A.1 Architecture

23.0663GPPRelease 17Stage 2Support of Mobile Number Portability (MNP)Technical realizationTS

A.1.1 Network Options

There are two IN-based solutions for querying the NPDB :-

– ETSI Core INAP

– ANSI IN Query.

The following network operator options are defined for the MT calls in the GMSC:

– Terminating call Query on Digit Analysis (TQoD);

– Query on HLR Release (QoHR).

In a GSM network that supports the IN-based approach for call related MNP, each GMSC shall support at least one of these options.

The following network operator option is defined for MO calls in VMSCA and for forwarded calls in the GMSC and VMSCB:

– Originating call Query on Digit Analysis (OQoD).

In a GSM network which supports the IN-based approach for call related MNP, it is a network operator decision, taking into account the regulatory and architectural constraints that may prevail, whether or not VMSCs and GMSCs support this option.

The use of OQoD in transit switches in a PLMN while avoiding multiple database interrogations is for further study.

The interworking between the CCF and the SSF for MNP is for further study.

Note that for different number ranges different options may be chosen.

An IN-based solution for querying the NPDB may also be used by the gsmSCF in order to be able to apply different charging tariffs for CAMEL pre-paid subscribers’ calls or short messages established/sent when roaming in their home PLMN and directed to ported and non-ported mobile subscribers, depending on whether or not the called and the calling subscriber subscribe to the same PLMN.

A.1.2 No NP Query required – Number is not subject for portability

Figure A.1.2 shows the architecture for a call to a number that is not subject for portability. This can be for several reasons like for example:

– the national regulator has stipulated some number series as being non-portable or;

– in an initial phase only a limited amount of subscribers might port in certain number blocks and some operators might want to treat the call routeing according to traditional routeing plans without any change.

Figure A.1.2: Call to a non-ported number, no NP query required

1 From an Originating Exchange a call is set up to MSISDN. The call is routed to the Number range holder network being the Subscription network.

2 When GMSCB receives the ISUP IAM, it requests routeing information by submitting a MAP SRI to the HLRB including the MSISDN in the request.

3 The HLRB requests an MSRN from the MSC/VLRB where the mobile subscriber currently is registered;

4 The MSC/VLRB returns an MSRN back to the HLRB.

5 The HLRB responds to the GMSCB by sending an SRI ack with an MSRN.

6 GMSCB uses the MSRN to route the call to VMSCB.

A.1.3 NP Query in Number Range Holder Network

A.1.3.1 TQoD – Number is not ported

Figure A.1.3.1 shows the architecture for a call where the Originating network has no knowledge whether the MSISDN is ported or not and uses the traditional routeing plans for routeing the call to the Number range holder network for further routeing decisions.

Figure A.1.3.1: Call to a non-ported number using TQoD procedure

1 From an Originating Exchange a call is set up to MSISDN. The call is routed to the Number range holder network being the Subscription network.

2 When GMSCB receives the ISUP IAM, it will send a database query to the NPDB as a result of analysis of the received MSISDN. The MSISDN is included in the query to the NPDB.

3 The NPDB detects that the MSISDN is not ported and responds back to the GMSCB to continue the normal call setup procedure for MT calls.

4 The GMSCB requests routeing information by submitting a MAP SRI to the HLRB, including the MSISDN in the request.

5 The HLRB requests an MSRN from the MSC/VLRB where the mobile subscriber owning the MSISDN currently is registered.

6 The MSC/VLRB returns an MSRN back to the HLRB.

7 The HLRB responds to the GMSCB by sending an SRI ack with an MSRN.

8 GMSCB uses the MSRN to route the call to VMSCB.

Note that the NPDB may be outside the number range holder network if a shared NPDB is used.

A.1.3.2 TQoD – Number is ported

Figure A.1.3.2 shows the architecture for a call where the Originating network has no knowledge whether the MSISDN is ported or not and uses the traditional routeing plans for routeing the call to the Number range holder network for further routeing decisions.

Figure A.1.3.2: Call to a ported number using TQoD procedure

1 From an Originating Exchange a call is set up to MSISDN. The call is routed to the Number range holder network.

2 When GMSCA receives the ISUP IAM, it will send a database query, including the MSISDN, to the NPDB as a result of analysis of the received MSISDN.

3 The NPDB detects that the MSISDN is ported and responds back to the GMSCA with a Routeing Number pointing out the Subscription network.

4 The call is routed to the Subscription network based on the Routeing Number carried in ISUP IAM message; also the MSISDN is included in IAM.

5 The GMSCB requests routeing information by submitting a MAP SRI to the HLRB, including the MSISDN in the request. The capability to route messages to the correct HLR is required.

6 The HLRB requests an MSRN from the MSC/VLRB where the mobile subscriber currently is registered.

7 The MSC/VLRB returns an MSRN back to the HLRB.

8 The HLRB responds to the GMSCB by sending an SRI ack with an MSRN.

9 GMSCB uses the MSRN to route the call to VMSCB.

Note that the NPDB may be outside the number range holder network if a shared NPDB is used.

A.1.3.3 QoHR – Number is ported

Figure A.1.3.3 shows the architecture for a call where the Originating network has no knowledge whether the MSISDN is ported or not and uses the traditional routeing plans for routeing the call to the Number range holder network for further routeing decisions.

Figure A.1.3.3: Call to a ported number using QoHR procedure

1 From an Originating Exchange a call is set up to MSISDN. The call is routed to the Number range holder network.

2 When GMSCA receives the ISUP IAM, it requests routeing information by submitting a MAP SRI to the HLRA including the MSISDN in the request.

3 The HLRA returns a MAP SRI ack with an "Unknown Subscriber" error since no record was found for the subscriber in the HLRA.

4 When GMSCA receives the error indication form the HLRA, this will trigger the sending of a database query to the NPDB, including the MSISDN in the query.

5 The NPDB detects that the MSISDN is ported and responds back to the GMSCA with a Routeing Number pointing out the Subscription network.

6 The call is routed to the Subscription network based on the Routeing Number carried in ISUP IAM message; also the MSISDN is included in IAM.

7 The GMSCB requests routeing information by submitting a MAP SRI to the HLRB, including the MSISDN in the request. The capability to route messages to the correct HLR is required.

8 The HLRB requests an MSRN from the MSC/VLRB where the mobile subscriber currently is registered.

9 The MSC/VLRB returns an MSRN back to the HLRB.

10 The HLRB responds to the GMSCB by sending an SRI ack with an MSRN.

11 GMSCB uses the MSRN to route the call to VMSCB.

Note that the NPDB may be outside the number range holder network if a shared NPDB is used.

A.1.4 NP Query in Originating Network

A.1.4.1 OQoD – Number is not ported

Figure A.1.4.1 shows the architecture for a call where already the Originating network has the knowledge whether the MSISDN is ported or not and can route the call directly to the Subscription network that in this case is the same as the Number range holder network.

Figure A.1.4.1: Call to a non-ported number using OQoD procedure

1 A call is initiated by Mobile Subscriber A towards Mobile Subscriber B, using the MSISDN of the called subscriber.

2 When VMSCA receives the call setup indication, it will send a database query to the NPDB as a result of analysis of the received MSISDN, including the MSISDN in the query.

3 The NPDB detects that the MSISDN is not ported and responds back to the VMSCA to continue the normal call setup procedure for MO calls. Depending on database configuration option, the NPDB could either return a Routeing Number on not ported calls, as done for ported calls, or the call is further routed using the MSISDN number only towards the Number range holder network.

4 The call is routed to the Number range holder/Subscription network based on the MSISDN or Routeing Number carried in ISUP IAM message.

5 The GMSCB requests routeing information by submitting a MAP SRI to the HLRB, including the MSISDN in the request.

6 The HLRB requests an MSRN from the MSC/VLRB where the mobile subscriber currently is registered.

7 The MSC/VLRB returns an MSRN back to the HLRB.

8 The HLRB responds to the GMSCB by sending an SRI ack with an MSRN.

9 GMSCB uses the MSRN to route the call to VMSCB.

Note that the NPDB may be outside the national originating network if a shared NPDB is used.

A.1.4.2 OQoD – Number is ported

Figure A.1.4.2 shows the architecture for a call where already the Originating network has the knowledge that the MSISDN is ported and can route the call directly to the Subscription network without involving the Number range holder network.

Figure A.1.4.2: Call to a ported number using OQoD procedure

1 A call is initiated by Mobile Subscriber A towards Mobile Subscriber B, using the MSISDN of the called subscriber.

2 When VMSCA receives the call setup indication, it will send a database query to the NPDB as a result of analysis of the received MSISDN including the MSISDN in the query.

3 The NPDB detects that the MSISDN is ported and responds back to the VMSCA with a Routeing Number pointing out the Subscription network.

4 The call is routed to the Subscription network based on the Routeing Number carried in ISUP IAM message; also the MSISDN is included in IAM.

5 The GMSCB requests routeing information by submitting a MAP SRI to the HLRB, including the MSISDN in the request. The capability to route messages to the correct HLR is required.

6 The HLRB requests an MSRN from the MSC/VLRB where the mobile subscriber currently is registered.

7 The MSC/VLRB returns an MSRN back to the HLRB.

8 The HLRB responds to the GMSCB by sending an SRI ack with an MSRN.

9 GMSCB uses the MSRN to route the call to VMSCB.

Note that the NPDB may be outside the national originating network if a shared NPDB is used.

A.1.4.3 IN-Query for CAMEL pre-paid service

Figure A.1.4.3 shows the architecture for a call or MO-Short-Message originated by a CAMEL pre-paid subscriber while roaming in the Home PLMN where the gsmSCF needs to know whether or not calling and called subscriber subscribe to the same PLMN in order to apply the correct charging tariff.

Figure A.1.4.3: IN-Query for pre-paid service

1 A call or short message is initiated by Mobile Subscriber A towards Mobile Subscriber B, using the MSISDN of the called subscriber.

2 When VMSCA receives the call setup indication, it will send a CAP IDP message to the gsmSCF. The IDP contains the called party’s MSISDN.

3 If the calling subscriber roams in her Home PLMN and the called subscriber’s MSISDN indicates that the called subscriber subscribes to a PLMN within the calling subscriber’s Home Country, the gsmSCF queries the NPDB based on the called party’s MSISDN.
Otherwise the tariff to be applied does not depend on the called subscriber’s porting status and enough information to apply the correct tariff is available; go to 5.

4 The NPDB returns a routing number to the gsmSCF pointing out the called subscriber’s subscription network. Based on this information the gsmSCF applies the appropriate tariff for pre-paid subscriber A.

5 The gsmSCF returns CAP AC and CAP CUE messages to the VMSCA.

6 The call or short message is set up.

Note that the NPDB and gsmSCF may be integrated within one physical entity.