Camel Phase 2 Etsi

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European Telecommunications Standards Institute

TS 101 044 V5.7.0 (1999-03)Technical Specification

Digital cellular telecommunications system (Phase 2+);Customized Applications for Mobile network Enhanced Logic

(CAMEL);Stage 2

(GSM 03.78 version 5.7.0 Release 1996)

GLOBAL SYSTEM FOR

MOBILE COMMUNICATIONS

R


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2(GSM 03.78 version 5.7.0 Release 1996) TS 101 044 V5.7.0 (1999-03)

ReferenceRTS/SMG-030378QR6 (9o002kc3.PDF)

Keywords

Digital cellular telecommunications system,Global System for Mobile communications (GSM)

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Contents

Intellectual Property Rights................................................................................................................................7

Foreword ............................................................................................................................................................7

1 Scope........................................................................................................................................................8

2 References................................................................................................................................................8

3 Definitions and abbreviations ..................................................................................................................93.1 Definitions ......................................................................................................................................................... 9

3.2 Abbreviations................................................................................................................................................... 10

4 Architecture............................................................................................................................................114.1 Functional Entities used for CAMEL............................................................................................................... 11

4.2 Interfaces defined for CAMEL ........................................................................................................................ 11

4.2.1 HLR - VLR interface.................................................................................................................................. 11

4.2.2 GMSC - HLR interface .............................................................................................................................. 12

4.2.3 GMSC - gsmSSF interface ......................................................................................................................... 124.2.4 gsmSSF - gsmSCF interface....................................................................................................................... 12

4.2.5 MSC - gsmSSF interface ............................................................................................................................ 12

4.2.6 gsmSCF - HLR interface ............................................................................................................................ 12

5 Detection Points (DPs)...........................................................................................................................125.1 Definition and description................................................................................................................................ 12

5.2 DP processing rules ......................................................................................................................................... 13

6 Description of CAMEL Subscriber Data...............................................................................................146.1 Description of Originating/Terminating CAMEL Subscription Information (O/T-CSI).................................. 14

6.1.1 Content of the O/T-CSI.............................................................................................................................. 14

6.1.1.1 gsmSCF address ................................................................................................................................... 14

6.1.1.2 Service Key .......................................................................................................................................... 14

6.1.1.3 Default Call Handling........................................................................................................................... 14

6.1.1.4 TDP List ............................................................................................................................................... 14

6.2 Description of Subscriber Information in S R I Ack indicator......................................................................... 14

7 Description of CAMEL BCSMs............................................................................................................147.1 General Handling............................................................................................................................................. 14

7.2 Originating Basic Call State Model (O-BCSM) .............................................................................................. 15

7.2.1 Description of O-BCSM............................................................................................................................. 15

7.2.1.1 Description of the call model (PICs) .................................................................................................... 15

7.2.1.1.1 O_Null & Authorise_Origination_Attempt_Collect_Info............................................................... 16

7.2.1.1.2 Analyse, Routing & Alerting........................................................................................................... 16

7.2.1.1.3 O_Active......................................................................................................................................... 17

7.2.1.1.4 O_Exception ................................................................................................................................... 17

7.3 Terminating Basic Call State Model (T-BCSM).............................................................................................. 17

7.3.1 Description of T-BCSM............................................................................................................................. 17

7.3.1.1 Description of the call model (PICs) .................................................................................................... 18

7.3.1.1.1 T_Null............................................................................................................................................. 18

7.3.1.1.2 Terminating Call Handling.............................................................................................................. 19

7.3.1.1.3 T_Active ......................................................................................................................................... 19

7.3.1.1.4 T_Exception.................................................................................................................................... 20

7.4 BCSM Modelling of Call Scenarios ................................................................................................................ 20

7.4.1 Mobile Originated Call............................................................................................................................... 20

7.4.2 Mobile Terminated Call ............................................................................................................................. 21

7.4.3 Call Forwarding at the GMSC.................................................................................................................... 21

7.4.4 Call Forwarding at the MSC....................................................................................................................... 22

8 Procedures for CAMEL.........................................................................................................................238.1 Handling of mobile originated calls................................................................................................................. 23

8.1.1 Handling of mobile originated calls in the originating VMSC................................................................... 23


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8.1.1.1 Procedure CAMEL_OCH_MSC_INIT ................................................................................................ 23

8.1.1.1.2 Actions on receipt of Int_Error ....................................................................................................... 23

8.1.1.1.3 Actions on receipt of Int_Continue ................................................................................................. 23

8.1.1.1.4 Actions on receipt of Int_Connect .................................................................................................. 23

8.1.1.2 Procedure CAMEL_OCH_MSC_ANSWER........................................................................................ 23

8.1.1.3 Procedure CAMEL_OCH_MSC_DISC1 ............................................................................................. 23

8.1.1.4 Procedure CAMEL_OCH_MSC_DISC2 ............................................................................................. 238.1.1.5 Procedure CAMEL_OCH_MSC_DISC3 ............................................................................................. 23

8.1.2 Handling of mobile originated calls in the originating VLR ...................................................................... 30

8.1.2.1 Procedure CAMEL_OCH_VLR........................................................................................................... 30

8.2 Retrieval of routeing information..................................................................................................................... 31

8.2.1 Retrieval of routeing informationin the GMSC.......................................................................................... 31

8.2.1.1 Procedure CAMEL_Set_ORA_Parameters.......................................................................................... 31

8.2.1.2 Procedure CAMEL_MT_GMSC_INIT................................................................................................ 31

8.2.1.2.1 Action on receipt of Int_Release_Call ............................................................................................ 31

8.2.1.2.2 Action on receipt of Int_Error......................................................................................................... 31

8.2.1.2.3 Action on receipt of Int_Continue................................................................................................... 31

8.2.1.2.4 Action on receipt of Int_Connect.................................................................................................... 31

8.2.1.2.5 Send Routeing Info negative response in state Wait_For_Routeing_Info_2................................... 32

8.2.1.2.6 Send Routeing Info ack with MSRN in state Wait_For_Routeing_Info_2..................................... 32

8.2.1.2.7 Send Routeing Info ack with FTN in state Wait_For_Routeing_Info_2......................................... 32

8.2.1.2.8 Send Routeing Info ack with O-CSI and FTN in state Wait_For_Routeing_Info_2....................... 32

8.2.1.3 Procedure CAMEL_MT_GMSC_ANSWER ....................................................................................... 32

8.2.1.4 Procedure CAMEL_MT_GMSC_DISC1............................................................................................. 32



8.2.2 Retrieval of routeing information in the HLR ............................................................................................ 42

8.2.2.1 Procedure CAMEL_HLR_INIT........................................................................................................... 42

8.2.2.2 Procedure CAMEL_CSI_Check_HLR................................................................................................. 42

8.2.2.3 Procedure CAMEL_T_CSI_CHECK_HLR ......................................................................................... 42

8.2.2.4 Procedure CAMEL_O_CSI_CHECK_HLR......................................................................................... 42

8.2.3 Handling of provide roaming number request in the VLR......................................................................... 468.2.3.1 Procedure CAMEL_SET_SOA............................................................................................................ 47

8.3 Handling of mobile terminated calls................................................................................................................ 48

8.3.1 Handling of mobile terminated calls handling in the terminating VMSC................................................... 48

8.3.2 Handling of mobile terminated calls in the terminating VLR..................................................................... 48

8.4 Handling of forwarded calls............................................................................................................................. 48

8.4.1 Procedure CAMEL_CF_INIT.................................................................................................................... 48

8.4.2 Procedure CAMEL_CF_ANSWER........................................................................................................... 48

8.5 Handling of mobile calls in the gsmSSF.......................................................................................................... 53

8.5.1 State Idle .................................................................................................................................................... 53

8.5.1.1 Int_Invoke_gsmSSF ............................................................................................................................. 53

8.5.1.2 Int_DP_O/T_Answer or Int_DP_O/T_Disconnect............................................................................... 53

8.5.1.3 Int_O/T_Exception............................................................................................................................... 53

8.5.2 State Wait_For_Request............................................................................................................................. 538.5.2.1 Int_DP_Collected_Info......................................................................................................................... 53

8.5.2.2 DP_Terminating_Attempt_Authorised................................................................................................. 53

8.5.2.3 Int_O/T_Exception............................................................................................................................... 53

8.5.3 Waiting_For_Instructions........................................................................................................................... 53

8.5.3.1 CAP_Request_Report_BCSM_Event .................................................................................................. 53

8.5.3.2 CAP_Continue...................................................................................................................................... 53

8.5.3.3 CAP_Connect ....................................................................................................................................... 54

8.5.3.4 CAP_Release_Call ............................................................................................................................... 54

8.5.3.5 Timer expire ......................................................................................................................................... 54

8.5.3.6 Int_O/T_Exception............................................................................................................................... 54

8.5.3.7 Int_DP_O/T_Disconnect ...................................................................................................................... 54

8.5.4 Monitoring ................................................................................................................................................. 54

8.5.4.1 Int_DP_O/T-Answer............................................................................................................................. 54

8.5.4.2 Int_DP_O/T_Disconnect ...................................................................................................................... 54

8.5.4.3 CAP_Release_Call ............................................................................................................................... 55


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8.5.4.4 Int_O/T_Exception............................................................................................................................... 55

8.5.5 Actions of the process gsmSSF in error cases ............................................................................................ 55

8.6 Any Time Interrogation ................................................................................................................................... 62

8.7 Procedure Provide_Subscriber_Info_HLR...................................................................................................... 63

8.8 CAMEL specific handling at subscriber data management in the HLR........................................................... 65

8.9 Processing of Non-Call Related Events ........................................................................................................... 65

9 Description of information flows...........................................................................................................659.1 gsmSSF to gsmSCF information flows ............................................................................................................ 65

9.1.1 Activity Test Response............................................................................................................................... 65

9.1.1.1 Description ........................................................................................................................................... 65

9.1.1.2 Information Elements ........................................................................................................................... 65

9.1.2 Event Report BCSM .................................................................................................................................. 65

9.1.2.1 Description ........................................................................................................................................... 65


9.1.3 Initial DP .................................................................................................................................................... 66

9.1.3.1 Description ........................................................................................................................................... 66


9.2 gsmSCF to gsmSSF information flows ............................................................................................................ 69

9.2.1 Activity Test............................................................................................................................................... 699.2.1.1 Description ........................................................................................................................................... 69


9.2.2 Connect ...................................................................................................................................................... 69

9.2.2.1 Description ........................................................................................................................................... 69


9.2.3 Continue ..................................................................................................................................................... 70

9.2.3.1 Description ........................................................................................................................................... 70


9.2.4 Release Call................................................................................................................................................ 70

9.2.4.1 Description ........................................................................................................................................... 70


9.2.5 Request Report BCSM Event..................................................................................................................... 70

9.2.5.1 Description ........................................................................................................................................... 709.2.5.2 Information Elements ........................................................................................................................... 70

9.3 gsmSCF to HLR information flows ................................................................................................................. 71

9.3.1 Any Time Interrogation Request ................................................................................................................ 71

9.3.1.1 Description ........................................................................................................................................... 71


9.4 HLR to gsmSCF information flows ................................................................................................................. 71

9.4.1 Any Time Interrogation Response.............................................................................................................. 71

9.4.1.1 Description ........................................................................................................................................... 71


9.5 HLR to VLR information flows....................................................................................................................... 72

9.5.1 Delete Subscriber Data............................................................................................................................... 72


9.5.2 Insert Subscriber Data................................................................................................................................ 72

9.5.2.1 Description ........................................................................................................................................... 72


9.5.3 Provide Roaming Number.......................................................................................................................... 73

9.5.3.1 Description ........................................................................................................................................... 73


9.5.4 Provide Subscriber Info.............................................................................................................................. 73

9.5.4.1 Description ........................................................................................................................................... 73


9.6 VLR to HLR information flows....................................................................................................................... 74

9.6.1 Insert Subscriber Data ack.......................................................................................................................... 74


9.6.2 Provide Subscriber Info ack....................................................................................................................... 74

9.6.2.1 Description ........................................................................................................................................... 74


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9.7 HLR to GMSC information flows.................................................................................................................... 74

9.7.1 Send Routeing Info ack.............................................................................................................................. 74

9.7.1.1 Description ........................................................................................................................................... 74


9.8 GMSC to HLR information flows.................................................................................................................... 75

9.8.1 Send Routeing Info..................................................................................................................................... 759.8.1.1 Description ........................................................................................................................................... 75


9.9 VMSC to GMSC information flows ................................................................................................................ 76

9.9.1 Resume Call Handling................................................................................................................................ 76

9.9.1.1 Description ........................................................................................................................................... 76


9.10 MSC to VLR information flows....................................................................................................................... 77

9.10.1 Send Info For Outgoing Call...................................................................................................................... 77

9.10.1.1 Description ........................................................................................................................................... 77


9.11 VLR to MSC information flows....................................................................................................................... 77

9.11.1 Complete Call............................................................................................................................................. 77

9.11.1.1 Description ........................................................................................................................................... 77


9.11.2 Send Info For Incoming Call ack ............................................................................................................... 78

9.11.2.1 Description ........................................................................................................................................... 78


9.11.3 Send Info For Incoming Call negative response......................................................................................... 78

9.11.3.1 Description ........................................................................................................................................... 78


Annex A (informative): Document Change History............................................................................79

History..............................................................................................................................................................80


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Intellectual Property Rights

IPRs essential or potentially essential to the present document may have been declared to ETSI. The information

pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found

in SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect

of ETSI standards", which is available free of charge from the ETSI Secretariat. Latest updates are available on theETSI Web server (http://www.etsi.org/ipr).

Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee

can be given as to the existence of other IPRs not referenced in SR 000 314 (or the updates on the ETSI Web server)

which are, or may be, or may become, essential to the present document.

Foreword

This Technical Specification (TS) has been produced by the Special Mobile Group (SMG).

The present document defines the stage 2 description of Customized Applications for Mobile network Enhanced Logic

(CAMEL) within the digital cellular telecommunications system.

The contents of the present document are subject to continuing work within SMG and may change following formal

SMG approval. Should SMG modify the contents of the present document, it will then be republished by ETSI with an

identifying change of release date and an increase in version number as follows:

Version 5.x.y

where:

5 indicates GSM Phase 2+ Release 1996

x the second digit is incremented for changes of substance, i.e. technical enhancements, corrections, updates,

etc.

y the third digit is incremented when editorial only changes have been incorporated in the specification.


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1 Scope

The present document specifies the stage 2 description for the first phase (see GSM 02.78 [2]) of the Customized

Applications for Mobile network Enhanced Logic (CAMEL) feature which provides the mechanisms to support services

of operators which are not covered by standardized GSM services even when roaming outside the HPLMN.

The CAMEL feature is a network feature and not a supplementary service. It is a tool to help the network operator to

provide the subscribers with the operator specific services even when roaming outside the HPLMN.

In the present document, the GSM Service Control Function (gsmSCF) is treated as being part of the HPLMN. The

regulatory environment in some countries may require the possibility that the gsmSCF and the HPLMN are controlled

by different operators, and the gsmSCF and the HPLMN are therefore distinct entities.

In the first phase the CAMEL feature supports:

- mobile originated and forwarded calls;

- mobile terminating calls;

- any time interrogation;

- suppression of announcements;

Note that CAMEL is not applicable to Emergency Setup (TS 12), i.e., in case an Emergency call has been requested the

gsmSSF shall not be invoked.

The mechanism described in the present document addresses especially the need for information exchange between the

VPLMN or IPLMN and the HPLMN for support of operator specific services. Any user procedures for the control of

operator specific services are outside the scope of the present document. Subscribers who have subscribed to operator

specific services and therefore need the functional support of the CAMEL feature shall be marked in the HPLMN and

VPLMN. In case a subscriber is marked to need CAMEL support, the appropriate procedures which provide the

necessary information to the VPLMN or to the HPLMN are invoked. It is possible for the HPLMN to instruct the

VPLMN or IPLMN to interact with a gsmSCF which is controlled by the HPLMN.

The specification of operator specific services in HPLMN are outside the scope of the present document.

2 References

The following documents contain provisions which, through reference in this text, constitute provisions of the present

document.

References are either specific (identified by date of publication, edition number, version number, etc.) or

non-specific.

For a specific reference, subsequent revisions do not apply.

For a non-specific reference, the latest version applies.

A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same

number.

[1] GSM 01.04 (ETR 350): "Digital cellular telecommunications system (Phase 2+); Abbreviations

and acronyms".

[2] GSM 02.78: "Digital cellular telecommunications system (Phase 2+); Customized Applications for

Mobile network Enhanced Logic (CAMEL) - stage 1

[3] GSM 03.18 (TS 101 043): "Digital cellular telecommunications system (Phase 2+); Basic call

handling; Technical realisation ".

[4] GSM 03.79 (TS 101 045): "Digital cellular telecommunications system (Phase 2+); Support of

Optimal Routeing (SOR); Technical realisation"


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[5] GSM 09.02 (ETS 300 974): "Digital cellular telecommunications system (Phase 2+); Mobile

Application Part (MAP) specification".

[6] GSM 09.78 (TS 101 046): "Digital cellular telecommunications system (Phase 2+); Customized

Applications for Mobile network Enhanced Logic (CAMEL): CAMEL Application Part (CAP)

specification".

[7] ITU-T Q.1214, May 1995: "Distributed Functional Plane for Intelligent Network CS-1"

3 Definitions and abbreviations

3.1 Definitions

For the purposes of the present document, the following definitions apply:

Basic Call State Model (BCSM): The BCSM provides a high-level model of GMSC- or MSC/VLR-activities required

to establish and maintain communication paths for users. As such, it identifies a set of basic call activities in a GMSC or

MSC/VLR and shows how these activities are joined together to process a basic call.

Detection Points (DP): The points in processing at which notifications (to the service logic) can occur and transfer of

control (to the gsmSCF) is possible are called Detection Points (DPs).

GSM Service Control Function (gsmSCF): A functional entity that contains the CAMEL service logic to implement

OSS. It interfaces with the gsmSSF and the HLR.

GSM Service Switching Function (gsmSSF): A functional entity that interfaces the MSC/GMSC to the gsmSCF. The

concept of the gsmSSF is derived from the IN SSF, but uses different triggering mechanisms because of the nature of the

mobile network.

Originating Basic Call State Model (O-BCSM): The originating half of the BCSM. The O-BCSM corresponds to that

portion of the BCSM associated with the originating party.

Originating CAMEL Subscription Information (O-CSI): The O-CSI identifies the subscriber as having originating

CAMEL services.

Point In Call (PIC): PICs identify MSC/VLR (GMSC) activities associated with one or more basic call/connection

states of interest to OSS service logic instances.

Location Information: Indicates the location of the served subscriber. The provision of location information is

independent of the MS status. As part of the location information, an indication of the age of this information shall be

delivered.

Service Key: The Service Key can identify to the gsmSCF the service logic that it should apply. The Service Key is

administered by the HPLMN, and is passed transparently by the VPLMN/IPLMN to the gsmSCF. The Service Key is

part of the T/O-CSI.

Subscriber State: See GSM 02.78 [2].

Terminating Basic Call State Model (T-BCSM): The terminating half of the BCSM. The T-BCSM corresponds to

that portion of the BCSM associated with the terminating party.

Terminating CAMEL Subscription Information (T-CSI): The T-CSI identifies the subscriber as having terminating

CAMEL services.


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3.2 Abbreviations

Abbreviations used in the present document are listed in GSM 01.04.

For the purposes of the present document, the following abbreviations apply.

BCSM Basic Call State ModelCAMEL Customized Applications for Mobile network Enhanced Logic

DP Detection Point

EDP Event Detection Point

GMSC Gateway MSC

gsmSCF GSM Service Control Function

gsmSSF GSM Service Switching Function

HLR Home Location Register

HPLMN Home PLMN

IE Information Element

IF Information Flow

IPLMN Interrogating PLMN

MSC Mobile service Switching Centre

O-BCSM Originating Basic Call State ModelO-CSI Originating CAMEL Subscription Information

ODB Operator Determined Barring

OSS Operator Specific Service

PIC Point In Call

PLMN Public Land Mobile Network

SLPI Service Logic Program Instance

SMF Service Management Function

T-BCSM Terminating Basic Call State Model

T-CSI Terminating CAMEL Subscription Information

TDP Trigger Detection Point

VLR Visitor Location Register

VPLMN Visited PLMN


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4 Architecture

4.1 Functional Entities used for CAMEL

This subclause describes the functional architecture needed to support CAMEL. Also the additions needed to the basicGSM functionality are described. Figure 4/1 shows the functional entities involved in calls requiring CAMEL support.

The architecture is applicable to the first phase of CAMEL.

HLR

GMSC

gsmSCF

MSC

Forwarded legMO call - Outgoing leg

(or Forwarding leg)

MSIncoming line

Visiting NetworkInterrogating Network

Home Network

gsmSSFVLR

Roaming leg

CAP CAP

MAP

MAP MAP

gsmSSF

Figure 4/1: Functional architecture for support of CAMEL

HLR: The HLR stores the O/T-CSI for subscribers requiring CAMEL support. The O-CSI is sent to the VLR in case of

Location Update or if the O-CSI is updated. The O/T-CSI is sent to the GMSC when the HLR responds to a request for

routing information. The HLR may provide an interface towards the gsmSCF for the Any Time Interrogation procedure.

GMSC: When processing the calls for subscribers requiring CAMEL support the GMSC receives a O/T-CSI from the

HLR, indicating the GMSC to request instruction from the gsmSSF. The GMSC monitors on request the call states

(events) and informs the gsmSSF of these states during processing enabling the gsmSSF to control the execution of the

call in the GMSC.

MSC: When processing the calls for subscribers requiring CAMEL support the MSC receives a O-CSI from the VLR

indicating the MSC to request instruction from the gsmSSF. The MSC monitors on request the call states (events) and

informs the gsmSSF of these states during processing enabling the gsmSSF to control the execution of the call in the

MSC.

VLR: The VLR stores the O-CSI as part of the subscriber data for subscribers roaming in the VLR area.

gsmSSF: see subclause 3.1.

gsmSCF: see subclause 3.1.

4.2 Interfaces defined for CAMEL

This subclause describes the different interfaces applicable to CAMEL. It specifies on a high level the functions specific

to CAMEL.

4.2.1 HLR - VLR interface

This interface is used to send the CAMEL related subscriber data to the visited PLMN and for provision of MSRN. The

interface is also used to retrieve subscriber status and location information of the mobile subscriber or to indicate

suppression of announcement for a CAMEL service.


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4.2.2 GMSC - HLR interface

This interface is used at terminating calls to exchange routing information, subscriber status, location information,

subscription information and suppression of announcements. The O/T-CSI that is passed to the IPLMN is sent over this

interface.

4.2.3 GMSC - gsmSSF interface

This is an internal interface. The interface is described in the specification to make it easier to understand the handling

of DPs (arming/disarming of DPs, DP processing etc.).

4.2.4 gsmSSF - gsmSCF interface

This interface is used by the gsmSCF to control a call in a certain gsmSSF. Relationships on this interface are opened as

a result of the gsmSSF sending a request for instructions to the gsmSCF.

4.2.5 MSC - gsmSSF interface

This an Internal interface. The interface is described in the specification to make it easier to understand the handling of

DPs (arming/disarming of DPs, DP processing etc.).

4.2.6 gsmSCF - HLR interface

This interface is used by the gsmSCF to request information from the HLR. Support of the gsmSCF - HLR interface is a

network operator option. As a network operator option the HLR may refuse to provide the information requested by the

gsmSCF.

5 Detection Points (DPs)

5.1 Definition and description

Certain basic call events may be visible to the GSM Service Control Function (gsmSCF). The DPs are the points in call

at which these events are detected. The DPs for Mobile Originated Calls and Mobile Terminated Calls are described in

subclauses 7.2 and 7.3.

A DP can be armed in order to notify the gsmSCF that the DP was encountered, and potentially to allow the gsmSCF to

influence subsequent handling of the call. If the DP is not armed, the processing entity continues the processing without

gsmSCF involvement.

Three different types of DPs are identified:

- Trigger Detection Point - Request (TDP-R)

This detection point is statically armed and initiates a CAMEL control relationship when encountered. Processing

is suspended when the DP is encountered.

- Event Detection Point - Request (EDP-R)

This detection point is dynamically armed within the context of a CAMEL control relationship. Processing is

suspended awaiting instructions from the gsmSCF when encountering the DP.

- Event Detection Point - Notification (EDP-N)

This detection point is dynamically armed within the context of a CAMEL control relationship. Processing is not

suspended when encountering the DP.

The DPs are characterized by the following attributes:


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a) Arming/disarming mechanism - The mechanism by which the DP is armed. A DP may be statically armed or

dynamically armed.

The following arming rules apply:

- A DP is statically armed by provisioning the O/T-CSI in the HLR. A statically armed DP remains armed until

the O/T-CSI is withdrawn.

- A DP is dynamically armed by the gsmSCF within the context of a CAMEL control relationship (between the

gsmSSF and the gsmSCF).

The following disarming rules apply:

- A statically armed DP is disarmed when a O/T-CSI is withdrawn in the HLR. Only TDP-Rs can be disarmed

using this mechanism.

- If an armed EDP is met, then it is disarmed.

- If an EDP is met that causes the release of the related leg, then all EDPs related to that leg are disarmed.

- If a call is released, then all EDPs related to that call are disarmed.

b) Relationship - given that an armed DP was encountered, the gsmSSF provides an information flow via a

relationship.

A relationship between the gsmSSF and the gsmSCF for the purpose of operator specific service processing is

considered to be a CAMEL relationship. There are two types of CAMEL relationships:

- A CAMEL control relationship if the gsmSCF is able to influence the call processing via the relationship.

- A CAMEL monitor relationship if the gsmSCF is not able to influence the call processing via the relationship.

5.2 DP processing rules

Since a DP may be armed as an EDP-N or an EDP-R for the same call, the gsmSSF should apply the following set of

rules during DP processing to ensure single point of control:

- A control relationship persists as long as there is 1 EDP-R armed for this portion of the call. A control

relationship terminates if there are no more EDP-Rs armed or the call clears. During a control relationship, EDPs

are disarmed by the gsmSSF as they are encountered and reported to the SCF, or when the call clears.

- A control relationship changes to a monitor relationship if there are no more EDP-Rs armed and 1 EDP-N

armed. A monitor relationship terminates if there are no more EDP-Ns armed or the call clears. During a monitor

relationship, EDP-Ns are disarmed by the gsmSSF as they are encountered and reported to the SCF, or when the

call clears.

When the armed TDP-R is encountered triggering is unconditional.


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6 Description of CAMEL Subscriber Data

6.1 Description of Originating/Terminating CAMEL Subscription

Information (O/T-CSI)6.1.1 Content of the O/T-CSI

This subclause defines the contents of the Originating/Terminating CAMEL Subscription Information.

6.1.1.1 gsmSCF address

Address to be used to access the gsmSCF for a particular subscriber. The address shall be an E.164 number to be used

for routing.

6.1.1.2 Service Key

The Service Key identifies to the gsmSCF the service logic that should apply.

6.1.1.3 Default Call Handling

The Default Call Handling indicates whether the call shall be released or continued as requested in case of error in the

gsmSSF to gsmSCF dialogue.

6.1.1.4 TDP List

The TDP List indicates on which detection point triggering shall take place. For O-CSI only DP2 is used. For T-CSI

only DP12 is used.

6.2 Description of Subscriber Information in S R I Ack indicator

This data indicates whether additional subscriber information shall be sent to the GMSC as part of the terminating call

handling.

- an indication that the HLR shall send the location information of the called subscriber.

- an indication that the HLR shall send the subscriber state of the called subscriber.

7 Description of CAMEL BCSMs

7.1 General Handling

The BCSM is used to describe the actions in an MSC/GMSC during originating, forwarded or terminating calls.

The BCSM identifies the points in basic call processing when Operator Specific Service (OSS) logic instances (accessed

through the gsmSCF) are permitted to interact with basic call control capabilities.

Figure 7.1/1 shows the components that have been identified to describe a BCSM.


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Point In Call (PIC)

DP

Transition

Figure 7.1/1: BCSM Components

7.2 Originating Basic Call State Model (O-BCSM)

7.2.1 Description of O-BCSM

The O-BCSM is used to describe the actions in an MSC during originating (MSC) or forwarded (MSC or GMSC) calls.

When encountering a DP the O-BCSM processing is suspended at the DP and the MSC/GMSC indicates this to the

gsmSSF which determines what action if any should be taken in case of the DP is armed.

O_Null & Authorise_Origination_

Attempt_Collect_Info

Analyse, Routing & Alerting

DP2

O_Exception

DP9 O_Active

DP7

Collected_Info

O_Answer

O_Disconnect

Figure 7.2/1: Originating BCSM for CAMEL

The following table defines the different DPs which apply to mobile originating and forwarded calls.

Table 1: Definition of CAMEL Detection Points

CAMEL Detection Point: [7]: DP Type Description:

DP2 Collected_Info DP2 TDP-R Indication that the O-CSI is analysed.

DP7 O_Answer DP7 EDP-N Indication that the call is accepted and answered by theterminating party.

DP9 O_Disconnect DP9 EDP-N, EDP-R A disconnect indication is received from the originatingparty or from the terminating party.

7.2.1.1 Description of the call model (PICs)This subclause describes the call model for originating and forwarded calls. For each PIC a description can be found of

the entry events, functions and exit events.


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It should be noted that although the names used for PICs match those used in ITU-T Q.1214 [7] the specific descriptions

differ.

7.2.1.1.1 O_Null & Authorise_Origination_Attempt_Collect_Info

Entry events:

- Disconnect and clearing of a previous call (DP9 - O_Disconnect) or default handling of exceptions bygsmSSF/(G)MSC completed.

Functions:

- Interface is idled.

- Originating call: SETUP message containing the dialled number is received from MS.

- Originating call: The supplementary services "barring of all outgoing calls" is checked and invoked if necessary.

- Originating call: The ODB categories "barring of all outgoing calls is checked and ODB is invoked if necessary.

NOTE: The ODB category Barring of outgoing calls when roaming causes the HLR to send the category

BAOC if the VLR is not in the HPLMN. - Originating call: CUG checks done in the originating MSC/VLR

are performed.

- Information being analysed e.g., O-CSI is analysed.

Exit events:

- Originating CSI is analysed.

- An exception condition is encountered. For this PIC, if the call encounters one of these exceptions during the PIC

processing, the exception event is not visible because there is no corresponding DP. Example exception

conditions are:

- Calling party abandons call.

7.2.1.1.2 Analyse, Routing & Alerting

Entry events:

- Originating CSI is analysed. (DP2 - Collected Info)

Functions:

- Information being analysed and/or translated according to dialling plan to determine routing address.

- Routing address being interpreted.

- Originating call: Outgoing barring services and ODB categories not already applied are checked and invoked if

necessary.

- Call is being processed by the terminating half BCSM. Continued processing of call setup (e.g., ringing) is taking

place. Waiting for indication from terminating half BCSM that the call has been answered by terminating party.

Exit events:

- Indication from the terminating half BCSM that the call is accepted and answered by terminating party. (DP7 -

O_Answer)

- An exception condition is encountered - this leads to the O_Exception PIC. Example exception conditions are:


- The called party is busy.

- The called party does not answer the call.

- Attempt to select the route for the call fails.


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7.2.1.1.3 O_Active

Entry events:

- Indication from the terminating half BCSM that the call is accepted and answered by the terminating party. (DP7

- O_Answer)

Functions:

- Connection established between originating and terminating party. Call release is awaited.

Exit events:

- A disconnection indication is received from the originating party, or received from the terminating party via the

terminating half BCSM. (DP9 - O_Disconnect)

- An exception condition is encountered.

7.2.1.1.4 O_Exception

Entry events:

- An exception condition is encountered. In addition to specific examples listed above, exception events include

any type of failure that means that the normal exit events for a PIC can not be met.

Functions:

- Default handling of the exception condition is being provided. This includes general actions necessary to ensure

no resources remain inappropriately allocated such as:

- If any relationship exists between the gsmSSF and the gsmSCF send an error information flow closing the

relationships and indicating that any outstanding call handling instructions will not run to completion

- The (G)MSC/gsmSSF should make use of vendor-specific procedures to ensure release of resources within

the (G)MSC/gsmSSF so that line, trunk and other resources are made available for new calls.

Exit events:

- Default handling of the exception condition by gsmSSF/(G)MSC completed.

7.3 Terminating Basic Call State Model (T-BCSM)

7.3.1 Description of T-BCSM

The T-BCSM is used to describe the actions in a GMSC during terminating calls.

When encountering a DP the T-BCSM processing is suspended at the DP and the GMSC indicates this to the gsmSSF

which determines what action if any should be taken in case of the DP is armed.


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T_Null

Terminating Call Handling

DP12

T_Exception

DP17 T_Active

DP15

Terminating_Attempt_Authorised

T_Answer

T_Disconnect

Figure 7.3/1: T-BCSM in the GMSC

In the following table the different DPs (in the T-BCSM) are described.

Table 2: Description of T-BCSM DPs in the GMSC

CAMEL Detection Point: [7]: DP Type Description:

DP12 Terminating_Attempt_Authorised DP12 TDP-R Indication that the T-CSI is analysed.

DP15 T_Answer DP15 EDP-N Call is accepted and answered byterminating party

DP17 T_Disconnect DP17 EDP-N, EDP-R

A disconnect indication is received fromthe terminating party or from theoriginating party.

7.3.1.1 Description of the call model (PICs)

This subclause describes the call model for terminating calls in the GMSC. For each PIC a description can be found of

the entry events, functions, information available and exit events.

It should be noted that although the names used for PICs match those used in ITU-T Q.1214 [7] the specific descriptions

differ.

7.3.1.1.1 T_Null

Entry events:

- Disconnect and clearing of a previous call (DP 17) or default handling of exceptions by gsmSSF/GMSC

completed.

Functions:

- Interface is idled.

- ISUP_IAM is received, the appropriate information is analysed.

- Send_Routeing_Info information flow is sent to HLR.

- The supplementary services "barring of all incoming calls" and "barring of incoming calls when roaming" are

checked and invoked if necessary.

- The ODB categories "barring of all incoming calls" and "barring of incoming calls when roaming" are checked

and ODB is invoked if necessary.

- The supplementary service "CUG" is checked and invoked if necessary.

- T-CSI is received and analysed.


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Exit events:

- Response is received from HLR and terminating CSI (if available) is analysed.

- An exception condition is encountered. For this PIC, if the call encounters one of these exceptions during the PIC

processing, the exception event is not visible because there is no corresponding DP.

Example exception condition is:


7.3.1.1.2 Terminating Call Handling

Entry events:

- Response is received from HLR and terminating CSI (if available) is analysed. (DP 12

Terminating_Attempt_Authorised)

Functions:

- The response from HLR is analysed.

- Routing address and call type being interpreted. The next route is being selected.

- The terminating party is being alerted. Waiting for the call to be answered by terminating party.

- The GSM supplementary service call forwarding is invoked if necessary.

Exit events:

- Call is accepted and answered by terminating party.

- An exception condition is encountered - this lead to the T_Exception PIC. Example exception conditions are:


- The call setup to the MSC/GMSC was not successful.

7.3.1.1.3 T_Active

Entry events:

- Indication that the call is accepted and answered by the terminating party. (DP15 - T_Answer)

Functions:

- Connection established between originating and terminating party. Call supervision is being provided.

- Call release is awaited.

Exit events:

- A disconnection indication is received from the terminating party, or received from the originating party via the

originating half BCSM. (DP17 - T_Disconnect)


any type of failure that means that the normal exit events for a PIC can not be met.


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7.3.1.1.4 T_Exception

Entry events:


any type of failure that means that the normal exit events for PIC cannot be met.

Functions:

- Default handling of the exception condition is being provided. This includes general actions necessary to ensure

no resources remain inappropriately allocated such as:

- If any relationship exists between the gsmSSF and the gsmSCF send an error information flow closing the

relationships and indicating that any outstanding call handling instructions will not run to completion

- The GMSC/gsmSSF should make use of vendor-specific procedures to ensure release of resources within the

GMSC/gsmSSF so that line, trunk and other resources are made available for new calls.

Exit events:

- Default handling of the exception condition by gsmSSF/GMSC completed.

7.4 BCSM Modelling of Call ScenariosThis subclause describes how the BCSMs defined above are used to model GSM call scenarios. For each scenario the

used and unused BCSMs involved in the call are shown.

In some cases these models may have an allocation to physical nodes different from that shown. However, the physical

separation of the logic functions shown shall not impact the modelling. This subclause describes the call scenarios

without optimal routing. If optimal routing is invoked the physical configurations may be different from those shown,

but the modelling is not changed.

CAMEL may be applied simultaneously and independently for each GSM subscriber involved in a call. This is not

shown in these scenarios.

Subscribers other than those being served by CAMEL may be either PSTN subscribers, other GSM subscribers or anyother addressable subscriber.

7.4.1 Mobile Originated Call

The O-BCSM for the call from A to B (labelled "O(A-B)") is invoked if the A-party has an active O-CSI. A control

relationship with gsmSCF (1) will be created.

MSC

gsmSSF/CCF

T(A-B)

B-PartyA-Party

O(A-B)

gsmSCF (1)

CAMEL relationship

Figure 7.4/1: BCSM Scenario for Mobile Originated Call


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7.4.2 Mobile Terminated Call

The T-BCSM for the call from A to B (labelled "T(A-B)") is invoked if the B-party has an active T-CSI. A control


GMSC

gsmSSF/CCF

T(A-B

B-PartyA-Party

O(A-B

gsmSCF (1)

CAMEL relationship

MSC

gsmSSF/CCF

Figure 7.4/2: BCSM Scenario for Mobile Terminated Calls

7.4.3 Call Forwarding at the GMSC



A new call leg to a "C" party is created if:

- a GSM call forwarding supplementary service forwards the call to C. In this case an O-BCSM is always invoked

for the forwarding party if an O-CSI has been received by the GMSC from the HLR; or

- a CAMEL service in a control relationship with T(A-B) performs a CAMEL-based call forwarding by using a

Connect information flow containing the the forwarding information. In this case an O-BCSM is only invoked for

the forwarding party if an O-CSI has been received by the GMSC from the HLR and O-CSI Applicable flag is

contained in the Connect information flow.

A control relationship with gsmSCF (2) will be created.

The relationships with gsmSCF (1) and gsmSCF(2) may exist simultaneously. The two relationships are treated

independently at the GMSC. The BCSM T(A-B) and BCSM O(B-C) are linked by an internal interface which is

assumed to behave in a similar way to an ISUP interface.

The nodes gsmSCF (1) and gsmSCF (2) may be the same or different physical entities.


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GMSC

gsmSSF/CCF

T(A-B)

B-Party

"surrogate"

A-Part

O(A-B)

gsmSCF (1)

CAMEL relationship

(1)

O(B-CT(B-C

C-Party

gsmSCF (2)

CAMEL relationship

(2)

Internal "ISUP-

like" interface

Figure 7.4/3: BCSM Scenario for Call Forwarding at the GMSC

7.4.4 Call Forwarding at the MSC


relationship with gsmSCF (1) will be created. Following processing at the GMSC the call will be extended to the MSC

serving the B-party. This MSC may be physically integrated with the GMSC, but it is shown as being separate in the

diagram below.

If a GSM call forwarding supplementary service acting at the MSC forwards the call to C, a new call leg to C is

established. If the B-party has an active O-CSI the BCSM O(B-C) is invoked. A control relationship with gsmSCF (2)

will be created.

The relationships with gsmSCF (1) and gsmSCF(2) may exist simultaneously.

The nodes gsmSCF (1) and gsmSCF (2) may be the same or different physical entities.

GMSC

gsmSSF/CCF

T(A-B

B-Party

"Surrogate"

A-Party

O(A-B

gsmSCF (1)

CAMEL relationship

(1)

MSC

gsmSSF/CCF

C-Party

T(B-C O(B-C

gsmSCF (2)

CAMEL relationship

(2)

Figure 7.4/4: BCSM Scenario for Call Forwarding at the MSC


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8 Procedures for CAMEL

8.1 Handling of mobile originated calls

8.1.1 Handling of mobile originated calls in the originating VMSC

The functional behaviour of the originating VMSC is specified in GSM 03.18 [3]. The procedures specific to CAMEL

are specified in this subclause.

8.1.1.1 Procedure CAMEL_OCH_MSC_INIT

A Release_Transaction is sent to the MS and an Abort to the VLR. The release cause received in the Int_Release_Call is

used. The procedure returns a Fail result.

8.1.1.1.2 Actions on receipt of Int_Error

The MSC checks the default Call Handling parameter in O-CSI.

If the default call handling is to release the call, a Release transaction is sent to the MS and an Abort to the VLR. The

procedure returns a Fail result.

If the default call handling is to continue the call, the MSC continues processing without CAMEL support. It sets the O-

CSI suppression parameter, sends a Send Info For Outgoing Call to the VLR and waits in state

Wait_For_MO_Call_Result_2.

8.1.1.1.3 Actions on receipt of Int_Continue

The MSC continues processing without any modification of call parameters. It sets the O-CSI suppression parameter,

sends a Send Info For Outgoing Call to the VLR and waits in state Wait_For_MO_Call_Result_2.

8.1.1.1.4 Actions on receipt of Int_Connect

The MSC continues processing with modified call parameters. The MSC shall transparently modify the call parameters

with the received information. The MSC then sends a PROGRESS message to the MS. Call parameters which are not

included in the Int_Connect message are unchanged. Signalling limitations or regulatory requirements may require the

Calling Partys Category, Generic Number, Original Called Party Number and Redirecting Party ID to be ignored or

modified.

The MSC sets the O-CSI suppression parameter, sends a Send Info For Outgoing Call to the VLR and waits in state

Wait_For_MO_Call_Result_2.

8.1.1.2 Procedure CAMEL_OCH_MSC_ANSWER

The procedure Send_Access_Connect_If_Required is specified in GSM 03.18 [3].

8.1.1.3 Procedure CAMEL_OCH_MSC_DISC1




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Procedure in the originating VMSCto perform initial CAMEL handling foran outgoing call request

Procedure CAMEL_OCH_MSC_INIT CAM_OMI1(2)

Signals to/from the rightare to/from the gsmSSF

O-CSI

invocation?

Result:=Pass

Allocatecall reference

number

Store originalcall parameters

Int_Invoke_gsmSSF(O-CSI)

Wait_for_

gsmSSF_Invoked

Int_gsmSSF_Invoked

Int_DP_Collected_Info

DP__Collected_

_Info

No

Yes

Figure 8.1-1: Procedure CAMEL_OCH_MSC_INIT (sheet 1 of 2)


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Procedure in the originating VMSCto perform initial CAMEL handling foran outgoing call request

Procedure CAMEL_OCH_MSC_INIT CAM_OMI2(2)

Signals to/from the leftare to/from the BSS;signals to/from the rightare to/from the gsmSSFif not otherwise stated.

DP_Collected_

Info

Int_Release_Call

Abort To VLR

Releasetransaction

Result:=Fail

Int_Error

Default call handling=continue call ?

Set O-CSISuppression

Send Info ForOutgoing Call To VLR

Wait_ForMO_Call_Result_2

Send InfoFor OutgoingCall negativeresponse

From VLR

Int_DP_O_Exception

CompleteCall

From VLR

Result:=Pass

Int_Continue Int_Connect

Send_Alerting_If_Required

See GSM 03.18

Modify callparameters

with receivedinformation

DP_Collected_InfoWait_For_MO_Call_Result_2Wait_for_gsmSSF_Invoked

Releasetransaction

Int_O-Exception

Result:=Fail

Yes

No

Figure 8.1-2: Procedure CAMEL_OCH_MSC_INIT (sheet 2 of 2)


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Procedure in the originating VMSCto handle an answer for a CAMEL call

Procedure CAMEL_OCH_MSC_ANSWER CAM_OMA1(1)


gsmSSFexists?

Int_DP_O_Answer

DP_O_Answer

Int_Continue

See GSM 03.18Send_Access_

Connect_If_Required

Result:=Pass

Int_Rlease_Call

Rleasetransaction

ReleaseTo destinationexchange

Result:=Fail

Releasetransaction

CAMEL_OCH_MSC_DISC1

ReleaseFrom destinationexchange

CAMEL_OCH_MSC_DISC2

Yes

No

Figure 8.1-3: Procedure CAMEL_OCH_MSC_ANSWER


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Procedure in the origito perform CAMEL hafrom the originating e

Procedure CAMEL_OCH_MSC_DISC_1 CAMOD1_1(1)


gsmSSF

exists?

Int_DP_O_Disconnect

/* legId = 1 */

DP_O_Disconnect_1

Int_Error

ReleaseTo destinationexchange

Result:=CAMEL_handling

Int_Continue Int_Release_Call ReleaseFrom destinationexchange

Int_DP_O_

Disconnect/* legId = 2 */

DP_O_Disconnect

Int_Error Int_Continue Int_Release_Call

Result:=Normal_handling

Yes

No

Figure 8.1-4: Procedure CAMEL_OCH_MSC_DISC1


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Procedure in the originating VMSCto perform CAMEL handling for a call releasefrom the destination end

Procedure CAMEL_OCH_MSC_DISC_2 CAMOD2_1(1)

Signals to/from the leftare to/from the BSS;signals to/from the rightare to/from the gsmSSF

gsmSSF

exists?

Int_DP_O_Disconnect

/* legId = 2 */

DP_O_Disconnect_2

Releasetransaction

Int_DP_O_


DP_O_Disconnect

Int_Error


Int_Continue Int_Release_Call

Int_Continue

Releasetransaction


Int_Release_Call Int_Error

Result:=Normal_handling

Yes

No



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Procedure in the originating VMSCto handle premature release of a CAMEL call

Procedure CAMEL_OCH_MSC_DISC3 CAMOD3_1(1)

gsmSSFexists?

Int_O_Exception

To gsmSSF

Yes

No



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8.1.2 Handling of mobile originated calls in the originating VLR

The functional behaviour of the originating VLR is specified in GSM 03.18 [3]. The procedure specific to CAMEL is

specified in this subclause.

8.1.2.1 Procedure CAMEL_OCH_VLR

Procedure in the originating VLRto handle an originating CAMEL call request

Procedure CAMEL_OCH_VLR CAMOVLR1(1)

Signals to/from the leftare to/from the VMSC

Completecall

Wait_For_SIFOC_2

Abort

Result:=Fail

Send Info ForOutgoing Call

Result:=Pass

Figure 8.1-7: Procedure CAMEL_OCH_VLR


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8.2 Retrieval of routeing information

8.2.1 Retrieval of routeing informationin the GMSC

The functional behaviour of the GMSC is specified in GSM 03.18 [3]. The procedures specific to CAMEL are specified

in this subclause.

8.2.1.1 Procedure CAMEL_Set_ORA_Parameters

8.2.1.2 Procedure CAMEL_MT_GMSC_INIT

8.2.1.2.1 Action on receipt of Int_Release_Call

The procedure returns a Fail result.

8.2.1.2.2 Action on receipt of Int_Error

The GMSC checks the default Call Handling parameter in T-CSI.

If the default call handling is to release the call, the procedure returns a Fail result.

If the default call handling is to continue the call, the GMSC continues call handling without CAMEL support as

described in subclause 8.2.1.2.3.

8.2.1.2.3 Action on receipt of Int_Continue

If an FTN has been stored the information received from the HLR is used to overwrite the corresponding call

parameters. Note that the MSISDN is replaced by the FTN as the Called party number. The redirection counter is

incremented.

If no FTN has been stored, a Send Routeing Info message including a T-CSI suppression parameter is sent to the HLR.The Send Routeing Info includes a parameter to indicate which phase of CAMEL is supported by the GMSC/gsmSSF.

8.2.1.2.4 Action on receipt of Int_Connect

The GMSC shall send an ACM towards the originating exchange in order to stop any call timers. The procedure

Send_ACM_If_Required is specified in GSM 03.18 [3].

If the Destination Number received from the gsmSCF (via the gsmSSF) is the same as the ISUP Called Party Number,

i.e. the MSISDN, any other parameters (Calling Partys Category and Generic Number) received in the Connect message

are used to overwrite the corresponding ISUP parameters (for mapping see GSM 09.78 [6]). If received, the

Announcement Suppression Indicator is stored. The further processing is described in subclause 8.2.1.2.3 with the

addition that the Announcement Suppression indicator, if stored, is sent to the HLR in the Send_Routeing_Info message.

If:

- the Destination Number received from the gsmSCF (via the gsmSSF) is not the same as the stored ISUP Called

party number, i.e. the MSISDN; and

- a CUG active indication was received from the HLR; and

- CUG information was received in the ISUP_IAM for the incoming call,

then an exception event is reported to the process gsmSSF, and the procedure returns a Fail result.

Otherwise the following parameters, if received, are used to overwrite the corresponding ISUP parameters (for mapping

see GSM 09.78 [6]): Destination Number, Calling Partys Category, Generic Number, Original Called Party ID,

Redirecting Party ID and Redirection Information. Call parameters which are not included in the Int_Connect message

are unchanged.


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As a network option loop prevention mechanisms may cause the redirection information to be ignored or modified

(e.g., if the Redirection counter has been decreased).

Signalling limitations or regulatory requirements may require the Calling Partys Category, Generic Number, Original

Called Party Number and Redirecting Party ID to be ignored or modified.

8.2.1.2.5 Send Routeing Info negative response in state Wait_For_Routeing_Info_2

An exception event is reported to the process gsmSSF. If the Announcement Suppression indicator has been received

from the gsmSCF (via the gsmSSF) any announcements or tones shall be suppressed. The procedure returns a Fail result.

8.2.1.2.6 Send Routeing Info ack with MSRN in state Wait_For_Routeing_Info_2

The procedure returns the MSRN as the result.

8.2.1.2.7 Send Routeing Info ack with FTN in state Wait_For_Routeing_Info_2

The redirection counter is incremented. The procedure returns the FTN as the result.

8.2.1.2.8 Send Routeing Info ack with O-CSI and FTN in state Wait_For_Routeing_Info_2

The redirection counter is incremented. The procedure returns the FTN as the result. The O-CSI is passed to the process

MT_CF_MSC in the Perform Call Forwarding request.

8.2.1.3 Procedure CAMEL_MT_GMSC_ANSWER

8.2.1.4 Procedure CAMEL_MT_GMSC_DISC1




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Procedure in the GMSCto set CAMEL parameters forthe procedure Obtain_Routeing_Address

Procedure CAMEL_Set_ORA_Parameters CSORAP1(1)

gsmSSFexists?

Call referencenumber allocated?

Allocate callreference

number

Yes

No

Yes

No

Figure 8.2-1: Procedure CAMEL_Set_ORA_Parameters


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Procedure in the GMSCto perform the initial handlingfor a CAMEL MT call

Procedure CAMEL_MT_GMSC_INIT CAM_TGI1(4)

CAMEL informationreceived in SRI ack?

MSRNreceived?

FTNreceived?

Result:=FTN

Result:=Fail

Result:=MSRN

Contentof

SRI ack

Set CSI=T-CSI

Int_Invoke_gsmSSF(CSI)

To gsmSSF

Wait_For_gsmSSF_Invoked

Set CSI=T-CSI

Store O-CSI

Set CSI=T-CSI

Store FTN

Set CSI=T-CSI

Store O-CSI& FTN

Set CSI=O-CSI

Set redirectioninformation

Result:=FTN

No

No

Yes

No

Yes

Yes

T-CSI T-CSI & O-CSI T-CSI & FTN T-CSI & O-CSI & FTN O-CSI & FTN

Figure 8.2-2: Procedure CAMEL_MT_GMSC_INIT (sheet 1 of 4)


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Wait_For_gsmSSF_Invoked

Release

Int_T_Exception

Result:=Aborted

Int_gsmSSFinvoked

Int_DP_Terminationattemptauthorised

DP_Termination_Attempt_

Authorised

Int_Error

Result:=Fail



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Signals to/from the leftare to/from the originating exchange;signals to/from the rightare to/from the gsmSSFunless marked otherwise

DP_Termination_Attempt_

Authorised

Release

Int_T_Exception

Result:=Aborted

Int_Continue

FTNstored?

Setredirectioninformation

2

Set T-CSIsuppression

SendRouteingInfo

To HLR

Wait_For_Routeing_

Info_2

Int_Connect

Send_ACM_If_Required

Destinationaddress

modified?

Modify callparameters

with received

information

Original Cdparty subscribed

to CUG?

CUG inforeceived for

incoming call?

Int_T_Exception

Result:=Fail

Modify call

parameterswith receivedinformation

Apply_O-CSIindicatorpresent?

O-CSIstored?

FTN:=Destination

address

Result:=FTN

CMN:=Destination

address

Result:=CMN

Int_Release_Call

Result:=Fail

Int_Error

Default CallHandling=Continue Call?

11

2

Yes

No

No

Yes

Yes

Yes

No

Yes

Yes

No

No

No

No

Yes



37/80

ETSI




Signals to/from the leftare to/from the originating exchange;signals to/from the rightare to/from the gsmSSFunless marked otherwise

Wait_For_Routeing_

Info_2

Release

Int_T_Exception

Result:=Aborted

Send RouteingInfo negativeresponse

From HLR

Int_T_Exception

Result:=Fail

Int_ReleaseCall

Send RouteingInfo ack

From HLR

Contentof

SRI ack

Result:=MSRN

Result:=FTN

Result:=FTN

MSRN FTN FTN & O-CSI



38/80

ETSI


Procedure in the GMSCto handle answer for a CAMEL call

Procedure CAMEL_MT_GMSC_ANSWER CAM_TGA1(1)

Signals to/from the leftare to/from the originating exchange;signals to/from the rightare to/from the destination exchangeunless marked otherwise

gsmSSFexists?

Result:=Pass

Int_DP_T_Answer

To gsmSSF

DP_T_Answer

Int_Release From gsmSSF

Release

Release

Result:=Fail

Int_Continue From gsmSSF

Result:=Pass

Release

CAMEL_MT_GMSC_DISC1

Result=CAMEL

handling?

Release

Result:=Fail

Release

CAMEL_MT_GMSC_DISC2

Result=CAMEL

handling?

Release

No

Yes

No

Yes

No

Yes

Figure 8.2-6: Procedure CAMEL_MT_GMSC_ANSWER


39/80

ETSI


Procedure in the GMSCto perform CAMEL handling for a call releasefrom the originating end

Procedure CAMEL_MT_GMSC_DISC1 CAMTD1_1(1)

Signals to/from the rightare to/from the gsmSSFif not otherwise stated.

gsmSSF

exists?

Int_DP_T_Disconnect

/* legId = 1 */

DP_T_Disconnect_1

Int_Error

ReleaseTo destinationexchange orprocess MT_CF_MSC

Result:=CAMELhandling

Int_Continue Int_Release_Call ReleaseFrom destinationexchange orprocess MT_CF_MSC

Int_DP_T_


DP_T_Disconnect

Int_Error Int_Continue Int_Release_Call

Result:=Normal

handling

Yes

No

Figure 8.2-7: Procedure CAMEL_MT_GMSC_DISC1


40/80

ETSI


Procedure in the GMSCto perform CAMEL handling for a call releasefrom the destination end

Procedure CAMEL_MT_GMSC_DISC2 CAMTD2_1(1)

Signals to/from the leftare to/from the originating exchange;signals to/from the rightare to/from the gsmSSF

gsmSSF

exists?

Int_DP_T_Disconnect

/* legId = 2 */

DP_T_Disconnect_2

Release

Int_DP_T_


DP_T_Disconnect

Int_Error

Result:=CAMELhandling

Int_Continue Int_Release_Call

Int_Continue

Rele

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Camel Phase 2 Etsi