Intelligent Networks (IN) and CAMEL

Intelligent Networks (IN):- 

Intelligent Networks is a concept service intelligence resides in a central node called an SCP and SSPs (residing on Switches) relinquish control to this node at particular stages in a call so that appropriate service logic can be applied.

Objectives of IN:

- Increased Service Velocity / Speed of Deployment

- Increased Range of Services

- Evolvability from Existing Networks

- Service & Vendor Independent Implementation

- MSC just focuses on core job of call processing

Network Before IN: Before IN application, there was messed network for every node:

Network with IN: After IN implementation, Network is organised.

Basic Concepts  – PIC and DPs & BCSM:

Point In Call (PIC) :  A state in a basic call state model.

Detection Point (DP) :  A point in basic call processing at which specific event is detected. Detection Points represent transitions between points in call processing (PICs). There are two types of DPs: TDP and EDP. EDP is also of two Type.

-Trigger Detection Point (TDP): statically armed DP at which the MSC/SSP first contacts the SCP to request for instructions or to provide information about call events. Processing is suspended when the DP is encountered.

-Event Detection Point -Notification (EDP-N): An EDP is a dynamically armed DP that is armed by the SCP. The  “call processing” point at which the MSC/SSP must contact the SCP to notify it of an event.  Processing is not suspended when encountering the DP.

- Event Detection Point – Request (EDP-R): This detection point is dynamically armed within the context of a CAMEL control relationship. Processing is suspended when encountering the DP and the gsmSSF waits for instructions from the gsmSCF.

- Service Switching Function (SSF) This is co-located with the MSC itself, and acts as the trigger point for further services to be invoked during a call.

- Service Control Function (SCF) This is a separate set of platforms that receive queries from the SSP.

- Service Data Function (SDF) This is a database that contains additional subscriber data, or other data required to process a call.

- Specialized Resource Function (SRF) or Intelligent Peripheral (IP) This is a node which can connect to both the SSP and the SCP and delivers additional special resources into the call, for example play voice announcements or collect DTMF tones from the user.

Customized Applications for Mobile networks Enhanced Logic, or CAMELfor short, is a set of standards designed to work on either a GSM core network or UMTS network. They allow an operator to define services over and above standard GSM services/UMTS services. The CAMEL architecture is based on the Intelligent Network (IN) standards, and uses the CAP protocol and it is particularly effective in allowing these services to be offered when a subscriber is roaming.

CAMEL Network Structure:

CSI identifies if the subscriber requires CAMEL support. CSI identifies which gsmSCF to use for that CAMEL support. CSI contains information related to the Operator Specific Service (OSS) of the subscriber, for example the Service Key.

Originating-CSI identifies subscriber as having originating CAMEL Services. O-CSI is stored in the VLR as part of subscriber data for roaming subscriber in the VLR area.

Terminating-CSI identifies subscriber as having terminating CAMEL Services. T-CSI is fetched by the GMSC when the HLR of the called subscriber is being interrogated by the GMSC. Originating-CSI is sent to the GMSC for forwarding.

CSI CONTENT -

gsmSCF address:   as an E.164 number

Service Key   : which identifies to the gsmSCF the service logic that should be used.

Default call handling:   that indicates how to proceed the call in case of error in the dialogue (release or continue).

TDP list: that indicates on which Detection Point (DP) triggering shall take place. Only DP2 for O-CSI and only DP12 for T-CSI.

DP2/ DP3 Trigger Detection Point:

A-Party                    MSC                           VLR                SCP               B-Party

============================================================

—–Setup—————>

                                    ——–SIOC(IN)——->

                                    <–Complete Call(IN)—

                                   ——————————INITDP(2)—–>

                                   <————————Continue————-

                                    ——–SIOC(No IN)—->

                                    <–Complete Call——

<—Call Proc/Assnmt—->

                                      ——————————————IAM——————>

DP2 (OCSI)

Service Screened in first SIOC: COS, ODB (BAOC & BAOC roaming outside the HPLMN Country), BAOC, CUG, IN (O-CSI)

Service screened in second SIOC: Remaining flavos if ODB and barring, LCO, OSSP screening.

DP12 Trigger Detection Point:

A-Party                    MSC                           HLR                SCP               B-Party

============================================================

————IAM———>

                                    ————SRI———->

                                    <—–SRI ACK(IN)—–

                                    ————————INITDP(12)———–>

                                    <——————CONTINUE—————-

                                    ————SRI———->

                                    <—–SRI ACK———

                                    ——————————–Paging ————————–>

Service screened in 1st SRI: DP12

Service screened in 2ndSRI: except IN all service.

 DP2 on Forwared forwarding Leg: In Call Forwarding, subscriber A calls subscriber B, who forwards the call to subscriber C. The forwarding leg to C is seen as a call origination (from B) as opposed to call termination of the call originated by A.

A-Party                    MSC-A                              HLR                SCP           PSTN

=================================================================

————IAM———>

                                    ————SRI———->

                                    <-SRI ACK(CFU & OCSI)–

                                    ———————-INITDP(2)———–>

                                    <—————-CONTINUE—————-

                            

                                    ——————————–IAM———————>

DP2 and DP12 on Forwarded forwarding Leg: In this example the subscriber B has been provisioned with both T-CSI service and O-CSI service. To simplify the diagram, the Terminating service makes no modification to the call set up and the Originating service is used to modify the CLI of the outgoing leg.

A-Party                    MSC-A                                    HLR                SCP           PSTN

==================================================================

————IAM———>

                                    ————SRI—————–>

                                    <-SRI ACK(CFU,TCSI & OCSI)–

                                    ———————-INITDP(12)———–>

                                    <—————–CONTINUE—————-

                                  ————————INITDP(2)———–>

                                    <——————CONNECT—————-

                                    —————————-IAM————————–>

Applying O-CSI to a call forwarded by CAMEL (T-CSI) : CAMEL can be used to forward calls, instead of using GSM Call Forwarding. It is possible to apply an O-CSI CAMEL service to the outgoing leg created by a CAMEL forwarding service.

A-Party                    MSC-A                                    HLR                SCP                    PSTN

===================================================================

————IAM———>

                                    ————SRI——————->

                                    <——-SRI ACK (TCSI & OCSI)–

                                    —————————-INITDP (12)——->

                                    <——-CONNNECT(DRA + OCSI)————

                                  ————————INITDP(2)————–>

                                    <—————CONNECT(CLI Modified)—-

                                    ——————————–IAM(with modified CLI)—–>

ANSWER Event Detection Point- Notify:

A-Party                      MSC                                    HLR                SCP                                  PSTN

==================================================================

————IAM———>

                                    ————SRI————->

                                    <——-SRI ACK(TCSI )—

                                    ——————–INITDP(12)———–>

                                    <———-RRBE(EDP, T_Answer)——–

                                  —————–CONNECT(PSTN)———->

                              

                                  ————————————-IAM——————————->

<————-ACM—  <———————-ACM—————————————–

<————-ANM—  <———————-ANM—————————————–                                    ————————ERB——————->

Disconnect Event Detection Point- Request:

A-Party                    MSC                                                    HLR                SCP                      PSTN

=================================================================

————IAM———>

                                    ————SRI————————>

                                    <——-SRI ACK(TCSI )———–

                                    —————————-INITDP(12)———–>

                                      <—————-RRBE(EDP, T_Answer)——–

                                       ———————CONNECT(PSTN)———->

                              

                                  ————————————-IAM——————————->

<————-ACM—  <———————-ACM——————————————–

<————-ANM—  <———————-ANM——————————————-

————–REL—->

                                 ———-ERB————————————>

                                 <————–Continue—————————

                                  ——————————————-REL—————————>

                                  <——————————————-REL—————————

<————–RLC—-

External IP Connection:

A-Party                    MSC                                    VLR                SCP                   IP                      MS

================================================================================

————setup———>

                                    ————SIOC———->

                                    <—–Continue(OCSI )—-

                                    ——————INITDP(2)———–>

                                    <——–ETC(IP)————————–

                                                                

                                  —-PRI Connection Established————————>

                                 <————————-DFC————

                                 <———————-PRI Connection Trerminated—–

                                 <————–Continue—————–

                                  ——————————-Paging————————————–>

Example of VPN: An example of MO CAMEL Phase 1 service is VPN. User A subscribes to VPN, the CSI (stored in the HLR) is copied to the VLR at Location Update. After dialing a short number (1) (e.g.colleague’s extension), the call is  stopped by the SSF which requests instructions from the SCF (2). The SCF gives the SSF the full number (3) that the VMSC uses to route the call to the GMSC (4).

Callee                            VMSC                                                                      SCP                        GMSC

================================================================================

————Setup(1234)———>

                              

                                    —————————-INITDP(1234)———–>

                                    <—————-CONNECT(0122334343)————

                                                                

                            

                                  —————————–IAM————————————–>

An example of an MT CAMEL Phase 1 service is Time Dependent Routing (TDR).  A subscriber can decide where his calls will be routed depending on the period of the month/ week or even the time of the day (e.g. to his mobile, voice mail, secretary fixed line).

When the GMSC receives the called party CSI (6),the SSF stops the call to request instructions from the SCF (7).The SCF provides routing information to the SSF so that the call is routed to the subscriber’s mobile since he is willing to accept calls at this time of the day (8).

Within CAMEL we are CAMEL Phase 1 compliant. Hence all the following CAMEL Phase 1 operations are available currently in the MSC/SSP:

ActivityTest

Connect

Continue

EventReportBCSM (ERB)

InitialDP

ReleaseCall

RequestReportBCSMEvent (RRBE)

The following new operations are implemented to support CAMEL Phase 2:

ETC (EstablishTemporaryConnection)

DFC (DisconnetForwardConnection)

FCI (FurnishChargingInformation)

ResetTimer

ApplyCharging (AC)

ApplyChargingReport (ACR)

Send Charging Information (SCI)

Play Announcement

Connect To Resource (for SRF)

Prompt and Collect User Information

Call Information Request (CIR)

Call Information Report

 IEs:

Initial DP (IDP):—- from gsmSSF to gsmSCF to collect the information

                           Called PartyNumber

                           Calling party Number

                           Calling Party category

                            Location Number

                            Original Called Party ID

                            Additional CallingParty Numer

                            Bearer Capability

                            Redirection PartyID (Redirection Number)

                            IMSI

                            Location Information

                            ext-Basic Service Code

                            Callforwarding SS Pending

                            MSC Address

                            time and timezone

                            carrier

                             service key (m)

                             highLayer capability (HLC)

                             eventtype BCSM

                             Redirection Information

                             subscriber state

                             cug-index/cug-interlock/cug-OutgoingAccess

                             High Layer Capability (HLC)

CONNECT:———- from gsmSCF to gsmSSF to connect to new number.

Destination Routing Address (DRA)

Alerting Pattern

Original Call party ID

carrier

Calling Party Category

Redirection Party ID

Redirection Info

Generic Number

charge number

supperssion of annoucement

oCSI Applicable

Activity Test:—- AT is used to check for the continued existance of a relationship between the gsmSCF and gsmSSF. no IE.

Apply Charging:- from gsmSCF to gsmSSF, charging mechanisms to control the call duration.

-ACh Billing Charging Characteristics:- Time Duration Charging:- Max call period Duration, Traffic Swtch Interval, Release if duration exceeds.

-Party to Charge

Play Tone

Call Information Request (CIR):- from gsmSCF to gsmSSF to record speceific information about call and report it.

-Request Information Type List (Call Attempt Elapsed Time, Call Stop Time, Call Connected Elapsed Time, release Cause)

-Leg ID

Cancel:- from gsmSCF to gsmSSF to cancel all EDPs and report.

- All Request

 Connect To Resource (CTR): used to connect from gsmSSF to gsmSRF.

- Service Intraction Indicators Two

- Resource Address ( IP Routing Address, None)

Continue:  from gsmSCF to gsmSSF to continue the basic call flow that was suspended.

Disconnect Forward Connection (DFC): to dissconnect the connection with gsmSRF connect with CTR IF.

Establish Temporary Connection (ETC): used to connection from gsmSSF to assisting gmsSSF as a part of assist procedure. can also be used to create connection between the gsmSSF and gsmSRF.

- Assisting IP Routing Address

- Correlation ID

- Carrier Information

- Originating Line Information

- – scf ID

Comparison of O-BCSM DPs in the Ph1 and Ph2:

Comparison of T-BCSM DPs in the Ph1 and Ph2: