4.5.2 Handling of mobile originated calls

23.0783GPPCustomised Applications for Mobile network Enhanced Logic (CAMEL) Phase 4Release 17Stage 2TS

4.5.2.1 Handling of mobile originated calls in the originating MSC

The functional behaviour of the originating VMSC is specified in 3GPP TS 23.018 [12]. The procedures specific to CAMEL are specified in this subclause:

– Procedure CAMEL_OCH_MSC_INIT;

– Procedure CAMEL_MO_Dialled_Services;

– Procedure CAMEL_OCH_MSC_ALERTING;

– Procedure CAMEL_OCH_MSC_ANSWER;

– Procedure CAMEL_OCH_MSC1;

– Procedure CAMEL_OCH_MSC2;

– Procedure CAMEL_OCH_MSC_DISC1;

– Procedure CAMEL_OCH_MSC_DISC2;

– Procedure CAMEL_OCH_MSC_DISC3;

– Procedure CAMEL_OCH_MSC_DISC4;

– Procedure CAMEL_Disconnect_CTR_SRF;

– Procedure CAMEL_OCH_ETC;

– Procedure CAMEL_OCH_CTR;

– Procedure CAMEL_Start_TNRy;

– Procedure CAMEL_Stop_TNRy;

– Procedure CAMEL_Store_Destination_Address;

– Procedure CAMEL_Modify_CUG_Info;

– Procedure CAMEL_N_CSI_CHECK_MSC;

– Procedure CAMEL_OCH_LEG1_MSC;

– Procedure CHECK_DIGIT_STRING_MSC;

– Process CAMEL_OCH_LEG2_MSC;

– Process CAMEL_OCH_RECONNECT_MSC;

– Procedure CAMEL_EXPORT_LEG_MSC;

– Process CAMEL_O_CHANGE_OF_POSITION_MSC;

– Procedure CAMEL_O_SCUDIF_MSC.

NOTE: Procedure CAMEL_OCH_MSC_DISC3 applies to CAMEL Phase 1 only.

The procedure Send_Access_Connect_If_Required is specified in 3GPP TS 23.018 [12].

The procedure CAMEL_OCH_LEG1_MSC supervises the originating party only. The process CAMEL_OCH_LEG2_MSC supervises the terminating party only. Hence, signals from the BSS are received by the procedure CAMEL_OCH_LEG1_MSC and signals from the destination exchange are received by the process CAMEL_OCH_LEG2_MSC.

The following paragraphs give details on the behaviour of the MSC in the procedures CAMEL_OCH_MSC_INIT, CAMEL_OCH_ETC, CAMEL_OCH_ANSWER and CAMEL_Store_Destination_Address.

4.5.2.1.1 Actions of the MSC on receipt of Int_Error

The MSC checks the default Call Handling parameter in the relevant CSI.

If the default call handling is release call, a Release is sent to the MS and an Abort to the VLR. The MSC then releases all call resources and the procedure CAMEL_OCH_MSC_INIT ends.

If the default call handling is continue call, the MSC continues processing without CAMEL support. It sends Send_Info_For_Ougoing_Call to the VLR and waits in state Wait_For_MO_Call_Result.

4.5.2.1.2 Actions of the MSC on receipt of Int_Continue

The MSC continues processing without any modification of call parameters. At DP Analysed_Information it sends Send Info For Ougoing Call information flow to the VLR and waits in state Wait_For_MO_Call_Result.

4.5.2.1.3 Actions of the MSC on receipt of Int_Continue_With_Argument

The MSC continues processing with modified call parameters. The MSC shall replace the call parameters by the information received in the Int_Continue_With_Argument signal. Call parameters which are not included in the Int_Continue_With_Argument signal 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.

4.5.2.1.4 Actions of the MSC 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 signal 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 network signalling system shall indicate that this is an internal network number.

At DP Collected_Information the MSC sets the O‑CSI suppression parameter. If D‑CSI and N‑CSI are not present, the MSC sends a Send Info For Outgoing Call to the VLR and waits in state Wait_For_MO_Call_Result.

At DP Analysed_Information it sets the D‑CSI suppression parameter, sends a Send Info For Outgoing Call to the VLR and waits in state Wait_For_MO_Call_Result.

4.5.2.1.5 Actions of the MSC on receipt of Int_Release_Call

A Release is sent to the MS, an abort to the VLR and a Release is sent to the destination exchange. The release cause received in the Int_Release_Call signal is used. The MSC then releases all call resources and the procedure CAMEL_OCH_MSC_INIT ends.

4.5.2.1.6 Actions of the MSC on receipt of Int_Disconnect_Leg (Leg 2)

If the MSC receives Int_Disconnect_Leg (Leg 2) signal from the gsmSSF, in response to an Initial DP information flow, the MSC will continue the handling of the calling party (Leg1) without routeing the call to a destination.

4.5.2.1.7 Actions of the MSC on receipt of Int_Apply_Warning_Tone

This section applies to all call cases. The MSC will play a tone to the indicated leg or call segment.

The following special cases exist when there is already an existing tone to a leg or call segment:

1 If the MSC is playing a tone to a leg and the Int_Apply_Warning_Tone instructs the MSC to play a tone for another leg (in the same or a different call segment), then the tones will be played independently;

2 The tones for different call segments are independent;

3 If the MSC is playing a tone to a leg and the Int_Apply_Warning_Tone instructs the MSC to play another tone for that leg, then the MSC will stop the existing tone and the latter tone will be played for that leg.

4 If the MSC is playing a tone to a call segment and the Int_Apply_Warning_Tone instructs the MSC to play another tone for that call segment, then the MSC will stop the existing tone and the latter tone will be played for that call segment.

5 If the MSC is playing a tone for the call segment and the Int_Apply_Warning_Tone instructs the MSC to play another tone for a leg in that call segment, then the particular leg shall hear (as an MSC option) either:

a The latter tone only, or

b Two tones. As an MSC option, the two tones may be played in parallel or in a sequence.

The other leg(s) shall keep hearing the (old) call segment tone.

6 If the MSC is playing a tone for a leg and the Int_Apply_Warning_Tone instructs the MSC to play another tone for that call segment, then the particular leg shall either hear (as an MSC option):

a The latter tone only, or

b Two tones. As an MSC option, the two tones may be played in parallel or in a sequence.

The other leg(s) shall start hearing the new call segment tone.

4.5.2.1.8 Action of the MSC in procedure CAMEL_OCH_MSC_ANSWER

If the MSC received a destination address from the GMSC in the ISUP Answer or Connect Message, the MSC relays the destination address to the gsmSSF in the Int_DP_O_Answer signal.

NOTE 1: The sending of e-parameters by the gsmSCF after receiving the DP_O_Answer indication may be to late.

NOTE 2: If the MO call is not subject to Basic OR, then the destination address is generated by the MSC. If the MO call is subject to Basic OR, the MSC will receive a destination address from the GMSC in the ISUP Answer or Connect Message.

4.5.2.1.9 Action of the MSC in procedure CAMEL_OCH_ETC

In procedure CAMEL_OCH_ETC (sheet 2) the MSC will remain in the Wait_For_Assisting_Answer state until it receives an ISUP Answer Message (ANM) or timeout occurs. This is to ensure that a call record is always generated for every successful establishment of a temporary connection to a gsmSRF, especially in the case where the connection is between PLMNs.

NOTE: This means that it may not be possible to access an SRF which does not generate an ISUP Answer Message (ANM).

If a Progress Message is sent towards the MS the progress indicator shall indicate "In Band Information".

4.5.2.1.10 Procedure CAMEL_OCH_LEG1_MSC

The Int_DTMF_Digit_Received information flow is received from an internal process in the MSC that receives DTMF signalling from the MS. The handling of the internal process that receives DTMF signalling is out of scope of the present document. The playing of the received DTMF tones to the other parties in the call segment is out of scope of the present document.

4.5.2.1.11 Process CAMEL_O_CHANGE_OF_POSITION_MSC

The signals HANDOVER COMPLETE and HANDOVER PERFORMED are specified in 3GPP TS 48.008 [39]. Signals RELOCATION REQUEST ACKNOWLEDGE, LOCATION REPORT and LOCATION REPORTING COMMAND are specified in 3GPP TS 25.413 [33].

4.5.2.1.12 Procedure CAMEL_Start_TNRy

The recommended value range in the gsmSSF for the default TNRy timer for CAMEL handling is 10 seconds to 3 minutes.

The CSE provided TNRy value is applied only once per outgoing leg. The decision "TNRy received?" decision box goes to "No" branch if the TNRy duration has been used for once and no new timer value has been received since previous call of this procedure.

The task box "Cancel TNRy received" ensures that the gsmSCF provided timer is applied only once per call leg. The task box prevents the use of previously received timer value from the gsmSCF in subsequent calls (e.g. as in the case of a follow-on call).

For example: The gsmSCF arms O_No_Answer EDP and also sent a TNRy timer duration. The call fails and EDP O_No_Answer is reported to the gsmSCF. The gsmSCF sends a Connect (i.e. follow-on call), and also arms EDP O_No_Answer, but this time, with no TNRy timer duration included. The gsmSSF does not use the TNRy timer previously provided by the gsmSCF. Instead, the network’s default TNRy timer is used if available for the follow-on call.

Figure 4.10-1: Procedure CAMEL_OCH_MSC_INIT (sheet 1)

Figure 4.10-2: Procedure CAMEL_OCH_MSC_INIT (sheet 2)

Figure 4.10-3: Procedure CAMEL_OCH_MSC_INIT (sheet 3)

Figure 4.10-4: Procedure CAMEL_OCH_MSC_INIT (sheet 4)

Figure 4.11-1: Procedure CAMEL_MO_Dialled_Services (sheet 1)

Figure 4.11-2: Procedure CAMEL_MO_Dialled_Services (sheet 2)

Figure 4.11-3: Procedure CAMEL_MO_Dialled_Services (sheet 3)

Figure 4.12-1: Procedure CAMEL_SDS_MO_Init (sheet 1)

Figure 4.12-2: Procedure CAMEL_SDS_MO_INIT (sheet 2)

Figure 4.12-3: Procedure CAMEL_SDS_MO_INIT (sheet 3)

Figure 4.12-4: Procedure CAMEL_SDS_MO_INIT (sheet 4)

Figure 4.13-1: Procedure CAMEL_NDS_MO_INIT (sheet 1)

Figure 4.13-2: Procedure CAMEL_NDS_MO_INIT (sheet 2)

Figure 4.13-3: Procedure CAMEL_NDS_MO_INIT (sheet 3)

Figure 4.13-4: Procedure CAMEL_NDS_MO_INIT (sheet 4)

Figure 4.14-1: Procedure CAMEL_OCH_MSC_ALERTING (sheet 1)

Figure 4.14-2: Procedure CAMEL_OCH_MSC_ALERTING (sheet 2)

Figure 4.14-3: Procedure CAMEL_OCH_MSC_ALERTING (sheet 3)

Figure 4.15-1: Procedure CAMEL_OCH_MSC_ANSWER (sheet 1)

Figure 4.15-2: Procedure CAMEL_OCH_ANSWER (sheet 2)

Figure 4.15-3: Procedure CAMEL_OCH_ANSWER (sheet 3)

Figure 4.16-1: Procedure CAMEL_OCH_MSC1 (sheet 1)

Figure 4.16-2: Procedure CAMEL_OCH_MSC1 (sheet 2)

Figure 4.16-3: Procedure CAMEL_OCH_MSC1 (sheet 3)

Figure 4.17-1: Procedure CAMEL_OCH_MSC2 (sheet 1)

Figure 4.17-2: Procedure CAMEL_OCH_MSC2 (sheet 2)

Figure 4.17-3: Procedure CAMEL_OCH_MSC2 (sheet 3)

Figure 4.18-1: Procedure CAMEL_OCH_MSC_DISC1 (sheet 1)

Figure 4.19-1: Procedure CAMEL_OCH_MSC_DISC2 (sheet 1)

Figure 4.19-2: Procedure CAMEL_OCH_MSC_DISC2 (sheet 2)

Figure 4.20-1: Procedure CAMEL_OCH_MSC_DISC3 (sheet 1)

Figure 4.21-1: Procedure CAMEL_OCH_MSC_DISC4 (sheet 1)

Figure 4.22-1: Procedure CAMEL_Disconnect_CTR_SRF (sheet 1)

Figure 4.23-1: Procedure CAMEL_OCH_ETC (sheet 1)

Figure 4.23-2: Procedure CAMEL_OCH_ETC (sheet 2)

Figure 4.23-3: Procedure CAMEL_OCH_ETC (sheet 3)

Figure 4.23-4: Procedure CAMEL_OCH_ETC (sheet 4)

Figure 4.24-1: Procedure CAMEL_OCH_CTR (sheet 1)

Figure 4.24-2: Procedure CAMEL_OCH_CTR (sheet 2)

Figure 4.24-3: Procedure CAMEL_OCH_CTR (sheet 3)

Figure 4.24-4: Procedure CAMEL_OCH_CTR (sheet 4)

Figure 4.24-5: Procedure CAMEL_OCH_CTR (sheet 5)

Figure 4.25-1: Procedure CAMEL_Start_TNRy (sheet 1)

Figure 4.26-1: Procedure CAMEL_Stop_TNRy (sheet 1)

Figure 4.27-1: Procedure CAMEL_Store_Destination_Address (sheet 1)

Figure 4.28-1: Procedure CAMEL_Modify_CUG_Info (sheet 1)

Figure 4.29-1: Procedure CAMEL_N_CSI_CHECK_MSC (sheet 1)

Figure 4.30-1: Procedure CAMEL_OCH_LEG1_MSC (sheet 1)

Figure 4.30-2: Procedure CAMEL_OCH_LEG1_MSC (sheet 2)

Figure 4.30-3: Procedure CAMEL_OCH_LEG1_MSC (sheet 3)

Figure 4.30-4: Procedure CAMEL_OCH_LEG1_MSC (sheet 4)

Figure 4.30-5: Procedure CAMEL_OCH_LEG1_MSC (sheet 5)

Figure 4.30-6: Procedure CAMEL_OCH_LEG1_MSC (sheet 6)

Figure 4.30-7: Procedure CAMEL_OCH_LEG1_MSC (sheet 7)

Figure 4.30-8: Procedure CAMEL_OCH_LEG1_MSC (sheet 8)

Figure 4.30-9: Procedure CAMEL_OCH_LEG1_MSC (sheet 9)

Figure 4.30-10: Procedure CAMEL_OCH_LEG1_MSC (sheet 10)

Figure 4.30-11: Procedure CAMEL_OCH_LEG1_MSC (sheet 11)

Figure 4.30-12: Procedure CAMEL_OCH_LEG1_MSC (sheet 12)

Figure 4.30-13: Procedure CAMEL_OCH_LEG1_MSC (sheet 13)

Figure 4.31-1: Procedure CHECK_DIGIT_STRING_MSC (sheet 1)

Figure 4.32-1: Process CAMEL_OCH_LEG2_MSC (sheet 1)

Figure 4.32-2: Process CAMEL_OCH_LEG2_MSC (sheet 2)

Figure 4.33-1: Procedure CAMEL_OCH_RECONNECT_MSC (sheet 1)

Figure 4.33-2: Procedure CAMEL_OCH_RECONNECT_MSC (sheet 2)

Figure 4.33-3: Procedure CAMEL_OCH_RECONNECT_MSC (sheet 3)

Figure 4.33-4: Procedure CAMEL_OCH_RECONNECT_MSC (sheet 4)

Figure 4.33-5: Procedure CAMEL_OCH_RECONNECT_MSC (sheet 5)

Figure 4.33-6: Procedure CAMEL_OCH_RECONNECT_MSC (sheet 6)

Figure 4.33-7: Procedure CAMEL_OCH_RECONNECT_MSC (sheet 7)

Figure 4.33-8: Procedure CAMEL_OCH_RECONNECT_MSC (sheet 8)

Figure 4.33-9: Procedure CAMEL_OCH_RECONNECT_MSC (sheet 9)

Figure 4.34-1: Procedure CAMEL_EXPORT_LEG_MSC (sheet 1)

Figure 4.34-2: Procedure CAMEL_EXPORT_LEG_MSC (sheet 2)

Figure 4.35-1: Process CAMEL_CHANGE_OF_POSITION_MSC (sheet 1)

Figure 4.36-1: Process CAMEL_O_CHANGE_OF_POSITION_MSC (sheet 1)

Figure 4.36-2: Process CAMEL_O_CHANGE_OF_POSITION_MSC (sheet 2)

Figure 4.37-1: Procedure Check_Criteria_Change_Of_Position (sheet 1)

Figure 4.38-1: Procedure CAMEL_O_SCUDIF_MSC (sheet 1)

4.5.2.2 Handling of mobile originating calls in the originating VLR

The functional behaviour of the originating VLR is specified in 3GPP TS 23.018 [12]. The procedure specific to CAMEL are specified in this subclause:

– Procedure CAMEL_OCH_VLR;

– Process CAMEL_Reconnected_Call_VLR.

Figure 4.39-1: Procedure CAMEL_OCH_VLR (sheet 1)

Figure 4.40-1: Process CAMEL_Reconnected_Call_VLR (sheet 1)