United States Patent c191
`Breeden et al.
`
`[11] Patent Number:
`[45] Date of Patent:
`
`4,959,648
`Sep. 25, 1990
`
`[75]
`
`[54] DUAL DYNAMIC PRIORITY CONTROL IN A
`SELCTIVE CALL SYSTEM
`Inventors: Robert L. Breeden; Douglas E.
`Griffin; John H. Kinney, Jr., all of
`Boynton Beach, Fla.
`[73] Assignee: Motorola, Inc., Schaumburg, Ill.
`[21] Appl. No.: 308,711
`Feb. 10, 1989
`[22] Filed:
`[51]
`Int. CI.5 ••••••••••••••••••••••• H04B 7/00; H04M 11/00
`[52] U.S. CI •.......................... 340/825.44; 340/825.51;
`379/57
`[58] Field of Search ..................... 379/57, 58, 59, 105;
`340/825.44, 825.47, 825.48, 825.51, 311.1;
`455/166
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`4,438,433 3/1984 Smoot et al .................... 340/825.44
`
`4,670,872 6/1987 Cordill ........................... 340/825.51
`4,825,193 4/1989 Siwiak et al ..................... 340/311.1
`Primary Examiner-Donald J. Yusko
`Assistant Examiner-Dervis Magistre
`Attorney, Agent, or Firm-William E. Koch
`ABSTRACT
`[57]
`A selective call control center is provided for transmis(cid:173)
`sion of calls to selective call receivers, such as paging
`receivers. In a first aspect, priorities are assigned to call
`sources and to call receivers and the order of transmis(cid:173)
`sion of calls is determined by the control center as a
`function of the priorities of the source and the receiver
`for each call. In a second aspect, at least one call re(cid:173)
`ceiver is provided having at least two addresses and the
`address to be selected from the at least two addresses
`for calling that receiver is determined dependent on the
`priority of the source of the call.
`
`11 Claims, 3 Drawing Sheets
`
`PRIORITY (P)
`_________________ ___.(17
`P=1 I a 1 I
`_
`..
`(8
`(9
`
`Motorola Solutions, Inc., Ex1019, p. 1
`
`

`

`U.S. Patent
`
`Sep. 25, 1990
`
`Sheet 1 of3
`
`4,959,648
`
`fl
`fl
`fl •
`
`•
`•
`
`/ 10
`
`,v
`
`I -
`
`FIG.1
`
`•
`•
`•
`
`26
`
`RAM
`
`27
`
`29
`
`31
`
`30
`
`25
`
`ROM
`
`FIG.2
`
`Motorola Solutions, Inc., Ex1019, p. 2
`
`

`

`US. Patent
`
`Sep. 2s, 1990
`
`Sheet 2 of 3
`
`. 4,959,648
`:17
`PRIORITY_(P_) _ _ _ _ _ _ _ _ _ _ _ _
`P=1 l1._a~1 ! _________ ,
`7
`.--....-----,---,-------------1(18
`I
`P=2 I b11 b21 bJI
`(19
`I
`
`P=3 I c1I c2 I cJI c.l c5I
`FIG.3
`
`INPUT
`
`PAGERS Pr
`
`CARDIAC
`ARREST
`GROUP
`
`14
`
`15
`
`1
`
`1
`
`OUTPUT
`PAGING ADDRESS
`
`ADDRESS 14A
`
`ADDRESS 15A
`
`FIG.4A
`
`INPUT
`
`14
`15
`16
`
`Pr
`
`2
`
`2
`
`3
`
`OUTPUT
`PAGING ADDRESS
`ADDRESS 148
`ADDRESS 158
`ADDRESS 168
`
`FIG.4B
`
`Motorola Solutions, Inc., Ex1019, p. 3
`
`

`

`US. Patent
`
`Sep.25,1990
`
`Sheet 3 of3
`
`4,959,648
`
`X
`
`,,.- 54
`
`WAIT FOR
`NEXT PAGE
`
`51
`
`52
`
`TRANSMIT
`NEXT PAGE
`IN QUEUES
`
`UPDATE
`QUEUES
`
`FIG.5
`
`NO
`
`P=P s
`
`66
`ASSIGN PAGE
`TO QUEUE P AND
`INCREMENT QUEUE
`COUNTER Np
`
`62
`
`PLACE NEW
`PAGE IN
`CORRECT QUEUE
`
`68
`RESET
`/;....
`YES PROGRAM
`TO POINT@
`
`/'""
`67
`
`69
`
`FIG.6
`
`Motorola Solutions, Inc., Ex1019, p. 4
`
`

`

`1
`
`4,959,648
`
`2
`sources are provided having different assigned priori(cid:173)
`ties, and call receivers are provided having different
`assigned priorities. The order of transmission of calls
`from the call sources to be transmitted to the call receiv-
`5 ers is determined as a function of the priorities of both
`the source and the receiver for each call. It is preferred
`that the greater of the priorities of the source and re(cid:173)
`ceiver determines the order of transmission of a call
`relative to other calls having higher or lower priorities.
`In a second aspect of the invention, a method and
`apparatus are provided for operation of a selective call
`system, in which call sources are provided having dif(cid:173)
`ferent assigned priorities and at least one call receiver is
`provided having at least two addresses. The particular
`address to be called is determined dependent on the
`priority of the source of the call. It should be under-
`stood, and will be explained hereinafter, that the ad(cid:173)
`dresses may take a number of forms. Dependant on
`which address is called, the call receiver may perform
`different functions, or operate in different manners.
`It is an advantage of the second aspect of the inven(cid:173)
`tion that a pager may perform different functions or
`operate in different manners dependent upon the source
`of a particular call, but without the need for the opera(cid:173)
`tor placing the call to specify the particular function or
`manner of operation.
`BRIEF DESCRIPTION OF THE DRAWINGS
`30 A preferred embodiment of the invention will now be
`described, by way of example, with reference to the
`accompanying drawings, in which:
`FIG. 1 shows a general paging system;
`FIG. 2 shows three priority levels, with calls assigned
`thereto;
`FIG. 3 shows a functional block diagram of a control
`center in accordance with the present invention;
`FIGS. 4A and 4B are look-up tables stored in mem(cid:173)
`ory 25 of the control center of FIG. 3;
`FIG. 5 is a flow diagram of the page transmission
`operation; and
`FIG. 6 is a flow diagram of the priority determination
`operation.
`
`DUAL DYNAMIC PRIORITY CONTROL IN A
`SELCTIVE CALL SYSTEM
`
`SUMMARY OF THE INVENTION
`In a first aspect of this invention, the invention pro(cid:173)
`vides a method and apparatus for assigning priorities to
`calls received by a selective call control center. Call
`
`BACKGROUND OF THE INVENTION
`This invention relates generally to the field of selec(cid:173)
`tive call control centers for transmission of calls to
`selective call receivers, such as paging receivers and
`more particularly to determining the order of transmis(cid:173)
`sion of calls to the receivers and/or determining which 10
`address within a receiver is to be called.
`As the use of pagers becomes more and more estab(cid:173)
`lished, the stage is already being reached where the
`control center of a paging system is becoming saturated
`at busy times, in the sense that more paging calls are 15
`being placed than the system is capable of transmitting
`to the destination paging receivers on the allocated
`radio frequency channels. To overcome this problem,
`control centers of paging systems administer a queue of
`calls for transmission, by storing each call in memory, 20
`and transmitting the calls, often on a first-in, first-out
`basis.
`"Priority" is a concept used in paging control centers,
`or terminals, to alter the processing of selected calls,
`primarily in regard to their insertion into an output 25
`queue. Specifically, calls assigned a priority higher than
`that of other calls waiting for output are given ad(cid:173)
`vanced placement in the output queue, so that they will
`be transmitted sooner than calls assigned lower priority.
`DESCRIPTION OF THE PRIOR ART
`Currently produced paging terminals generally treat
`priority in one of two manners:
`(1) Semipermanent individual assignment of call pri(cid:173)
`ority level by means of a parameter in the pager data 35
`base (i.e. stored in the paging terminal memory), or
`(2) The use of a special "priority" input to momen(cid:173)
`tarily raise the priority level of a call placed via that
`input.
`-
`These two manners of treating priority will be ex- 40
`plained by reference to the generalized paging system
`shown in FIG. 1.
`In this figure there is shown a paging control center
`10, three paging inputs in the form of telephones 11, 12
`and 13, and three pagers 14, 15 and 16.
`In the first prior art system, each of the pagers 14, 15
`and 16 is assigned a priority level, and these levels are
`stored in a memory in the paging control center 10.
`Each time a call is placed to the address of a particular
`pager, the control center 10 is aware of the priority of 50
`that address, and determines the order of transmission
`of calls accordingly.
`In the second prior art system, one of the telephones
`11, 12 and 13 is designated as a "code blue" telephone,
`i.e. if a call is placed via that telephone (e.g. telephone 55
`11), such a call is immediately given pre-emptive status,
`whereby any existing call in progress is interrupted and
`the code blue call is immediately transmitted. This sys(cid:173)
`tem is useful where the code blue telephone is assigned
`for emergency use.
`Neither of the above prior art systems is sufficiently
`flexible to meet present day requirements of paging
`systems.
`
`45
`
`DESCRIPTION OF THE PREFERRED
`· EMBODIMENT
`The preferred embodiment of the invention may be
`described in general terms with reference to FIG. 1, the
`elements of which have already been described with
`reference to the prior art.
`When a call is placed, that call is assigned a priority
`and an identification code identifying the call is placed
`in a queue corresponding to that priority. This is illus(cid:173)
`trated in FIG. 2.
`Referring to that figure, three queues established by a
`microprocessor in the control center 10 are shown as
`blocks 17, 18 and 19. The blocks represent locations in
`memory (described below) within the control center, in
`which identification codes of different calls may be
`stored on a first-in, first-out basis. Sufficient memory is
`set aside for each block so as to ensure that each block
`is notationally endless. Identification codes for different
`calls are represented as a,, b1, c1, etc., queue 17 has top
`priority (priority P= 1), queue 18 has second priority
`65 (P=2) and queue 19 has the lowest priority (P=3). In
`the figure it is shown that there is one call (a1) in queue
`17, three calls (b1, b2, b3,) in queue 18, and five calls
`(c,-cs) in queue 19. In this situation, call a, has been
`
`60
`
`Motorola Solutions, Inc., Ex1019, p. 5
`
`

`

`4,959,648
`
`4
`operators of the pagers cannot disable in advance. The
`system may be configured such that telephone 11 is
`dedicated only to page those addresses as a group.
`Thus, telephone 11 may be unable to page pager 16, or
`other pagers. As an alternative, telephone 11 may be
`configured to address pager 16 by dialing the appropri-
`ate number, and by virtue of the fact that the call has
`been placed via telephone 11, the call is immediately
`given pre-emptive status.
`In contrast to the above, if a call is placed via tele-
`phone 12 to any one of telephones 14, 15 and 16, such a
`call is a priority 2 call to a priority 2 address (in this case
`pagers 14 and 15 are addressed via their B addresses)
`and such a call is placed in a priority 2 queue as de-
`15 scribed above with reference to FIG. 2. If, by dialing an
`appropriate number into telephone 12, the system is
`configured to address pager 14 via its A address, then
`such a call is treated with pre-emptive status by virtue
`of the fact that the destination of the call has priority 1.
`
`3
`transmitted, the code a1 will be deleted from queue 17,
`and call bt will be the next to be transmitted. Call bt will
`be followed by calls b2 and b3, and provided no other
`calls have arrived in the meantime, call c1 the next to be
`transmitted after call b3, followed by calls c2-c5. As 5
`soon as a new call comes in, its identification code is
`assigned to the appropriate queue in accordance with
`the priority allocated to it. If a priority 2 call arrives its
`code will be added to the end of queue 18. From queue
`18, it will be transmitted in advance of any remaining IO
`calls in queue 19. Likewise, if a priority 1 call arrives
`any priority 2 or 3 call currently being transmitted will
`be interrupted, queues 18 and 19 will remain un(cid:173)
`changed, and the priority 1 call, which is immediately
`added to queue 17 is immediately transmitted.
`In the preferred embodiment of the present invention,
`each of the input devices, shown in FIG.1 as telephones
`11, 12 and 13, is assigned a priority level (Ps)- There may
`be a large number of input devices, and there may be a
`large number of priority levels, but for the purposes of 20
`illustration, it will be assumed that there are three prior-
`ity levels and that telephone 11 is assigned the top prior-
`ity level, level 1, telephone 12 ( and other telephones
`not shown) is assigned the next priority level, level 2,
`and telephone 13 (and other telephones not shown) is 25
`assigned the lowest priority level, level 3. As an exam(cid:173)
`ple, the system may be arranged in a hospital, where
`telephone 11 is an emergency "code blue" telephone for
`use only for calling a cardiac arrest team, while tele(cid:173)
`phone 12 (and other telephones of similar priority) is 30
`assigned to a doctor or head of nursing staff, and tele(cid:173)
`phone 13 (and other telephones of similar priority) is
`assigned for general use.
`Each of the pagers 14, 15 and 16 (and other pagers
`not shown) has two addresses. By paging the first ad- 35
`dress, the addressed pager responds with a loud audible
`tone, while by paging the second address, the pager
`responds by a silent vibration. It will be understood that
`the responses of the separate addresses may take a num(cid:173)
`ber of forms, including different volumes of tone, differ- 40
`ent combinations of tone and/or vibration and/or visi(cid:173)
`ble indicators, or different mode of operation, such as
`variable volume alert and fixed volume alert. There
`may be more addresses for each pager, typically up to
`eight.
`In addition to the priority levels assigned to the input
`devices, each of the pagers has an assigned priority level
`(P,). For the purposes of the present example, it may be
`assumed that address A of pager 14 has priority 1, and
`address B has priority 2, and the same for pager 15, 50
`while both addresses of pager 16 are priority 2. Other
`pagers not shown have priority 3. In this example, the
`operators of pagers 14 and 15 may have special duties as
`members of a cardiac arrest team, while at the same
`time they operate as members of the hospital having 55
`non-particular duties. Pager 16 is an operator having
`non-particular duties (not being a member of the cardiac
`arrest team), and there are other operators of pagers of
`lower rank. The operators of pagers 14, 15 and 16 may,
`for example, be doctors and nurses, while the operators 60
`of other pagers are orderlies.
`The operation of the system is as follows. In the event
`that there is a cardiac arrest in the hospital, a member of
`staff places a call through telephone 11, and this has the
`effect of immediately pre-empting any existing calls 65
`being transmitted, and pagers 14 arid 15 are paged via
`their A addresses. In so paging these pagers via their A
`addresses, those pagers issue an audible tone which the
`
`45
`
`From the above, it can be seen that priority 1 takes
`precedence over priority 2, irrespective of whether the
`priority 1 results from a priority 1 source (telephone 11;
`Ps= 1) or a priority 1 destination receiver (address A of
`pager 14 or 15; p,= 1).
`To continue the above example, if a call is placed via
`telephone 13 to pager 16, that call is placed in the prior(cid:173)
`ity 2 queue, because the destination of the call (pager
`16) has been assigned priority 2. If a call is placed via
`telephone 13 to another pager (not shown) of priority 3,
`tjiat call is placed in a priority 3 queue, by virtue of the
`fact that the source has priority 3 and the destination
`also has priority 3. None of the calls in the priority 3
`queue will be transmitted until all the calls in the prior(cid:173)
`ity 2 queue have been transmitted.
`The manner in which the above features are imple(cid:173)
`mented is described with reference to FIGS. 3-6.
`In FIG. 3, the three input telephones 11, 12 and 13 of
`FIG. 1 are shown. These telephones are connected to
`telephone inputs of DTMF decoder and supervisor 20.
`A data bus 21 connects the decoder and supervisor 20 to
`a microprocessor 22. Included in the data bus 21 are
`source identifier lines 23 which identify the input of the
`decoder and supervisor to which a particular telephone
`making a call is connected. Also included in the data bus
`21 are destination receiver identifier lines 24, which
`identify the telephone number being dialed. It will be
`understood that one of the telephones, e.g. telephone
`11, can be dedicated to dial a particular number, this
`number being stored in decoder and supervisor 20 and
`being sent on data lines 24 automatically upon use of
`telephone 11. Connected with microprocessor 22 is a
`read only memory 25, which is preferably an EE(cid:173)
`PROM. This EEPROM contains a look-up table, which
`will be described in more detail with reference to FIG.
`4. Microprocessor 22 provides an output on data bus 27
`to a transmit controller and paging encoder 28, which in
`tum passes information on data bus 29 to a transmitter
`30. The transmitter controller and paging decoder also
`controls transmitter 30 by an on/off control line 31.
`The operation of the apparatus is as follows. A user
`makes a paging call by picking up one of the telephones,
`e.g. telephone 12 and dialing a 3-digit number identify(cid:173)
`ing that a call is to be made. The user hears a prere(cid:173)
`corded message provided by decoder and supervisor 20,
`telling the user to dial the number of the pager to which
`the page is to be transmitted. At this stage a number of
`further features may be possible, including providing a
`
`Motorola Solutions, Inc., Ex1019, p. 6
`
`

`

`4,959,648
`
`5
`voice message, keying in an alphanumeric message into
`a keyboard (not shown) and/or dialing in a call-back
`number, e.g. through a touch-tone pad, for the person
`being paged to call back. The decoder and supervisor 20
`identifies the telephone input being operated from the 5
`hardwired connection to the decoder and supervisor 20,
`and it passes this information, together with the three
`digit number paged, on data lines 23 and 24 any other
`information provided (message, voice etc.) is also
`passed on data bus 21.
`The microprocessor 22 receives this information and
`performs the following operations. If the call is identi(cid:173)
`fied as coming from telephone 11, then the micro(cid:173)
`processor performs a look-up operation in the table of
`FIG. 4A and determines that pagers 14 and 15 are to be 15
`paged as a cardiac arrest team on their A addresses. The
`call is treated as a priority 1 call. If the call originates
`from any other source, the microprocessor 22 deter(cid:173)
`mines that only the pager identified by the user originat-
`ing the call is to be paged and a look-up operation is 20
`made on the look-up table of FIG. 4B. All this informa(cid:173)
`tion is contained in EEPROM 25.
`From the table of FIG. 4B, a number defining pager
`15 for example is input and the table identifies that the
`priority of pager 15 is priority 2. The table also provides 25
`the actual address that the transmitter 30 has to transmit
`to reach that pager on address B. This address is given
`in the right-hand column. It will be understood that this
`address could include post-digit addressing, wherein a
`code is included in the header information at the start of 30
`a call/page, that code determining the function that the
`pager is to perform, e.g. in terms of the type of alarm
`response.
`FIG. 5 shows a flow diagram of the overall queue
`management performed by microprocessor 22. For the 35
`purposes of explanation of the diagram, let it be sup(cid:173)
`posed that there are a number of calls waiting for trans(cid:173)
`mission in queues, as shown in FIG. 2. From this situa(cid:173)
`tion, the operations of the flow diagram will commence
`from point X. The uppermost priority call, in this case 40
`call a1 is transmitted first, as represented by step 51.
`Once this page has been transmitted, step 52 is executed
`in that the queues are updated by deleting code a1 from
`queue 17. Next, a test is carried out, step 53, and if there
`are more calls still queuing the program returns to point 45
`X, and the next call in the queue is transmitted as repre(cid:173)
`sented by step 51. In this case, there are indeed more
`calls queuing, and the next call to be transmitted is call
`b1. Thus steps 51, 52 and 53 are repeated until all the
`queues 17-19 are vacant. At this point, the program 50
`passes from step 53 to step 54, and the system waits for
`the next incoming call from input devices 11-13 etc.
`FIG. 6 illustrates the operation of microprocessor 22
`on receipt of a new call The program of FIG. 5 is inter(cid:173)
`rupted, as represented by step 61, whenever a new call 55
`is received from one of the input devices and the identi(cid:173)
`fication code of the new call is placed in the correct
`queue, as represented by step 62. On the left hand side
`of the figure, it is shown that step 62 comprises a num(cid:173)
`ber of smaller steps, in which the priority of the call 60
`source (Ps) associated with the source 11, 12, or 13 is
`compared with the priority of the call destination re(cid:173)
`ceiver (Pr) i.e. the priority of pager 14, 15, 16. If the
`priority (Ps) of the source is greater (numerically
`lower), then the priority P assigned to that call is made 65
`equal to Ps (step 64). On the other hand, if the priority
`of the call receiver (Pr) is greater than that of call source
`(Ps) then the priority of the call (P) is made equal to Pr
`
`6
`(step 65). Based on the priority P of the call, that call is
`assigned to the appropriate queue and a queue counter
`Np of that queue is incremented (step 66).
`Referring again to the right hand side of the diagram,
`the next step to be implemented is step 67 in which the
`queue counter of the priority 1 queue i.e. N 1, is tested. If
`N1 is greater than or equal to l, then the program of
`FIG. 5 is reset to point X. The reason for this test is to
`ascertain whether a pre-emptive priority call is to be
`10 made (a code blue call), and if so, to interrupt the trans(cid:173)
`mission of the current call, and immediately transmit the
`priority 1 call by resetting the program to step 51, at
`which point the program recognizes the priority 1 call
`as being the next call in the queues. Upon completion of
`step 67 or 68, as the case may be, the program of FIG.
`6 is exited at step 69, and the program of FIG. 5 resumes
`normal operation, with the new call having been as(cid:173)
`signed to its appropriate queue. From FIG. 6, it can be
`seen that the priority of a call is made equal to the
`greater of the priority of the source and the priority of
`the call receiver or destination.
`The above description of the preferred embodiment
`has been given by way of example, and it will be under(cid:173)
`stood that modifications can be made within the scope
`of the invention. Thus, for example, the comparison of
`P5 and Pr may take various other forms. These priorities
`may, for example, be numerically added, and the result(cid:173)
`ing sum be taken as the overall priority P. In the above
`case, the highest overall priority would be P = 2. In such
`a case, P=2, and P=3 could be made pre-emptive pri(cid:173)
`orities, since these values can only be reached if Ps or
`Pr= 1. Many other functions can be envisaged in which
`P depends on both Ps and Pr, Further look-up functions
`would be another example.
`What is claimed is:
`1. A selective call controller comprising:
`means for receiving calls from call sources, for identi(cid:173)
`fying the source of each call, each of said call
`sources having a predetermined priority;
`means for transmitting said calls to call receivers,
`each of said call receivers having a predetermined
`priority; and
`means for determining an order of transmission of the
`calls to the receivers as a function of the priorities
`of the source and the receiver for each call.
`2. The controller of claim 1, further comprising
`means for comparing the priority of the source of each
`call with the priority of the receiver for that call and
`means, responsive to the means for comparing, for as(cid:173)
`signing an overall priority to that call, said overall pri(cid:173)
`ority corresponding to the greater of said priorities,
`wherein the overall priority of a call determines the
`order of transmission of the call relative to other calls
`having higher or lower overall priorities.
`3. A selective call system comprising:
`a plurality of call sources having different assigned
`priorities;
`a plurality of call receivers having different assigned
`priorities;
`a selective call control center including means for
`assigning priorities to calls received by the control
`center from the call sources for transmission to the
`call receivers;
`transmission means for transmitting the calls to the
`call receivers; and
`means for determining an order of transmission of the
`calls to the receivers as a function of the priorities
`of the source and the receiver for each call.
`
`Motorola Solutions, Inc., Ex1019, p. 7
`
`

`

`4,959,648
`
`7
`4. A selective call system comprising:
`at least call receiver having at least two addresses;
`a selective call controller having means for receiving
`calls from call sources, for identifying the source of
`each call, and for assigning a priority to said source
`and having means for determining which of said at
`least two addresses is to be called dependent upon
`the priority of the source of the call whereby the
`priority of a source is used to determine both the
`order of transmission of calls and the address in the
`receiver which is called.
`5. A method of assigning priorities to calls received
`by a selective call control center, comprising the steps
`of:
`providing call sources having different assigned pri(cid:173)
`orities;
`providing call receivers having different assigned
`priorities;
`receiving a plurality of calls from the call sources for 20
`transmission to the call receivers; and
`determining an order of transmission of the calls to
`the receivers as a function of the priorities of the
`source and the receiver for each call.
`6. The method of claim 5, wherein the priority of the
`source of each call is compared with the priority of the
`receiver for that call and an overall priority is assigned
`to that call, said overall priority corresponding to the
`greater of said priorities, wherein the overall priority of 30
`a call determines the order of transmission or the call
`relative to other calls having higher or lower overall
`priorities.
`
`8
`7. The method of claim 6, wherein calls of equal
`overall priority are formed into a queue on a first-in
`first-out basis.
`8. The method of claim 7, wherein all calls in a queue
`~ of higher overall priority are transmitted before the first
`call in a queue of lower overall priority is transmitted.
`9. The method of claim 8 further comprising the steps
`of interrupting a call of lower overall priority, transmit(cid:173)
`ting a call of highest overall priority and re-transmitting
`10 the interrupted call when there are no more calls of the
`highest overall priority.
`10. The method of claim 5 wherein an overall priority
`is assigned to each call; wherein the overall priority of
`a call determines the order of transmission of the call
`15 relative to other calls having higher or lower overall
`priorities; wherein a predetermined number of overall
`priorities are assignable to calls; and wherein a call
`having the highest overall priority is transmitted on a
`pre-emptive basis such that calls oflower overall priori(cid:173)
`ties are interrupted to transmit the call having the high(cid:173)
`est overall priority.
`11. A method of operating a selective call system,
`comprising the steps of:
`providing call sources having different assigned pri(cid:173)
`orities;
`providing at least one call receiver having at least
`two addresses;
`,
`determining which of said at least two addresses is to
`be called dependent upon the priority of the source
`of the call wherein the priority of a source is used
`to determine both the order of transmission of calls
`and the address in the receiver which is called.
`* * * * *
`
`25
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`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`Motorola Solutions, Inc., Ex1019, p. 8
`
`