`
`International Bureau
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`
`
`
`PCT/GB93/00235
`
`Published
`With intemott'onot seam}: report.
`Before the expiration of the time limit for amending the
`dainty and to be repubttsheo’ in the event of the receipt of
`amendments.
`
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`
`
`
`(51} International Patent Classification 5 :
`W0 93f15566
`
`(11} International Publication Number:
`
`19 August 1993 (19.08.93)
`H040 7N4, H0413 7/26
`(43} International Publication Date:
`
`
`
`(21) International Application Number:
`
`
`(81) Designated States: AU, CA, JP, US, European patent (AT,
`BE, CH, DE, DK, ES, FR, GB, GR, IE, IT, LU, MC,
`
`
`(22) International Filing Date:
`4 February 1993 (04.02.93)
`NL, PT, SE).
`
`
`
`(30} Priority data:
`
`
`
`5 February 1992 (05.02.92)
`GB
`9202461.l
`
`
`
`(71) Applicant for all dett'gnated States except US): GEC-MAR-
`
`
`CON] LIMITED [GB/GB]; The Grove, Warren Lane,
`
`Stanmore, Middlesex HA7 4LY (GB).
`
`(72) Inventor; and
`
`
`(75} InventorlApplicant {Tor US only) : HOLLIS, John [63/GB];
`
`
`Upalong, Standon Road, Little Hadham, Nr. Ware,
`
`
`Hens SGll ZDD (GB).
`
`(74) Agent: ELLIOTT, Frank, Edward; GEC Patent Dept, Wa-
`terbouse Lane, Chelmsford, Essex CM] 20X (GB).
`
`
`
`
`(54) Title: PRIVATE TRUNKED MOBILE RADIO SYSTEM
`
`
`
`EXHIBIT
`
`EX. 1018
`
` EX. 1018
`
`
`
`{57) Abstract
`
`
`A [ranked private mobile radio system provides on demand an open channel communication between a plurality of desig-
`nated mobile radio terminals of the system.
`
`
`Page 1 0f 23
`
`PETITIONER'S EXHIBIT 1018
`
`Q
`8.
`a.“
`m
`
`2‘"
`
`'9
`
`
`
`
`
`
`
`
`Page 1 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`J
`
`a
`
`I“
`
`Muuriluniil
`Malawi
`Nulhurfilluln
`Nurwuy
`New Zunluml
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`Sudan
`chdun
`Slumk Rupnhliu
`Senegal
`Swim Uniun
`t‘dlaul
`'l‘ngn
`Uluil'lllu
`Unilud Slums nil America
`Vic! Nam
`
`FOR THE PURPOSES 0F INFORMA NON ONLY
`
`Codes used It) identify States parly m ihL' PC'I' on Ihe from pages of pamphlets puhiishing international
`applicatinns under the PCT.
`
`Mongolia
`
`AT
`AU
`BB
`BE
`BF
`BC
`BJ
`BR
`CA
`CF
`CG
`CH
`CI
`
`CS
`C2
`DE
`DK
`ES
`Fl
`
`Aualriu
`Australia
`Barbados
`Bulglilnl
`finrkinu Fusu
`Bulgaria:
`Benin
`Brazil
`Canada
`(inmmf African: Runubi‘n:
`{Tough
`Swilzurlund
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`(icrnhlny
`Dullmnri
`Spain
`Finland
`
`‘
`
`Frunuu
`Gabon
`Unilud Kingdom
`Guinm
`fiwccu
`Hungary
`Ireland
`Iluly
`L'Ipm!
`Unlllflcrflllt‘ l'uoplu'a Rupuhliu
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`Rupuhliu ul Knruu
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`
`.
`
`.
`
`Page 2 of 23
`
`_
`
`.
`
`PETITIONER'S EXHIBIT 1018
`
`Page 2 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`W0 93! 16566
`
`PCT/0393100235
`
`[(4
`
`PRIVATE TRUNKED MOBILE RADIO SYSTEM
`
`This
`
`invention concerns private mobile
`
`radio
`
`(PMR)
`
`‘ systems
`
`such as those used by Military and Law Enforcement
`
`Agencies.
`
`FMR
`
`systems are known and generally comprise
`
`a
`
`base station and a plurality of mobile terminals.
`
`Each base
`
`station serves
`
`a particular area and can communicate with
`
`mobile terminals within its area and with other similar base
`
`stations serving respective areas through switching centers.
`
`The mobile terminals can communicate with each other via the
`
`respective base stations or directly.
`
`There
`is
`an increasing reliance on such PMR
`systems
`and, with increased use,
`there is a need more efficiently to
`
`utilise the
`
`limited radio Spectrum. Narrow band
`
`channels
`
`enable more efficient utilisation but it has been recognised
`that significant
`advantages are obtained by "trunking" i.e.
`
`where traffic communication channels are only allocated and
`
`used whilst
`
`a call is in progress. This is similar
`
`to a
`
`telephone
`
`communication
`
`system.
`
`DTI
`
`document MPT
`
`1318
`
`describes
`
`such
`
`advantages and indicates that the
`
`carrying
`
`capacity of a channel within a "trunked" group greater than
`
`-v
`
`10 can approach 0.9E (erlang).
`
`The "erlang" is a measure of
`
`channel
`
`loading {see MPT 1318 pages 16—19).
`
`Page 3 0f 23
`
`, PETITIONER'S EXHIBIT 1018
`
`Page 3 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`WO 93116566
`
`PCT} G 1393100235
`
`A
`
`trunking technique, as described in MPT 1327
`
`(and
`
`associated documents MPT 1343 and MPT 1347), requires
`
`the
`
`mobile
`
`radio terminals to relax to a control channel
`
`over
`
`which channel call
`
`control messages are passed.
`
`In this
`
`way, a mobile radio terminal may be directed to a particular
`
`communication
`
`channel when a call is made. Similarly, when
`
`a call
`
`is
`
`terminated,
`
`the
`
`radio terminal
`
`releases
`
`the
`
`communication
`
`channel
`
`and relaxes to the control
`
`channel.
`
`The same
`
`communication
`
`channel is then available to other
`
`users .
`
`The
`
`technique
`
`of call control is similar to that
`
`Iof
`
`telephony and
`
`inevitably has a delay which may be of
`
`the
`
`order of
`
`500m secs. This, coupled with a probability of
`
`a
`
`delay in acquiring a'
`
`radio channel if all
`
`resources
`
`are
`
`actually in use,
`
`is causing concern as, without discipline,
`
`speech or word clipping may result.
`
`The problem of
`
`the
`
`'Don’t Shoot’ command becoming ’Shoot’ is one aspect of such
`
`a problem.
`
`Currently,
`
`this problem is largely avoided by
`
`the communications being undertaken over an
`
`’Open’,
`
`all
`
`available, channel. There is therefore no call set up delay
`
`and, as all units
`
`are permanently tuned to the
`
`channel,
`
`there is
`
`a
`
`comfort to everyone in that all
`
`communications
`
`'
`
`are received.
`
`Page 4 0f 23
`
`.
`
`_
`
`-
`
`PETITIONER'S EXHIBIT 1018
`
`Page 4 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`W0 93116566
`
`PCTIG 393!00235
`
`The Shoot/Don‘t Shoot problem, along with the comfort
`
`aspect,
`
`is causing significant concern in the organisations
`
`defining future radio communication
`
`strategies
`
`for
`
`the
`
`Military and
`
`Law Enforcement Agencies.
`
`It
`
`is believed
`
`an
`in accordance with the disclosure herein,
`that,
`however
`capability can
`be achieved with a
`trunking
`open channel
`system and still maintain the channel efficiencies for
`one
`
`to one
`
`communications on an "on demand" basis. Further,
`
`in
`
`recognition of the requirement to support covert operations
`and/or
`any
`'low probability of detection'
`communications,
`
`encrypted communications
`
`and ’frequency agile'
`
`techniques
`
`can be incorporated.
`
`Such a system is described below.
`
`The
`
`communications
`
`requirements of
`
`a
`
`PMR
`
`system
`
`according to the present invention can be summarised to be:—
`
`a) One to one private calls.
`
`b) Group, or conference calls.
`
`c) Open channel all available communications.
`
`w
`
`Requirements (a) and (b) are supported by the MPT 1327
`
`systems described above
`
`and are established by
`
`similar
`
`Page 5 0f 23
`
`PETITIONER'S EXHIBIT 1018
`
`Page 5 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`W0 93l16566
`
`PCTI G 393/ 00235
`
`_ 4 i
`
`system call control techniques i.e. Mobile/Radio units are
`
`normally tuned to a control channel over which call control
`
`is exercised.
`
`If
`
`it is established that both units to be
`
`involved
`
`in a
`
`one
`
`to one call are
`
`available,
`
`both are
`
`instructed to re—tune to a traffic channel.
`
`Should both
`
`radios
`
`be within the coverage of, a single Base Station,
`
`then both would utilise a common traffic channel. HOWever,
`
`where two base
`
`stations are used, different R.F.
`
`traffic
`
`channels may be used and switch connected by
`
`the
`
`system
`
`infrastructure.
`
`The
`
`establishment
`
`of
`
`a group call is similar
`
`to a
`
`’private’
`
`call
`
`except
`
`that
`
`a call
`
`control message
`
`is-
`
`broadcast
`
`to a pro—defined group of mobile radios terminals
`
`to re-tune
`
`to a particular traffic channel.
`
`Again
`
`this
`
`arrangement
`
`could encompass multiple R.F.
`
`base
`
`stations
`
`which would
`
`be
`
`conferenced to form a wide-area,
`
`group
`
`connection.
`
`Both
`
`‘one to one' and group calls would be set up
`
`on
`
`demand and suffer the call establishment delay.
`
`For general
`
`communications
`
`and
`
`’ad hoc' non strategic control
`
`(e.g.
`
`Traffic Wardens etc) this should not be a problem as system
`
`use discipline could be exercised. Under pressure, however,
`
`'
`
`the discipline cannot
`
`be guaranteed and
`
`the
`
`’Shoot/Don’t
`
`Page 6 0f 23
`
`'
`
`-
`
`PETITIONER‘S EXHIBIT 1018
`
`Page 6 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`WO 93116566
`
`PCI‘IGB93/00235
`
`_5_
`
`Shoot' difficulty,
`
`gives rise to the requirement for
`
`open
`
`channel type communications.
`
`In principle,
`
`the difficulty of words being missed
`
`because of call set up delays can be overcome by introducing
`a speech delay in the radio equipment.
`The
`speech delay
`
`would then enable
`
`a group call to be established on,
`
`for
`
`example,
`
`receipt of a 'Press to Talk’ command whereby to
`
`minimise
`
`the risk of missed instructions.
`
`The use of
`
`digitised speech would simplify such realisations as, with
`
`Bkb/sec traffic, relatively small digital delay lines (shift
`
`registers)
`
`could be used. Further,
`
`the delay could,
`
`processor control,
`
`he dynamically controlled to adapt
`
`by
`
`to
`
`various call
`
`set
`
`up
`
`times and after
`
`the
`
`first
`
`speech
`
`interchange
`
`be effectively switched out by detection of
`
`a
`
`"non-speech" interval.
`
`Although the above would minimise the missed message
`difficulty it would fundamentally still suffer a call set up
`
`delay.
`
`The
`
`open
`
`channel facility would
`
`avoid all
`
`such
`
`difficulties
`
`and wou1d
`
`be provided by pre-allocating a
`
`channel
`
`(or channels on conference connected base stations)
`
`to form an
`
`open group.
`
`Pre—defined groups of mobile
`
`.,
`
`terminals would
`
`then automatically be instructed via Ithe
`
`call control
`
`channel
`
`to re-tune
`
`to the
`
`pre—allocated
`
`Page 7 0f 23
`
`PETITIONER'S EXHIBIT 1018
`
`Page 7 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`W0 931'16566
`
`PCTIG393!00235
`
`—.6_
`
`channelfs}. All mobile radio terminals would then be openly
`
`conferenced.
`
`Further,
`
`by periodically transmitting the re—tune 'to
`
`group’
`
`instruction on the call control channel new arrivals
`
`(i.e.
`
`radios
`
`that have just been switched on)
`
`could be
`
`instructed to join the group.
`
`The arrangement is not of
`
`course
`
`restricted to organising a single open group as
`
`by
`
`pre—allocating several
`
`channels
`
`a number of
`
`independent
`
`groups can be established and mobiles/radios having specific
`
`ranges
`of
`addresses etc directed to the appropriate group
`call conference.
`Similarly different open channel
`groups
`
`can be established and cleared as necessary.
`
`The 'formation of the open channels will be
`
`effected,
`
`in general, by commanding mobile terminals having particular
`
`address
`
`ranges.
`
`Each mobile terminal however would have
`
`a
`
`unique
`
`identity within the
`
`group range.
`
`Therefore
`
`by
`
`employing
`
`command
`
`signalling over
`
`the
`
`traffic channel
`
`allocated to the group {MPT 1327 signalling enables
`
`this)
`
`individual mobile terminals can be instructed to re—tune to
`
`another
`
`channel
`
`for a one-to—one call,
`
`to be
`
`temporarily
`
`part of
`
`a dynamically
`
`established group call or to be
`
`a
`
`member of another open channel.
`
`'
`
`Page 8 0f 23
`
`PETITIONER'S EXHIBIT 1018
`
`Page 8 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`W0 93l16566
`
`PCT/GB93/00235
`
`-7...
`
`By providing the Open Channel operation within a
`
`conventional
`
`trunked system,
`
`both user
`
`requirements
`
`and
`
`radio channel use efficiency can therefore be achieved.
`
`The
`
`invention will be described further, by way of
`
`example with reference to the accompanying drawings,
`which:-
`
`in
`
`_ Figure
`
`1
`
`is a schematic diagram of a private mobile
`
`radio system in accordance with the present invention: and
`
`Figure
`
`2
`
`is
`
`a diagram 'indicating the additional
`
`features of
`
`such
`
`a system incorporating “Open Channel"
`
`communication.
`
`Referring firstly to Figure 1, a private mobile radio
`
`system comprises
`a
`first base station 10
`arranged for
`broadcast
`communication over a first area 12 to a plurality
`
`of-mobile
`
`radio terminals 14 located within such area.
`
`An
`
`adjacent
`
`area
`
`16
`
`is
`
`served by a base
`
`station 18
`
`and
`
`broadcasts
`
`to mobile terminals 14 within the adjacent area.
`
`A plurality
`
`of
`
`such areas
`
`adjacent,
`
`contiguous
`
`or
`
`overlapping may be provided and a switching centre 20 serves
`to connect
`the various base stations to each other and to
`
`1
`
`.
`
`other networks.
`
`Page 9 0f 23
`
`PETITIONER'S EXHIBIT 1018
`
`Page 9 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`W0 93(16566
`
`PCTfGB93/00235
`
`The system has allocated thereto a plurality of narrow
`
`band radio channels,
`
`for example, 100 and these,
`
`in turn,
`
`are allocated to the base stations 10, 18 etc in accordance
`
`with the
`
`traffic demand in the respective areas 12, 16
`
`etc
`
`and in accordance with minimum
`radio interference
`adjacent Iareas.
`The allocated channels comprise, for
`
`in
`each
`
`area, at
`
`least
`
`one call control channel and one or more
`
`communication channels for carrying communication traffic.
`
`Such
`
`a system is described fully in document MPT 1327
`
`issued by
`
`the Department of Trade
`
`and
`
`Industry.
`
`Its
`
`operation is also there described. MPT 1327 is incorporated
`
`herein by reference.
`
`A
`
`one—to-one call by one mobile radio terminal 14
`
`to
`
`another mobile
`
`radio terminal 14 whether in the same or
`
`a
`
`different
`
`area is initiated and made in accordance with the
`
`protocols described' in MPT 1327.
`
`The mobile
`
`terminal
`
`14
`
`firstly hunts for the strongest control channel system and
`
`makes a
`
`request
`
`on this frequency. When the bass
`
`station
`
`acknowledges,
`
`the mobile indicates the address of a terminal
`
`to be called.
`
`The
`
`base
`
`station
`
`then determines
`
`the
`
`availability of the called mobile terminal.
`
`If the called
`
`'
`
`terminal is available,
`
`the base station sends to the calling
`
`Page 10 0f 23
`
`PETITIONER'S EXHIBIT 1018
`
`Page 10 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`W0 93/165615
`
`PCT/GB93/00235
`
`_ 9 _
`
`mobile
`
`terminal a go—to-traffic—channel signal.
`
`A
`
`similar
`
`9
`
`signal
`is
`station if
`centre and
`
`sent to the called mobile terminal by
`it
`is in the same area or via
`the
`the appropriate base station if it
`
`the base
`switching
`is
`in a
`
`different area.
`established.
`
`The one-to~one
`
`communication
`
`is
`
`then
`
`Similarly,
`
`a group or conference call is made from a
`
`mobile
`
`terminal 14 to a plurality of other mobile terminals
`
`in the same or different areas as described in MPT- 1327.
`
`The initiation is the same as before.
`
`The base station then
`
`ascertains the availability of a traffic channel and advises
`
`the
`and all
`to go to this channel
`'the calling terminal
`called terminals (either directly or through the
`switching
`centre and
`the
`respective base stations) to go
`to the
`
`allocated traffic channel
`
`(or channels).
`
`In
`
`accordance with the present invention the
`
`above
`
`system is modified to provide "Open Channel" communications
`
`when required.
`
`The open channel will be established in similar manner
`
`to that of an MPT 1327 group call.
`
`In this case, however, a
`
`-.
`
`System Manager or Controller 22 provided at
`
`a
`
`switching
`
`centre
`
`20 or at a base station, would define the range of
`
`Page 11 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`Page 11 of 23
`
`PETITIONER'S EXHIBIT 1018
`
`
`
`W0 93/ 1 6566
`
`PCT/ GB 93/011235
`
`mobile
`
`radio terminal 14 addresses to form the
`
`group and
`
`.
`
`_ 10 -
`
`would define the duration of the group call.
`
`The Controller
`
`22 would
`
`instigate the call and initiate its clear
`
`down.
`
`The system would also be organised periodically to broadcast
`
`the 'group call'
`
`instruction on the control channel to catch
`
`late comers
`
`and
`
`to allow for personnel shift
`
`changes
`
`on
`
`instances of long duration communication requirements.
`
`Mobility of
`
`radios is catered for to ensure use
`
`of
`
`Base Stations covering specific locations. Under normal MPT
`
`1327 system‘ operation the ’useability’ of a particular base
`
`station is established by assessment of the control channel.
`
`With open
`
`channel operation this,
`
`of
`
`course,
`
`is
`
`not
`
`practical. Assessment of the received traffic channel radio
`
`signal
`
`strength is therefore undertaken at the mobile radio
`
`terminal
`
`14.
`
`If then the level is too low,
`
`the terminal or‘
`
`terminals would relax to the control channel and proceed to
`
`hunt for
`
`another useable
`
`one.
`
`Upon acquisition
`
`and
`
`registration with a different base
`
`station,
`
`the mobile
`
`terminal
`
`14 would
`
`then be instructed to rejoin the
`
`open
`
`channel group by the periodic control channel message.
`
`As
`
`indicated in Figure
`
`2,
`
`the call
`
`control
`
`is
`
`full—duplex (as far as the base station is concerned) and is
`
`'
`
`tranSparent
`
`to a user of a mobile
`
`radio terminal.
`
`The
`
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`
`transmission by the base stations are in frames each divided
`into a plurality of slots.
`The duration of each frame is an
`
`integral
`
`number of time slots but such number may
`
`increase
`
`or decrease depending on traffic demand.
`
`The
`
`frame
`
`size
`
`accordingly varies.
`
`The communication channels (of which
`
`only four are shown) are half duplex.
`
`As described above,
`
`the system controller 22 initiates
`
`the Open Channel
`
`by reserving at least
`
`one
`
`communication
`
`channel
`terminals
`reserved
`
`and
`instructing the
`assigned group
`of mobile
`14 via the call control channel to tune
`to the
`channel.
`Thereafter,
`communication
`by
`the
`
`controller
`
`22 with a particular mobile terminal within the
`
`group may
`channel.
`
`be made by digital instructions on the
`reserved-
`1 Such "flash" instructions are unlikely to disturb
`
`normal
`
`communication on the reserved "open channel" and may
`
`be of such brief duration as
`
`to pass unnoticed.
`
`The
`
`controller
`
`22 may wish so to communicate with an individual
`
`mobile
`
`terminal 14 to instruct the terminal to participate
`
`in a one—to-one or a group call on another channel.
`
`The use of a trunked mobile radio communication system
`
`including an
`
`"open
`
`channel facility by Military and
`
`Law
`
`Enforcement Groups may require levels of system security not
`
`normally required of civil use systems.
`
`Problems of speech
`
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`_12...
`
`secrecy,
`
`jamming
`
`and
`
`low
`
`probability of
`
`communication
`
`.
`
`detection may therefore have to be resolved.
`
`a] Speech Secrecy
`
`This
`
`can readily be achieved by speech scramblers or
`
`encrypters.
`
`Such devices have been developed and could be
`
`adapted to the trunking environments. Further the
`
`secrecy
`
`could be switched in or out depending upon requirements.
`
`b) Jamming
`
`As discussed above,
`
`the MPT 1327 trunking system is
`
`organised via a control channel, and jamming of this
`
`could
`
`therefore effectively disable the system.
`
`Such
`
`a
`
`state
`
`could generally be detected by both mobile
`
`terminals
`
`and
`
`fixed infrastructure by virtue of continuous receipt of non
`
`MPT messages.
`
`The system could then establish a new control
`
`channel
`
`and rely upon the mobile terminals ’finding' it via
`
`normal
`
`channel hunt protocols. Elaborate forms of
`
`jamming
`
`may of
`course
`be
`realised such
`that MPT messages
`are
`generated whilst holding out any access by mobile terminals.
`
`This would
`
`have
`
`to be avoided by continually changing_
`
`the
`
`control
`
`channel
`
`frequency and
`
`avoiding any
`
`that
`
`are
`
`identified as potentially jammed.
`
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`Frequency
`
`change of
`
`the control
`
`channel
`
`frequency
`
`would result
`
`in mobile
`
`terminals being 'out of
`
`service’
`
`whilst
`
`they sought
`
`the
`
`latest
`
`control
`
`channel.
`
`The
`
`establishment of calls to the 'hunting’ mobile
`
`terminals
`
`would then not be possible.
`
`It would then be beneficial to
`
`positively move
`
`the mobile radio terminals to ’the next'
`
`control
`
`channel via a fully encrypted message. Of
`
`course
`
`the ’fail safe' mechanism would be the mobile hunt routines.
`
`Use of _an
`
`’agile' call control
`
`channel may
`
`cause
`
`'mobile
`
`radio terminals involved in an Open Channel to spend
`
`significant'
`time
`locating its own call
`control
`channel.
`This however would be minimised by transmitting on the open
`
`channel(s},
`
`in encrypted form,
`
`the identity of the ’in use'
`
`call control channel.
`
`Jamming
`
`could of
`
`course
`
`be directed at
`
`specific
`
`channels
`
`and probably the strategically important
`
`"Open
`
`Channel’. Making these frequency agile would minimise this
`
`and can
`
`be
`
`achieved by specific ’Move’ or ’Go To Channel’
`
`commands broadcast in encrypted form over the currently used
`
`channels. Mobiles that fail to follow such commands would
`
`be organised to hunt for the call control channel and
`
`then
`
`be redirected to the open channel frequency in use.
`
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`
`_14..
`
`c) Low Probability of Detection
`
`This characteristic would be realised by the use of
`
`both encrypted speech
`
`and a totally channel agile system.
`
`This latter
`
`aspect probably
`
`considering the
`
`channels
`
`available
`to a system e.g.
`100 as a pool of resources that
`are dynamically used Irather than restricting agility to a
`
`set of channels allocated to a base station.
`
`Page 16 of 23
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`
`-15-
`
`CLAIMS
`
`1.
`
`A private mobile radio system comprising at least
`
`one base
`
`station serving to communicate via a
`
`control
`
`channel with a plurality of mobile radio terminals within
`its broadcast
`area
`to provide,
`on
`demand,
`one-to-one
`
`communication or conference communication therebetween over
`
`an assigned communication
`
`channel and connected to the at
`
`least one base
`
`station,
`
`or respective base
`
`stations
`
`in
`
`respective ’areas,
`
`through a switching centre,
`
`there being a
`
`system controller
`
`arranged,
`
`on
`
`demand,
`
`dynamically to
`
`reserve, at the or each base station a communication channel
`
`and to command designated mobile radio terminals to switch
`
`to the
`
`reserved
`
`channels
`
`to
`
`provide
`
`open
`
`channel
`
`communication for the designated mobile radio terminals.
`
`2.
`
`In a private mobile
`
`radio system permitting
`
`one-to-one communication or conference communication between
`
`mobile
`
`radio terminals on an assigned communication channel
`
`via at
`
`least
`
`one base
`
`station and, where
`
`there
`
`are
`
`a
`
`plurality
`
`of base
`
`stations,
`
`a
`
`switching centre,
`
`the
`
`improvement
`
`comprising a system controller for causing the
`
`n
`
`or each base
`
`station, on demand,
`
`to reserve at
`
`least
`
`one
`
`communication channel and, via a control channel for causing
`
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`
`_l6_
`
`a plurality of designated mobile radio terminals dynamically
`to switch to'
`the reserved channel or channels
`to provide
`
`open channel communication therebetween.
`
`3.
`
`A method of radio communication, via communication
`
`channels,
`
`between
`
`a plurality of mobile
`
`radio terminals
`
`served by at least one base station and, where there are
`
`a
`
`plurality of base stations, a switching centre,
`
`the or each
`
`base station
`
`broadcasting over
`
`a
`
`respective area
`
`and
`
`communicating with mobile radio terminals within the
`
`area
`
`via a call
`channels,
`reversing,
`
`control channel and a plurality of communication
`the method comprising the steps of‘ dynamically
`on
`demand,
`in each area, at least one of
`the
`
`communication
`
`channels
`
`and instructing designated ones of
`
`the plurality of mobile radio terminals to switch to the
`
`reserved channel
`
`of
`
`its area
`
`to provide
`
`open
`
`channel
`
`communication therebetween.
`
`Page 18 0f 23
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`W0 93/165156
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`PCI‘K393100235
`
`II 2
`
`
`
`PSTN
`
`Page 19 0f 23
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`
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`W0 93ll6566
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`PCTIGB93100235
`
`2/2
`
`9
`
`
`
`
`
`224:0gomkzoo.jd‘o
`
`
`
`qmzzdfuZO_._.<U_ZDEZOU
`
`I.
`
`.M522410
`
`-.q$22.20
`
`N4m22<Io
`
`Illulll'llllllullllllflllllllllllllllll
`
`_gmzquu
`
`Page 20 of 23
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`PETITIONER'S EXHIBIT 1018
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`
`
`
`PCT/GB 93/00235
`
`H04B7/26
`
`INTERNATIONAL SEARCH REPORT
`Intel-animal Agitation No
`
`
`(If mall classification symbols apply. indicate an)‘
`I. CIASSIFICATION 0F swear MATI'EI
`Awarding to International Patent Classification (IPC) or to both Nathan! Classifiutinn and [PC
`
`
`Int.C1. 5 HO4Q?/04;
`
`
`ll. FIELDS SEARCHED
`
`
`Minimum Dmmentat‘ton Searched”
`
`Classtflceflnn 53mm
`(Justification Symbnls
`
`
`
`
`
`
`Dnmmmtlttnn Searched other than Minimum Docuumtafinn
`
`tn the Extent that such Deanna“: m Included In the Fields Searched.
`
`It
`
`'3'
`
`Int.C1. 5
`
`
`
`In. nacummrs cousmmn To BE mvmfl
`
`Cam "
`
`
`
`COMMUTATION ET TRANSMISSION
`v01. 11, no. 3, 1989, PARIS FR
`
`
`,pages 45 - 58
`'Rubis: un Réseau
`MAZERES ET AL.
`Radionumérique de Sécurité'
`see page 47, Ieft column, 1ine 31 - line
`42
`-
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`see page 50, middle column,
`
`line 1 - 1ine
`
`ee page 55. right coiumn. Iine 19 - page
`56, right cqumn,
`line 50
`see page 5?, right column, Iine 4 - line
`34
`
`7 s
`
`
`'1" later augment panama after the internment filing am
`° Sneu'al categories at am Mann: : 1°
`an? mfi‘fit'émm‘ sun:of the In uhieh Is an:
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`inment I: combined with one In- more other such incu-
`
`
`nthu- means
`meets. sud: cemhineflnn being am to a gem skilled
`'I" Mm! published prior m the lnlcnminnzl filing em hut
`in “1" "'-
`
`later than the priority date diluted
`'5' Meat member of the me patent family
`
`a
`
`Date of the Actual Cmnluinn of the International Search
`
`Date at Mailing of this Immune! Search Report
`
`.
`
` 1_
`18 MAY 1993
`3 7 05 33
`International Sardting Authority
`Signal": of Authorized Officer
`
`
`
`
`Fem FCl'flStlmfl I“ “I (cl-III! [I51
`
`
`
`Page 21 of 23
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`
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`Ill. DOCUMENTS CONSIDERED TO BE REIEVANT
`
`(CONTINUED FROM THE SECOND SHEET]
`
`Citation of Dominant. with indication, whee appmprilte. a! the ulnar passages
`
`Relevant Io ClaJIa No.
`
`[mu-national Application No
`
`PCT/GB
`
`93/00235
`
`PHILIPS TELECOMMUNICATION REVIEW
`v01. 49, no. 3, September 1991, HILVERSUM
`NL
`
`pages 88 - 92
`'Digita] Trunked Networks;
`CAYLA ET AL.
`the future of PriVate Mobile radio'
`
`
`
`
`
`see paragraph 2.3; figure 1
`see paragraph 4.2
`
`WO,A,8 810 54? (MOTOROLA)
`29 December
`1988
`
`see page 2,
`
`line 1 — 1ine 28
`
`
`Fu- PCTJW In!!! H] III-u 1K9
`
`Page 22 of 23
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`
`
`ANNEX TO THE INTERNATIONAL SEARCH REPORT
`ON INTERNATIONAL PATENT APPLICATION No.
`
`:2 9300§3§85
`
`This annex in: the patent fanfly members relating to the palm documents Ited in the nheve-menh'ened internalioml and: report.
`The memhers fire as contained in file European Patent Office EDP file on
`The human Pm: Olfiee is in no way liable [or fllese particulars which are merely given for the pun-pose of informalion.
`
`18/05/93
`
`H0-A-8810547
`
`29-12-88
`
`US-A-
`AU-B-
`AU-A-
`CA-A-
`EP-A-
`JP-T-
`
`4723264
`601344
`1423388
`1270525
`0364447
`2502958
`
`02-02-88
`06*09-90
`19-01-89
`19-06-90
`25-04-90
`
`13-09-90
`
`Sm3mmmm For more details shout this tune: : see Official Journal of the European Patent Ofliee, No. HIS:
`
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