.
`Ulllted States Patent
`
`[19]
`
`USOOS377186A
`[11] Patent Number:
`
`5,377,186
`
`Wegner et a1.
`
`[45] Date of Patent:
`
`Dec. 27, 1994
`
`[54] SYSTEM FOR PROVIDING ENHANCED
`SUBSCRIBER SERVICES USING ISUP
`CALL-SETUP PROTOCOL
`I
`.
`.
`2:5“;1iffimogeléolo
`Inventors'
`[75]
`'
`p
`’
`[73] Assignee: Telefonaktiebolaget L M Ericsson,
`Stockholm, Sweden
`
`'
`
`.
`[21] Appl‘ No" 95’300
`[22] Filed:
`Jul. 21, 1993
`
`Int. Cl.5 ................................................ H04J 3/12
`[51]
`[52] US. Cl. ................................... 370/62; 370/ 110.1;
`379/201; 379/207; 379/211; 379/230
`[58] Field of Search ..................... 370/94.1, 110.1, 62;
`379/157, 201, 207, 210, 211, 212, 213, 224, 230,
`258
`
`56
`]
`
`[
`
`Ci d
`R f
`te
`e erences
`U.S. PATENT DOCUMENTS
`4,811,334
`3 1
`...................................... 3 0
`5,193,110 3513:? it: eta].
`£432
`
`370/1101
`5,204,861
`4/1993 Wiebe
`5,237,604 8/1993 Ryan ........................... 379/220
`
`.
`5,241,588 8/1993 Babson, III et al.
`379/201
`5,251,255 10/1993 Epley ..................1............... 379/242
`OTHER PUBLICATIONS
`
`Advanced Intelligent Network (AIN) 0.1 Switch—Service
`Control Point (SCP) Application Protocol Interface Ge-
`neric Requirements, Bellcore, Bell Communications Re-
`search, Technical Advisory, TA-NWT—001285, Issue
`1, Jan. 1992.
`Switching System Generic Requirements Supporting
`ISDN Access Using the ISDN User Par, Bellcore, Bell
`
`Communications Research, Technical Advisory,
`TA—NWT—OOO444, Issue 4, Aug. 1992.
`Switching System Generic Requirements for Interex-
`change Carrier Interconnection Using the Integrated Ser—
`vices Digital Network User Part (ISDNUP), Bellcore,
`Bell Communications Research, Technical Advisory,
`TA—NWT-OOO394, Issue 5, Apr. 1993.
`Advanced Intelligent Network (AIN) Service Control
`Point (SCP) Generic Requirements, Bellcore, Bell Com-
`munications Research, Technical Advisory, TA-NW-
`T-001280, Issue 1, Aug. 1992.
`
`Primary Examiner—Douglas W. Olms
`Assistant Examiner—Russell W. Blum
`Attorney, Agent, or Firm—Johnson & Wortley
`
`ABSIRACI
`[57]
`A system and method for retrieving enhanced sub-
`scriber services from at least one database and deliver-
`ing those services to the subscribers of a telecommuni-
`cations network without requiring the expensive up-
`gradmg °f 1°C” S‘l’lt?hes (LS?) t.° °Perate With the
`Transaction Capabihties Application Part/Advanced
`Intelligent Network (TCAP/AIN) communications
`protocol. The system comprises a plurality of LSs
`which are connected to an Advanced Intelligent Net-
`work (AIN) and provide the subscribers with access to
`the network. The system also includes at least one v1r-
`tual service switching point (ViSSP) within the AIN for
`storing the database of enhanced subscriber services.
`LSs or tandem switches may retrieve enhanced sub-
`scriber services from the ViSSP utilizing the Integrated
`Services Digital Network User Part (ISUP) call-setup
`protocol.
`'
`
`6 Claims, 8 Drawing Sheets
`
`new“
`Is
`112
`1s 57
`
`N0
`
`511%???
`urmuux
`
`143 113
`m B
`
`“6
`
`53‘,
`
`144
`
`.YES
`1111 some:
`
`No
`
`147
`
`
`
`m mm111111 mp
`115mm 51:11
`5 W111111011124
`“3
`
`153
`
`154
`
`155
`
`[5 1'55up
`WW
`11:5
`
`NO
`'5‘
`152
`
`TAEIETOENDIAMTOWSSPVMSTP
`
`01110111111. 15 RSERVES CIRCUIT
`
`ISUP 1111010001. 111mm 111 115511
`MP5 11111 12111111151515 11110 551
`1115 10 011017 1111118115:
`52m: 1001:: 9110011111 111 551
`PERFWS DATABASE LOOKUP AND
`mums 11011 1101111110 1111113511
`
`
`
`
`
`151111 PROIOCOL 11141151111011 1111111514811
`15"
`(%§mmolmm
`
`m157 11255111: 10 0111011111 1:
`ORIGINAL 1s 112—1111111155 m1 5:101:
`158
`to 1:111 02511111111011 110110211 16
`51101111 111 new: 20 111111 3
`
`YMAX EXHIBIT 1037
`
`00 000 1
`
`|PR2016-01260
`
`YMAX CORP. V. FOCAL IP
`
`000001
`
`YMAX EXHIBIT 1037
`YMAX CORP. V. FOCAL IP
`IPR2016-01260
`
`

`

`US. Patent
`
`Dec. 27, 1994
`
`Sheet 1 of 8
`
`5,377,186
`
`12
`'/
`r ---------------- ‘-JL—-'fl
`180
`:
`- :
`SCP
`I
`I
`I
`.
`\\ //
`:
`- 190
`X
`I
`'
`,’ \
`I \ |
`--
`SCP
`
`:I
`
`I
`19n
`18n
`l- — — — - - _ _ _ _ - _ _ _ _ _ — _ - _ _ _ _-.J
`
`7
`
`(PRIOR ART)
`
`23
`
`21
`
`@
`
`FIG. 2
`
`23
`
`21
`
`i
`
`|
`I
`|
`I
`.J |
`I
`I
`--JJ:
`
`F
`l
`I
`-:
`I
`I
`I:
`
`STP —-
`\
`
`/
`
`.
`I
`'
`
`l
`I
`'
`
`STP
`
`
`
`2:22:22: 21?:
`
`000002
`
`

`

`US. Patent
`
`Dec. 27, 1994
`
`Sheet 2 of 8
`
`5,377,186
`
`CALLING SUBSCRIBER
`DIALS NUMBER
`
`101
`
`(SEE FIG. 2)
`
`NO
`
`102
`
` ARE
`
`LSs ISUP
`CAPABLE
`?
`
`
`
`103
`
`104
`
`105
`
`105
`
`107
`
`108
`
`109
`
`HO
`
`SIGNAL ROUTED TO
`SSP/T VIA MF TRUNK
`
`ISUP CALL SETUP
`INVOKED IN SSP/T
`
`SSP/T RECOGNIZES
`DIALED NUMBER AND
`SEIZES ISUP TRUNK
`
`
`
`ORIGINAL SSP/T SENDS IAM
`TO DESTINATION SSP/T VIA
`STP REQUESTING CALLED
`
`NUMBER STATUS
`
`DESTINATION SSP/T QUERIES
`DESTINATION LS ABOUT
`CALLED NUMBER STATUS
`
`DESTINATION Ls DETERMINES
`STATUS AND RETURNS STATUS
`TO DESTINATION SSP T
`
`DESTINATION SSP/T
`RETURNS ACM TO ORIGINAL
`SSP
`VIA STP
`
`DESTINATION SSP/T
`RETURNS ANM TO ORIGINAL
`SSP T VIA STP
`
`MF TRUNK CONNECTED
`
`m BETWEEN ORIGINAL SSP/T
`
`AND DESTINATION SSP T
`
`112
`
`REL MESSAGE SENT AFTER
`CALL TERMINATION, AND
`RLC SENT IN RESPONSE
`
`000003
`
`YES
`
`(SEE FIG. 20)
`
`ISUP CALL SETUP
`INVOKED IN LS
`
`ORIGINATING LS RECOGNIZES
`DIALED NUMBER AND
`SEIZES ISUP TRUNK
`
`ORIGINATING LS SENDS IAM
`TO DESTINATION LS VIA
`STP REQUESTING CALLED
`
`NUMBER STATUS
`
`113
`
`H 4
`
`115
`
`DESTINATION LS DETERMINES
`STATUS AND RETURNS ACM To
`ORIGINAL LS VIA STP
`
`116
`
`DESTINATION LS RETURNS ANM H7
`TO ORIGINAL Ls VIA STP
`
`MF TRUNK CONNECTED
`BETWEEN ORIGINAL SSP/T
`AND DESTINATION SSP/T
`
`REL MESSAGE SENT AFTER
`CALL TERMINATION, AND
`RLC SENT IN RESPONSE
`
`118
`
`119
`
`FIG. 3
`(PRIOR ART)
`
`
`
`000003
`
`

`

`US. Patent
`
`Dec. 27, 1994
`
`Sheet 3 of 8
`
`5,377,186
`
`150
`
`13
`
`14
`
`FIG. 3a
`(PRIOR ART)
`18
`
`
`
`@---fi
`
`24
`
`23
`
`21
`
`SEIZURE
`MF TRUNK
`
`COMPLETE
`
`221
`
`000004
`
`000004
`
`

`

`US. Patent
`
`I
`
`Dec. 27, 1994
`
`Sheet 4 of 8
`
`5,377,186
`
`CALLING SUBSCRIBER
`DIALS NUMBER
`
`121
`
`N0
`
`
`LS SS7
`
`
`CAPABLE?
`
`
`DOES LS
`13”
`
`HAVE LATEST AIN
`RELEASE
`
`'2
`
`YES
`
`SIGNAL ROUTED TO SSP/T
`VIA MF TRUNK
`
`AIN SERVICE
`INVOKED IN LS
`
`
`
`
`
`
`
`SCP PERFORMS
`DATABASE LOOKUP
`
`123
`
`124
`
`125
`
`‘25
`
`127
`
`‘28
`
`129
`
`
`
`132
`
`133
`
`134
`
`135..
`
`135
`
`‘37
`
`LS RECOGNIZES
`DIALED NUMBER AS
`AIN SUBSCRIBER
`
`
`
`LS SENDS QUERY MESSAGE
`VIA STP TO SCP
`
`AIN SERVICE
`INVOKED IN SSP/T
`
`SSP/T RECOGNIZES
`DIALED NUMBER AS
`AIN SUBSCRIBER
`
`
`
`SSP/T SENDS QUERY
`MESSAGE VIA STP T0
`SCP REQUESTING
`PROCESSING INSTRUCTIONS
`
`
`
`
`REQUESTING CALL
`PROCESSING INSTRUCTIONS
`
`SCP PERFORMS
`DATABASE LOOKUP
`
`SCP RETURNS ROUTING
`INSTRUCTIONS TO LS
`
`SCP RETURNS ROUTING
`INSTRUCTIONS TO SSP/T
`
`SSP/T CONNECTS MF
`TRUNK BETWEEN LSs
`
`SSP/T CONNECTS MF
`TRUNK BETWEEN LSS
`
`FIG. 4
`
`(PRIOR ART)
`
`000005
`
`000005
`
`

`

`US. Patent
`
`Dec. 27, 1994
`
`Sheet 5 of 8
`
`5,377,186
`
`L___________...____J
`
`(O
`
`_,
`
`I I I I V I
`
`II I I I I I I I l I I I I I I
`
`.J
`
`44
`
`4:5
`
`
`
`SERVICE MANAGEMENT
`APPLICATION SYSTEM
`(SMAS)
`
`
`
`
`
`
`SERVICE SCRIPT
`INTERPRETER
`(SSI
`
`
`
`
`
`
`
`800
`
`
`
`
`AIN
`RELEASE
`
`SERVICE
`0.1
`
`
`
`
`
`FIG. 6
`
`(PRIOR ART)
`
`000006
`
`000006
`
`

`

`US. Patent
`
`Dec. 27, 1994
`
`Sheet 6 of 8
`
`5,377,186
`
`I I I I I I I I I I I I I I I I I I I I I I I I I I I
`
`.I
`
`
`
`SERVICE MANAGEMENT
`APPLICATION SYSTEM
`(SMAS)
`
`SERVICE SCRIPT
`INTERPRETER
`(SSI)
`
`-
`
`55
`
`
`
`
`54
`
`
`
`
`
`
`
`
`J
`
`511.....-
`
`I._.._.._______.__.......___
`
`FIG. 7
`
`RDIRNR‘Tag
`
`AIN
`
`- 800
`
`52
`
`ss7 lNTERFACE
`
`53
`
`\fiSSP
`CCS NEIWORK
`r I I I I I I I I I I I I I I I I I I I I I I I I I I I
`
`IAM and IAM (Call—Forward) Parameters
`
`551 Tag
`
`Nature of connection indicators
`Forward call
`indicators
`Calling party’s category
`User service information
`Called party number
`Calling party number
`Charge number
`Originating line information
`Transit network selection
`Carrier selection
`
`Service code indicator
`Redirection information
`Original called party
`Redirecting number
`
`NCI Tag (new)
`FCI Tag (new)
`ACAT Tag
`USl Tag (new)
`BNR Tag
`ANR Tag
`BN Tag
`OST Tag
`TNS Tag (new)
`First Word
`
`of CID Tag
`SCl Tag (new)
`RDlRlNF Tag
`ORIGBNR Tag
`
`9
`
`000007
`
`

`

`
` FIG. 70
`
`SIGNAL ROUTED
`TO SSP/T VIA
`‘43 YES
` I46
`MF TRUNK
`
`
`DOES Ls
`N0
`HAVE LATEST
`
`
`
`AIN SERVICE
`m R
`
`
`EMS
`I
`149
`INVOKED IN
`
`
`‘44
`'
`S
`SSP/T
`
`LS ISUP
`YES
`-
`
`
`AIN SERVICE
`CAPABLE?
`151
`
`
`
`
`INVOKED IN LS
`YES
`
`
`
`
`147
`
`SERVICE
`RETRIEVED
`WITH VISSP
`REPLACING
`Scp AS SHOWN
`IN FIGURE 4
`
`
`
`
`
`
`
`
`
`
`
`SERVICE RETRIEVED
`WITH VISSP
`REPLACING SCP
`
`
`
`AS SHOWN
`
`
`
`
`IN FIGURE 4
`
`
`
`
`I45
`
`I48
`
`
`ORIGINAL LS RESERVES CIRCUIT
`AND INCLUDES CIC IN IAM
`
`
`
`
`ISUP PROTOCOL TRANSLATOR IN WSSP
`
`US. Patent
`
`Dec. 27, 1994
`
`Sheet 7 of 8
`
`5,377,186
`
` CALLING SUBSCRIBER
`DIALS NUMBER I41
`
`
`
`ISUP CALL SETUP INVOKED IN LS
`
`I52
`
`ORIGINATING Ls USES MODIFIED ROUTING
`TABLE TO SEND IAM TO VISSP VIA STP
`
`153
`
`
`
`TAGS To QUERY DATABASE
`
`154
`
`MAPS IAM PARAMETERS INTO SSI
`
`
`
`
`SERVICE LOGIC PROGRAM IN SSI
`155
`PERFORMS DATABASE LOOKUP AND
`
`RETURNS NEW ROUTING NUMBER
`
` ISUP PROTOCOL TRANSLATOR FORMS IAM
`
`156
`(CALL-FORWARD) MESSAGE INCLUDING
`
`
`REDIRECTION NUMBER AND NEW CIC
`
`
`
`\fiSSP RETURNS IAM CALL—FORWARD
`MESSAGE TO ORIGINAL LS
`
`
`
`
`
`157
`
`158
`
`ORIGINAL LS RE—INITIATEs CALL SETUP
`To NEw DESTINATION NUMBER As
`SHOW IN FIGURES 20 AND 3
`
`000008
`
`000008
`
`

`

`US. Patent
`
`Dec. 27, 1994
`
`Sheet 8 of 8
`
`5,377,186
`
`FIG.
`
`7 7
`
`160
`
`310
`
`320
`
`50
`
`32b
`
`31b
`
`15b
`
`@—-—-@
`
`
`
`SEIZURE
`MF TRUNK
`
`
`
`RELEASE
`COMPLETE
`
`181
`
`000009
`
`000009
`
`

`

`
`
`1
`
`SYSTEM FOR PROVIDING ENHANCED
`SUBSCRIBER SERVICES USING ISUP
`CALL-SETUP PROTOCOL
`
`5,377,186
`
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`
`This invention relates to telephone switching and,
`more particularly, to a telecommunications system hav-
`ing local telephone switches capable of retrieving and
`deploying enhanced subscriber services from an Ad-
`vanced Intelligent Network (AIN) using a call-setup
`protocol.
`2. History of the Prior Art
`Modern telecommunications systems offer subscrib-
`ers a large number of enhanced subscriber services.
`These services may include the provision of an 800
`Services Database, a Credit Card Verification Data-
`base, Geographic Call Routing, Incoming Call Routing,
`Multi-location Extension Dialing, Network Automatic
`Call Distribution, Flexible Call Routing, Flexible Car-
`rier Selection, CLASS Calling Name Delivery Data-
`base, and others. Some telephone service providers are
`currently analyzing the use of a system known as the
`Advanced Intelligent Network (AIN) to provide these
`services.
`
`FIG. 1 is a simplified block diagram of a typical tele-
`communications system 11 using an Advanced Intelli-
`gent Network (AIN) 12 to provide enhanced subscriber
`services. The AIN 12 and its associated Signaling Sys-
`tem Number 7 (SS7) protocol are described in the in-
`dustry standard, “TR-NWT-000246, Bell Communica-
`tions Research Specification of Signaling System Num-
`ber 7,” which is hereby incorporated by reference. A
`large number of Local Switches (LSs) 13a—n may be
`connected to a Service Switching Point/Tandem
`(SSP/T) 14 via multi-frequency (MF) links 15. “tan-
`dem”, as used herein, may be a local, LATA, or access
`tandem. The LSs 13a—n provide connections for sub-
`scribers 16a—n into the telecommunications system 11.
`The AIN 12 uses a system of high speed telecommuni-
`cations links known as a Common Channel Signaling
`(CCS) network which employs the standard SS7 signal-
`ing protoeol to link all of the components of the AIN
`12. Standard telephony diagrams, and all figures herein,
`indicate links utilizing the SS7 signaling protocol as
`dotted lines and MF trunks as solid lines.
`The components of the AIN 12 may include the
`SSP/T 14, one or more Signal Transfer Points (STPs)
`18a—n which act as intermediate switching nodes, and
`one or more Service Control Points (SCPs) 190—71. The
`SCPs 19 each contain a database of enhanced subscriber
`services which are accessed and controlled by a Service
`Logic Program (SLP). The SCP 19 currently utilizes a
`standardized protocol known as Transaction Capabili-
`ties Application Part (TCAP) for coordination of func-
`tions. The current version of the protocol required for
`communication with the SCP 19 is TCAP/AIN Release
`0.1. The SCP 19 is described in the Bellcore standard,
`“TA-NWT-001280, Advanced Intelligent Network
`(AIN) Service Control Point (SCP) Generic Require-
`ments,” which is hereby incorporated by reference. The
`SCP l9 acts as a repository for enhanced subscriber
`services which may be accessed by any one of the LSs
`13a—n. In the past, each LS had to be individually up-
`graded with enhanced subscriber services. With the
`implementation of the AIN 12, and the required com-
`
`'
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`60
`
`65
`
`000010
`
`2
`munications capabilities in the LSs, new enhanced ser-
`vices need only be added to the SCP 19.
`L83 13 which have been upgraded to communicate
`utilizing the SS7 signaling protocol, and the latest re-
`lease of the TCAP/AIN communications protocol,
`may communicate directly with an STP 18 and from
`there with an SCP 19 or other SSP/Ts, utilizing the
`high speed CCS network. LSs 13 which have not been
`upgraded with SS7 signaling capability, or with the
`TCAP/AIN communications protocol, must communi-
`cate over lower speed MF trunks 15 with the SSP/T 14
`which, in turn, utilizes the SS7 signaling protocol, the
`TCAP/AIN communications protocol, and the CCS
`network to communicate with the STPs 18 and the
`SCPs 19. Dependence on MF trunks for access to the
`AIN 12 can substantially lengthen the time required to
`retrieve subscriber services, and ties up an expensive
`MF trunk which remains open and occupied during the
`retrieval period. The message flow utilized to retrieve
`an enhanced subscriber is described in more detail in
`conjunction with FIG. 4 below.
`Another transaction often carried out utilizing the
`CCS network is call setup. Call-setup messages utilize a
`call-setup protocol known as the Integrated Services
`Digital Network (ISDN) User Part (ISUP) call-setup
`protocol. The ISUP call-setup protocol is described in
`the Bellcore standards, “TR-NWT-000317. Switching
`System Generic Requirements for Call Control Using
`the Integrated Services Digital Network User Part
`(ISDNUP)”, “TR-NWT000394, Switching System Ge-
`neric Requirements for Interexchange Carrier Intercon-
`nection Using the Integrated Services Digital Network
`User Part (ISDNUP)”, and “TR-NWT000444, Switch-
`ing System Requirements Supporting ISDN Access
`Using the ISDN User P ”, which are hereby incorpo-
`rated by reference.
`FIG. 2 is a simplified block diagram illustrating a
`typical message flow utilized for call setup between two
`local telephone switches (LSs) 13 and 23 which have
`not been upgraded to utilize the ISUP call-setup proto-
`col. Each non-I SUP LS is typically connected through
`a MF trunk 15 to an associated SSP/T. Thereafter, a
`series of ISUP messages is sent back and forth between
`an originating SSP/T 14, associated with a calling sub-
`scriber 16, and a destination SSP/I‘ 24, associated with
`the called subscriber 21. The ISUP messages during call
`setup include an Initial Address Message (IAM) 22, an
`Address Complete Message (ACM) 25, an Answer
`Message (ANM) 26, a Release Message (REL) 27, and
`a Release Complete Message (RLC) 28. The ISUP mes-
`sages are routed via the STP 18.
`Many LSs in use today have been upgraded to utilize
`the ISUP call-setup protocol. FIG. 2a is a simplified
`block diagram illustrating a typical message flow uti-
`lized for call setup between two local
`telephone
`switches (LSs) 13 and 23 which have been upgraded to
`utilize the ISUP call-setup protocol. This upgrade al-
`lows ISUP-capable LSs to bypass the MF trunk link to
`the SSP/T, and communicate directly through the STP
`18. Thus, the LS may perform call setup entirely over
`the CCS high speed telecommunications network. The
`CCS network is capable of transmitting at much higher
`data rates than multi-frequency (MF) trunks, and call
`setup can be completed over the CCS network much
`faster and more efficiently than in the past.
`When utilizing the SS7 signaling protocol and the
`ISUP call-setup protocol for call setup, out-of-band
`signaling messages replace Multi -frequency (MF) and
`
`
`
`000010
`
`

`

`
`
`5,377,186
`
`3
`other in-band interoffice signaling mechanisms on se-
`lected circuits. The out-of-band messages are used to
`report circuit seizure and to transport address informa-
`tion, answer supervision, circuit release, etc. Thus, the
`network use of the SS7 signaling protocol for circuit-
`switched call connection and release differs fundamen-
`tally from traditional in-band circuit signaling. Instead
`of sending information on the facilities used for subscri-
`ber-to-subscriber communication, the switching system
`sends signaling information via a separate signaling
`network. The SS7 signaling protocol thereby allows
`switching systems to exchange information related to a
`circuit-switched connection even when the circuit is in
`the conversation mode.
`
`FIG. 3 is a flow chart illustrating the typical manner
`in which a call is set up via the ISUP call-setup proto-
`col, for both non-ISUP LSs and ISUP-capable LSs. At
`step 101, a calling subscriber 16 (FIGS. 2 and 2a) dials
`the telephone number of a distant subscriber 21. At step
`102, if the LSs are not ISUP-capable, the call is routed
`over MF trunks to an originating SSP/T 14 at step 103.
`At step 104, ISUP call setup is invoked in the SSP/T 14
`which then recognizes the dialed number as a number
`which requires ISUP routing, and seizes an ISUP trunk
`at 105. At 106, the originating SSP/T 14 then utilizes
`the ISUP call-setup protocol to send an Initial Address
`Message (IAM) 22, via the STP 18, to a destination
`SSP/T 24, asking for the status of the dialed subscriber’s
`phone 21. At step 107, the destination SSP/T 24 queries
`the destination LS 23 about the status of the called
`subscriber’s phone 21. The destination LS 23 determines
`the status of the called subscriber’s phone 21, i.e., busy,
`idle, forwarded, out of service, etc. , at step 108, and
`returns this status to the destination SSP/T 24. At 109,
`the destination SSP/T 24 returns, via the STP 18, an
`Address Complete Message (ACM) 25 to the originat-
`ing SSP/T 14, containing the status of the called sub-
`scriber’s phone 21. The originating SSP/T 14 receives
`the ACM 25 and at step 110, the destination SSP/T 24
`returns, via the STP 18, an Answer Message (ANM) 26
`to the originating SSP/T 14 indicating that a MF trunk
`should be set up between the two SSP/Ts 14 and 24. At
`step 111, the MF trunk 15 between the originating
`SSP/T 14 and the destination SSP/T 24 is connected
`thereby providing speech capability between the calling
`subscriber 16 and the called subscriber 21. Once the call
`is terminated at step 112, a Release Message (REL) 27 is
`sent from the switch serving the first subscriber to hang
`up, to the switch serving the other subscriber. In re-
`sponse, a Release Complete Message (RLC) 28 i 5 re-
`turned.
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`subscriber 21. Once the call is terminated at step 119, a
`'REL 27 is sent from the switch serving the first sub-
`scriber to hang up, to the switch serving the other sub-
`scriber.
`In response, a Release Complete Message
`(RLC) 28 i s returned.
`FIG. 3a is a message flow diagram illustrating the
`flow of messages from a non-ISUP LS 13 to an ISUP-
`capable LS 23 during call setup and call release. At 201,
`the non-ISUP LS 13 seizes an MP trunk to the SSP/T
`14. At 202, the SSP/T 14 sends an Initial Address Mes-
`sage (IAM) to the STP 18 which forwards it to the
`SSP/T 24 serving the called subscriber 21. At 204, the
`IAM is sent to the ISUP-capable LS 23 serving the
`called subscriber 21.
`An Address Complete Message (ACM) is returned to
`the SSP/T 24 at 205. At 206, the ACM is sent to the
`STP 18 where it is forwarded to the SSP/T 14 at 207.
`An Answer message (ANM) is returned from the LS 23
`to the SSP/T 24 at 208. At 209, the ANM is sent to the
`STP 18 where it is forwarded to the SSP/T 14 at 211.
`At 212, an answer signal is sent over the MF trunk to
`the non-I SUP LS 13.
`Termination of the call is begun after the first sub-
`scriber hangs up (in this example, subscriber 16a). At
`213, a release signal is sent over the MF trunk from the
`non-I SUP LS 13 to the SSP/T 14. A Release message
`(REL) is sent from the SSP/T 14 to the STP 18 at 214
`which forwards the REL to the SSP/T 24 at 215. At
`216, the REL is received by the LS 23 which returns a
`Release Complete Message (RLC) to the SSP/T 24 at
`217. At 218, the SSP/T 24 sends the RLC to the STP
`which forwards the RLC to the SSP/T 14 at 219. At
`221, a release complete signal over the MF trunk results
`in the disconnection of the call.
`Referring again to FIG. 1, it can be seen that LSs
`13a—n may access the AIN 12 either through MF trunks
`15 and the SSP/T 14, or directly through SS7 links 17
`to the STP 18. The message flows involved in determin-
`ing the type of access, and in the method of service
`retrieval from the database in the SCPs 19, is shown in
`the flow diagram of FIG. 4. At step 121, a calling sub-
`scriber 16a (FIG. 1) dials the telephone number of a
`called subscriber 16n. At 122, it is determined whether
`or not the originating LS 130 has been upgraded to
`utilize the SS7 signaling protocol. If not, then the LS.
`cannot directly access the AIN 12, and the signal is
`routed, at step 123, to the associated telephone Service
`Switching Point/1‘andem (SSP/T) 14 via a low speed
`MF trunk 15. At step 124, AIN service is invoked in the
`SSP/T 14 which recognizes the dialed number as an
`AIN subscriber at 125. At step 126, the SSP/T 14 sends
`a Query message via the STP 18 to the SCP 19 request-
`ing call processing instructions. The SCP performs a
`database lockup on the called subscriber’s service that is
`being invoked at step 127, and then returns routing
`instructions to the SSP/T 14 at step 128. This response
`contains all of the information that is necessary to route
`the call (i.e., routing number, carrier, billing number,
`etc.). The SSP/T 14 receives the routing instructions
`from the SCP 19, and completes the call at step 129 by
`setting a MF trunk 15 between the calling subscriber
`16a and the called subscriber 16n.
`If, however, at step 122 it is determined that the LS is
`SS7-capable, then the message flow moves to step 131
`where it is determined whether or not the LS has been
`upgraded with the latest release of the TCAP/AIN
`communications protocol. If not, then the flow again
`moves to step 123 where the signal is routed to the
`
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`If, however, at step 102 it was determined that the
`LSs are ISUP-capable, then the message flow moves to
`step 113 where ISUP call setup is invoked in the origi-
`nating LS 13. The originating LS 13 recognizes the
`dialed number as a number which requires I SUP rout-
`ing and seizes an ISUP trunk at 114, and at 115 sends an
`I AM 22 to the destination LS 23 via the STP 18 re-
`questing the status of the dialed subscriber’s phone 21.
`At 116, the destination LS 23 determines the status of 60
`the dialed subscriber’s phone and returns an ACM 25 to
`the originating LS 13 containing the status. At step 117,
`the originating LS 13 returns an ANM 26 indicating
`that a MF trunk should be set up between the two
`SSP/Ts 14 and 24. At step 118, the MF trunk 15 be-
`tween the originating SSP/T 14 and the destination
`SSP/T 24 is connected thereby providing speech capa-
`bility between the calling subscriber 16 and the called
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`associated SSP/T 14 via MF trunk 15. Steps 124
`through 129 are then utilized to retrieve the enhanced
`subscriber service.
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`If, at step 131, it is determined that the LS has been
`upgraded with the latest release of the TCAP/AIN
`communications protocol, then the LS may directly
`access the AIN 12. At step 132, AIN service is invoked
`in the LS which recognizes the dialed number as an
`AIN subscriber at 133. At step 134, the LS sends a
`Query message via the STP 18 to the SCP 19 requesting
`call processing instructions. The SCP performs a data-
`base lookup on the called subscriber’s service that is
`being invoked at step 135, and then returns routing
`instructions to the LS 13 at step 136. This response
`contains all of the information that is necessary to route
`the call (i.e., routing number, carrier, billing number,
`etc.). The LS 13 receives the routing instructions from
`the SCP 19, and completes the call at step 137 by setting
`a MF trunk 15 between the calling subscriber 16a and
`the called subscriber 1611.
`
`A major problem with the full implementation of
`enhanced subscriber services through the AIN 12 is the
`extremely high cost of the system to the service provid-
`ers. The major factor in the expense of implementing an
`AIN is that each of the hundreds of LSs must be hard-
`ware/software upgraded to be able to communicate
`with the SCP 19 in order to access each of the stored
`subscriber services. The current interface requirements
`for the SCP 19 are described in the Bellcore standard,
`“TR-NWT001285 Advanced
`Intelligent Network
`(AIN) 0.1 Switch-Service Control Point (SCP) Appli-
`cation Protocol
`Interfaces Generic Requirements,”
`which is hereby incorporated by reference. The up-
`grade to the LSs includes the implementation of the
`most recent version of the TCAP/AIN communica-
`tions protocol (currently Release 0.1) in the LSs. Tele-
`phone service providers typically have hundreds of
`LSs, and although the cost for each provider will vary,
`each provider may, for example, be faced with an ex-
`pense in excess of $500 million to upgrade its LSs to
`operate with the current release of the TCAP/AIN
`protocol.
`Another problem is encountered by LSs which are
`SS7 and ISUP-capable, but are not AIN-capable and
`have not been upgraded to access a particular sub-
`scriber services such as 800 service, which currently
`requires its own communications protocol. As shown in
`FIG. 4, these LSs 13 (FIG. 1) must set up low data rate
`MF trunks to the SSP/T 14 in order to access the AIN
`and the SCP 19 which stores the 800 service. Thereaf-
`ter, the SSP/T l4 communicates via the high speed
`CCS network and SS7 signaling protocol with the SCP
`19 in order to retrieve the requested service. Modern
`industry regulations and service expectations are requir-
`ing LSs to provide enhanced services at faster connec-
`tion times than are achievable with MF trunks.
`
`It would be a distinct advantage to have a system
`which provides a database of enhanced subscriber ser-
`vices which may be accessed by LSs utilizing the high
`speed CCS network, but does not require the expensive
`upgrading of LSs to operate with the TCAP/AIN com-
`munications protocol. It would be another advantage to
`have a system which enables all LSs to connect directly
`into the AIN via the SS7 signaling protocol rather than
`using slower MF trunks through the SSP/I‘. The pres-
`ent invention provides such a system.
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`SUMMARY OF THE INVENTION
`
`In one aspect, the present invention is a system for
`retrieving enhanced subscriber services from at least
`one database and delivering those services to the sub-
`scribers of a telecommunications network. The system
`comprises a plurality of local switches (LSs), or tandem
`switches, which are connected to the telecommunica-
`tions network and provide the subscribers with access
`to the network. The system also includes at least one
`virtual service switching point (ViSSP) within the tele-
`communications network for storing the database of
`enhanced subscriber services. Means are also provided
`for enabling the LSs or tandems to retrieve the sub-
`scriber services from the ViSSP utilizing a call-setup
`protocol. The call-setup protocol utilized in the pre-
`ferred embodiment is the Integrated Services Digital
`Network User Part (ISUP) call-setup protoool. The
`system does not require the expensive upgrading of the
`LSs to operate with the TCAP/AIN communications
`protocol.
`In another aspect, the present invention is a method
`of retrieving subscriber services from at least one data.
`base within a telecommunications network and deliver-
`ing those services to subscribers of the telecommunica-
`tions network. The method first provides the subscrib-
`ers with access to the network. The subscriber services
`are then stored in at least one database within the net-
`work, and are retrieved from the database utilizing a
`call-setup protocol which may be, for example,
`the
`ISUP call-setup protocol.
`BRIEF DESCRIPTION OF THE DRAWING
`
`The invention will be better understood and its nu-
`
`merous objects and advantages will become more ap-
`parent to those skilled in the art by reference to the
`following drawing, in conjunction with the accompany-
`ing specification, in which:
`FIG. 1 (Prior Art) is a simplified block diagram of a
`typical telecommunications system using an Advanced
`Intelligent Network (AIN) to provide enhanced sub-
`scriber services;
`FIG. 2 (Prior Art) is a simplified block diagram illus-
`trating a typical message flow utilized for call setup
`between two local telephone switches (LSs) which
`have not been upgraded to utilize the Integrated Ser-
`vices Digital Network User Part (ISUP) call-setup pro-
`tocol;
`FIG. 2a (Prior Art) is a simplified block diagram
`illustrating a typical message flow utilized for call setup
`between two LSs which have been upgraded to utilize
`the ISUP call-setup protocol;
`FIG. 3 (Prior Art) is a flow chart illustrating the
`typical message flows involved in setting up a call via
`the ISUP call-setup protocol, for both non-ISUP and
`ISUP-capable LSs;
`FIG. 3a (Prior Art) is a message flow diagram illus-
`trating the flow of messages from a non-I SUP LS to an
`ISUP-capable LS during call setup and call release;
`FIG. 4 (Prior Art) is a flow chart illustrating the
`message flows involved in determining the type of ac-
`cess provided for different LSs, and in the method of
`service retrieval, from a database stored in a Service
`Control Point (SCP);
`FIG. 5 is a simplified block diagram of the preferred
`embodiment of a telecommunications system using an
`AIN to provide enhanced subscriber services, and
`which is equipped with Virtual Service Switching
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`7
`Points (ViSSPs) and LSs and Service Switching Point
`Tandems (SSP/Ts) modified in accordance with the
`teachings of the present invention;
`FIG. 6 (Prior Art) is a simplified block diagram of a
`portion of the architecture of an existing SCP within an
`AIN;
`FIG. 7 is a simplified block diagram of a portion of
`the architecture of a ViSSP within an AIN, which has
`been constructed in accordance with the teachings of
`the present invention;
`FIG. 8 is a block diagram illustrating the signaling
`links and looped circuits between the ViSSP and the
`SSP/T in the preferred embodiment of the present in-
`vention;
`FIG. 9 is an illustration of the mapping of the parame-
`ters of an ISUP Initial Address Message (IAM) and an
`IAM (Call -Forward) message to Service Script Inter-
`preter (881) tags, which occurs in an ISUP protocol
`translator in the preferred embodiment of the present
`invention;
`FIG. 10 is a flow chart of a typical message flow
`utilized in the preferred embodiment of the present
`invention when a modified LS or SSP/T retrieves en-
`hanced subscriber services from a ViSSP; and
`FIG. 11 is a message flow diagram illustrating the
`flow of messages utilized for the retrieval of an en-
`hanced subscriber service from the ViSSP 50, call
`setup, and call release in the preferred embodiment of
`the present invention.
`DETAILED DESCRIPTION
`
`FIG. 5 is a simplified block diagram of the preferred
`embodiment of a telecommunications system using an
`AIN to provide enhanced subscriber services, and
`which is equipped with Virtual Service Switching
`Points (ViSSPs) and LSs and SSP/Ts modified in ac-
`cordance with the teachings of the present invention.
`The modified LSs 3la—n utilize the ISUP call-setup
`protocol, previously used only for call setup, to access
`a modified SCP known as a Virtual Service Switching
`Point (ViSSP) 50 and retrieve the subscriber services
`stored in the database therein. The ISUP call -setup
`protocol is widely deployed in many LSs (such as 13a—n
`shown in FIG. 1) today, and only minor changes are
`made to a routing table stored within each existing LS
`13 in order to enable the modified LSs Sla—n to utilize
`the present invention. The routing table is modified to
`route the IAM 22 (FIG. 2) to the ViSSP 50. For LSs
`which are not ISUP-capable, the modified routing table
`is located in a modified SSP/T 32 associated with the
`originating LS 3111. The techniques for modifying a
`routing table are well known within the art, and need
`not be elaborated on here. The modifications made to
`the SCP 19 of FIG. 1, in creating the ViSSP 50 of FIG.
`5, are described below.
`FIG. 6 is a simplified block diagram of a portion of
`the architecture of an existing SCP 19 within an Ad-
`vanced Intelligent Network (AIN). The SCP 19 in-
`cludes an interface for the SS7 signaling protocol 41,
`Transaction Capabilities Application Part
`(TCAP)
`blocks of software called “protocol translators” 42, a
`database program known as the Service Script Inter-
`preter ($51) 43, and an operational support system
`known as the Service Management Applica