5 Handling of completion of calls to busy subscriber

23.0933GPPRelease 17Stage 2Technical realization of Completion of Calls to Busy Subscriber (CCBS)TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

Registration and erasure of CCBS are not applicable. Activation and Invocation of CCBS are intrinsic parts of the operation of the service, and are described in this section.

5.1 CCBS Timers

The timers used to control the operation of CCBS can be considered to consist of two groups i.e. the timers which operate on a per subscriber basis (see table 1) and the service duration timers (T3 and T7) which operate on a per CCBS Request basis (see table 2).

Table 1: CCBS Service Timers

Timer	Name	Value	Run At	Started	Stopped	Expiry
T1	Retention	>15s	MSC A	Busy (CCBS Possible) sent to MS A	CCBS Request received from MS A	Discard retained information
T4	Recall	20-30s	MSC A	CCBS Recall sent to MS A and MS A is idle	Subscriber A initiates CCBS setup or rejects CCBS Recall	Cancel request
T8	Destination idle guard	0-15s	HLR B	Event Report received from VLR B indicating destination B is idle	Event Report received from VLR B indicating destination B is no longer idle	Inform originating network that Destination B is free
T9	Recall B	40-55s	HLR B	Remote User Free sent to the A-side	Request cancelled, completed or suspended	Cancel request
T10	CCBS notification	20-30s	MSC A	CCBS Recall sent to MS A and MS A is not idle	Subscriber A initiates CCBS setup, rejects CCBS Recall or requests suspension	Suspend request
T11	CCBS resume	20-25s	HLR A	HLR A receives a resume request and there are more than one suspended request in subscriber A’s queue	Remote User Free received from destination network	Resume next suspended request in queue
T12	CCBS Call Guard	20-30s	HLRA	HLRA receives a CCBS RUF Ack and starts to wait CCBS Call Report	CCBS Call Report received	Cancel request

Table 2: Service Duration Timers

Timer	Name	Value	Run At	Started	Stopped	Expiry
T3	Originating service duration	15-45m	HLR A	Acknowledgement to CCBS Request received from destination network	Request cancelled or completed	Cancel request
T7	Terminating service duration	>45m	HLR B	HLR B acknowledges successful activation of a CCBS Request	Request cancelled or completed	Cancel request

5.2 Information flows

Figures 5.2.1 and 5.2.2 show the flow of information between network elements for a mobile to mobile call for the following:

Figure 5.2.1: Successful CCBS request, destination B busy when request made, subscriber A free when destination B becomes free.

Figure 5.2.2: Subscriber A is not idle when destination B becomes free.

Figures 5.2.3 and 5.2.4 show the flow of information between network elements for a mobile to fixed call for the same situations described in figures 5.2.1 and 5.2.2 respectively.

Each information flow diagram has been divided where appropriate into four distinct phases of operation. These are as follows:

(1) Pre-conditions (Initial Call encountering NDUB and CCBS possible in the destination network). The detailed description of the basic call handling can be found in TS 23.018;

(2) Activation;

(3) Invocation;

(4) Operation (CCBS Call Set-up).

Figure 5.2.1: Successful CCBS request. Destination B busy when request activated, subscriber A free when destination B becomes free (mobile-to-mobile)

Figure 5.2.2: Subscriber A not idle when destination B becomes free (mobile-to-mobile);
Processing of a single request

Figure 5.2.3: Successful CCBS request. Destination B busy when request activated, subscriber A free when destination B becomes free (mobile-to-fixed)

Figure 5.2.4: Subscriber A not idle when destination B becomes free (mobile-to-fixed)

5.3 Activation

Activation of a CCBS Request is carried out by subscriber A. VLR A is considered to be transparent during the activation operation.

The information flows shown in figures 5.2.1 to 5.2.4 inclusive show the information flow for the activation process.

5.4 Deactivation

Subscriber A may deactivate CCBS in any of the following ways:

– Deactivate all outstanding CCBS requests; or

– Deactivate a specific CCBS Request.

The different deactivation operations are identified by different MMI commands as specified in TS 22.030.

Deactivation of CCBS requests by subscriber A shall be performed at HLR A.

To deactivate all outstanding CCBS requests, the Deactivate CCBS operation request shall contain the SS-Code only.

To deactivate a specific CCBS request, the Deactivate CCBS operation request shall contain the following parameters:

– SS-Code;

– CCBS Index.

On receipt of the deactivation request, HLR A shall cancel the CCBS request, i.e. remove all record of a CCBS request from the subscriber A’s originating CCBS queue and instruct the destination B network to cancel the corresponding CCBS request in the destination CCBS queue of subscriber B. HLR A shall return a result indicating whether the deactivation attempt was successful or not.

MS A		MSC A		VLR A		HLR A		Destination B Network

	Deactivate CCBS ——————->
			Deactivate CCBS ———————>
					Deactivate CCBS ——————->
							CCBS Cancel ——————->
							(note)
					Acknowledge <——————-
			Acknowledge <——————–
	Acknowledge <———————

Figure 5.4.1: Successful deactivation of all CCBS Requests/a specific CCBS request

NOTE: CCBS Cancel shall be sent for each CCBS Request that is cancelled in HLR A.

NOTE: In the case where a subscriber attempts to perform a deactivation operation but the subscriber is not provisioned with the CCBS service then, the subscriber shall receive an indication that the CCBS service is not provisioned for him.

5.5 Interrogation

Interrogation of CCBS shall be carried by request to HLR A. HLR A then returns the required information or error to MS A, see figure 5.5.1. MSC A and VLR A are considered to be transparent during the interrogation operation.

MS A		MSC A		VLR A		HLR A

	Interrogate CCBS ——————————>
			Interrogate CCBS —————————–>
					Interrogate CCBS ——————————->

					Acknowledge <——————————-
			Acknowledge <—————————–
	Acknowledge <——————————–

Figure 5.5.1: General interrogation of completion of calls to busy subscriber

The Interrogate CCBS operation request shall contain the SS-Code only.

In response to a general interrogation, MS A shall be given the AddressOfB, BasicServiceCode and CCBS index for each CCBS Request in the queue. The entries shall be ordered in the chronological order, the oldest entry shall be presented first.

If there are no CCBS Requests in the queue, MS A shall be given an indication that no entries exist in the queue.

NOTE: In the case where a subscriber attempts to perform an interrogation operation but the subscriber is not provisioned with the CCBS service then, the subscriber shall receive an indication that the CCBS service is not provisioned for him.

5.6 Messages and their contents

This clause contains the detailed description of the information flows used by CCBS.

Each Information Element, IE is marked as (M) Mandatory, (C) Conditional or (O) Optional. A mandatory information element shall always be present. A conditional information shall be present if certain conditions are fulfilled; if those conditions are not fulfilled it shall be absent. An optional information element may be present or absent, at the discretion of the application at the sending entity. This categorisation is a functional classification, i.e., stage 2 information and not a stage 3 classifications to be used for the protocol.

The stage 2 and stage 3 message and information element names are not necessarily identical.

5.6.1 Information elements used in the messages

In this clause constructed information elements are described.

5.6.1.1 Call Information information element

Call Information information element is formed in the MSC A during the CCBS activation. This information element contains unmodified copy of the SETUP message received from the MS A. If CCBS Request is activated, the Call Information is stored in the HLR A. During CCBS Recall Call Information is relayed back to the MS. Refer to SETUP Container information element defined in TS 24.008.

5.6.1.2 AddressOfB information element

AddressOfB information element is formed in the MSC A during the CCBS activation. It contains the number of the destination B dialled by the A-user.

Table 5.6.1.2: Structure of AddressOfB information element

Parent Information Element

Child Information element name

Information element Required

Information element description

AddressOfB

B subscriber number,

B subscriber subaddress

The number of the destination B dialled by the A-user;

Shall be present if it was dialled by the A-user;

otherwise shall be absent

5.6.1.3 CCBS Description information element

CCBS Description information element is formed in the HLR A during the CCBS activation.

Table 5.6.1.3: Structure of CCBS Description information element

Parent Information Element

Child Information element name

Information element Required

Information element description

CCBS Description

CCBS Index,

AddressOfB,

BasicServiceGroup

CCBS Index (range 1 – 5) identifies the request in the network.

The structure of the AddressOfB is defined in table 5.6.1.2;

BasicServiceGroup related to the original call.

5.6.2 Messages between MS and MSC

These messages are used in the originating network.

Table 5.6.2: Messages between MS and MSC

Message	Message sender	Information element name	Information element Required	Information element description
CCBS POSSIBLE	MSC	–	–	This message contains no information elements.
CCBS REQUEST	MS	–	–	This message contains no information elements.
CCBS REQUEST ACK	MSC	CCBS Index, AddressOfB, BasicServiceGroup	M O O	CCBS Index (range 1 – 5) identifies the request in the network. The structure of the AddressOfB is defined in table 5.6.1.2 BasicServiceGroup related to the original call.
CCBS REQUEST ERROR	MSC	Error	M	The information element can take the following values: – Short term denial – Long term denial
DEACTIVATE CCBS	MS	CCBS Index	C	If CCBS Index is present the corresponding request shall be deleted, otherwise all requests shall be deleted.
DEACTIVATE CCBS ACK	MSC	DeactivateResult	M	The information element can take the following values: – Success – Not Provisioned
INTERROGATE CCBS	MS	–	–	This message contains no information elements.
INTERROGATE CCBS ACK	MSC	List(1-5) of CCBS Description; No Entries; Not Provisioned	C C C	The list shall contain one entry for each CCBS Request for which the HLR stores data or; the queue is empty or; CCBS is not provisioned for the subscriber Exactly one of these information elements shall be present. The structure of the CCBS Description is defined in table 5.6.1.3.
CCBS CALL INFO	MSC	Call Information	M	The content of the Call Information is defined in the clause 5.6.1.1.
CCBS CALL INFO ACK	MS	GSM BC	M	GSM BC indicates the BC the MS prefers to use. The network may allocate a traffic channel accordingly.
CCBS CALL INFO ERROR	MS	Error	M	The information element can take the following values: – Incompatible Terminal
CCBS RECALL	MSC	CCBS Description, Alerting Pattern	M, C	The structure of the CCBS Description is defined in table 5.6.1.3. Alerting Pattern shall be present if it was received in the CCBS RUF message
CCBS SETUP	MS	–	–	The content of the message is the same as the MO Set-up message has. Refer to TS 24.008.
CCBS RECALL REJECT	MS	Cause	M	The MS shall indicate the reason of CCBS Recall rejection. The information element can take the following values: – Recall Rejected by the user – UDUB – ACMmax exceeded

5.6.3 Messages between MSC and VLR (B-interface)

5.6.3.1 Messages between MSC and VLR in the originating network

These messages are used in the originating network. Some messages are used also in the terminating network. They are marked accordingly.

Table 5.6.3.1: Messages between MSC and VLR in the originating network

Message	Message sender	Information element name	Information element Required	Information element description
CALL END	MSC	–	–	This message contains no information elements. The message is used also in the terminating network.
CCBS CALL DELIVERY	MSC	Outcome	M	The information element indicates whether CCBS Call was successful or failure. It can take the following values: – Success; – Failure; – NDUB; – Busy; – Absent Subscriber.. The message is used also in the terminating network.
CCBS REQUEST	MSC	–	–	This message contains no information elements
CCBS REQUEST ACK	VLR	CCBS Index, AddressOfB, BasicServiceGroup	M O O	CCBS Index (range 1 – 5) identifies the request in the network. The structure of the AddressOfB is defined in table 5.6.1.2 BasicServiceGroup related to the original call.
CCBS REQUEST ERROR	VLR	Error	M	The information element can take the following values: – Short term denial; – Long term denial.
COMPLETE RECALL	VLR	Call Information	M	The content of the Call Information is defined in the clause 5.6.1.1.
COMPLETE RECALL ACK	MSC	–	–	This message contains no information elements
COMPLETE RECALL NEGATIVE RESPONSE	MSC	Negative Response	M	The negative information element can take the following values: – Absent Subscriber; – Incompatible Terminal; – Radio Congestion.
DEACTIVATE CCBS	MSC	CCBS Index	C	If CCBS Index is present the corresponding request shall be deleted, otherwise all requests shall be deleted.
DEACTIVATE CCBS ACK	VLR	DeactivateResult	M	The information element can take the following values: – Success; – Not Provisioned.
INTERROGATE CCBS	MSC	–	–	This message contains no information elements

Table 5.6.3.1: Messages between MSC and VLR in the originating network, cont.

Message	Message sender	Information element name	Information element Required	Information element description
INTERROGATE CCBS ACK	VLR	List(1-5) of CCBS Description; No Entries; Not Provisioned	C C C	The list shall contain one entry for each CCBS Request for which the HLR stores data; or the queue is empty; or CCBS is not provisioned for the subscriber. Exactly one of these information elements shall be present. The structure of the CCBS Description is defined in table 5.6.1.3.
NOT IDLE	MSC	–	–	This message contains no information elements. The message is used also in the terminating network.
PAGE MS FOR RECALL	VLR	Location area ID, TMSI	M O	Location area in which the MS is to be paged TMSI to be broadcast to identify the MS
PAGE MS FOR RECALL NEGATIVE RESPONSE	MSC	Negative Response	M	The negative information element can take the following values: – Unknown LAI; – Absent Subscriber; – Busy Subscriber.
PROCESS ACCESS REQUEST	MSC	–	–	Refer to TS 23.018
RADIO FAILURE	MSC	–	–	This message contains no information elements. The message is used also in the terminating network.
RECALL	VLR	CCBS Description Alerting Pattern	M C	The structure of the CCBS Description is defined in table 5.6.1.3. Alerting Pattern shall be present if it was received in the CCBS RUF message
RECALL ACK	MSC	Cause	M	The information element can take the following values: – Accept; – Rejected; – T4 Expiry; – T10 Expiry; – Radio Failure; – UDUB, busy; – UDUB, idle; – Incompatible terminal.
SEARCH FOR MS MSC FOR RECALL	VLR	–	–	This message contains no information elements
SEARCH FOR MS MSC FOR RECALL ACK	MSC	–	–	This message contains no information elements
SEARCH FOR MS MSC FOR RECALL NEGATIVE RESPONSE	MSC	Negative Response	M	The negative information element can take the following values: – Absent Subscriber; – Busy Subscriber;
SEND INFO FOR OUTGOING CALL	MSC	–	–	Refer to TS 23.018
START STATUS ENQUIRY	VLR	–	–	This message contains no information elements. The message is used also in the terminating network.
STATUS ENQUIRY RESULT	MSC	Status	M	The information element can take the following vales: – CCBS Idle; – CCBS Not Idle. The message is used also in the terminating network.
STOP STATUS ENQUIRY	VLR	–	–	This message contains no information elements. The message is used also in the terminating network.

5.6.3.2 Messages between MSC and VLR in the destination network

These messages are used in the destination network. Some messages are used also in the originating network. They are marked accordingly.

Table 5.6.3.2: Messages between MSC and VLR in the destination network

Message	Message sender	Information element name	Information element Required	Information element description
CALL END	MSC	–	–	Refer to table 5.6.3.1
CCBS CALL DELIVERY	MSC	–	–	Refer to table 5.6.3.1
START STATUS ENQUIRY	VLR	–	–	Refer to table 5.6.3.1
STATUS ENQUIRY RESULT	MSC	–	–	Refer to table 5.6.3.1
STOP STATUS ENQUIRY	VLR	–	–	Refer to table 5.6.3.1
RADIO FAILURE	MSC	–	–	Refer to table 5.6.3.1
NOT IDLE	MSC	–	–	Refer to table 5.6.3.1
COMPLETE CALL	VLR	– Indicator	– C	Refer to TS 23.018 In addition: The information element shall be present if the call is CCBS Call; otherwise it shall be absent.
PROCESS CALL WAITING	VLR	– Indicator	– C	Refer to TS 23.018 In addition: The information element shall be present if the call is CCBS Call; otherwise it shall be absent.
SEND INFO FOR INCOMING CALL ACK	VLR	– CCBS Target	– C	Refer to TS 23.018 In addition: The information element shall be present if the B subscriber can be target of CCBS request; otherwise it shall be absent.
SEND INFO FOR INCOMING CALL NEGATIVE RESPONSE	VLR	– CCBS Target	– C	Refer to TS 23.018 In addition: The information element shall be present if the B subscriber can be target of CCBS request; otherwise it shall be absent.

5.6.4 Messages between VLR and HLR (D-interface)

5.6.4.1 Messages between VLR and HLR in the originating network

These messages are used between VLR – HLR in the originating network. Some messages are used also in the destination network. They are marked accordingly.

Table 5.6.4.1: Messages between VLR and HLR in the originating network

Message	Message sender	Information element name	Information element Required	Information element description
CCBS REQUEST	VLR	Call Information ISDN BC ISDN HLC ISDN LLC Presentation Indicator Translated B No CAMEL Invoked Basic Service Group AddressOfB	M M C C C M C M M	The content of the Call Information is defined in the clause 5.6.1.1. ISDN BC derived for the initial call. Shall be present if ISDN HLC was present in the initial call; otherwise shall be absent. Shall be present if ISDN LLC was present in the initial call; otherwise shall be absent. Shall be present if CLIR was invoked for the initial call; otherwise shall be absent. The number used for routing purposes stored in international E.164 format. Shall be present if MO CAMEL was invoked in the initial call; otherwise shall be absent. GSM Elementary Basic Service Group which corresponds to the basic service used for initial call set-up The structure of the AddressOfB is defined in table 5.6.1.2
CCBS REQUEST ACK	HLR	CCBS Index AddressOfB Basic Service Group	M O O	CCBS Index (range 1 – 5) identifies the request in the network. The structure of the AddressOfB is defined in table 5.6.1.2 BasicServiceGroup related to the original call.
CCBS REQUEST ERROR	HLR	Error	M	The information element can take the following values: – Short term denial; – Long term denial;
CCBS RUF	HLR	Call Information CCBS Description Translated B No Replace B No Alerting Pattern	M M M C C	The content of the Call Information is defined in the clause 5.6.1.1. The content of the CCBS Description is defined in table 5.6.1.3. The number used for routing purposes in international E.164 format. The information element shall be present if the HLR instructs the MSC to replace the destination B number with the translated B number; otherwise it shall be absent. Alerting Pattern shall be present if the HLR has determined an alerting category or an alerting level for the CCBS recall
CCBS RUF ACK	VLR	Result	M	The information element indicates whether CCBS Recall was accepted. It can take the following values: – RUF Accepted; – RUF Rejected; – T4 Expiry; – T10 Expiry; – UDUB, idle; – UDUB, busy.
CCBS RUF ERROR	VLR	Error	M	The information element indicates the reason why CCBS Recall could not be successfully delivered. It can take the following values: – IMSI Detached; – Restricted Area; – No Page Response; – Incompatible Terminal; – Absent Subscriber; – Radio Failure; – Ccomp Busy; – System Failure.

Table 5.6.4.1: Messages between VLR and HLR in the originating network, cont.

Message	Message sender	Information element name	Information element Required	Information element description
EVENT REPORT	VLR	Status	M	The information element contains subscriber status. It can take the following values: – CCBS Idle; – CCBS Not Idle; – CCBS Not Reachable. The message is used also in the terminating network.
EVENT REPORT ACK	HLR	–	–	This message contains no information elements The message is used also in the terminating network.
EVENT_REPORT_ ERROR	HLR	Error	M	The information element contains no application specific error values. The message is used also in the terminating network.
START REPORTING	HLR	–	–	This message contains no information elements. The message is used also in the terminating network.
START REPORTING ACK	VLR	Status	M	The information element contains subscriber status. It can take the following values: – CCBS Idle; – CCBS Not Idle; – CCBS Not Reachable. The message is used also in the terminating network.
START REPORTING ERROR	VLR	Error	M	The information element contains no application specific error values. The message is used also in the terminating network.
CONTINUE MONITORING	HLR	–	–	This message contains no information elements. The message is used also in the terminating network.
STOP REPORTING	HLR	–	–	This message contains no information elements. The message is used also in the terminating network.
CCBS CALL REPORT	VLR	Mode Outcome Status	M M C	The information element indicates the reporting mode. It can take the following values : – A; – B. The information element indicates the outcome of the CCBS Call. It can take the following values: – Success; – Busy (only for mode A); – NDUB (only for mode B) – Failure. The information element contains subscriber status. It is set only for mode B. It can take the following values: – CCBS Idle; – CCBS Not Idle; – CCBS Not Reachable. The message is used also in the terminating network.
CCBS CALL REPORT ACK	HLR	–	–	This message contains no information elements. The message is used also in the terminating network.
CCBS CALL REPORT ERROR	HLR	Error	M	The information element contains no application specific error values. The message is used also in the terminating network.
DEACTIVATE CCBS	VLR	CCBS Index	C	If CCBS Index is present the corresponding request shall be deleted, otherwise all requests shall be deleted.
DEACTIVATE CCBS ACK	HLR	DeactivateResult	M	The information element can take the following values: – Success; – Not Provisioned.
DEACTIVATE CCBS ERROR	HLR	Error	M	The information element contains no application specific error values.

Table 5.6.4.1: Messages between VLR and HLR in the originating network, cont.

Message	Message sender	Information element name	Information element Required	Information element description
INTERROGATE CCBS	VLR	–	–	This message contains no information elements.
INTERROGATE CCBS ACK	HLR	List(1-5) of CCBS Description; No Entries; Not Provisioned	C C C	The list shall contain one entry for each CCBS Request for which the HLR stores data or; the queue is empty or; CCBS is not provisioned for the subscriber. Exactly one of these information elements shall be present. The structure of the CCBS Description is defined in table 5.6.1.3.
INTERROGATE CCBS ERROR	HLR	Error	M	The information element contains no application specific error values.

5.6.4.2 Messages between VLR and HLR in the destination network

These messages are used between VLR – HLR in the destination network. Some messages are used also in the originating network. They are marked accordingly.

Table 5.6.4.2: Messages between VLR and HLR in the destination network

Message	Message sender	Information element name	Information element Required	Information element description
EVENT REPORT	VLR	–	–	Refer to table 5.6.4.1
EVENT REPORT ACK	HLR	–	–	Refer to table 5.6.4.1
EVENT REPORT ERROR	HLR	–	–	Refer to table 5.6.4.1
START REPORTING	HLR	–	–	Refer to table 5.6.4.1
START REPORTING ACK	VLR	–	–	Refer to table 5.6.4.1
START REPORTING ERROR	VLR	–	–	Refer to table 5.6.4.1
CONTINUE MONITORING	HLR	–	–	Refer to table 5.6.4.1
STOP REPORTING	HLR	–	–	Refer to table 5.6.4.1
CCBS CALL REPORT	VLR	–	–	Refer to table 5.6.4.1
CCBS CALL REPORT ACK	HLR	–	–	Refer to table 5.6.4.1
CCBS CALL REPORT ERROR	HLR	–	–	Refer to table 5.6.4.1
PROVIDE ROAMING NUMBER	HLR	– CCBS Call Reporting Request	– C	Refer to TS 23.018 In addition: The information element shall be present for CCBS Call roaming number enquiry; otherwise it shall be absent.

5.6.5 Messages between MSC and HLR (C-interface)

Table 5.6.5: Messages between MSC and HLR

Message	Message sender	Information element name	Information element Required	Information element description
SEND ROUTING INFO	MSC	– CCBS Supported CCBS Call Indicator	– C C	Refer to TS 23.018 In addition: The information element shall be present if GMSC supports CCBS; otherwise it shall be absent. The information element shall be present, if SRI is for CCBS Call; otherwise it shall be absent.
SEND ROUTING INFO_ACK	HLR	– CCBS Target Keep CCBS Call Indicator Forwarding Reason	– C C C	Refer to TS 23.018 In addition: The information element shall be present if the call is forwarded on busy and the subscriber B can be target of CCBS requests; otherwise it shall be absent. The information element shall be present if the VMSC supports CCBS and SRI enquiry was for CCBS Call; otherwise it shall be absent. The reason CFBusy shall be present if the HLR has determined that the call is to be forwarded for that CCBS case.
SEND ROUTING INFO NEGATIVE RESPONSE	HLR	– Negative Response	– –	Refer to TS 23.018 New value(s) for existing parameter(s): – Busy_CCBS_Possible; – Busy_CCBS_Not_Possible.

5.6.6 Messages between MSC – MSC (E-interface)

Table 5.6.6: Messages between MSC and MSC

Message

Message sender

Information element name

Information element Required

Information element description

RESUME CALL HANDLING

MSC

–

CCBS Target

–

Refer to TS 23.079

In addition:

The information element shall be present if the call is forwarded on busy and the subscriber B can be target of CCBS requests; otherwise it shall be absent.

5.6.7 Existing parameters containing CCBS specific information

Mobile Station Classmark 2 (refer to TS 24.008 contains information whether "Network initiated MO CM connection request" is supported or not. This information is vital for the recall mechanism.

CC capabilities (refer to TS 24.008) contains information whether "Prolonged Clearing Procedures" are supported or not. This information is vital for the activation mechanism.

SS-Code and SS-Status (refer to TS 29.002) contains information whether CCBS service is provisioned to the subscriber. Both originating and destination CCBS service have their own SS-Code.