United States Patent [19]
`Byrne
`
`[54] MULTI-MODE RADIO TELEPHONE
`
`[75]
`
`Inventor: John D. Byrne, Shepperton, United
`Kingdom
`
`[73] Assignee: Nokia Mobile Phones Ltd., Salo,
`Finland
`
`[21]
`
`Appl. No.: 407,682
`
`[22]
`
`Filed:
`
`Mar. 21, 1995
`
`[30]
`
`Foreign Application Priority Data
`
`[GB] United Kingdom ................... 9405659
`
`Mar. 22, 1994
`Int. Cl.6
`.................•...•..•........................•...•. H04Q 7/38
`[51]
`[52] U.S. Cl . ................................. 379/58; 379/59; 379/61;
`370/95.3
`[58] Field of Search .................................. 379/58, 59, 60,
`379/61; 370/95.1-95.3
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`3,836,721
`4,989,230
`5,127,042
`
`9/1974 Sugioka .
`1/1991 Gillig et al ............................... 379/59
`6/1992 Gillig et al ............................... 379/59
`
`100
`
`110
`
`\ ~ - - ' - - - -~
`
`OFFICE
`
`114
`
`CORDLESS
`BASE
`STATION
`
`I 1111111111111111 11111 lllll lllll 111111111111111 1111111111111111 Ill lllll llll
`US005533099A
`[11] Patent Number:
`[ 45] Date of Patent:
`
`5,533,099
`Jul. 2, 1996
`
`5,212,684
`5,260,988
`5,367,558
`5,392,462
`5,442,680
`5,463,674
`
`5/1993 MacNamee et al ...................... 379/61
`11/1993 Schellinger et al. ................. ..... 379/59
`11/1994 Gillig et al. ............. ................. 379/59
`2/1995 Komaki ..................................... 379/59
`8/1995 Schellinger et al. ...................... 379/58
`10/1995 Gillig et al. .............................. 379/59
`
`FOREIGN PATENT DOCUMENTS
`
`2249922
`2270237
`
`5/1992 United Kingdom .
`3/1994 United Kingdom .
`
`Primary Examiner-Dwayne D. Bost
`Attorney, Agent, or Firm-Perman & Green
`
`[57]
`
`ABSTRACT
`
`A radio telephone (200) is operable in a cordless telephone
`system or in a cellular telephone system, in each of which
`reception and transmission occur in time slots. A micropro(cid:173)
`cessor (210) of the telephone has an additional control entity
`(212) which predicts temporal overlap or coincidence of
`receive and transmit slots in the two systems. This informa(cid:173)
`tion is used either to alter the time slots to avoid the
`predicted overlap or coincidence or to reduce the effect of
`interference, for example by muting certain slots or repeat(cid:173)
`ing signals in previous slot or slots.
`
`10 Claims, 4 Drawing Sheets
`
`120
`
`134 v
`
`CELLULAR
`BASE
`STATION
`
`130
`
`117
`
`/
`
`PSTN
`
`~ / . - -~ - - - - - ' - " - - - , 238
`
`CELLULAR
`CORDLESS
`TELEPHONE
`
`COMMUNITY
`CORDLESS
`BASE STATION
`
`118
`
`200
`
`136
`
`138
`
`BASE
`STATION
`CONTROLLER
`
`MOBILE
`SWITCHING
`CENTRE
`
`137
`
`VLR
`
`HLR
`
`139
`
`117
`
`Ex.1034
`APPLE INC. / Page 1 of 8
`
`

`

`\.a = \0
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`
`PSTN
`
`139
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`
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`
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`SWITCHING
`
`MOBILE
`
`CONTROLLER
`
`STATION
`
`BASE
`
`138
`
`136
`
`200
`
`118
`
`TELEPHONE
`CORDLESS
`CELLULAR
`
`"-----238
`
`BASE STATION
`
`CORDLESS
`COMMUNITY
`
`119/
`
`PSTN
`
`117
`
`STATION
`
`BASE
`
`CORDLESS
`
`114
`
`130
`
`STATION
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`BASE
`
`CELLULAR
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`STATION
`
`CORDLESS
`
`BASE
`
`116
`
`134 v
`
`132 ~
`
`l.--o-FF-1c_E__,__ ____________ I
`
`110
`
`100
`
`\
`
`Fig.1.
`
`Ex.1034
`APPLE INC. / Page 2 of 8
`
`

`

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`----200
`
`PREDICTOR n
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`CLASH ~
`
`~
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`'----
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`TEMPORAL
`
`PROCESSOR
`
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`
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`
`REGISTER
`AVAILABLE
`SERVICE
`
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`
`205
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`
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`V
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`232 j
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`...
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`
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`
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`
`231)
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`
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`
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`y
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`
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`
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`
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`
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`
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`
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`
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`
`Fig.2.
`
`Ex.1034
`APPLE INC. / Page 3 of 8
`
`

`

`U.S. Patent
`
`Jul. 2, 1996
`
`Sheet 3 of 4
`
`5,533,099
`
`Fig.3.
`
`~ - - - - - - -FRAME - - - - - - - . . . . . ,
`I
`7
`4
`:sLOT0 1
`6
`2
`5
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`
`5 ..... 0
`
`4
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`
`1
`I
`
`2
`
`I
`
`Fig.4.
`
`CALCULATE TIMING
`OF RECEIVE/
`MONITOR SLOT
`
`CALCULATE PARAMETERS
`FOR INTERFERING
`TRANSMISSION SLOTS
`
`USE EQUATION (1) TO TEST
`FOR OVERLAP OF TRANSMISSION
`WITH RECEIVE/ MONITOR
`
`TAKE
`YES
`---~-COUNTER
`MEASURES
`
`!NO
`
`CONTINUE
`
`Ex.1034
`APPLE INC. / Page 4 of 8
`
`

`

`U.S. Patent
`
`Jul. 2, 1996
`
`Sheet 4 of 4
`
`5,533,099
`
`Fig.5.
`
`SLOT CLASH PREDICTED
`
`y
`,w
`
`SELECT SLOT WITH NO
`CLASH FOR MAXIMUM TIME
`POSSIBLE
`, .
`PERFORM HANDOVER TO THE
`NEW SLOT
`
`j l
`
`Fig.6.
`
`SCALING
`
`COEFFICIENT
`1: NO CLASH
`<1:: CLASH
`
`BIT DETECTION
`
`CLASH
`PREDICTION
`
`VITERBI
`DECODER
`
`DECODED
`BITS
`
`Ex.1034
`APPLE INC. / Page 5 of 8
`
`

`

`5,533,099
`
`1
`MULTI-MODE RADIO TELEPHONE
`
`FIELD OF INVENTION
`
`The present invention relates to a radio telephone, and in 5
`particular to a radio telephone operable in more than one
`system and to a method of operating such a radio telephone.
`
`BACKGROUND TO INVENTION
`
`2
`so-called cellular radio telephone systems having base sta(cid:173)
`tions which cover a wide geographical area (cell), eg 35 km
`diameter. However, in urban areas where the user density is
`high the cells are much smaller and operate at lower powers
`to facilitate frequency re-use thereby increasing the com(cid:173)
`munication channel density.
`Cellular systems have advantages over cordless systems
`since they allow a user to place and receive calls over a large
`area. Additionally they are suitable for use in moving
`lO vehicles. This is because cellular telephone systems have
`sophisticated handover procedures to facilitate switching
`between cells as a user's vehicle crosses from one cell to
`another. This ensures continuity of service and is particularly
`important during a call. However, the cost of a cellular
`telephone call is significantly greater than the cost of a
`cordless telephone call, since cordless telephone calls are
`made by way of the user's land line PSTN link and cost the
`same as Iandline calls, whilst cellular telephone calls arc
`made by way of expensive cellular base stations and cellular
`20 switching equipment and cost much more than land line
`telephone calls.
`In order for a user to be able to utilise both cellular and
`cordless telephone systems via a single radio telephone
`handset a so-called cellular cordless telephone (CCT) has
`25 been proposed in U.S. Pat. No. 4,989,230.
`Time Division Multiple Access (TDMA) telephones
`divide time into a number of slots during which the tele(cid:173)
`phone receives, transmits or does neither. A single mode
`telephone can therefore arrange never to have receive while
`it is transmitting and this has the benefit that self-interfer-
`ence of the transmit channel into the receive channel is
`avoided. With a multi-mode radio telephone this condition
`may no longer be true, as interference between modes
`becomes possible. The invention aims to solve this problem.
`
`15
`
`30
`
`35
`
`Over the last ten years there has been a rapid growth in the
`use and availability of radio telephone systems. As part of
`this growth there has been a proliferation of different types
`of radio telephone system, offering the user a variety of
`services, geographical coverage and cost. Many of these
`different radio telephone systems cover the same, or a part
`of the same, geographical area as each other. Typically,
`different radio systems operate on different radio frequen(cid:173)
`cies, utilise different modulation techniques, signalling tech(cid:173)
`niques and intra-system protocols etc. to each other. Thus, a
`radio telephone designed for one system is generally unable
`to be used on another system. Thus if a user wishes to have
`access to more than one system it is necessary to have either
`more than one radio telephone or a radio telephone capable
`of operating in more than one system. Having more than one
`radio telephone is inconvenient for the user. Known radio
`telephones capable of operating in more than one system
`typically consist of little more than two separate telephones
`combined in a single housing. The preference for operating
`in a particular system is user defined as disclosed in U.S. Pat.
`No. 4,989,230.
`A particularly useful and appropriate environment for
`multi-mode radio telephones is the recently available cellu-
`lar and cordless telephone systems. In the prior art, cordless
`telephones are typically used in the home and office to allow
`the user to place and receive calls at any point throughout the
`house via an RF link with a home base station located within
`the house or office. Such cordless telephones are connected
`via the home base station to the user's telephone Iandline
`which is in turn connected to the Public Switched Telephone 40
`Network (PSTN). Further, there are known second genera(cid:173)
`tion cordless telephone systems such as CT-2 or DECT
`which are digital systems. Such CT-2 or DECT systems
`extend beyond conventional domestic operation of cordless
`telephones by allowing the user to establish an RF link 45
`between a CT-2 or DECT radio telephone and a base station
`in a more publicly accessible location, eg outside the user's
`home, a railway station, shopping mall or airport. Such base
`stations are known as telepoint base stations and are linked
`to the PSTN in much the same way as a home base station. 50
`Some cordless (and in particular DECT) radio telephones,
`are now able to receive calls via telepoint base stations
`whereas hitherto they were only able to place them. A
`description of such a system can be found in PCT Interna(cid:173)
`tional Patent Application WO 92/03006. Thus, placing and 55
`receiving calls whilst geographically roaming is possible in
`cordless telephone systems.
`However, cordless telephone systems are generally low
`power systems and each base station provides telecommu(cid:173)
`nications within only approximately a 150 meter radius of 60
`the base station, dependent upon the terrain and any man(cid:173)
`made objects which could interfere with signalling between
`a cordless telephone handset and the base station. Such
`systems arc generally only used in areas of high user density
`and thus tend to be limited to urban areas. This clearly 65
`restricts the geographical mobility of a CT-2, DECT or the
`like cordless telephone user. In the prior art there are known
`
`BRIEF SUMMARY OF THE INVENTION
`
`According to one aspect of the invention there is provided
`a radio telephone operative in two telephone systems in each
`of which transmission and reception occur in time slots, the
`radio telephone comprising first means for predicting the
`temporal overlap or coincidence of receive and transmit
`slots in the two systems and second means, responsive to the
`first means, for avoiding or reducing the interference con(cid:173)
`sequent upon the predicted overlap or coincidence.
`Preferably, the radio telephone operates in TDMA and
`may itself be responsible for making channel selection, as in
`DECT (Digital European Cordless Telephone).
`The second means may be operative to alter the time slots
`in which transmission or reception occurs to avoid the
`incidence of overlap or coincidence. Alternatively, the sec(cid:173)
`ond means may utilise knowledge of the predicted overlap
`or coincidence to reduce the extent of interference. For
`example, the second means may be operative to effect
`muting in time slots during which interference is predicted
`to occur, or may be operative to repeat signals in a previous
`slot or slots.
`According to another aspect of the invention there is
`provided a method of operating a radio telephone which is
`operative in two telephone systems in each of which trans(cid:173)
`mission and reception occur in time slots, comprising pre(cid:173)
`dicting the temporal overlap or coincidence or receive and
`transmit slots in the two systems and using the prediction to
`avoid or reduce the interference consequent upon, the pre(cid:173)
`dicted overlap or coincidence.
`
`Ex.1034
`APPLE INC. / Page 6 of 8
`
`

`

`5,533,099
`
`5
`
`3
`The two telephone systems are preferably a macro-cellu(cid:173)
`lar system (eg so-called "cellular") and a micro-cellular
`system (eg so-called "cordless") respectively.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a block diagram of two telephone systems (one
`cellular and the other cordless) and a cellular cordless
`telephone according to the invention,
`FIG. 2 is a block diagram of the cellular cordless tele(cid:173)
`phone of FIG. 1,
`FIG. 3 is a block diagram illustrating how time slot
`interference can occur, and
`FIGS. 4 to 6 are logic diagrams illustrating how a micro(cid:173)
`processor of the radio telephone predicts time slot interfer(cid:173)
`ence and reduces its deleterious effects on signal quality.
`
`DETAILED DESCRIPTION OF EMBODIMENTS
`OF THE INVENTION
`
`4
`FIG. 2 illustrates a detailed block diagram of an embodi(cid:173)
`ment of a CCT 200 in accordance with the present invention.
`The CCT 200 comprises a cellular telephone transceiver 230
`and antenna 238, a cordless telephone transceiver 220 and
`antenna 228, a microprocessor 210, keypad 201, display
`205, audio switch 260, microphone 261 and speaker 262.
`The microphone 261, speaker 262 and keypad 201 may
`alternatively be located in a handset separate from the rest of
`the CCT 200. An alternative embodiment is shown by
`IO dashed line 272, in which cordless transceiver 220 and
`cellular transceiver 230 may be coupled to a single antenna
`238 by way of band pass filter (BPF) 270 and a band pass
`filter (BPF) 271, respectively. The cordless telephone trans(cid:173)
`ceiver 220 may be any conventional cordless transceiver.
`15 However, it would be advantageous if the cordless telephone
`transceiver 220 conformed to a common air interface for
`cordless telephones, since this would facilitate roaming of
`the CCT 200 between different cordless systems. The cel(cid:173)
`lular transceiver 230 may likewise be any conventional
`20 cellular transceiver. The keypad 201, microprocessor 210,
`display 205 and the like can be any available type, connected
`and arranged to operate in the CCT 200. The microprocessor
`210 includes a Service Available Register (SAR) 221 for
`storing which radio systems arc currently available to the
`25 CCT 200.
`When operating as a cordless telephone control signals
`from the microprocessor 210 enable cordless receiver 221
`and cordless transmitter 222. The microprocessor 210 also
`monitors signals from the cordless receiver 221, indicating
`received signal strength and for detecting receive data, and
`from the cordless transmitter 222 for sending transmit data.
`Additionally, the microprocessor 210 monitors control sig(cid:173)
`nals from the cordless transceiver 220 for detecting incom(cid:173)
`ing calls (ringing), security codes and broadcast information
`35 relevant to the cordless system, and for sending dialling
`information.
`The microprocessor 210 controls the CCT 200 in a similar
`way when operating as a cellular telephone, but appropri(cid:173)
`ately modified for the signalling protocols and data encryp-
`tion used in the cellular system. The signalling protocols,
`data encryption techniques and the like used in respective
`telephone systems, are well known in the art, and the
`microprocessor can be arranged to operate in a known
`manner to effect control of the signals in such systems.
`The audio switch 260 is controlled by the microprocessor
`210 to link the cordless audio channel 240 or the cellular
`audio channel 250 to the microphone 261 and loudspeaker
`262 as appropriate.
`The CCT 200 operates in TDMA. Being a dual mode
`telephone, the timing structures of one mode will not be
`synchronous with the timing structures of the other mode.
`Therefore, the TDMA slots of one mode will, with the
`passage of time, "slide across" the TDMA slots of the other
`55 mode. This is illustrated in FIG. 3 where the upper row of
`time slots (marked MODE A) represents the time slots in the
`cordless mode and the lower row of time slots (marked
`MODE B) represents the time slots in the cellular mode. In
`FIG. 3, "T' represents Transmit, "R" represents Receive and
`60 "I" represents Idle or Monitor. In the example of FIG. 3, it
`can be seen that there is partial overlap between T and R
`slots in slots O and 4 of the cordless mode. Hence, interfer(cid:173)
`ence is likely to occur in these slots, but by recourse to the
`invention this interference can be avoided or at least mini-
`65 mised.
`It will be appreciated that the receive and transmit fre(cid:173)
`quencies in either mode could be different, ie either MODE
`
`40
`
`An embodiment of the invention will now be described,
`by way of example, with reference to the accompanying
`drawings.
`FIG. 1 illustrates a block diagram of cellular and cordless
`telephone systems 100 with either of which a cellular
`cordless telephone 200 can communicate. In practice there
`will be a plurality of telephones 200. The systems include a
`Public Switched Telephone Network (PSTN) 117, connected
`by landlines to cordless base stations 114, 116 and 118 30
`having respective landline telephone numbers and respec(cid:173)
`tively located in an office building 110, domestic residence
`120 and some other geographical location.
`The cordless base stations 114, 116 and 118 communicate
`with the cellular cordless telephone (CCT) 200 via respec(cid:173)
`tive antennas 112, 119 and 122. The antennas 112, 119 and
`122 may be implemented as any sort of suitable antenna
`such as a whip antenna, helical antenna or printed antenna.
`The cordless base stations 114 and 116 may be conventional
`cordless base stations. A cordless base station 118 is a
`community cordless base station and such base stations may
`be located throughout an urban area, or common user area
`such as a railway station, shopping mall or airport, for
`providing a shared telephone service to CCTs 200. In such
`a case, the cordless base station 118 may include additional
`equipment not usually found in conventional cordless base
`stations for billing calls to a telephone number of the CCT
`200.
`Also connected through telephone landlines to the PSTN 50
`117 is the mobile switching centre (MSC) 138 associated
`with Base station controllcr(s) (BSC) 136 for controlling a
`cellular base station(s) 130. The cellular base station 130
`comprises both a receive antenna 132 and a transmit antenna
`134 for communicating with CCTs 200.
`The CCT 200 may be a mobile unit installed in a vehicle,
`a so called transportable unit, or a hand-held portable unit.
`The CCT 200 comprises an antenna 228 for cordless com(cid:173)
`munication and an antenna 238 for cellular communication.
`The CCT 200 may alternatively comprise a single antenna
`238 for both cellular and cordless communication and
`arranged as illustrated in FIG. 2 by the dotted line 272.
`Typically in the UK cordless telephone systems operate in
`frequency bands DECT 1.88-1.9 GHZ and CT2 864--868
`MHz and cellular telephone systems in frequency bands
`890-905 MHz and 935-950 MHz (TACS) or 905-915 MHz
`and 950-960 MHz (GSM).
`
`45
`
`Ex.1034
`APPLE INC. / Page 7 of 8
`
`

`

`5,533,099
`
`10
`
`5
`Aor MODE B could be FDMA (frequency division multiple
`access), as in GSM. Also, the receive and transmit frequency
`bands could be the same, ie time division duplex, as in
`DECT.
`A dual mode TDMA radio telephone usually carries out 5
`measurements in its receive radio channels to determine
`which is more likely to offer the better performance. This is
`normally carried out by measuring the received power in
`each receive slot and for each frequency. This information is
`then either used by the telephone to set up radio links or else
`transmitted to the base station for use thereby.
`In addition to the received signal strength information, the
`CCT 200 uses its own knowledge of where its modes are
`transmitting in time to avoid temporal overlap or coinci(cid:173)
`dence, so-called temporal clashes. To provide this function,
`the microprocessor 210 incorporates an additional control
`entity or module 212 (FIG. 2) in the form of a temporal clash
`predictor. To this control entity 212, information is sent
`regarding which time slots are in use. The control entity or
`module 212 then sends to each mode control information
`indicating in which time slots a temporal clash is predicted.
`The CCT 200 thus predicts the temporal coincidence of
`receive and transmit slots from the two modes and then takes
`avoiding action or utilises knowledge of probable error in 25
`some other way. The process involves:
`a) prediction of a temporal clash, and
`b) avoiding action or damage limitation.
`Considering first prediction of a temporal clash, in the
`general case it must be assumed that the timing of the modes
`are relatively asynchronous. Clashes may appear to be
`relatively random but the CCT 200 has knowledge of the
`timing of each mode. The CCT 200 predicts when trans(cid:173)
`mission occurs in each mode. The CCT 200 can then
`determine whether a certain time has a transmission from 35
`each of the modes by testing the condition.
`
`NTf+ To<t<NTf+ To+ Tslot
`
`(Equation 1)
`
`where
`N: Integer 0,1,2 ... (any integer)
`Tf: Frame time
`To: A time offset, a constant
`t: Time for applying test
`Tslot: Slot duration
`If a given time fits this condition then a transmission is
`occurring.
`The prediction may be carried out for both modes or just
`for one mode, depending on
`the counter-measures
`employed.
`The logic steps carried out by the additional control entity
`or module 212 of the microprocessor 210 are illustrated in
`the diagram of FIG. 4 which shows how the module 212
`utilises Equation 1 above.
`The avoidance of temporal clashes is particularly suitable
`for radio interfaces employing dynamic channel allocation
`(DCA) controlled by the CCT 200. This is where the
`communication channels are selected by the CCT 200 and
`the radio channel supports rapid re-allocation. The predic(cid:173)
`tion of a time clash will normally be made by the CCT 200
`well in advance, to enable the DCA algorithms performed in
`the microcontroller to change to a new slot position. That
`new slot position is selected to give the maximum time
`before another temporal clash occurs. The affected commu(cid:173)
`nication is then handed over to the newly selected slot. This
`particular counter-measure is best suited to the case where
`
`6
`slot clashes are less frequent. This particular logic sequence,
`carried out in the control entity or module of the micropro(cid:173)
`cessor, is illustrated in FIG. 5.
`Instead of changing to a new slot position, the CCT 200
`may operate to reduce the extent of interference. Following
`prediction of a clash, this method uses the information to
`reduce the perceived effect to the equipment user. The
`method actually utilised will depend upon the communica(cid:173)
`tion structure, for example if bit interleaving between dif(cid:173)
`ferent frames is used then the method will be different than
`if it is not. Two examples are given.
`The first example relates to a system with no interleaving
`of bits between the frames, eg DECT. In this case, if a clash
`is detected and it is known that clashes reduce speech
`quality, then that frame may be deleted and replaced with a
`l5 repetition of the last received word. Alternatively, a mute
`word could be sent to the speech codec.
`The second example concerns a system employing inter(cid:173)
`leaving and correction coding with soft decision inputs, eg
`GSM. In this case, the bits received in the predicted cor-
`20 rupted slot are scaled by a factor to indicate their lack or
`reliability. The code is then corrected by use of the Viterbi
`algorithm, as illustrated in FIG. 6.
`What I claim is:
`1. A radio telephone operative in two radio telephone
`systems in each of which transmission and reception occur
`in time slots, the radio telephone comprising first means for
`predicting the temporal overlap or coincidence of receive
`and transmit slots in the two systems and second means,
`responsive to the first means, for avoiding or reducing the
`interference consequent upon the predicted overlap or coin-
`30 cidence.
`2. A radio telephone according to claim 1, wherein the
`radio telephone operates in TDMA.
`3. A radio telephone according to claim 1, wherein the
`radio telephone is responsible for making channel selection.
`4. A radio telephone according to claim 1, wherein the
`second means are operative to alter the time slots in which
`transmission or reception occurs to avoid the incidence of
`overlap or coincidence.
`5. A radio telephone according to claim 1, wherein the
`40 second means utilise knowledge of the predicted overlap or
`coincidence to reduce the effect of interference.
`6. A radio telephone according to claim 5, wherein the
`second means are operative to effect muting in the time slots
`during which interference is predicted to occur.
`7. A radio telephone according to claim 5, wherein the
`second means are operable to repeat signals in a previous
`time slot or slots.
`8. A radio telephone according to claim 7, wherein the first
`and second means are incorporated in a microprocessor of
`the radio telephone.
`9. In combination, a micro-cellular telephone system, a
`macro-cellular telephone system, in each system transmis(cid:173)
`sion and reception occurring in time slots, and at least one
`radio telephone capable or operating in either system, the
`combination comprising first means for predicting the tem-
`55 poral overlap or coincidence of receive and transmit slots in
`the two systems and second means, responsive to the first
`means, for avoiding or reducing the interference consequent
`upon the predicted overlap or coincidence.
`10. A method of operating a radio telephone which is
`60 operative in two telephone systems in each of which trans(cid:173)
`mission and reception occur in time slots, comprising pre(cid:173)
`dicting the temporal overlap or coincidence of receive and
`transmit slots in the two systems and using the prediction to
`avoid or reduce the interference consequent upon the pre-
`65 dieted overlap or coincidence.
`
`45
`
`50
`
`* * * * *
`
`Ex.1034
`APPLE INC. / Page 8 of 8
`
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