout a large metropolitan area. How-
`ever, the cost of a cellular telephonecall is as much as
`seven times the cost of a cordless telephonecall, since
`cordless telephone calls are made by wayof the user’s
`telephone landline and cost the sameas landline tele-
`phonecalls, while cellular telephone calls are made by
`way of expensive cellular base stations and cellular
`switching equipment and cost much morethan landline
`telephonecalls.
`OBJECTS OF THE INVENTION
`
`-
`
`Accordingly, it is an object of the present invention
`to provide an improved cellular cordless telephone that
`may place both cellular telephone calls and cordless
`telephonecalls.
`It is another object of the present invention to pro-
`vide an improved cellular cordless telephone that auto-
`matically operates as a cordless telephone wheneverit
`is.in range of its corresponding cordless base station.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG.1 is a block diagram of a cellular cordless tele-
`phone system embodying the present invention.
`FIG.2 is a block diagram of a cellular cordless tele-
`phone embodying the present invention.
`FIG.3 is a block diagram of another embodiment of
`a cellular cordless telephone according to the present
`invention.
`FIG. 4 is a flow chart for the process used by the
`cellular cordless telephones in FIGS. 2 and 3 for placing
`and receiving cellular and cordless telephonecalls.
`FIG. 5 is a flow chart for the process used by the
`cellular cordless telephones in FIGS.2 and 3 for origi-
`nating a telephone call as a cellular telephone call or a
`cordless telephone call according to user selectable
`preference.
`:
`FIG.6 is a flow chart for the process used by the
`cellular cordless telephones in FIGS. 2 and 3 for receiv-
`ing a telephone call as a cellular telephone call or a
`cordless telephone call according to user selectable
`preference.
`.
`:
`FIG. 7 is a flow chart for the process used by the
`cellular cordless telephones in FIGS. 2 and 3 for simul-
`taneously processing both a cellular telephone call and
`a cordless telephone call and three-way linking both
`calls.
`FIG.8 is a flow chart for the process used by the
`cellular cordless telephones in FIGS. 2 and 3 for auto-
`
`5
`
`20
`
`30
`
`40
`
`45
`
`60
`
`2
`matically transfering between a cellular telephone call
`and a cordless telephonecall.
`FIG.9 is a detail circuit diagram for audio switch 150
`in FIG.2.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`
`In FIG. 1, there is illustrated a block diagram of a
`cellular cordless telephone system embodying the pres-
`ent invention. The system includes a telephone com-
`pany phone system (TELCO) 184, connected by tele-
`phone landlines to a cordless base station 180 having a
`landline telephone number located in a homeoroffice
`181 and to a community cordless base station 188 hav-
`ing a landline telephone numberin anotheroffice, build-
`ing, or other geographical location. Cordless base sta-
`tions 180 and 188 communicate with the cellular cord-
`less telephone (CCT) 10 through antennas 182 and 189.
`Antennas 182 and 189 may be implemented as telescop-
`ing whip antennas. Cordless base stations 180 and 188
`may be any conventional cordless base station, such as,
`for example, the base station shown and described in
`Panasonic operating instructions, entitled “Cordless-
`phone Model No. KX-T3000 EASA-PHONE”, pub-
`lished by and available from the Panasonic Company,
`One Panasonic Way, Secaucus, NJ, 07094. Additional
`community cordless base stations 188 may be located
`throughout a metropolitan area for providing shared
`telephone service to CCTs10.In this case, cordless base
`station 188 may include additional equipmentforbilling
`calls to the cellular telephone number of CCT 10.
`Also connected through telephone landlines to the
`same or a different telephone company phone system
`(TELCO)198 is the cellular control terminal 196 (see
`U.S. Pat. No. 4,268,722) with its associated cellular base
`station(s) 190 (see U.S. Pat. No. 4,485,486 incorporated
`herein by reference). Cellular base station 190 incorpo-
`rates both a receive antenna 192 and a transmit antenna
`194 (see U.S. Pat. No. 4,369,520 incorporated herein by
`reference) for communicating with CCTs10.
`CCT 10 may be a mobile unit installed in a vehicle, a
`transportable unit which is'a mobile unit and battery
`installed in a carrying case, or a hand-heid portableunit.
`CCT 10 includes an antenna118 for the cordless radio
`channels and an antenna 128 for the cellular radio chan-
`nels as illustrated by the embodiment of CCT 200 in
`FIG.3, or may includea single antenna,is illustrated by
`the embodiment of CCT 100 in FIG.2. In the U.S.A.,
`the cordless radio channels are in the frequency band
`from 46-49 mHz and the cellular radio channels are in
`the frequency band from 824-894 mHz.
`In FIG.2, thereis illustrated a detailed block diagram
`of a first embodiment of a CCT 100 according to the
`present invention. CCT 100 includes a cordless tele-
`phonetransceiver 110, antenna 118, cellular telephone
`transceiver 120, antenna 128, microcomputer 130, key-
`pad 140, display 180, audio switch 150, and handset 160
`including speaker 162 and microphone 164. Alterna-
`tively, as shown by dashed-lines in FIG. 2, cordless
`telephone transceiver -110 and cellular telephone trans-
`ceiver 120 may be coupled to a single antenna 119 in
`place of antennas 118 and 128 by way of low-passfilter
`185 and high-pass filter 187, respectively. Cordless tele-
`phonetransceiver 110 may be any conventional cord-
`less telephone transceiver, such. as, for example the
`transceiver shownand described in the aforementioned
`Panasonic operating instructions, entitled ‘‘Cordless-
`phone Model No. KX-T3000 EASA-PHONE”. Cellu-
`
`9
`
`

`

`4,989,230
`
`3
`lar telephone transceiver 120, microcomputer 130, key-
`pad 140, and handset 160 likewise may be any commer-
`cially available cellular transceiver, such as, for exam-
`ple, the transceiver shown and described in Motorola
`instruction manual number 68P81049E55,
`entitled
`“DYNATAC Cellular Mobile Telephone”, published
`by and available from Motorola C & E Parts, 1313 East
`Algonquin Road, Schaumburg, IL 60196.
`Referring to FIG. 9, audio switch 150 may be imple-
`mented with two-to-one multiplexing analog switches
`151-155 which select between audio signals of audio
`circuitry 116 in cordless transceiver 110 and audio cir-
`cuitry 126 in cellular transceiver 120 under control of
`select signals SELECT1, SELECT2 and LINK from
`microcomputer 130. Select signal SELECT2 enables
`switches 151 and 152 when it has a binary onestate,
`select signal SELECT1 enables switches 153 and 154
`whenit has a binary onestate, and select signal LINK
`enables switches 152, 154 and 155 whenit has a binary
`one state. Depending. on which is enabled, analog
`switches 151 and 153 couple speaker 162 to receive
`audio from audio circuitry 116 and audio circuitry 126,
`respectively. Similarly, depending on whichis enabled,
`analog switches 152 and 154 couple microphone 164 to
`transmit audio of audio circuitry 116 and audio circuitry
`126, respectively. If three-way linking is selected, ana-
`log switches 152 and 154 couple microphone 164 to
`transmit audio of both audio circuitry 116 and audio
`circuitry 126, and analog switch 155 couples speaker
`162 to receive audio of both audio circuitry 116 and
`audio circuitry 126 by way of summing amplifier 159.
`Referring to CCT 100 in FIG. 2, microcomputer 130
`is programmed in accordance with FIGS. 4-8 for oper-
`ating as a cellular telephone, a cordless telephone, or a
`cellular cordless telephone. That is, according to the
`present invention, CCT 100 may simultaneously oper-
`ate as a cellular telephone and a cordless telephone.
`When operating as a cellular telephone, control signals
`131 TX ENABLE and 132 RX ENABLE.of mi-
`crocomputer 130 enable cellular transmitter 124 and
`cellular receiver 122, respectively. In addition to con-
`trol signals 131 and 132 to cellular transceiver 120,
`microcomputer 130 also monitors control signals 133
`RSSI, 134 RX DATAand 135 TX DATAfor detecting
`signal strength, for detecting receive data and for send-
`ing transmit data, respectively, used in operation of:
`cellular transceiver 120. When operating as a cordless
`telephone, control signals 141 and 146 of microcom-
`puter 130 enable cordless receiver 112 and cordless
`transmitter 114, respectively.
`In’ addition to control
`signals 141 and 146 to cordless transceiver 110, mi-
`crocomputer 130 also monitors control signals 142 SIG-
`NAL QUALITY, 143 RING, 144 RX SECURITY
`CODEand 145 TX SECURITY CODEfordetecting
`signal strength, ringing, and the receive security code,
`and for sending the transmit security code and dialed
`digits, respectively, used in operation of cordless trans-
`ceiver 110. Dialed digits may also be encoded by key-
`pad 140 as conventional multi-frequency. tones which
`are coupled to transmit audio of cordless transceiver
`110 by audio switch 150 during cordless operation.
`Referring next to FIG.3, there is illustrated a block
`diagram of another embodiment of a cellular cordless
`telephone (CCT) 200 according to the present inven-
`tion. CCT 200 includes a cordless telephone transceiver
`210 in a separate housing with antenna 218 and connec-
`tor 270, and a cellular telephone 220 in a separate hous-
`ing with antenna 228 and connector 272. Cordlesstele-
`
`= 0
`
`fan 5
`
`40
`
`60
`
`4
`phone transceiver 210 may be a plug-in accessory
`which couples via connectors 270 and 272 to cellular
`telephone 220. When cordless telephonetransceiver 210
`is plugged into microcomputer 230 ofcellular telephone
`220, it operates in accordance with FIGS. 4-8. Cellular
`telephone 220 includescellular transmitter 222, cellular
`receiver 224, microcomputer 230, keypad 240, display
`280, audio circuitry 226, audio switch 250 and handset
`260 including speaker 262 and microphone 264. Cord-
`less telephone transceiver 210 may be any conventional
`cordless telephone transceiver, such as, for example the
`transceiver shown and described in the aforementioned
`Panasonic operating instructions, entitled ‘“Cordless-
`phone Model No. KX-T3000 EASA-PHONE”. Cellu-
`lar telephone 220 likewise may bé any commercially
`available cellular transceiver, such as, for example, the
`transceiver shown and described in the aforementioned
`Motorola instruction manual number 68P81049E55,
`entitled “DYNATAC Cellular Mobile Telephone”.
`Microcomputer 230 of cellular telephone 220 is cou-
`pled to the cordless telephone transceiver 210 via the
`same control signals used in FIG. 2. These controlsig-
`nals are TX/RX enable signals, signal quality signal,
`ring signal and TX/RX security code signals.
`Audio circuitry 226 of cellular telephone 220 is cou-
`pled to audio switch 250 which can be implemented
`with two-to-one multiplexing analog switches (see FIG.
`9) which select between audio signals from the cellular
`receiver 224 and transmitter 222 and cordless telephone
`receiver 214 and transmitter 212.
`Referring now to FIG.4, there is illustrated a flow
`chart for the process used by the CCTs 100 and 200 in
`FIGS. 2 and 3, respectively, for placing and receiving
`cellular and cordless telephone calls. Entering at block
`302, the user activates the CCT. The microcomputer
`130 and 230 monitors both the cellular and cordless
`systems for availability thereof and for incoming and
`outgoing calls. If the cellular system and/or cordless
`system are available, a corresponding availability indi-
`cator is enabled in display 180 and 280. In cellular sys-
`tems, the microcomputer scans pre-selected signalling
`channels to determine if cellular service is available.
`Next, at decision block 304, a check is made to deter-
`mine if a call has been received. If not, NO branch is
`taken to decision block 316 to determine if a call has
`beeninitiated by the user of theCCT.If not, NO branch
`is taken back to block 304 to continue monitoring both
`the cellular and cordless systems for telephonecalls.
`Returning to decision block 304, if an incomingcall
`has been received, YES branch is taken to decision
`block 306 where a check is made to determine if the
`incoming call is a cellular call. If so, YES branch is
`taken to block 308 where a cellular call indicator is
`activated or entered in display 180 and 280, and the
`incoming call
`is connected as a cellular call (e.g.,
`in
`FIG. 2, cellular transceiver 120 is enabled by mi-
`crocomputer 130). If the incomingcall is not a cellular
`call, NO branchis taken from block 306 to block 320
`wherea cordless call indicatoris activated or entered in
`display 180 and 280, and the incoming call is connected
`as a cordless call (e.g., in FIG. 2, cordless transceiver
`110 is enabled by microcomputer 130).
`Returning to decision block 316, if a call has been
`initiated by the user of the CCT, YESbranchis taken to
`decision block 318 where a check is made to determine
`if the initiated call is a cellular call. If so, YES branch is
`taken to block 308 where the initiated call is connected
`as a cellular call. If the initiated call is not a cellular call,
`
`10
`
`10
`
`

`

`4,989,230
`
`40
`
`50
`
`60
`
`5
`NO branchis taken from decision block 318 to block
`320 wheretheinitiated call is connected as a cordless
`call.
`Referring now to FIG.5, there is illustrated a flow
`chart for the process used by the CCTs 100 and 200 in
`FIGS. 2 and 3, respectively, for originating a telephone
`call as a cellular telephone call or a cordless telephone
`call according to user selectable preference.
`Entering at block 400, the user activates the CCT.
`Next, at block 402, a check is made to determineifa call
`has been originated by the CCT.If not, NO branchis
`taken to wait for a call to be originated.If a call has been
`originated, YES branch is taken from decision block
`402 to decision block 404, where a check is made to
`determineif the user’s preference is for cordless phone
`operation. If not, NO branch is taken to block 406 to
`determine if a call can be placed on the cellular system.
`If so, YES branch is taken to block 416 where the call
`origination is connected as a cellular call. If not, NO
`branch is taken to decision block 408 to determine if a
`call can be successfully placed on the cordless system.
`Referring back to decision block 404,if preferenceis for
`cordless, YES branch is also taken to decision block
`408. If a cordiess cali can be successfully placed, YES
`branch is taken from decision block 408 to decision
`block 414 wherethe call is connected as a cordless call.
`If not, NO branch is taken to decision block 410 to
`determineif a call had been tried unsuccessfully on the
`cellular system. If so, YES branchis taken to block 402
`to wait for a call origination. If not, NO branchis taken
`to decision block 406 to determine if the call can be
`placed on the cellular system.
`Referring now to FIG.6, there is illustrated a flow
`chart for the process used by the CCTs 100 and 200 in
`FIGS.2 and 3, respectively, for receiving a telephone
`call as a cellular telephone call or a cordless telephone
`call according to user selectable preference.
`Entering at block 500, the user activates the CCT.
`Next, at decision block 502, a check is made to deter-
`mine if a call is being received by the CCT.If not, NO
`branchis. taken back to decision block 502. If a call has
`been received, YES branchis taken from decision block
`502 to decision block 504 to determine if the user’s
`system preference matches the system of the incoming
`call. If so, YES branchis taken to decision block 508 to
`determine if the call is on the cordless system. If so, the
`YES branchis taken to block 510 where the incoming
`call is connected as a cordless call. If not, the NO
`branchis taken to block 512 where the incomingcall is
`connected as a cellular call.
`Returning to decision block 504, if the user’s system
`preference does not match the system of the incoming
`call, NO branchis taken to decision block 506 to deter-
`mine if the preference is for the cordless system.If so,
`the YESbranchis taken to decision block 514 to deter-
`mine if the CCT is within range of the cordless base
`station (e.g., by sending the transmit security code and
`waiting for the receive security code from the cordless
`base station). If not, the NO branchis taken to block 512
`where the incomingcall is connected as a cellular call.
`If the cellular cordless telephone is within range of the
`cordless base station, YES branchis taken from decision
`block 514 to decision block 516 to determine if the
`cellular system will forward the unanswered incoming
`call to the landline of the cordless base station when the
`cellular phone cannotbe reached. This type ofservice is
`generally referred to as “call forwarding” (a process
`whichredirects a call from the dialed cellular telephone
`
`11
`
`6
`numberof CCT 10 to the landline telephone numberof
`cordless base station 180) and can be determined by
`polling stored information in the memory associated
`with the CCT microcomputer. If not, NO branch is
`taken to block 512 where the incomingcall is connected
`as.a cellular call. If the cellular system will forward the
`unanswered incoming call, YES branch is taken from
`decision block 516 to block 518 wherethecellular page
`from the cellular base station is ignored and thereafter
`to decision block 502 to wait for the incoming call to be
`received as a cordless call.
`Returning to decision block 506, if the preference is
`for a cellular call, NO branchis taken to decision block
`520 to determine if the CCTis within rangeofthe cellu-
`lar base stations (does it have cellular service). This is
`typically determined by scanning and selecting the
`strongestsignalling channel from the surrounding cellu-
`lar base stations. If not, NO branchis taken to block 510,
`where the incomingcall is connected as a cordless call.
`If the CCTis within range of the cellular base stations,
`YESbranchis taken from decision block 520 to decision
`block 522 to determine if the landline system will for-
`ward the unanswered incoming call to the cellular sys-
`tem. This typeofservice is generally referred to as “call
`forwarding” and can be determined bypolling stored
`information in the memory associated with the CCT
`microcomputer. If not, NO branchis taken to block 510
`where the incoming call is connected as a cordless call.
`If the landline telephone system will forward the unan-
`swered incoming call, YES branch is taken from deci-
`sion block 522 to block 524 where the cordless page
`from the cordless basestation is ignored and thereafter
`back to decision block 502 to wait for the incomingcall
`to be received as a cellularcall.
`Referring now to FIG. 7, thereis illustrated a flow
`chart for the process used by the CCTs 100 and 200 in
`FIGS.2 and3, respectively, for simultaneously process-
`ing both a cellular telephone call and a cordless tele-
`phonecall and, if desired, three-way linking both calls.
`Entering at block 600, the user activates the CCT.
`Next, at block 602, one call is assumed to be in process
`on either the cellular system or cordless system. Pro-
`ceeding from block 602 to decision block 604, a checkis
`made to determine if a call has been received on the
`opposite system from the call in process. If so, YES
`branchis taken to decision block 608 to determineif the
`user has selected the dual-mode feature (e.g., by enter-
`ing a predetermined code from the keypad). If not, NO.
`branchis taken back to decision block 604 and the cur-
`rent call remains in process. If the user has selected the
`dual-mode feature, YES branchis taken from decision
`block 608 to block 610 which alerts the user of an in-
`comingcall on the alternate system. This type of service
`is generally referred to as “call waiting”. Next, at deci-
`sion block 612, a check is made to see if the user ac-
`knowledges the secondcall. If not, NO branchis taken
`- back to decision block 604 and the currentcall remains
`in process. If the user acknowledges the second call
`(e.g., by flashing the hookswitch), YES branchis taken
`from decision biock 612 to decisionblock 614 to deter-
`mine if the user has selected three-way linking (e.g., by
`entering a predetermined code from the keypad). If so,
`YESbranchis taken to block 616 which enables three-
`waylinking of the user and the twocalls, each of which
`is on a different system. Three-way linking may be
`accomplished by switchably coupling the combined
`receive audio signals from summing amplifier 159 via
`analog gate 155 to the speaker, and enabling both trans-
`
`11
`
`

`

`4,989,230
`
`45
`
`50
`
`8
`7
`mit audio switches 152 and 154 in FIG.9. If the user has
`are preferably originated on the cordless system, or if
`not selected three-way linking, NO branchis taken from
`currently in process, are transferred to the cordless
`decision block 614 to block 618 to process both calls
`telephone system.
`:
`Weclaim:
`simultaneously, one over each system, but selection
`between them is madebythe user so that only one party
`1. A cellular cordless telephone for making and re-
`is in conversation with the user at a time. Selection
`-ceiving cellular telephone calls on cellular radio chan-
`between the calls may be made pressing a pre-selected
`nels of a cellular telephone system and cordless tele-
`key or set of keys on the keypad.
`phonecalls on at least one cordless radio channel of a
`Returning to decision block 604, if a call has not been
`base station coupled to a telephone landline having a
`received on the opposite system, NO branchis taken to
`landline telephone number, said cellular cordless tele-
`decision block 606 to determineif a call has been origi-
`phone comprising in combination asasingle unit:
`nated on the opposite system. If not, NO branchis taken
`a cellular telephoneincludingafirst antenna, cellular
`back to decision block 604. If a call has been originated
`transceiver means having a cellular telephone num-
`on the opposite system, YES branchis taken from deci-
`ber and being coupled to said first antenna for
`sion block 606 to decision block 614 to determineif the
`communicating cellular telephonecalls on cellular —
`user wants three-waylinking, as described hereinabove.
`radio channels, and control means coupled to said
`Referring now to FIG.8, there is illustrated a flow
`cellular transceiver means for making and receiv-
`chart for the process used by the CCTs 100 and 200 in
`ing cellular telephone calls; and
`FIGS.2 and3, respectively, for automatically transfer-
`cordless transceiver means including a second an-
`ing between a cellular telephone call and a cordless
`tenna for communicating cordless telephone calls
`telephonecall.
`a
`on the cordiess radio channel, and said control
`Entering at block 700, the user activates the CCT.
`means further being coupled to said cordless trans-
`Next at block 702, a call is assumed to be in process on
`ceiver means for making and receiving cordless
`one of the two systems. Proceeding from block 702 to
`telephonecalls.
`decision block 704, a check is made to determine if the
`2. The cellular cordless telephone according to claim
`call in process is on the cordless system. If so, YES
`1, further including first housing means for enclosing
`branchis taken to decision block 708 to determine if the
`said cellular telephone and‘second housing means for
`CCTis still within range of the cordless base stations
`enclosing said cordless transceiver means, said first
`(e.g., Signal quality is good). If so, YES branchis taken
`housing meansincluding first connector means coupled
`back to decision block 704. If the cellular cordless tele-
`to said control means, and said second housing includ-
`phoneis out of range of the cordless base stations, NO
`branch is taken from decision block 708 to decision
`ing second connector means coupled to said cordless
`biock 710 to determineif the user has selected transfer
`transceiver means and adapted to be coupled to said
`first connector means.
`of the cordless call to the cellular system (e.g., by enter-
`3. The cellular cordless telephone according to claim
`ing a predetermined code from the keypad). If so, YES
`1, further including display means for providingafirst
`branch is taken to block 714 where an attempt is made
`visual indication of a cellular telephone cail and a sec-
`to transfer the cordless call to the cellular system. As-
`ond visual indication of a cordless telephonecall.
`suming thecalled party has “call waiting”, the transfer
`4. The cellular cordless telephone according to claim
`‘is attempted by placing another call on the cellular
`1, further including display means for providinga first
`system and waiting for the called party to answer.
`visual indication of the availability of one ofthe cellular
`Thereafter, the path returns to decision block 704. If the
`radio channels and a second visual indication of the
`user has not selected call transfer, NO branch is taken
`from decision block 710 to block 712 where the cordless
`availability of the cordless radio channel.
`5. A cellular cordless telephone for making and re-
`call is maintained as long as possible.
`ceiving cellular telephonecalls on cellular radio chan-
`Returning to decision block 704,if the call is not on
`nels of a cellular telephone system and cordless tele-
`the cordless system, NO branch is taken to decision
`phonecalls on at least one cordless radio channel of a
`block 706 to determineif the CCTisstill within range of
`base station coupled to a telephone landline having a
`the cellular base stations(e.g., signal quality is good). If
`so, YES branchis taken back to decision block 704. If
`landline telephone number, said cellular cordless tele-
`phone comprising in combination as a single unit:
`the CCTis out of rangeof the cellular base stations, NO
`branch is taken from decision block 706 to decision
`a cellular telephone having a cellular telephone num-
`block 716 to determine if the user has selected transfer
`berand including a handset,a first antenna,cellular
`transceiver means coupledto said first antenna for
`of the cellularcall to the cordless system (e.g., by enter-
`communicating cellular telephonecails on cellular
`ing a predetermined code from the keypad). If not, NO
`branchis taken to block 720 where the cellular call is
`radio channels, and control means coupled to said
`maintained as long as possible. If the user has selected
`cellular transceiver means for making and receiv-
`call transfer, YES branch is taken from decision block
`ing cellular telephone calls;
`716 to block 718 where an attempt is madeto transfer
`cordless transceiver means including a second an-
`the cellular call to the cordless system. Assuming the
`tenna for communicating cordless telephone calls
`on the cordless radio channel, and said control
`called party has “‘call waiting”, the transfer is attempted
`by placing anothercall on the cordless system and wait-
`meansfurther being coupled to said cordless trans-
`ing for the called party to answer. Thereafter, the path
`ceiver means for making and receiving cordless
`returns to decision block 704.
`telephone calls; and
`In summary, a unique cellular cordless telephone has
`audio switching means responsive to said control
`been described that may be advantageously utilized for
`means for coupling said cellular transceiver means
`making both cellular telephone calls and cordless tele-
`to said handset during cellular telephone calls and
`phonecalls. Wheneverthecellular cordless telephoneis
`coupling said cordless transceiver mean