CHANGE REQUEST No. A022r1

Transcription

1 ETSI SMG#27 Tdoc SMG 0722/98 Praha, 12 to 16 October 1998 Agenda Item: 6.3 CHANGE REQUEST. A022r1 Technical Specification GSM version Submitted to SMG for approval without presentation ("non-strategic") [ ] with presentation ("strategic") [x] Status at SMG [#27]: Approved [ ] Rejected [ ] Postponed [ ] Phase 1: [ ] Phase 2: [ ] Phase 2+: [R97] Work item: CAMEL Phase 2, CCBS Other phase(s) affected: [ ] If yes, linked CR(s): Proposed change affects: SIM [ ] ME [ ] Network [x] Source: SMG3 (Tdoc SMG3 98C469) Date: September 1998 Subject: Corrections and alignments for CAMEL phase 2 & CCBS Category: F - Correction [x] A - Corresponds to a Phase 2 correction [ ] B - Addition of Feature [ ] C - Functional modification of Feature [ ] D - Editorial modification [ ] Reason for change: The combination of the CAMEL phase 2 & CCBS CRs to GSM has revealed several errors, as listed below Sections affected, and additional explanation of details of change (if needed): Clause 2: add reference to CAMEL phase 2 stage 2 specification Subclauses , , , , , , : add reference to CAMEL phase 2 specification for those procedures which are defined for both phase 1 & phase 2. Subclauses , , , : replace reference to CAMEL phase 1 specification by reference to CAMEL phase 2 specification for those procedures which are defined only for CAMEL phase 2. Figure 8f: stop CAMEL TNRy on reconnect in procedure OG_Call_Setup_MSC. Figure 13: set global variable to indicate TCH allocated after successful traffic channel allocation in procedure Establish_Originating_TCH_If_Required. Figure 18: remove redundant task " call resources" for failure cases of procedure Send_Access_Connect_If_Required. Subclause & figure 36b: show distinct handling for CAMEL phase 1 & CAMEL phase 2 for the case when OR is not allowed. Subclause & figure 42a: show distinct handling for CAMEL phase 1 & CAMEL phase 2 for the case when call forwarding is cancelled. Subclause & figures 56a & 56b: remove explicit request for location information from VLR to MSC; delete the insertion of the VLR number. Figure 57: remove handling for request for location info received from the VLR.

2 2 Subclause & figures 61a, 61b & 61d: rename procedures CCBS_ICH_Report_Failure & CCBS_ICH_Report_Success to CCBS_ICH_MSC_Report_Failure & CCBS_ICH_MSC_Report_Success, to distinguish them from the corresponding VLR procedures. Subclause & figures 62a & 62c: rename procedures CCBS_ICH_Report_Failure & CCBS_ICH_Report_Success to CCBS_ICH_MSC_Report_Failure & CCBS_ICH_MSC_Report_Success, to distinguish them from the corresponding VLR procedures. Figure 58c: Move procedure call "CCBS_Check_Last_Call" from inlet to test "Aborted?" to outlets from test "Aborted?", to align with text description of handling for case where OR is not supported. Figure 65: set global variable to indicate TCH allocated after successful traffic channel allocation in procedure Establish_Terminating_TCH_If_Required. Subclause & figures 68a, 68b & 68c: rename procedure CCBS_ICH_Report_Failure to CCBS_ICH_VLR_Report_Failure, to distinguish it from the corresponding MSC procedure. Subclause : delete redundant parameter "Location information requested". Subclause : delete redundant parameters "Cell global identity" and "Age of location information" If other core Specifications are affected, necessary (and attached) Joint CRs: Affects (possibly): MS Test Specifications [ ] BSS Test Specifications [ ] O&M Specifications [ ] Attached CRs?: Cross Phase Compatibility: Change affects operation of: Phase 1 MS in Phase 2(+) NW [ ] Phase 2(+) MS in Phase 1 NW [ ] CR to attached: Change affects operation of: Phase 1 SIM in Phase 2(+) ME[ ] CR to attached: Phase 2(+) SIM in Phase 1 ME [ ] CR to attached: Other comments:

3 3 2 rmative references References may be made to: a) specific versions of publications (identified by date of publication, edition number, version number, etc.), in which case, subsequent revisions to the referenced document do not apply; or b) all versions up to and including the identified version (identified by "up to and including" before the version identity); or c) all versions subsequent to and including the identified version (identified by "onwards" following the version identity); or d) publications without mention of a specific version, in which case 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] ETS (1994): "Digital cellular telecommunications system (Phase 2); Principles of telecommunication services supported by a GSM Public Land Mobile Network (PLMN) (GSM 02.01)". [2] ETS (1994): " Digital cellular telecommunications system (Phase 2); Numbering, addressing & identification (GSM 03.03)". [3] ETS (1994): " Digital cellular telecommunications system (Phase 2); Security related network functions (GSM 03.20)". [4] GSM (TS ) "Digital cellular telecommunications system (Phase 2+);Description for the use of a Shared Inter Working Function /SIWF) in a GSM PLMN Stage 2 ". [5] GSM 03.60: "Digital cellular telecommunications system (Phase 2+); General Packet Radio Service; Service description; Stage 2". [6] TS (GSM 03.78): "Digital cellular telecommunications system (Phase 2+); Customized Applications for Mobile network Enhanced Logic (CAMEL) - Stage 2". [7] GSM 03.78: "Digital cellular telecommunications system (Phase 2+); Customized Applications for Mobile network Enhanced Logic (CAMEL) - Phase 2; Stage 2". [8] TS (GSM 03.79): "Digital cellular telecommunications system (Phase 2+); Support of Optimal Routeing (SOR); Technical Realization". [9] ETS (1994): " Digital cellular telecommunications system (Phase 2); Line identification supplementary services - Stage 2 (GSM 03.81)". [10] ETS (1994): "Digital cellular telecommunications system (Phase 2); Call Forwarding (CF) supplementary services - Stage 2 (GSM 03.82)". [11] ETS (1994): "Digital cellular telecommunications system (Phase 2); Call Waiting (CW) and Call Hold (HOLD) supplementary services - Stage 2 (GSM 03.83)". [12] ETS (1994): "Digital cellular telecommunications system (Phase 2); Multi Party (MPTY) supplementary services - Stage 2 (GSM 03.84)". [13] ETS (1994): "Digital cellular telecommunications system (Phase 2); Closed User Group (CUG) supplementary services - Stage 2 (GSM 03.85)". [14] ETS (1994): "Digital cellular telecommunications system (Phase 2); Advice of Charge (AoC) supplementary services - Stage 2 (GSM 03.86)". [15] ETS (1994): "Digital cellular telecommunications system (Phase 2); Call Barring (CB) supplementary services - Stage 2 (GSM 03.88)".

4 4 [16] GSM 03.93: "Digital cellular telecommunications system (Phase 2); Technical realization of Completion of Calls to Busy (CCBS) - Stage 2". [17] ETS (1995): "Digital cellular telecommunications system (Phase 2); Mobile radio interface layer 3 specification (GSM 04.08)". [18] ETS (1994): "Digital cellular telecommunications system (Phase 2); General on Terminal Adaptation Functions (TAF) for Mobile Stations (MS) (GSM 07.01)". [19] ETS (1995): "Digital cellular telecommunications system (Phase 2); Mobile-services Switching Centre - Base Station System (MSC - BSS) interface Layer 3 specification (GSM 08.08)". [20] ETS Fourth Edition (1997): "Digital cellular telecommunications system (Phase 2); Mobile Application Part (MAP) specification (GSM 09.02)". [21] ETS (1994): "Digital cellular telecommunications system (Phase 2); General requirements on interworking between the Public Land Mobile Network (PLMN) and the Integrated Services Digital Network (ISDN) or Public Switched Telephone Network (PSTN) (GSM 09.07)". [22] ETS (1995): "Digital cellular telecommunications system (Phase 2); Information element mapping between Mobile Station - Base Station System (MS - BSS) and Base Station System - Mobile-services Switching Centre (BSS - MSC) Signalling procedures and the Mobile Application Part (MAP) (GSM 09.10)". [23] ETS (1996): "Digital cellular telecommunications system (Phase 2); and equipment trace (GSM 12.08)". [24] ETS (1995): "Integrated Services Digital Network (ISDN); Signalling System. 7; ISDN User Part (ISUP) version 2 for the international interface; Part 1: Basic services". [25] ITU-T Recommendation Q.850 (1996): "Usage of cause and location in the Digital Signalling System. 1 and the Signalling System. 7 ISDN User Part". *** Next modified section *** Procedure OG_Call_Setup_MSC Sheet 1: the variables Alerting sent, MS connected and Reconnect are global data, accessible to the procedures CCBS_Check_OG_Call, CCBS_OCH_Report_Failure, CCBS_OCH_Report_Success, CCBS_Check_If_CCBS_Possible, Send_Alerting_If_Required and Send_Access_Connect_If_Required. Sheet 1: the VMSC converts the GSM bearer capability negotiated between the VMSC and the MS to a GSM basic service according to the rules defined in ETS [18]. Sheet 1, sheet 2, sheet 5: the procedure CCBS_OCH_Report_Failure is specific to CCBS; it is specified in GSM [16]. Sheet 1, sheet 5, sheet 6, sheet 8: at any stage after the Setup has been received, the MS may terminate the with the network by sending a request. Sheet 2: the procedure Set_CLI_Presentation_Indicator_MSC is specific to CLIR. If the VMSC does not support CLIR, processing continues from the "" exit of the test "Call allowed?". Sheet 2: the procedure CAMEL_OCH_MSC_INIT is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the VMSC does not support CAMEL, processing continues from the "" exit of the test "Pass?". Sheet 2: the procedure CCBS_Check_OG_Call is specific to CCBS; it is specified in GSM [16]. If the VMSC does not support CCBS, processing continues from the "" exit of the test "Pass?". Sheet 3: the procedure CCBS_OCH_Report_Success is specific to CCBS; it is specified in GSM [16].

5 5 Sheet 3, sheet 6: the procedures CAMEL_Start_TNRy and CAMEL_Stop_TNRy are specific to CAMEL phase 2; they are specified in GSM [7]TS [6]. Sheet 4: the procedure CAMEL_OCH_MSC_ANSWER is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the VMSC does not support CAMEL, processing continues from the "" exit of the test "Pass?". Sheet 4: the procedure Set_COLP_Info_MSC is specific to COLP. Sheet 4: the procedure Handle_AoC_MO_MSC is specific to AoC. Sheet 5: the procedures CCBS_Check_If_CCBS_Possible and CCBS_Activation_MSC are specific to CCBS; they are specified in GSM [16]. The task "Store CCBS Result" is executed only if the VMSC supports CCBS. If the VMSC does not support CCBS, processing continues from the "CCBS t Possible" exit of the test "CCBS Result". Sheet 5, sheet 6: the procedures CAMEL_OCH_MSC_DISC3 and CAMEL_OCH_MSC_DISC4 are specific to CAMEL; they are specified in TS [6] and GSM [7] respectively. Sheet 5, sheet 6: the procedure CAMEL_OCH_MSC1 is specific to CAMEL phase 2; it is specified in GSM [7]TS [6]. If the VMSC does not support CAMEL phase 2, processing continues from the "" exit of the test "Reconnect?" Sheet 5, sheet 6, sheet 8: the processing in the branch beginning with the Int Call input will occur only if the VMSC supports CAMEL. Sheet 7: the input signal TNRy expired and all the subsequent processing are specific to CAMEL phase 2, and will occur only if the VMSC supports CAMEL phase 2. The procedure CAMEL_OCH_MSC2 is specified in GSM [7]TS [6]. Sheet 8: the procedure CAMEL_OCH_MSC_DISC1 is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the VMSC does not support CAMEL, processing continues from the "" exit of the test "CAMEL handling?". Sheet 8: the procedure CAMEL_OCH_MSC_DISC2 is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the VMSC does not support CAMEL, processing continues from the "" exit of the test "CAMEL handling?". *** Next modified section *** Procedure Set_COLP_Info_MSC The MS may terminate the with the network by sending a message while a is awaited from the process COLP_MAF006. The message is saved for processing after return from the procedure Procedure Send_Access_Connect_If_Required The test "Acknowledgment required" refers to the result returned by the procedure Handle_AoC_MSC. If the VMSC does not support AoC, processing continues from the "" exit of the test "Acknowledgment required". If no useful information would be carried in the Facility message, it is not sent Procedure Handle_AoC_MO_MSC The charging parameters and the Boolean variable Acknowledgement required are global data which can be read by the parent process.

6 6 Procedure OG_Call_Setup_MSC OCS_MSC6(8) Procedure in the originating VMSC to set up an outgoing call after a Setup message has been received from the MS Connect_Ack Answer are to/from the BSS; signals to/from the right are to/from the destination exchange unless otherwise marked. From gsmssf Int Call CAMEL Phase 2 Supported? CAMEL Phase 2 Supported? cause= answer from user? 4 CAMEL_OCH_ MSC_DISC3 CAMEL_OCH_ MSC_DISC4 CAMEL_OCH_ MSC_DISC3 CAMEL_OCH_ MSC1 See GSM Reconnect? CAMEL_ Stop_TNRy 3

7 7 Procedure OG_Call_Setup_MSC OCS_MSC6(8) Procedure in the originating VMSC to set up an outgoing call after a Setup message has been received from the MS Connect_Ack Answer are to/from the BSS; signals to/from the right are to/from the destination exchange unless otherwise marked. From gsmssf Int Call CAMEL Phase 2 Supported? CAMEL Phase 2 Supported? cause= answer from user? 4 CAMEL_OCH_ MSC_DISC3 CAMEL_OCH_ MSC_DISC4 CAMEL_OCH_ MSC_DISC3 CAMEL_OCH_ MSC1 See GSM Reconnect? 3 Figure 8f: Procedure Outgoing_Call_Setup _MSC (sheet 6)

8 8 Procedure Establish_Originating_TCH_If_Required EOTCIR1(1) Procedure in the originating VMSC to establish a Traffic Channel if one has not been established for this call are to/from the BSS TCH allocated True False Allocate channel Pass Allocation_ Complete Allocation failure Allocation complete TCH allocated:= True Fail Pass

9 9 Procedure Establish_Originating_TCH_If_Required EOTCIR1(1) Procedure in the originating VMSC to establish a Traffic Channel if one has not been established for this call are to/from the BSS TCH established True False Allocate channel Pass Allocation_ Complete Allocation failure Allocation complete Fail Pass Figure 13: Procedure Establish_Originating_TCH_If_Required

10 10 Procedure Send_Access_Connect_If_Required Procedure to send a Connect message to the MS if one is required for this call SACONIR1(1) are to/from the BSS; signals to/from the right are to/from the destination exchange True MS connected False Facility Connect Acknowledgment required? Acknowledgment required? Start AoC acknowledgment timer Start AoC acknowledgment timer AoC_Ack_F AoC_Ack_C Charging Parameters ack AoC acknowledgment timer expired Charging Parameters ack Connect Ack AoC acknowledgment timer expired Facility sent Fail Connect sent Fail

11 11 Procedure Send_Access_Connect_If_Required Procedure to send a Connect message to the MS if one is required for this call SACONIR1(1) are to/from the BSS; signals to/from the right are to/from the destination exchange True MS connected False Facility Connect Acknowledgment required? Acknowledgment required? Start AoC acknowledgment timer Start AoC acknowledgment timer AoC_Ack_F AoC_Ack_C Charging Parameters ack AoC acknowledgment timer expired Charging Parameters ack Connect Ack AoC acknowledgment timer expired call resources call resources Facility sent Fail Connect sent Fail Figure 18: Procedure Send_Access_Connect_If_Required

12 12 *** Next modified section *** Procedure OG_Call_Subscription_Check_VLR Sheet 1: it is an implementation option to carry out the check for operator determined barring of all outgoing calls before the check on provisioning of the requested basic service. Sheet 1: the procedure OG_CUG_Check is specific to CUG. If the VLR does not support CUG, processing continues from the "" exit of the test "Call allowed?". Sheet 1: the procedure Get_LI_Subscription_Info_MO_VLR is specific to CLIR and COLP. If the VLR supports neither CLIR nor COLP, the procedure call is omitted. Sheet 1: the procedure Get_AoC_Subscription_Info_VLR is specific to AoC. Sheet 1: the procedure CAMEL_OCH_VLR is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the VLR does not support CAMEL, processing continues from connector 1 to the call to the procedure Check_OG_Barring. Sheet 2: the negative "call barred" indicates whether the reason is operator determined barring or supplementary service barring, according to the result returned by the procedure Check_OG_Barring. *** Next modified section *** Process MT_GMSC Sheet 1: the variables ACM sent, Answer sent, Network connect sent, Reconnect and Resume call are global data, accessible to the procedures CCBS_MT_GMSC_Check_CCBS Possible, CCBS_Set_Diagnostic_For_, Obtain_Routeing_Address, Send_ACM_If_Required, Send_Answer_If_Required and Send_Network_Connect_If_Required. Sheet 1: the procedure OR_Set_ORA_Parameters is specific to Support of Optimal Routeing; it is specified in TS [8]. Sheet 1: the procedure CAMEL_Set_ORA_Parameters is specific to CAMEL; it is specified in TS [6] and GSM [7]. Sheet 1: the parameters "Reference address", "OR" and "Own PLMN" are passed to the procedure Obtain_Routeing_Address only if the GMSC supports Optimal Routeing. The parameter "Destination address" is returned by the procedure Obtain_Routeing_Address only if the GMSC supports Optimal Routeing. The Send Routeing Info negative information element received in the execution of the procedure Obtain_Routeing_Address is global data, available to the parent process. Sheet 1: the suggested mapping from values of the Send Routeing Info negative information element to values of the ISUP release cause (see ITU-T Recommendation Q.850 [25]) is shown in table 1. The mapping used is a matter for the network operator, depending on the telephony signalling system used.

13 13 Table 1: Suggested mapping of Send Routeing Info (SRI) negative s to ISUP release causes SRI negative ISUP release cause number ISUP release cause name Absent subscriber 20 absent Bearer service not provisioned 57 Bearer capability not authorised Call barred (ODB) 21 Call rejected Call barred (SS barring) 21 Call rejected CUG reject (Called party SS 21 Call rejected interaction violation) CUG reject (Incoming calls 55 Incoming calls barred within CUG barred within CUG) CUG reject ( not 87 User not member of CUG member of CUG) CUG reject (Requested basic 87 User not member of CUG service violates CUG constraints) Data missing 111 Protocol error, unspecified Facility not supported 69 Requested facility not implemented Forwarding violation 21 Call rejected Number changed 22 Number changed System failure 111 Protocol error, unspecified Teleservice not provisioned 57 Bearer capability not authorised Unexpected data value 111 Protocol error, unspecified Unknown subscriber 1 Unallocated (unassigned) number Sheet 1: the called party address sent in the IAM to the process MT_CF_MSC is the Forwarded-to number received in the Perform Call Forwarding ack. Sheet 1: it is an operator option whether to send an Address Complete message if the HLR returns forwarding information. Sheet 2: the procedures CAMEL_Start_TNRy and CAMEL_Stop_TNRy are specific to CAMEL phase 2; they are specified in GSM [7]TS [6]. Sheet 2, sheet 3: the procedure CAMEL_MT_GMSC_ANSWER is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the GMSC does not support CAMEL, processing continues from the "Pass" exit of the test "Result". Sheet 2, sheet 3: the task "Set destination address parameter" is executed only if the GMSC supports Optimal Routeing. Sheet 3: the procedure Handle_COLP_Forwarding_Interaction is specific to COLP. Sheet 4: the input signal Resume Call Handling and all the subsequent processing on this sheet are specific to Support of Optimal Routeing, and will occur only if the GMSC supports Optimal Routeing. The procedure OR_Handle_RCH is specified in TS [8]. Sheet 4, sheet 6: the procedure CCBS_MT_GMSC_Check_CCBS_Possible is specific to CCBS; it is specified in GSM [16]. Sheet 5: the input signal TNRy expired and all the subsequent processing are specific to CAMEL phase 2, and will occur only if the GMSC supports CAMEL phase 2. The procedure CAMEL_MT_GMSC_DISC5 is specified in GSM [7]TS [6]. Sheet 6: the procedures CAMEL_MT_GMSC_DISC3, CAMEL_MT_GMSC_DISC4 and CAMEL_MT_GMSC_DISC6 are specific to CAMEL; they are specified in TS [6] (CAMEL_MT_GMSC_DISC3) and GSM [7] (CAMEL_MT_GMSC_DISC4 and CAMEL_MT_GMSC_DISC6). Sheet 6: the procedure CCBS_Set_Diagnostic_For_ is specific to CCBS; it is specified in GSM [16]. Sheet 5: the procedures CAMEL_MT_GMSC_DISC1 and CAMEL_MT_GMSC_DISC2 are specific to CAMEL; they are specified in TS [6] and GSM [7]. If the GMSC does not support CAMEL, processing continues from the "" exit of the test "CAMEL handling?".

14 14 Sheet 6: the processing in the branch beginning with the Int Call input will occur only if the MSC supports CAMEL. Sheet 7: the procedure CAMEL_MT_GMSC_DISC1 is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the GMSC does not support CAMEL, processing continues from the "" exit of the test "CAMEL handling?". Sheet 7: the procedure CAMEL_MT_GMSC_DISC2 is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the GMSC does not support CAMEL, processing continues from the "rmal handling" exit of the test "Result?". Sheet 7: in the upper subtree, the processing in the branch beginning with the Int Call input will occur only if the GMSC supports CAMEL. Sheet 7: after the GMSC has sent an IAM to the destination VMSC or the forwarded-to exchange (via the process MT_CF_MSC), it acts as a relay for messages received from the originating exchange and the destination VMSC or the process MT_CF_MSC. Any message other than Address Complete, Connect, Answer or causes no change of state in the process MT_GMSC Procedure Obtain_Routeing_Address Sheet 1: the procedures CCBS_MT_GMSC_Check_CCBS_Call and CCBS_MT_GMSC_Check_CCBS_Indicators are specific to CCBS; they are specified in GSM [16]. Sheet 1: The procedure OR_Handle_SRI_Negative_Response is specific to Support of Optimal Routeing. It is specified in TS [8]. If the GMSC does not support Optimal Routeing, processing continues from the "" exit of the test "Pass?". Sheet 1: the procedure CAMEL_MT_GMSC_INIT is specific to CAMEL; it is specified in TS [6] and GSM [7]. Sheet 2: the task "Store Forwarding Interrogation Required indicator" is executed only if the GMSC supports Optimal Routeing. Sheet 1: the task "Destination address:=vmsc address" is executed only if the GMSC supports Optimal Routeing. Sheet 2: the procedures CCBS_MT_GMSC_Remove_Indicators and CCBS_MT_GMSC_Remove_Indicators_Store_FWT are specific to CCBS; they are specified in GSM [16]. Sheet 2: the procedure Route_Permitted is specific to Support of Optimal Routeing. It is specified in TS [8]. If the GMSC does not support Optimal Routeing, processing continues from the "True" exit of the test "Route permitted". Sheet 2: the tasks "Destination address:=ftn" and "OR:=True" are executed only if the GMSC supports Optimal Routeing. Sheet 2: the procedures CAMEL_MT_MSC_DISC3 and CAMEL_MT_MSC_DISC4 areis specific to CAMEL; they areit is specified in TS [6] and GSM [7]. Sheet 2: if the GMSC does not support CAMEL and the Send Routeing Info ack contains neither an MSRN nor an FTN, processing continues from the "" exit of the test "CMN?". Sheet 2: the tasks "Destination address:=cmn" and "OR:=True" are executed only if the GMSC supports Optimal Routeing. The processing in the branch beginning with the Int Call input will occur only if the MSC supports CAMEL. *** Next modified section *** Process MT_CF_MSC Sheet 1: the procedure CAMEL_CF_MSC_INIT is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the MSC does not support CAMEL, processing continues from the "" exit of the test "Pass?".

15 15 Sheet 1: the procedures CAMEL_OCH_MSC_DISC3 and CAMEL_OCH_MSC_DISC4 isare specific to CAMEL; they areit is specified in TS [6] and GSM [7]. Sheet 2: the procedures CAMEL_Start_TNRy and CAMEL_Stop TNRy are specific to CAMEL phase 2; they are specified in GSM [7]TS [6]. Sheet 2: the procedure CAMEL_CF_MSC_ANSWER is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the MSC does not support CAMEL, processing continues from the "" exit of the test "Pass?". Sheet 3: the procedures CAMEL_OCH_MSC_DISC3 and CAMEL_OCH_MSC_DISC4 are specific to CAMEL; they are specified in TS [6] and GSM [7] respectively. Sheet 3: the procedure CAMEL_OCH_MSC1 is specific to CAMEL phase 2; it is specified in GSM [7]TS [6]. Sheet 3: the procedure CAMEL_Stop TNRy is specific to CAMEL phase 2; it is specified in GSM [7]TS [6]. Sheet 3: the processing in the branch beginning with the Int_O_ input will occur only if the MSC supports CAMEL. Sheet 4: the input signal TNRy expired and all the subsequent processing are specific to Support of CAMEL phase 2, and will occur only if the GMSC supports CAMEL phase 2. The procedure CAMEL_OCH_MSC2 is specified in GSM [7]TS [6]. Sheet 5: the procedure CAMEL_OCH_MSC_DISC1 is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the MSC does not support CAMEL, processing continues from the "" exit of the test "CAMEL handling?". Sheet 5: the procedure CAMEL_OCH_MSC_DISC2 is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the MSC does not support CAMEL, processing continues from the "" exit of the test "Reconnect?". Sheet 5: the processing in the branch beginning with the Int_O_ input will occur only if the MSC supports CAMEL. Sheet 5: after the process MT_CF_MSC has sent an IAM to the forwarded-to exchange, it acts as a relay for messages received from the parent process and the forwarded-to exchange. Any message other than Address Complete, Connect, Answer or causes no change of state in the process MT_GMSC

16 16 Procedure Obtain_Routeing_Address ORA2(2) Procedure in a GMSC to determine the address to which a call should be routed 1 FTN? Activate_ CF_Process Aborted? Fail? CMN? CCBS_MT_ GMSC_Remove_ Indicators_ Store_FWT Aborted Fail CCBS_MT_ GMSC_Remove_ Indicators Aborted Route_Permitted (OR,FTN, Reference Address) See GSM Route_Permitted (OR,FTN, Reference Address) See GSM Route permitted True False Route permitted True False CAMEL phase 2 supported? CAMEL phase 2 supported? See GSM CAMEL_MT_ GMSC_DISC3 CAMEL_MT_ GMSC_DISC4 CAMEL_MT_ GMSC_DISC3 CAMEL_MT_ GMSC_DISC4 To process MT_CF_MSC CF cancelled Routeing address:= FTN Routeing address:= Reference address Routeing address:= CMN Routeing address:= Reference address Destination address:= FTN Destination address:= Reference address Destination address:= CMN Destination address:= Reference address OR:=True OR:=False OR:=True OR:=False Forward Pass Pass Pass

17 17 Procedure Obtain_Routeing_Address ORA2(2) Procedure in a GMSC to determine the address to which a call should be routed 1 FTN? Activate_ CF_Process Aborted? Fail? CMN? CCBS_MT_ GMSC_Remove_ Indicators_ Store_FWT Aborted Fail CCBS_MT_ GMSC_Remove_ Indicators Aborted Route_Permitted (OR,FTN, Reference Address) See GSM Route_Permitted (OR,FTN, Reference Address) Route permitted False Route permitted False True True See GSM CAMEL_MT_ GMSC_DISC3 See GSM CAMEL_MT_ GMSC_DISC3 To process MT_CF_MSC CF cancelled Routeing address:= FTN Routeing address:= Reference address Routeing address:= CMN Routeing address:= Reference address Destination address:= FTN Destination address:= Reference address Destination address:= CMN Destination address:= Reference address OR:=True OR:=False OR:=True OR:=False Forward Pass Pass Pass Figure 36b: Procedure Obtain_Routeing_Address (sheet 2)

18 18 Process MT_CF_MSC Process in the MSC to handle call forwarding MTCFMSC1(5) are to/from the parent process; signals to/from the right are to/from the destination exchange Perform call forwarding CAMEL_CF_ MSC_INIT See GSM Pass? Perform call forwarding ack(ftn) Perform Call Forwarding negative IAM 1 Initial Address CF cancelled CAMEL phase 2 supported? Initial Address CAMEL_OCH_ MSC_DISC3 See GSM CAMEL_OCH_ MSC_DISC4 See GSM ACM

19 19 Process MT_CF_MSC Process in the MSC to handle call forwarding MTCFMSC1(5) are to/from the parent process; signals to/from the right are to/from the destination exchange Perform call forwarding CAMEL_CF_ MSC_INIT See GSM Pass? Perform call forwarding ack(ftn) Perform Call Forwarding negative IAM 1 Initial Address CF cancelled Initial Address CAMEL_OCH_ MSC_DISC3 See GSM ACM Figure 42a: Process MT_CF_MSC (sheet 1)

20 20 *** Next modified section *** Process SRI_HLR Sheet 1: the procedures Check_Parameters and Subscription_Check_HLR can set the negative parameter which is used by the process SRI_HLR to construct the Send Routeing Info negative message. This negative parameter is global data, accessible by the process SRI_HLR. Sheet 1: the procedure Handle_OR_HLR_CF is specific to Support of Optimal Routeing; it is specified in TS [8]. If the HLR does not support Optimal Routeing, processing continues from the "" exit of the test "Forward?". Sheet 1: the procedure CAMEL_HLR_INIT is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the HLR does not support CAMEL, processing continues from the "" exit of the test"fail?". Sheet 2: the procedure First_Forwarding_HLR can set the negative parameter which is used by the process SRI_HLR to construct the Send Routeing Info negative message. This negative parameter is global data, accessible by the process SRI_HLR. Sheet 2: the procedure CAMEL_CSI_Check_HLR is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the HLR does not support CAMEL, processing continues from the "" exit of the test"csi active?". Sheet 2: the procedure CCBS_Handling_HLR is specific to CCBS; it is specified in GSM [16]. If the HLR does not support CCBS, processing continues from the "" exit of the test "Result = OK?". Sheet 3: the procedure OR_HLR_Interrogate_VLR is specific to Optimal Routeing. It is specified in TS [8]. If the HLR does not support Optimal Routeing, processing continues from the "" exit of the test "Forward". Sheet 3: if the HLR does not support Network Indication of Alerting, the test "Alerting pattern required" and the task "Set Alerting Pattern" are omitted. Sheet 4: the procedure PRN_Error_HLR can set the negative parameter which is used by the process SRI_HLR to construct the Send Routeing Info negative message. This negative parameter is global data, accessible by the process SRI_HLR. Sheet 4: the procedure Forward_CUG_Check is specific to CUG. If the HLR does not support CUG, processing continues from the "" exit of the test "Call allowed?". Sheet 4: the test "Forwarding enquiry" is specific to Support of Optimal Routeing. If the HLR does not support Optimal Routeing, processing continues from the "" exit of the test. Sheet 4: the procedure CAMEL_CSI_Check_HLR is specific to CAMEL; it is specified in TS [6] and GSM [7]. If the HLR does not support CAMEL, processing continues from the "" exit of the test "CSI active?". Sheet 4: the procedures CAMEL_T_CSI_CHECK_HLR and CAMEL_O_CSI_CHECK_HLR are specific to CAMEL; they are specified in TS [6] and GSM [7]. *** Next modified section *** Process PRN_VLR Sheet 1: the procedure Check_Parameters is specified in subclause Error! Reference source not found.. Sheet 1, sheet 3: the procedure CAMEL_SET_SOA is specific to CAMEL; it is specified in TS [6] and GSM [7]. Sheet 2, sheet 3: the task "Store alerting pattern (if received)" is executed only if the VLR supports the feature Network Indication of Alerting.

21 21 Sheet 2, sheet 3: the procedure CCBS_Handle_PRN is specific to CCBS; it is specified in GSM [16]. Sheet 2: the number of unused authentication sets which triggers the VLR to request further authentication sets from the HLR is an operator option. Sheet 2: the process Fetch_Authentication_Sets_VLR is specified in subclause Error! Reference source not found.. *** Next modified section *** Process PSI_VLR Sheet 1: the procedure Check_Parameters is specified in subclause If the HLR requests neither location information nor subscriber state, the VLR treats this as a missing parameter. Sheet 1, sheet 2: the task "Set Location Info" encompasses: - Insertion of the stored cell ID; - Derivation of the location number and geographical information from the cell ID or location area ID if the VLR is capable of doing so (the mapping from cell ID and location area to location number is network-specific and outside the scope of the GSM standard); - Insertion of the age of the location information. received from the MSC; - Insertion of the VLR number.

22 22 Process PSI_VLR Process in the VLR to handle a request from the HLR for subscriber information PSI_VLR1(2) are to/from the HLR; signals to/from the right are to/from the MSC Provide Info Check_ Parameters Pass? IMSI known in VLR? state requested? state requested? IMSI detached? Roaming in LA allowed? Set subscriber state requested state:= Network determined not reachable state:= Assumed idle Location info requested? Set location info Obtain Info Provide Info ack Provide Info negative MSC_Response

23 23 Process PSI_VLR Process in the VLR to handle a request from the HLR for subscriber information PSI_VLR1(2) are to/from the HLR; signals to/from the right are to/from the MSC Provide Info Check_ Parameters Pass? IMSI known in VLR? state requested? state requested? IMSI detached? Roaming in LA allowed? Set subscriber state requested atate:= Network determined not reachable state:= Assumed idle Location info requested? Location info requested? Set location info requested Obtain Info Provide Info ack Provide Info negative MSC_Response Figure 56a: Process PSI_VLR (sheet 1)

24 24 Process PSI_VLR Process in the VLR to handle a request from the HLR for subscriber information MSC_Response are to/from the HLR; signals to/from the right are to/from the MSC PSI_VLR2(2) Obtain Info ack state received? Set subscriber state Location info requested? Set location info Provide Info ack

25 25 Process PSI_VLR Process in the VLR to handle a request from the HLR for subscriber information MSC_Response are to/from the HLR; signals to/from the right are to/from the MSC PSI_VLR2(2) Obtain Info ack Location info received? Set location info state received? Set subscriber state Provide Info ack Figure 56b: Process PSI_VLR (sheet 2) *** Next modified section *** Process OSI_MSC If the MS is engaged on a circuit-switched call, the state is busy, otherwise assumed idle.

26 26 Process OSI_MSC OSI_MSC1(1) Process in the MSC to handle a request from the VLR for information on the subscriber's location and state are to/from the VLR Obtain Info state requested? Set subscriber state Obtain Info ack

27 27 Process OSI_MSC OSI_MSC1(1) Process in the MSC to handle a request from the VLR for information on the subscriber's location and state are to/from the VLR Obtain Info Location info requested? Set age of location info MS in radio contact? Set cell global identity state requested? Set subscriber state Obtain Info ack Figure 57: Process OSI_MSC *** Next modified section *** Procedure Complete_Call_In_MSC Sheet 1: the procedure Set_CLIP_Info_MSC is specific to CLIP.

28 28 Sheet 1: the VMSC and the MS may negotiate the bearer capability to be used for the call by the exchange of information in the Setup and Call Confirmed messages. Sheet 1: the procedure CCBS_Report_t_ is specific to CCBS; it is specified in GSM [16]. Sheet 1, sheet 2, sheet 4: the procedure CCBS_ICH_MSC_Report_Failure is specific to CCBS; it is specified in GSM [16]. Sheet 2: the procedure CCBS_ICH_MSC_Report_Success is specific to CCBS; it is specified in GSM [16]. Sheet 2: the procedure Send_ACM_If_Required is specified in subclause Sheet 2, sheet 3: the procedure Handle_AoC_MT_MSC is specific to AoC. If the VMSC does not support AoC, processing continues from the "" exit of the test "Pass?". Sheet 2, sheet 3: the procedure Set_COL_Presentation_Indicator_MSC is specific to COLP. Sheet 2: the procedure Send_Network_Connect_If_Required is specified in subclause Sheet 3: the procedure Send_Answer_If_Required is specified in subclause Procedure Process_Call_Waiting_MSC Sheet 1: the procedure Set_CLIP_Info_MSC is specific to CLIP. Sheet 1: the VMSC and the MS may negotiate the bearer capability to be used for the call by the exchange of information in the Setup and Call Confirmed messages. Sheet 1: the procedure CCBS_Report_t_ is specific to CCBS; it is specified in GSM [16]. Sheet 1: the procedure CCBS_ICH_MSC_Report_Success is specific to CCBS; it is specified in GSM [16]. Sheet 1, sheet 3: the procedure CCBS_ICH_MSC_Report_Failure is specific to CCBS; it is specified in GSM [16]. Sheet 1: the Call Confirmed message indicates "busy" for the successful case. Sheet 1: the procedure Send_ACM_If_Required is specified in subclause Sheet 1, sheet 2: the (reject) message covers all unsuccessful cases not otherwise indicated. Sheet 2: the procedure Handle_AoC_MT_MSC is specific to AoC. If the VMSC does not support AoC, processing continues from the "" exit of the test "Pass?". Sheet 2: the procedure Set_COL_Presentation_Indicator_MSC is specific to COLP. Sheet 2: the procedure Send_Answer_If_Required is specified in subclause

29 29 Process ICH_MSC Process in the MSC to handle an incoming (MT) call MT_Call_ Result are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise ICH_MSC3(6) 1 Send Info For Incoming Call ack Call is to be forwarded Handle_ ORLCF_VMSC See GSM Clear? Aborted? CCBS_Check_ Last_Call CCBS_Check_ Last_Call Set redirection information Clear Send_ACM_ If_Required Activate_ CF_Process Fail? Initial Address Message To process MT_CF_MSC Forward_ACM

30 30 Process ICH_MSC Process in the MSC to handle an incoming (MT) call MT_Call_ Result are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise ICH_MSC3(6) 1 Send Info For Incoming Call ack Call is to be forwarded Handle_ ORLCF_VMSC See GSM Clear? CCBS_Check_ Last_Call Aborted? Set redirection information Clear Send_ACM_ If_Required Activate_ CF_Process Fail? Initial Address Message To process MT_CF_MSC Forward_ACM Figure 58c: Process ICH_MSC (sheet 3)

31 31 Procedure Complete_Call_In_MSC CCI_MSC1(5) Procedure in the MSC to complete an MT call on request from the VLR Set_CLIP_ Info_MSC are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise Derive_ GSM_BC_ MSC Setup CCBS_Report_ t_ Setup_ Response Call Confirmed Setup failure Establish_ Terminating_ TCH_If_ Required Fail? Set negative : Radio congestion Set negative : Absent Aborted Abort Complete Call negative CCBS_ICH_MSC_ Report_Failure Aborted Fail Alerting

32 32 Procedure Complete_Call_In_MSC CCI_MSC1(5) Procedure in the MSC to complete an MT call on request from the VLR Set_CLIP_ Info_MSC are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise Derive_ GSM_BC_ MSC Setup CCBS_Report_ t_ Setup_ Response Call Confirmed Setup failure Establish_ Terminating_ TCH_If_ Required Fail? Set negative : Radio congestion Set negative : Absent Aborted Abort Complete Call negative CCBS_ICH_ Report_Failure Aborted Fail Alerting Figure 61a: Procedure Complete_Call_In_MSC (sheet 1)

33 33 Procedure Complete_Call_In_MSC Procedure in the MSC to complete an MT call on request from the VLR Alerting are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise CCI_MSC2(5) Alerting Connect Alerting failure CCBS_ICH_MSC_ Report_Success CCBS_ICH_MSC_ Report_Success CCBS_ICH_MSC_ Report_Failure NRCT provided? Handle_AoC_ MT_MSC Abort Start Reply Call Timer Pass? To GMSC Send_ACM_ If_Required To GMSC Connect ack Aborted Wait_for_ Answer Set_COL_ Presentation_ Indicator_MSC To GMSC Send_Network_ Connect_If_ Required To GMSC Complete Call ack Abort Pass Aborted

34 34 Procedure Complete_Call_In_MSC Procedure in the MSC to complete an MT call on request from the VLR Alerting are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise CCI_MSC2(5) Alerting Connect Alerting failure CCBS_ICH_ Report_Success CCBS_ICH_ Report_Success CCBS_ICH_ Report_Failure NRCT provided? Handle_AoC_ MT_MSC Abort Start Reply Call Timer Pass? To GMSC Send_ACM_ If_Required To GMSC Connect ack Aborted Wait_for_ Answer Set_COL_ Presentation_ Indicator_MSC To GMSC Send_Network_ Connect_If_ Required To GMSC Complete Call ack Abort Pass Aborted Figure 61b: Procedure Complete_Call_In_MSC (sheet 2)

35 35 Procedure Complete_Call_In_MSC CCI_MSC4(5) Procedure in the MSC to complete an MT call on request from the VLR Setup_Response, Alerting are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise From GMSC CCBS_ICH_MSC_ Report_Failure CCBS_ICH_MSC_ Report_Failure User busy? Set negative : Busy subscriber (UDUB) To GMSC Complete Call negative Abort Fail Aborted

36 36 Procedure Complete_Call_In_MSC CCI_MSC4(5) Procedure in the MSC to complete an MT call on request from the VLR Setup_Response, Alerting are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise From GMSC CCBS_ICH_ Report_Failure CCBS_ICH_ Report_Failure User busy? Set negative : Busy subscriber (UDUB) To GMSC Complete Call negative Abort Fail Aborted Figure 61d: Procedure Complete_Call_In_MSC (sheet 4)

37 37 Procedure Process_Call_Waiting_MSC PCW_MSC1(3) Procedure in the MSC to handle a Process Call Waiting request from the VLR Call being set up are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise Set_CLIP_ Info_MSC Derive_ GSM_BC_ MSC Set negative : Busy subscriber(ndub) Process Call Waiting negative Setup Fail CCBS_Report_ t_ Setup_ Response Call Confirmed Setup failure (reject) (UDUB) Alerting Clear pending call Set negative : Busy subscriber(udub) Alerting Alerting failure Process Call Waiting negative CCBS_ICH_MSC_ Report_Success CCBS_ICH_MSC_ Report_Failure NRCT provided? To GMSC of waiting call Start Reply Call Timer Start Acceptance timer Abort CCBS_ICH_MSC_ Report_Failure Send_ACM_ If_Required To GMSC of waiting call Aborted Fail Acceptance

38 38 Procedure Process_Call_Waiting_MSC PCW_MSC1(3) Procedure in the MSC to handle a Process Call Waiting request from the VLR Call being set up are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise Set_CLIP_ Info_MSC Derive_ GSM_BC_ MSC Set negative : Busy subscriber(ndub) Process Call Waiting negative Setup Fail CCBS_Report_ t_ Setup_ Response Call Confirmed Setup failure (reject) (UDUB) Alerting Clear pending call Set negative : Busy subscriber(udub) Alerting Alerting failure Process Call Waiting negative CCBS_ICH_ Report_Success CCBS_ICH_ Report_Failure NRCT provided? To GMSC of waiting call Start Reply Call Timer Start Acceptance timer Abort CCBS_ICH_ Report_Failure Send_ACM_ If_Required To GMSC of waiting call Aborted Fail Acceptance Figure 62a: Procedure Process_Call_Waiting_MSC (sheet 1)

39 39 Procedure Process_Call_Waiting_MSC PCW_MSC3(3) Procedure in the MSC to handle a Process Call Waiting request from the VLR Wait_for_ Acceptance are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise (busy) (reject) Acceptance timer expired Reply Call Timer expired For waiting call Set negative : subscriber reply Set negative : Busy subscriber(udub) To GMSC of waiting call Process Call Waiting negative Process Call Waiting negative Abort For waiting call Fail Aborted Fail Acceptance Setup_Response, Alerting From GMSC of waiting call From GMSC of waiting call CCBS_ICH_MSC_ Report_Failure For waiting call For waiting call Abort Abort call resources For waiting call call resources For waiting call Aborted Aborted

40 40 Procedure Process_Call_Waiting_MSC PCW_MSC3(3) Procedure in the MSC to handle a Process Call Waiting request from the VLR Wait_for_ Acceptance are to/from the BSS; signals to/from the right are to/from the VLR unless marked otherwise (busy) (reject) Acceptance timer expired Reply Call Timer expired For waiting call Set negative : subscriber reply Set negative : Busy subscriber(udub) To GMSC of waiting call Process Call Waiting negative Process Call Waiting negative Abort For waiting call Fail Aborted Fail Acceptance Setup_Response, Alerting From GMSC of waiting call From GMSC of waiting call CCBS_ICH_ Report_Failure For waiting call For waiting call Abort Abort call resources For waiting call call resources For waiting call Aborted Aborted Figure 62c: Procedure Process_Call_Waiting_MSC(sheet 3)

41 41 Procedure Establish_Terminating_TCH_If_Required Procedure in the terminating VMSC to establish a Traffic Channel if one has not been established for this call are to/from the BSS; signals to/from the right are to/from the GMSC ETTCIR1(1) TCH allocated True False Allocate channel Pass Allocation_ Complete Allocation failure Allocation complete TCH allocated:= True Fail Pass Aborted

42 42 Procedure Establish_Terminating_TCH_If_Required Procedure in the terminating VMSC to establish a Traffic Channel if one has not been established for this call are to/from the BSS; signals to/from the right are to/from the GMSC ETTCIR1(1) TCH established True False Allocate channel Pass Allocation_ Complete Allocation failure Allocation complete Fail Pass Aborted Figure 65: Procedure Establish_Terminating_TCH_If_Required

43 43 *** Next modified section *** Process ICH_VLR Sheet 1: if the MSRN received in the Send Info For Incoming Call is not allocated or there is no IMSI record for the IMSI identified by the MSRN, this is treated as an unknown MSRN. Sheet 1: the procedure CCBS_ICH_Set_CCBS_Call_Indicator is specific to CCBS; it is specified in GSM [16]. Sheet 1: the test "Paging via SGSN possible" takes the "yes" exit if: - the Gs interface is implemented; and - there is an association established for the MS between the MSC/VLR and the SGSN. Sheet 1, sheet 2, sheet 3: the procedure CCBS_ICH_VLR_Report_Failure is specific to CCBS; it is specified in GSM [16]. Sheet 1, sheet 2: the procedure CCBS_ICH_Report_t_Reachable is specific to CCBS; it is specified in GSM [16]. Sheet 2: the test "NDUB?" takes the "" exit if the Page MS negative or the Search for MS negative had the value Busy (NDUB). Sheet 2: the procedure Get_CW_Subscription_Info_VLR is specific to Call Waiting. If the VLR does not support Call Waiting, processing continues from the "" exit of the test "CW available?". Sheet 2: the VLR uses the basic service returned in the Page MS negative or the Search for MS negative Busy (More calls possible) to determine whether call waiting is available. Sheet 2: the procedure Get_LI_Subscription_Info_MT_VLR is specific to CLIP and COLR. If the VLR supports neither CLIP nor COLR, the procedure call is omitted. Sheet 2: the procedure Get_AoC_Subscription_Info_VLR is specific to AoC; it is specified in subclause Sheet 2: the procedure CCBS_ICH_Handle_NDUB is specific to CCBS; it is specified in GSM [16]. If the VLR does not support CCBS, processing continues from the "Forward" exit of the test "Result". Sheet 2: the procedure Process_Access_Request_VLR is specified in subclause Sheet 2: the output signal Page MS towards the SGSN includes the Location area identity parameter. Sheet 2: if the VLR does not support CUG, handling continues from the "" exit of the test "CUG info present?". Sheet 3, sheet 4: the procedure CCBS_ICH_Handle_UDUB is specific to CCBS; it is specified in GSM [16]. Sheet 4: the test "NDUB?" is executed only if the VLR supports CCBS. If the VLR does not support CCBS, processing continues from connector 5. Sheet 5: the procedure CCBS_ICH_Set_CCBS_Target is specific to CCBS; it is specified in GSM [16]. Sheet 5: the procedure Handle_CFNRc is specified in subclause Sheet 6: the procedure Forward_CUG_Check is specific to CUG; it is specified in subclause If the VLR does not support CUG, processing continues from the "" exit of the test "Call allowed?".

44 44 Process ICH_VLR ICH_VLR1(6) Process in VLRB to handle a request for information for an incoming (MT) call are to/from the MSC. Send Info For Incoming Call MSRN known? CCBS_ICH_ Set_CCBS_ Call_Indicator Data confirmed by HLR True False Derive_Requested_ Basic_Service_VLR Set negative : System Failure Set negative : Unallocated Roaming Number IMSI detached? CCBS_ICH_VLR_ Report_Failure Location area ID known? Roaming in LA allowed? Paging via SGSN possible? Set Paging via SGSN possible Search_For_ MS_VLR Page type= circuit-switched call Page MS Pass? Fail? CCBS_ICH_ Report_t_ Reachable Send Info For Incoming Call negative CCBS_ICH_VLR_ Report_Failure 2 Access_ Request 1

45 45 Process ICH_VLR ICH_VLR1(6) Process in VLRB to handle a request for information for an incoming (MT) call are to/from the MSC. Send Info For Incoming Call MSRN known? CCBS_ICH_ Set_CCBS_ Call_Indicator Data confirmed by HLR True False Derive_Requested_ Basic_Service_VLR Set negative : System Failure Set negative : Unallocated Roaming Number IMSI detached? CCBS_ICH_ Report_Failure Roaming in LA allowed? Location area ID known? Paging via SGSN possible? Set Paging via SGSN possible Search_For_ MS_VLR Page type= circuit-switched call Page MS Pass? Fail? CCBS_ICH_ Report_t_ Reachable Send Info For Incoming Call negative CCBS_ICH_ Report_Failure 2 Access_ Request 1 Figure 68a: Process ICH_VLR (sheet 1)