4.5.4 Handling of mobile terminating calls

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

4.5.4.1 Handling of mobile terminating calls in the terminating VMSC

The functional behaviour of the terminating VMSC is specified in 3GPP TS 23.018 [12].

The behaviour specific to CAMEL is:

– the inclusion of the O‑CSI and/or D‑CSI parameter in the Perform Call Forwarding information flow sent to the process MT_CF_MSC if O‑CSI and/or D‑CSI was received in the Send Info For Incoming Call ack information flow;

– the requirement to suppress the connection of announcements or tones if the VLR includes the suppression of announcements parameter in the Send Info For Incoming Call negative response information flow.

The processes and procedures specific to CAMEL are specified in this subclause:

– Procedure CAMEL_ICH_VLR;

– Procedure CAMEL_O_CSI_Check_VLR;

– Procedure CAMEL_D_CSI_Check_VLR;

– Procedure CAMEL_VT_CSI_Check_VLR;

– Procedure CAMEL_ICH_MSC_INIT;

– Procedure CAMEL_MT_VMSC_Notify_CF;

– Procedure CAMEL_ICH_LEG2_MSC;

– Procedure CAMEL_ICH_LEG2_CF_MSC;

– Process CAMEL_ICH_LEG1_MSC;

– Procedure CAMEL_ICH_RECONNECT_MSC;

– Process CAMEL_T_CHANGE_OF_POSITION_MSC.

The procedure CAMEL_ICH_LEG2_MSC supervises the terminating party only. The procedure CAMEL_ICH_LEG2_CF_MSC supervises the forwarded-to party only. The process CAMEL_ICH_LEG1_MSC supervises the originating party only. Hence, signals from the BSS are received by the procedure CAMEL_ICH_LEG2_MSC, signals from the destination exchange are received by the procedure CAMEL_ICH_LEG2_CF_MSC and signals from the originating exchange are received by the process CAMEL_ICH_LEG1_MSC.

4.5.4.1.1 Action of the VMSC in procedure CAMEL_MT_VMSC_Notify_CF

The Forwarding reason is taken from the Complete Call information flow from the VLR.

The Int_DP_T_No_Answer signal and Int_DP_T_Busy signal include a parameter to indicate that the call has encountered conditional call forwarding. The gsmSSF will transfer this parameter to the Event Report BCSM information flow which it sends to the gsmSCF.

4.5.4.1.2 Action of 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.

4.5.4.1.3 Procedure CAMEL_ICH_LEG2_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.

4.5.4.1.4 Process CAMEL_T_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].

Figure 4.65-1: Procedure CAMEL_ICH_VLR (sheet 1)

Figure 4.66-1: Procedure CAMEL_O_CSI_Check_VLR (sheet 1)

Figure 4.67-1: Procedure CAMEL_D_CSI_Check_VLR (sheet 1)

Figure 4.68-1: Procedure CAMEL_VT_CSI_Check_VLR (sheet 1)

Figure 4.69-1: Procedure CAMEL_ICH_MSC_INIT (sheet 1)

Figure 4.69-2: Procedure CAMEL_ICH_MSC_INIT (sheet 2)

Figure 4.69-3: Procedure CAMEL_ICH_MSC_INIT (sheet 3)

Figure 4.69-4: Procedure CAMEL_ICH_MSC_INIT (sheet 4)

Figure 4.69-5: Procedure CAMEL_ICH_MSC_INIT (sheet 5)

Figure 4.70-1: Procedure CAMEL_MT_VMSC_Notify_CF (sheet 1)

Figure 4.70-2: Procedure CAMEL_MT_VMSC_Notify_CF (sheet 2)

Figure 4.71-1: Procedure CAMEL_ICH_LEG2_MSC (sheet 1)

Figure 4.71-2: Procedure CAMEL_ICH_LEG2_MSC (sheet 2)

Figure 4.71-3: Procedure CAMEL_ICH_LEG2_MSC (sheet 3)

Figure 4.71-4: Procedure CAMEL_ICH_LEG2_MSC (sheet 4)

Figure 4.71-5: Procedure CAMEL_ICH_LEG2_MSC (sheet 5)

Figure 4.71-6: Procedure CAMEL_ICH_LEG2_MSC (sheet 6)

Figure 4.71-7: Procedure CAMEL_ICH_LEG2_MSC (sheet 7)

Figure 4.71-8: Procedure CAMEL_ICH_LEG2_MSC (sheet 8)

Figure 4.71-9: Procedure CAMEL_ICH_LEG2_MSC (sheet 9)

Figure 4.72-1: Process CAMEL_ICH_LEG2_CF_MSC (sheet 1)

Figure 4.72-2: Process CAMEL_ICH_LEG2_CF_MSC (sheet 2)

Figure 4.73-1: Process CAMEL_ICH_LEG1_MSC (sheet 1)

Figure 4.73-2: Process CAMEL_ICH_LEG1_MSC (sheet 2)

Figure 4.73-3: Process CAMEL_ICH_LEG1_MSC (sheet 3)

Figure 4.73-4: Process CAMEL_ICH_LEG1_MSC (sheet 4)

Figure 4.73-5: Process CAMEL_ICH_LEG1_MSC (sheet 5)

Figure 4.74-1: Procedure CAMEL_ICH_RECONNECT_MSC (sheet 1)

Figure 4.74-2: Procedure CAMEL_ICH_RECONNECT_MSC (sheet 2)

Figure 4.74-3: Procedure CAMEL_ICH_RECONNECT_MSC (sheet 3)

Figure 4.74-4: Procedure CAMEL_ICH_RECONNECT_MSC (sheet 4)

Figure 4.74-5: Procedure CAMEL_ICH_RECONNECT_MSC (sheet 5)

Figure 4.74-6: Procedure CAMEL_ICH_RECONNECT_MSC (sheet 6)

Figure 4.74-7: Procedure CAMEL_ICH_RECONNECT_MSC (sheet 7)

Figure 4.75-1: Process CAMEL_T_CHANGE_OF_POSITION_MSC (sheet 1)

Figure 4.75-2: Procedure CAMEL_T_CHANGE_OF_POSITION_MSC (sheet 2)

4.5.4.2 Handling of mobile terminating calls in the VLR

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

– Process Reconnected_MT_Call_VLR.

The behaviour specific to CAMEL is:

– the inclusion of the O‑CSI and/or D‑CSI parameter in the Send Info For Incoming Call ack information flow if the call is to be forwarded and O‑CSI and/or D‑CSI is included in the subscriber data for that subscriber in the VLR;

– the inclusion of the suppression of announcements parameter in the Send Info For Incoming Call negative response information flow if it was received in the Provide Roaming Number information flow from the HLR.

Figure 4.76-1: Process Reconnected_MT_Call_VLR (sheet 1)