.
`
`Unlted States Patent [19]
`Schwendeman
`
`USOO5396537A
`
`1111 Patent Number:
`[45] Date of Patent:
`
`5,396,537
`Mar. 7, 1995
`
`[54] RELIABLE MESSAGE DELIVERY SYSTEM
`
`[75] Inventon Robert J - Schwendemau, Pompano
`Beach, Fla.
`_
`[73] Assignee: Motorola, Inc., Schaumburg, Ill.
`[21] App1-N9-= 963,370
`[22] Filed:
`Oct- 199 1992
`
`Related 135- Application Data
`Continuation-impart of Ser. No. 954,106, Sep. 30, 1992,
`
`[63]
`
`5,138,311 8/1992 Weinberg -
`5,151,899 9/1992 Thomas et a1. .................. .. 370/94.l
`5,315,635 5/1994 Kane et al. .......................... .. 379/57
`
`OTHER PUBLICATIONS
`_
`EMBARC Advanced Messagmg by Motorola, Bro
`61111115 No. RC-5-60 Sep. 1992.
`Primary Examiner—Curtis Kuntz
`Assistant Examiner-G. J. Oehling
`Attorney, Agent, or Firm—Kelly A. Gardner; John H.
`Moore
`
`
`
`Pat. N0. 5,315,635. Int. CL6 .......................................... ..
`379/57; 379/58;
`340/825-44
`_
`[58] Fleld of Search ..................... .. 379/ 56, 57, 58, 93,
`379/97’ 98’ 99; 340/ 825144’ 311-1’ 825'07’
`825-15’ 825-175 370/941; 358/437’ 439’ 441
`References Cited
`
`[52]
`
`[56]
`
`U‘S' PATENT DOCUMENTS
`4,644,351 2/1987 Zabarsky et a1. ............... .. 379/57 X
`4,803,487 2/1989 William er a1- -
`418751038 10/1989 sfwfak at 211- ~
`4’882'579 11/1989 slwmk '
`isgr‘giriliingfn at al‘ '
`4:952:929 8/199O D eLuca et a1'_ "
`4,991,197 2/1991 Morris ................................. .. 379/58
`5,043,721 8/1991 May .
`5,051,992 9/1991 DeLuca et a1. .
`
`A method and apparatus for reliably delivering mes
`sages (200) from a central terminal (102) to a communi
`cation receiver (130) in a communication system (100),
`Such as an electronic mail system_ The central terminal
`(102) transmits messages (1300) to the communication
`receiver (130) and the communication receiver (130)
`receives transmitted messages (1300) over a ?rst com
`munication medium (122). The communication receiver
`(130) reconciles messages that it failed to receive over
`the ?rst communication medium (122) with the central
`terminal (102) over a second communication medium
`(152). The reconciliation process between the commu
`nication receiver (130) and the central terminal (102)
`utilizes cyclic redundancy codes (CRCs) transmitted
`with the messages (1300) to identify the messages (1300)
`bemg recOnclled
`
`12 Claims, 11 Drawing Sheets
`
`1122
`f
`INPUT
`
`108
`
`-—> SECTIONS
`OTHER
`iggii
`INPUTS
`_---~
`
`NON‘
`PSTN
`
`1
`
`122 \ V f 124
`120
`114
`CENTRA- TERMINAL§
`PAGING
`CONTROL
`ENCODER
`-
`115 BUS
`r118
`1 r
`MEMORY
`
`130
`\ K
`
`132
`
`‘[7
`
`PABTH
`
`\ PAGING
`\\\§_
`RECEIVE?
`126
`154
`
`REMOTE UNIT
`
`136
`/ '
`CONTROL/
`A DECODER
`
`140
`MEMORY J
`
`INPUT SECTIONS PSTN
`
`INPUTS
`
`TRANSMITTER
`MODEM
`TX/RX \ SYSTEM
`111
`
`107
`PSTN
`
`REAL
`TIME CLOCK
`
`MODEM BUS
`TX/RX
`\
`\144 \138 142i USER
`INPUT
`)
`
`146
`
`141
`
`TELEPHONE TELEPHONE
`‘ INTERFACE INTERFACE
`CIRCUITRY CIRCUITRY
`\ 150
`\148
`
`19g
`
`DEVICES
`
`Microsoft Ex. 1008
`Page 1 of 25
`
`

`
`U.S. Patent
`
`.teehS
`
`11
`
`.0
`
`£1
`
`11.
`
`5,396,537
`
`
`QVNmm>HmommI»<¢zbmmmp:mzH
`>mo:m2mm~m>mo2mz
`
`
`
`
`
`
`
`
`muooomoezHo<mzozzoz
`
`xdomkzoo.mmzho
`
`
`
`
`
`EH2:mpozmmmzoHHomm
`
`om~ozHo<¢Jompzoo
`mmooozm»:azH
`
`mom
`
`«S
`
`4<zHzmmp4<mpzmoN:
`
`o3V:«/
`
`Izhwm
`
`xoo4om2H»~:
`
`
`4<mmzm»m»mxm\xp
`
`
`mmH»H:mz<mFzmoozzkmmmzoH»ommp:azH
`
`
`
`
`mo<mmm_zHuo<mmmhzH
`>m»H=omHo»mHH:omHo<IH<m
`
`
`Nmm
`
`mmoH>mo
`
`Microsoft Ex. 1008
`Page 2 of 25
`
`

`
`US. Patent
`
`Mar. 7, 1995
`
`Sheet 2 of 11
`
`5,396,537
`
`202
`I N
`
`200
`]
`
`MESSAGE
`MESSAGE
`m SEQUENCE REPETITION m MEDSAST’>\(;E
`NUMBER '
`COUNT
`
`210 j 212 J 204 J
`402 \ 206 J 208 J
`1
`Fl¢22
`
`404 \ ,
`
`2
`
`406 N y
`
`4
`
`408 \ V
`
`302 \
`
`1
`
`304 \ ,
`
`HG 3
`
`2
`
`f 306
`
`30s \
`
`3
`
`1
`
`‘
`
`\ 412 \
`
`310 X I
`
`2
`
`"
`
`3
`
`3
`
`1
`
`HG4 4”“ '
`
`312
`
`2
`
`416 x V
`
`3
`
`418 X I
`
`4
`
`420 \ V
`
`A
`
`Microsoft Ex. 1008
`Page 3 of 25
`
`

`
`US. Patent
`
`Mar. 7, 1995
`
`Sheet 3 of 11
`
`5,396,537
`
`
`
`208 x 210 x 1 3
`
`
`
`
`
`208 \‘ 1
`
`210
`
`3
`
`f
`502
`
`2
`
`3
`
`4
`
`5
`
`3
`
`1
`
`1
`
`1
`
`\
`504
`
`2
`
`4
`
`5
`
`3
`
`1
`
`1
`
`CENTRAL MEMORY
`
`REMOTE UNIT MEMORY
`
`118 J
`
`\ 140
`
`506
`RECONCILE TX MSGS AGAINST RX MSGS
`FIG5
`
`Microsoft Ex. 1008
`Page 4 of 25
`
`

`
`US. Patent
`
`Mar. 7, 1995
`
`Sheet 4 of 11
`
`5,396,537
`
`604
`
`606\ 1
`STORE MSG
`START TIMER
`
`612 \ '
`FLAG
`MISSING
`
`M868
`
`614
`
`7 02 \
`
`= =
`
`HGG
`
`1
`
`703
`J
`704\ v HG 7
`
`706
`
`708
`
`2
`
`v
`4
`
`v
`5
`
`705
`*J 4
`I
`:\
`| 708
`_ _ J1
`4
`'\
`_ _ J‘ 712
`
`702 \
`
`1
`
`703
`>6 _/
`
`70% v
`2
`
`706\ v
`
`705
`* J 802
`(‘79/
`804
`4 *n/
`
`710 \ V
`5
`
`t
`:\
`712
`“J
`
`Microsoft Ex. 1008
`Page 5 of 25
`
`

`
`US. Patent
`
`Mar. 7, 1995
`
`Sheet 5 of 11
`
`5,396,537
`
`902
`
`NEW
`MESSAGE?
`
`REACHABLE VIA PATH
`= 2 WAY PATH (E.G. IS MODE
`CONNECTED AND OPERATING
`
`YES
`
`v r910
`INCREMENT MESSAGE
`COUNTER FOR THIS
`UNIT’S ADDRESS
`ON PATH A
`
`_
`
`INCREMENT MESSAGE
`COUNTER ON
`APPROPRIATE ADDRESS
`FOR PATH B
`
`V
`K912
`SEND MESSAGE (INCLUDING ID
`AND CRC) VIA APROPRIATE PATH
`
`914
`
`YES
`
`NO
`
`[-916
`DISCARD
`MESSAGE
`OR PUT IN
`HISTORY
`FILE
`
`>
`
`HG 9
`-
`
`[-918
`SAVE MESSAGE IN
`RETRANSMISSION MEMORY
`FOR THIS ADDRESS
`
`Microsoft Ex. 1008
`Page 6 of 25
`
`

`
`US. Patent
`
`Mar. 7, 1995
`
`Sheet 6 of 11
`
`5,396,537
`
`I5
`A REMOTE
`UNIT CONNECTED TO PATH
`A REQUESTING
`UPDATES?
`
`1002
`
`K1004
`FOR IT’S ADDRESSES, CHECK FOR
`ENTRIES IN RETRANSMISSION MEMORY FILE
`
`A
`
`1016
`
`MARK
`CHECKED
`FOR THIS
`INDIVIDUAL
`ID
`
`(‘1008
`u
`SEND END
`OF UPDATE" _
`MESSAGE
`VIA PATH A
`{1014
`DELETE FROM
`RETRANsMIssIoN
`MEMORY FILE
`
`1006
`
`1010
`
`REMOTE UNIT HAVE
`THIS ID/CRC IN IT’S ID/CRC
`FILE AND MARKED
`
`TVNO (ACK’D AS "BAD")
`SEND MESSAGE \
`TO REMoTE UNIT 1018
`VIA PATH A
`l
`
`YES
`
`NO
`3RD
`NO ACK
`FOR THIS MESSAGE,
`THIS CYCLE’?
`
`1020
`
`ACK
`RECEIVED?
`
`HGZO
`
`Microsoft Ex. 1008
`Page 7 of 25
`
`

`
`US. Patent
`
`Mar. 7, 1995
`
`Sheet 7 of 11
`
`V
`
`1116
`
`: wAIT FOR
`MESSAGE
`
`1130/ MEFssOAOE
`R M
`UPDATE
`ROUTINE
`
`[1118
`PUT ID/CRC IN
`ID/CRC MEMORY
`AND MARK "GOOD"
`
`IT INSEWQ
`.
`(NO COPY MARKED
`"GOOD" IN 10/
`CRC FILE)
`
`K1106
`PUT MESSAGE
`IN MEMORY
`
`K1108
`DISCARD ADND
`MARK OL
`A MESSAGE As
`DUPLICATE
`RECEIVE
`
`1112
`
`RECEIVED
`ON PATH
`A?
`
`[-1114
`V
`PUT ID/CRC IN
`ID/CRC MEMORY AND
`DON'T MARK "GOOD
`1122
`
`SEND
`MESSAGE
`f BACK
`1126
`
`1120
`
`NO
`
`gicEplg/gg
`
`SEND
`Y
`ES MESSAGE
`
`A?
`
`’
`
`ACK
`
`.
`
`=
`
`1124
`
`WAS
`MESSAGE
`FROM UPDATE
`ROUTINE?
`
`NO
`
`HGJJ
`
`YES
`
`K1128
`RETURN TO
`UPDATE ROUTINE
`
`Microsoft Ex. 1008
`Page 8 of 25
`
`

`
`US. Patent
`
`Mar. 7, 1995
`
`Sheet 8 of 11
`
`5,396,537
`
`/ CONNECT PATH A AND
`1201 LOG IN BY ADDRESS(ES)
`
`1210
`
`"N0" AT
`POINT (QRWWITHOUT
`"YES"
`
`[-1202
`>"
`REQUEST UPDATE
`(AUTOMATICALLY
`OR MANUALLY)
`v‘
`
`YES
`
`1204
`YES
`
`RECEIVE
`"END OF UPDATE"
`MESSAGE
`
`1128
`f
`RETURN FROM
`RECESIIDN
`ROUTINE
`
`r1206
`TO OTHER
`ROUTINES
`
`NOTIFY USER
`OF ERRoR
`A312 wAgT
`
`1208
`
`RECEIVE
`ID/CRC?
`
`r1216
`ACK AS ‘
`"GOOD"
`
`YES
`
`1214
`
`IS
`ID/CRC IN
`MEMORY AND MARKED
`GOOD?
`
`1218
`
`WAS
`MESSAGE
`N0 DELETED FROM
`MESSAGE
`MEMORY
`
`[-1222 '
`ACK AS "BAD"
`
`V
`
`1224
`
`RECEIVE
`MESSAGE WITHIN
`X SECONDS?
`
`K1226
`"NO" ACK
`
`YES K1220
`DELETE FROM
`ID/CRC
`MEMORY
`
`YES
`
`1130 f
`GO TO MESSAGE
`RECEPTION ROUTINE
`
`FY6212
`
`Microsoft Ex. 1008
`Page 9 of 25
`
`

`
`US. Patent
`
`Mar. 7, 1995
`
`Sheet 9 of 11
`
`1302\
`
`‘
`
`i
`
`1300
`
`ADDRESS
`
`CRC
`
`...
`
`1306 J
`
`1308/ 1310/
`
`MESSAGE
`DATA
`1304-)
`
`1404
`
`REMOTE UNIT
`CONNECTED TO PATH
`A REQUESTING
`UPDATE
`
`[1408
`FOR REMOTE UNIT ADDRESSES,
`CHECK RETRANSMISSION MEMORY
`
`V
`
`1410
`
`UNCHECKED CRC IN
`FILE?
`
`1412
`/
`SEND
`"END UPDATE" __
`MESSAGE
`VIA PATH A
`
`(1416
`DELETE FROM
`RETRANSMISSION
`MEMORY
`1
`
`YES
`
`1414 -
`
`REMOTE
`UNIT HAVE
`THIS CRC MARKED
`
`NO I‘
`r1418
`SEND MESSAGE TO
`REMOTE UNIT’ VIA PATH A
`
`Microsoft Ex. 1008
`Page 10 of 25
`
`

`
`US. Patent
`
`Mar. 7, 1995
`
`Sheet 10 of 11
`
`5,396,537
`
`( ENTER §150‘2
`V
`CONNECT
`PATH A,
`LOG IN BY
`ADDRESSES
`="
`{1506
`REQUEST UPDATE (AUTOMATICALLY
`OR MANUALLY), SET TIMER
`
`["1504
`
`V
`
`1508
`
`RECEIVE
`IIEND UPDATE"
`MESSAGE’?
`
`NOTIFY USER
`OR ERROR
`AND WAIT
`
`RECEIVE
`CRC?
`
`512
`
`1522
`
`K1520
`WAIT
`
`K1524
`SENAOSEK
`
`OF NTSSSCRéE
`IN
`E A
`MEMORY AND
`
`MESSAGE
`
`DELETE CRC
`FROM MEMORY
`
`No K1530
`SEND
`ACK "BAD"
`
`HG 15
`
`Microsoft Ex. 1008
`Page 11 of 25
`
`

`
`US. Patent
`
`Mar- 7, 1995
`
`Sheet 11 of 11
`
`5,396,537
`
`1532 1534\1
`RECEIVE
`MESSAGE WITHIN
`SEND
`X SECONDS?
`NACK
`
`1
`
`K1536
`
`[-1540
`PUT CRC
`
`1542 /
`
`SEND ACK;
`SET TIMER
`
`1544
`SEND MESSAGE NACK;
`SET TIMER
`
`HGJé'
`
`Microsoft Ex. 1008
`Page 12 of 25
`
`

`
`1
`
`5,396,537
`
`2
`nication receiver reconciles messages that it failed to
`receive, e.g., missed messages and erroneously received
`messages, over the ?rst communication medium with
`the communication system over a second communica
`tion medium. The reconciliation process between the
`communication receiver and the communication system
`utilizes message identi?ers transmitted with the mes
`sages to identify the messages being reconciled.
`
`RELIABLE MESSAGE DELIVERY SYSTEM
`
`This is a continuation-in-part of US. patent applica
`tion Ser. No. 07/954,106, now US. Pat. No. 5,315,635,
`?led Sep. 30, 1992 by Kane et al., entitled “Reliable
`Message Communication System”.
`FIELD OF THE INVENTION
`This invention relates generally to message delivery
`systems, such as for electronic mail systems, and more
`speci?cally to a method and apparatus for reliably de
`livering messages to one or more remote units from a
`central communication system utilizing a paging trans
`mitter system.
`
`15
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a block diagram of a communication system
`in accordance with the preferred embodiment of the
`present invention.
`I
`FIG. 2 is a message block diagram illustrating a trans
`mitted message according to the preferred embodiment
`of the present invention.
`FIG. 3 is a message sequence diagram illustrating a
`?rst example of received messages being stored in the
`memory of a remote unit of the communication system
`according to the preferred embodiment of the present
`invention.
`FIG. 4 is a message sequence diagram illustrating a
`second example of received messages being stored in
`the memory of a remote unit of the communication
`system according to the preferred embodiment of the
`present invention.
`FIG. 5 is a block diagram illustrating messages stored
`in the memory of a central terminal of the communica
`tion system and messages stored in the memory of a
`remote unit before a reconciliation of messages between
`the central terminal and the remote unit, in accordance
`with the preferred embodiment of the present inven
`tion.
`FIG. 6 is a ?ow diagram illustrating an operational
`sequence for a remote unit, according to the preferred
`embodiment of the present invention.
`FIGS. 7 and 8 are message sequence diagrams illus
`trating a timing aspect of the second example of FIG. 4,
`in accordance with the preferred embodiment of the
`present invention.
`FIGS. 9 and 10 are flow diagrams illustrating opera
`tional sequences for the central terminal of FIG. 1,
`according to the preferred embodiment of the present
`invention.
`FIGS. 11 and 12 are flow diagrams illustrating opera
`tional sequences for the remote unit of FIG. 1, accord
`ing to the preferred embodiment of the present inven
`tion.
`FIG. 13 is a message block diagram illustrating a
`transmitted message according to an alternative em
`bodiment 15 of the present invention.
`FIG. 14 is a flow diagram illustrating an operational
`sequence for the central terminal of FIG. 1, according
`to the alternative embodiment of the present invention.
`FIGS. 15 and 16 are ?ow diagrams illustrating an
`operational sequence for the remote unit of FIG. 1,
`according to the alternative embodiment of the present
`invention.
`
`20
`
`25
`
`BACKGROUND OF THE INVENTION
`Communication systems, such as paging systems,
`typically communicate messages from an originating
`device to one or more destination devices. These mes
`sages can include numeric and alphanumeric informa
`tion for a user of the destination device. The destination
`device, e.g., a selective call receiver or pager, typically
`presents the information received to the user by display
`ing the information on a display.
`Contemporary paging systems offer a limited mes
`sage length for communicating information. For exam
`ple, an alphanumeric message may be typically 80 l
`characters or less. These typical message lengths have
`provided reasonably reliable delivery Of messages to the
`users of the communication system.
`On the other hand, a distinct trend in the market is for
`customers desiring much longer messages, such as from
`ten to one hundred times longer messages or more.
`Transmission of these messages over a paging channel
`can encounter a number of obstacles to reliable delivery
`of the longer messages, such as different types of inter
`ference, fading, noise, and other phenomena detracting
`from error-free and reliable communication of the mes
`sages to the destination devices.
`This dif?culty in reliable transmission of the longer
`messages is especially frustrating to customers that are
`used to communicating long messages over a more
`reliable communication medium, such as direct wire
`line or dial-up telephone communication. Thiszis partic
`ularly the case for electronic mail system users which
`typically desire to send relatively long messages with a
`high degree of certainty that the messages are received
`error free. Typically, an originating device, such as a
`personal computer or workstation, can send long mes
`sages to one or more destination devices, such as other
`personal computers or workstations, over a direct wire
`line interface, or over a local area network (LAN), or
`over a dial-up telephone line connection using the pub
`lic switched telephone network (PSTN).
`55
`Therefore, a need exists to enhance the reliability of
`transmitting messages, including long messages, in com
`munication systems that utilize paging systems for de
`livering the messages.
`
`45
`
`SUMMARY OF THE INVENTION
`According to an embodiment of the present inven
`tion, there is provided a method and apparatus for reli
`ably delivering messages to a communication receiver
`in a communication system. The communication system
`transmits messages to the communication receiver and
`the communication receiver receives transmitted mes
`sages over a ?rst communication medium. The commu
`
`65
`
`DESCRIPTION OF A PREFERRED
`EMBODIMENT
`FIG. 1 shows a communication system 100 utilizing a
`paging transmitter system 120, 122, 124, 126, for deliv
`ering messages to at least one portable remote unit, e. g.,
`a portable selective call receiver 130, in accordance
`with the preferred embodiment of the present inven
`tion. A central terminal 102 comprises input sections
`110, 112 for receiving inputs from a number of different
`
`Microsoft Ex. 1008
`Page 13 of 25
`
`

`
`15
`
`20
`
`25
`
`30
`
`35
`
`5,396,537
`3
`4
`devices 104, 106, 108, including receiving page requests
`paging receiver 134 of the general type shown in FIG.
`for initiating pages that are transmitted by the paging
`1 is well known and is more fully described in US. Pat.
`transmitter system 120, 122, 124, 126, to the at least one
`No. 4,518,961 issued May 21, 1985, entitled, “Universal
`portable remote unit 130. The central terminal 102 has
`Paging Device With Power Conservation”, which is
`input sections 110 that interface with the telephone
`assigned to the same assignee as the present invention
`company equipment, such as the public switched tele
`and is incorporated herein by reference.
`phone network (PSTN) 107. Personal computers or
`The paging receiver 134 couples a received message
`other computing devices 104 can access the input sec
`to the controller 136 through the bus 138. The control
`tions 110 through the PSTN using a dial-up telephone
`ler 136 address information in the received message and
`line and modem communication. Other calling devices,
`then match predetermined address in the selective call
`such as telephone input devices 106 can access the input
`receiver 130. In this way, the controller 136 can deter
`sections 110 of the central terminal 102 through the
`mine whether the received message is intended for the
`PSTN 107. Typically, these input devices 104, 106, can
`particular selective call receiver 130. Further, a mem
`remotely initiate page requests through the central ter
`ory 140 is coupled to the paging receiver 134 and the
`minal 102 by calling up the input sections 110 of the
`controller 136 through the bus 138 for storing the re
`central terminal 102 over dial-up telephone lines of the
`ceived message in the memory 140. A user can access
`PSTN 107.
`user input means 141, such as buttons or switches, at the
`Alternatively, other input sections 112 of the central
`remote unit 130 to cause the message data of a received
`terminal 102 can receive inputs, such as page requests,
`message to be displayed on a display, e. g., a liquid crys
`from local computing devices 108, such as a local per
`tal display (not shown). The user can then read the
`sonal computer or console or other terminal device.
`message that is visible on the display. User input at the
`Typically, the one or more local input devices 108 inter
`remote unit 130 can also cause the remote unit 130 to
`face with the input sections 112 of the central terminal
`perform other functions that are well known to users of
`102 via direct wire line connections using standard
`selective call receivers and portable personal comput
`ing devices.
`RS-232 or RS-422 interface.
`The input sections 110, 112, communicate page re
`A real time clock 142 is also coupled through the bus
`quests to a controller 114 through a communication bus
`138 to the controller 136 for providing time information
`116. The controller 114 may comprise controller cir
`thereto. The remote unit 130 is then capable providing
`cuitry and associated memory such that an incoming
`time information to the user by displaying the time
`page request may be accepted and stored into available
`information on the display (not shown). Additionally,
`memory for subsequent transmission to one or more
`the controller 136 can utilize the, time information pro
`selective call receivers 130. Additionally, a non-volatile
`vided by the real time clock 142 to keep track of the
`memory device 118, such as battery backed up RAM,
`time when messages were received at the remote unit
`130 and to perform and other useful operations that will
`one or more disc drive units, or other non-volatile stor
`age medium, is utilized by the controller 114 for longer
`be more fully discussed below.
`term storage of messages destined for the one or more
`Furthermore, the selective call receiver 130 includes
`selective call receivers 103. The controller 114 typically
`a modem transmitting unit and a modem receiving unit
`couples the message information and other associated
`144 and the associated telephone interfacing circuitry or
`other suitable communications apparatus (e.g., packet
`information to the memory device 118 via the bus 116.
`The message information, which can include numeric,
`radio modem) which allows the user of the selective call
`alphanumeric, or binary information, and other associ
`receiver 130 to connect the selective call receiver to a
`ated information stored in the memory 118 can be used
`telephone interface 150, such as may be provided by an
`by the controller 114 for reliable delivery of the mes
`RJll plug 148 and associated wiring 146 at the selective
`call receiver 130 and the complimentary wall jack 150
`sage to the destination or remote unit 130, as will be
`more fully discussed below.
`and associated wiring 152 thereof. This telephone inter
`The controller 114 couples messages to the paging
`face 144, 146, 148, 150, 152, allows the controller 136 of
`encoder 120 over the bus 116 for encoding the messages
`the selective call receiver 130 to remotely access the
`for transmission over a paging channel. The paging
`central terminal 102 through a dial-up telephone line
`encoder 120 then couples the encoded messages over a
`and the PSTN 107. At the central terminal 102, a
`communication path 122’ to one or more paging trans
`modem transmitting unit and a modem receiving unit
`mitter systems 124, 126, for transmission over a paging
`111 is capable of communicating with the modem 144 at
`communication channel. The communication path 122,
`the selective call receiver 130. In this way, the selective
`in this example, will be labeled path B which routes the
`call receiver 130 can communicate with the central
`messages from the central terminal 102 to a paging
`terminal 102 and receive message information there
`transmitter system 124, for transmission and over a
`from through a separate communication path which, in
`paging communication channel for reception by the one
`this example, is labeled path A 152. Therefore, the selec
`or more selective call receivers 130. The general opera
`tive call receiver 130 cab receive message information
`tion of a communication system including a paging
`from the central terminal 102 via path A 152 and via
`system of the type shown in FIG. 1 is more fully de
`path B 122. The path A 152 communication medium
`scribed in US. Pat. No. 5,138,311, issued Aug. 11, 1992,
`and the path B 122 communication medium can com
`entitled, “Communication System Having adaptable
`prise any communication paths, such as direct wired
`Message Information Formats”, which is assigned to
`line path, telephone line path, or wireless communica
`the same assignee as the present invention and is incor
`tion path including at least one radio communication
`porated herein by reference.
`channel preferably path A 152 is different than path B
`The selective call receiver 130 preferably incorpo
`122.
`rates a paging receiver 134 that operates to receive
`In the preferred embodiment, path A 152 is a dial-up
`messages transmitted over the paging communication
`telephone line using modem communication between
`channel through the antenna 132. The operation of a
`the central terminal 102 and the remote unit 130. Also,
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`Microsoft Ex. 1008
`Page 14 of 25
`
`

`
`15
`
`25
`
`5,396,537
`5
`preferably path B includes a paging communication
`channel for transmitting messages to the selective call
`receiver 130. Alternatively, path A may be a one-way
`or two-way radio frequency communication channel
`between the remote unit 130 and the central terminal
`102, and path B can be a paging communication chan
`nel. Additionally, in another alternative, path A and
`path B can be one-way or two-way radio frequency
`communication channels. An advantage of delivering
`messages to the remote unit 130 through the paging
`communication channel Over the two-way radio fre
`quency communication channel is that typically more
`messages can be delivered through the medium in the
`paging communication channel. This in turn enhances
`the commercial viability of the communication system.
`However, using two-way radio frequency communica
`tion channels for both path A and path B may be per
`fectly acceptable in some systems.
`By using a dial up telephone line interface for path A
`152, and utilizing modern communication between the
`20
`remote unit 130 and the central terminal 102 in the
`preferred embodiment, the reliability of transferring
`messages between the central terminal 102 and the re
`mote unit 130 is relatively high and approaches the
`reliability that users of conventional computing systems
`have previously experienced. Hence, it is advantageous
`to transfer messages over the dial-up telephone line
`interface 152 because it is a more reliable communica
`tion medium than transmission over the paging commu
`nication channel 122, e.g., over a radio paging channel.
`On the other hand, the dial-up telephone line interface
`152 has several draw backs. First, dial-up telephone line
`interfacing typically interfaces between one originating
`and one receiving device which signi?cantly reduces
`the number of remote units that can subscribe to any
`type of communication system. Second, the telephone
`line interface 152 normally requires that the remote unit
`130 connect to a telephone line interface which may not
`always be available. Third, the remote unit is not as
`portable due to the requirement that it be intercon
`nected with the telephone interface. In the case of a
`paging communication channel transmission, the re
`mote unit 130 is portable and can receive messages
`transmitted over the paging communication channel
`while the remote unit 130 is being carried by a user.
`Hence, although the telephone line interface communi
`cation tends to be more reliable than the paging channel
`communication, it can signi?cantly limit the number of
`subscribing remote units 130 in the communication
`system, and it tends to inconvenience users by requiring
`them to connect their remote units 130 to a telephone
`line interface 152 for communication with the central
`terminal 102. Therefore, the preferred embodiment of
`the present invention utilizes both path A and path B
`communication of messages in a manner that signi?
`55
`cantly increases the reliability of transmission of mes
`sages between the central terminal 102 and the remote
`units 130 while allowing large numbers of portable
`remote units 130 to be serviced in the communication
`system, as will be more fully discussed below.
`The communication system 100 of the preferred em
`bodiment of the present invention allows high through
`put of messages between the central terminal 102 and
`the portable remote units 130 by transmitting messages
`over the path B 122, e.g., a radio frequency paging
`channel, for normal communication of new messages
`between the central terminal 102 and the remote units
`130. Additionally, for a higher grade of service, the
`
`6
`central terminal 102 can transmit messages multiple
`tinges over path B 122 to better guarantee that the re
`mote unit 130 will receive at least one of the transmis
`sions of the same message. For example, the central
`terminal 102 can transmit a message three separate times
`over the paging channel 122 where each subsequent
`transmission of the same message is delayed by a prede
`termined time interval from the previous transmission,
`e. g., three minutes. In this way, the remote unit 130 has
`a higher probability of receiving the message transmit
`ted over the paging channel 122.
`Nonetheless, there may be times when the message is
`not received by the remote unit 130. In such event the
`communication system 100 provides a means at the
`remote unit 130 for determining that a message was
`missed and further for reconciling with the central ter
`minal 102 to receive at least the message information of
`a missed message over a more reliable communication
`medium, such as provided through path A 152. How
`ever, the required throughput of path A 152 can be
`much lower than the throughput of messages through
`path B 122 because the number of missed messages will
`be much lower than the number of new transmitted
`messages for the communication system 100. Hence, the
`bulk of communication transmission including the trans
`mission of new messages can be handled through path B
`122, e.g., the radio frequency paging channel. The rec
`onciliation of missed messages between the remote units
`130 and the central terminal 102 can be handled over
`the more reliable communication medium provided
`through path A 152. Further the portable remote units
`130 can be carried by a user while receiving new mes
`sage transmissions over the paging channel 122. The
`users of the remote units 130 will be minimally inconve
`nienced by requiring that the remote unit 130 be con
`nected with the telephone line interface 152 to perform
`reconciliation of missed messages because messages
`typically will be missed relatively infrequently. Option
`ally, as mentioned earlier, path A 152 can be con?gured
`as a one-way or two-way radio frequency communica
`tion channel between the central terminal 102 and the
`remote units 130. In this case, the message reconcili
`ation can be performed while the users carry the remote
`selective call receivers 130 such that. Hence, the users
`are minimally inconvenienced.
`PIG. 2 is a message block diagram illustrating a trans
`mitted message according to the preferred embodiment
`of the present invention. The transmitted message 200
`typically includes identi?cation and control information
`202, as well as message data information 204. The mes
`sage data 204 normally is the information that is com
`municated between an originating party and the destina
`tion remote unit 130. That is, the message data 204 is the
`message information communicated to the user of the
`selective call receiver 130. The message data 204 can
`include numeric information, alphanumeric informa
`tion, and binary data. The identi?cation and control
`information 202 included with the message 200 nor
`mally is required for delivering the message in the com
`munication system 100. Such information 202 includes
`address information 206 which identi?es one or more
`remote units 130 as the destination of that message data
`204. Hence, when a remote unit 130 receives a message
`200 that was transmitted from the central terminal 102,
`the remote unit 130 can determine whether that particu
`lar message 200 was intended for reception by the par
`ticular remote unit 130. Normally, the address informa
`tion 206 included with the message 200 is decoded by
`
`35
`
`45
`
`65
`
`Microsoft Ex. 1008
`Page 15 of 25
`
`

`
`5,396,537
`7
`8
`the remote unit 130 and compared to a predetermined
`edly transmitted three times for delivery to a receiving
`address in the remote unit 130. If the address informa
`remote unit 130, where the repeatedly transmitted mes
`tion 206 in the message 200 matches the predetermined
`sages have the same destination address 206, a received
`address in the remote unit 130 then the message 200 was
`message 200 including a message repetition count 210 of
`intended for that particular remote unit 130. The remote
`two may identify to the receiving remote unit 130 that
`unit 130 can then store the received message data 204 in
`the received message 200 was the second transmission
`a memory 140 in the remote unit 130, or optionally in a
`of that message from the central terminal 102.
`computer memory of a computing device associated
`Other information can be transmitted with a transmit
`with the remote unit 130 for later processing. A user of
`ted message 200, such as error detecting and/ or correct
`the remote unit 130 can subsequently review the mes
`ing code. For example, a cyclic redundancy code
`sage data 204 to communicate the message to the user.
`(CRC) 212 can be included with each transmitted mes
`Typically, the user reviews the message on a display on
`sage 200 to help identify at the receiving remote unit
`the remote unit 130. That is, for example, the user can
`130 when received message data 204 has-been errone
`read the message on a display screen such as commonly
`ously received, e.g., when the message data 204 has
`available on portable personal computers and portable
`been received with errors included therein. In this cage,
`selective call display receivers.
`although the message 200 has been received by the
`Additionally, in the preferred embodiment of the
`remote unit 130, the message data 204 may not ba com
`present invention, the message 200 includes other iden
`pletely and correctly communicated to the user of the
`ti?cation information fox enhancing the reliability of
`remote unit 130. Hence, the remote unit 130 has failed to
`delivering the message from the central terminal 102 to
`receive the message 200 accurately enough to commu
`20
`the portable selective call receiver 130. For example,
`nicate the message information to the user of the remote
`each message 200 can include a message sequence num
`unit 130. Hence, two possible conditions can identify
`ber 208 which identi?es the relative sequence of the
`when the remote unit 130 has failed to receive a trans
`message 200 in a transmission sequence for messages
`mitted message. The ?rst is when the remote unit re
`transmitted from the central terminal 102 to the remote
`ceives a transmitted message out of sequence with a
`unit 130 for a particular address information 206. That
`previously established transmission sequence. The sec
`is, each message that includes the same address informa
`ond is when the remote unit 130 receives a transmitted
`tion 206, i.e., that is destined for reception by the same
`message having errors in the message data 204. The
`one or more remote units 130, can be tagged with a
`CRC 212 can be used by the r