It shall be possible to specify which of the following initial service events shall initiate contact with the CSE:

• Terminating Attempt Authorised;
• Detection of unsuccessful call establishment.
  Unsuccessful call establishment may be caused by:
  • Called subscriber busy;
  • Called subscriber not reachable;
  • No answer from called subscriber.

Upon detection of unsuccessful call establishment no new relationship is opened if there is already a dialogue opened due to same CSI.

The purpose of this procedure is to detect an incoming call request and allow the CSE to modify the handling of the incoming call. If (according to the CSI):

• The subscriber is provisioned with a CAMEL based terminating service; and
• The incoming call request event occurs

Then the IPLMN/VPLMN shall suspend call processing, make contact with the CSE and await further instructions. When the IPLMN/VPLMN has made contact with the CSE, the CSE shall be able to instruct the IPLMN/VPLMN to act as described below:

• Perform charging activities;
• Activate subsequent control service events for the call. The CSE shall have the possibility to send the following information:
  • The subsequent service event which shall be detected and reported:
    • Called party alert;
    • Called party connection;
    • Call disconnection;
    • Calling party abandon;
    • Unsuccessful call establishment. In the case of no answer the CSE may provide a no answer timer.
    • Mid call event (DTMF). The CSE shall specify the digit string(s) for which the instruction is valid. The arming and detection of the mid call event shall be limited to the VPLMN;
    • Change of Position. The CSE may specify notification criteria. The arming and detection of the Change of Position event shall be limited to the VPLMN;
    • Change of basic service.
  • The party in the call for which the event shall be detected and reported (calling or called party);
  • The type of monitoring (control or notification).
• Suppress tones and announcements which may be played to the calling party, if an unsuccessful call establishment occurs.
• Order in-band user interaction.

There shall be no restriction regarding the order of the above instructions or the number of times each of the above instructions can be repeated. Once the CSE has concluded issuing the above instructions, it shall issue one and only one of the following instructions:

• Bar the call (i.e. release the call before connection);
• Continue the call processing;
• Continue the call processing with modified information;
• Continue the handling of the calling party without routeing the call to the destination.

If the CSE instructs the IPLMN/VPLMN to continue the call processing with a changed called party number, the CSE shall indicate whether the resulting call shall be treated by the IPLMN/VPLMN as a forwarded call. Any forwarded call resulting from a CSE Call Forwarding service may cause an invocation of any mobile originated CAMEL based service in the IPLMN/VPLMN. If the CSE instructs the IPLMN to allow the call processing with modified information, the CSE may send to the IPLMN an alerting pattern in order to alert the called subscriber in a specific manner. This alerting pattern shall be transferred to the VPLMN.

The purpose of this subsequent procedure is to manage an incoming call set-up at the time it is terminated by the calling party before the call is established. If the CSE has activated this service event for this call in notify mode and the calling party abandon event occurs the IPLMN/VPLMN shall:

• Notify the CSE and continue.

The following information shall be provided to the CSE:

• Event met;
• Type of monitoring.

If the CSE has activated this subsequent service event for the call in request mode and the calling party abandon event occurs the IPLMN/VPLMN shall suspend call processing, make contact with the CSE and await further instructions. When the IPLMN/VPLMN has made contact with the CSE in request mode, the CSE shall be able to instruct the IPLMN/VPLMN to act as described below:

• Perform charging activities;

There shall be no restriction regarding the number of times the above instruction can be repeated. Once the CSE has concluded issuing the above instruction, it shall issue the following instruction:

• Continue the call processing.

The purpose of this procedure is to manage an incoming call set-up at the time when the call establishment is unsuccessful. If no relationship for the given call exists and

• The unsuccessful call establishment procedure is defined as an initial service event (according to the CSI); and
• The call attempt is unsuccessful; and
• The triggering criteria are satisfied

Then the VPLMN/IPLMN shall suspend call processing, make contact with the CSE and await further instructions. If a relationship for the given call already exists and the CSE has activated this subsequent service event for this call and the unsuccessful call establishment event occurs the VPLMN/IPLMN shall:

• Suspend call processing, notify the CSE and await further instructions, or
• Notify the CSE and continue call processing.

In both cases above the following information shall be provided to the CSE:

• Event met;
• Type of monitoring;
• Cause for unsuccessful call establishment:
  • Not reachable;
  • Busy;
  • No answer;
  • Forwarding notification.

If the unsuccessful call establishment procedure is armed as an initial service event, and the IPLMN/VPLMN has made contact with the CSE, the CSE shall be able to instruct the IPLMN/VPLMN to act as described below:

• Perform charging activities;
• Activate subsequent control service events for the call. The CSE shall have the possibility to send the following information:
  • The subsequent service event which shall be detected and reported:
    • Called party alert;
    • Called party connection;
    • Call disconnection;
    • Calling party abandon;
    • Unsuccessful call establishment. In the case of no answer the CSE may provide a no answer timer;
    • Mid call event (DTMF). The CSE shall specify the digit string(s) for which the instruction is valid. The arming and detection of the mid call event shall be limited to the VPLMN;
    • Change of Position. The CSE may specify notification criteria. The arming and detection of the Change of Position event shall be limited to the VPLMN;
    • Change of basic service.
  • The party in the call for which the event shall be detected and reported (calling or called party);
  • The type of monitoring (control or notification).
• Order in-band user interaction.

There shall be no restriction regarding the order of the above instructions or the number of times each of the above instructions can be repeated. Once the CSE has concluded issuing the above instructions, it shall issue one and only one of the following instructions:

• Release the call;
• Continue the call processing;
• Continue the call processing with modified information.

The purpose of this procedure is to manage an incoming call set-up at the time when the called party answers and the call is successfully established. If the CSE has activated this subsequent service event for this call and the called party connection event occurs, the IPLMN/VPLMN shall:

• Suspend call processing, notify the CSE and await further instructions, or
• Notify the CSE and continue call processing.

The following information shall be provided to the CSE:

• Event met;
• The party in the call for which the event is reported (only called party applicable);
• The charge indicator which will be used in the Call Data Record if available;
• Type of monitoring.

When the IPLMN/VPLMN has made contact with the CSE, the CSE shall be able to instruct the IPLMN/VPLMN to act as described below.

• Perform charging activities;
• Activate subsequent control service events for the call. The CSE shall have the possibility to send the following information:
  • The subsequent service event which shall be detected and reported:
    • (Call disconnection);
    • Mid call event (DTMF). The CSE shall specify the digit string(s) for which the instruction is valid. The arming and detection of the mid call event shall be limited to the VPLMN.
    • Change of Position. The CSE may specify notification criteria. The arming and detection of the Change of Position event shall be limited to the VPLMN;
    • Change of basic service.
  • The party in the call for which the event shall be detected and reported (calling or called party);
  • The type of monitoring (control or notification).
• Order in-band user interaction;

There shall be no restriction regarding the order of the above instructions or the number of times each of the above instructions can be repeated. Once the CSE has concluded issuing the above instructions, it shall issue one and only one of the following instructions:

• Release the call;
• Continue the call processing;

When the CSE instructs the VPLMN to arm the mid-call event it shall specify a criterion against which digits entered by the terminating subscriber using the DTMF procedure shall be matched. It shall be possible for the CSE to instruct the VPLMN to re-arm the mid-call event when it is encountered. In the following each digit shall be taken from the ordered set (0 9, *, #). The criterion consists of a list defining:

• The minimum number of digits to be collected, and
• The maximum number of digits to be collected, and
• The maximum delay between successive digits, and optionally
• The digit(s) used to indicate the start of the input, and optionally
• The digit(s) used to indicate the end of the input, and optionally
• The digit(s) used to indicate that the input shall be cancelled.

The minimum and maximum number of digits to be collected includes the digit(s) used to indicate the start and end of the input. A digit string has been cancelled if:

• The CSE has specified digit(s) used to indicate that the input shall be cancelled, and
• The specified digit(s) has/have been received from the user.

If the CSE has specified digit(s) used to indicate the start of the input, then the input has started if:

• The specified digit(s) has/have been received from the user, and
• The digit string has not been cancelled.

If the CSE has not specified digit(s) used to indicate the start of the input, then the input has started if:

• At least one digit has been received from the user, and
• The digit string has not been cancelled.

If the CSE has specified digit(s) used to indicate the end of the input, then the input has ended if:

• The specified digit(s) has/have been received from the user, or
• The maximum number of digits has been received, or
• The maximum delay between successive digits has been exceeded.

If the CSE has not specified digit(s) used to indicate the end of the input, then the input has ended if:

• The maximum number of digits has been received, or
• The maximum delay between successive digits has been exceeded.

A digit string satisfies the criterion for the Mid call detection point if:

• The input has started, and
• The digit string contains at least the minimum number of digits, and
• The input has ended.

Triggering of the mid-call event shall occur immediately after the criterion has been satisfied. Once the triggering occurs the VPLMN shall disarm the mid-call event. Digits collected from the subscriber shall be relayed as DTMF towards the destination subscriber independent of any CAMEL processing. If the CSE has activated this service event for this call and a mid call event (as determined by the criterion for the mid-call procedure being satisfied) occurs the VPLMN shall:

• Suspend call processing, notify the CSE and await further instructions, or
• Notify the CSE and continue call processing.

The following information shall be provided to the CSE:

• Event met;
• The party in the call for which the event is reported;
• Type of monitoring;
• Event specific data:
  • Received DTMF digits.

When the VPLMN has made contact with the CSE, the CSE shall be able to instruct the VPLMN to act as described below:

• Perform charging activities
• Activate other control service events for the call. The CSE shall have the possibility to send the following information:
  • The service event which shall be detected and reported:
    • Call disconnection;
    • Mid call event (DTMF). The CSE shall specify the digit string(s) for which the instruction is valid;
    • Change of Position. The CSE may specify notification criteria.
  • The party in the call for which the event shall be detected and reported (calling or a called party);
  • The type of monitoring (control or notification).
• Order in-band user interaction

There shall be no restriction regarding the order of the above instructions or the number of times each of the above instructions can be repeated. Once the CSE has concluded issuing the above instructions, it shall issue one and only one of the following instructions:

• Release the call;
• Continue the call processing.

The purpose of this procedure is to manage the actions on disconnection of an established call. If the CSE has activated this subsequent service event for the call and the call disconnection event occurs the IPLMN/VPLMN shall:

• Suspend call processing, notify the CSE and await further instructions, or
• Notify the CSE and continue call processing.

The following information shall be provided to the CSE:

• Event met;
• The party in the call for which the event is reported;
• Type of monitoring;
• Disconnection reason.

When the IPLMN/VPLMN has made contact with the CSE, the CSE shall be able to instruct the IPLMN/VPLMN to act as described below.

• Perform charging activities;
• Activate subsequent control service events for the call. The CSE shall have the possibility to send the following information:
  • The service subsequent event which shall be detected and reported:
    • Called party alert;
    • Called party connection;
    • Call disconnection;
    • Calling party abandon;
    • Unsuccessful call establishment. In the case of no answer the CSE may provide a no answer timer;
    • Mid call event (DTMF). The CSE shall specify the digit string(s) for which the instruction is valid. The arming and detection of the mid call event shall be limited to the VPLMN;
    • Change of Position. The CSE may specify notification criteria. The arming and detection of the Change of Position event shall be limited to the VPLMN;
    • Change of basic service.
  • The party in the call for which the event shall be detected and reported (calling or called party);
  • The type of monitoring (control or notification).
• Order in-band user interaction.

There shall be no restriction regarding the order of the above instructions or the number of times each of the above instructions can be repeated. Once the CSE has concluded issuing the above instructions, it shall issue one and only one of the following instruction:

• Continue the call processing, i.e. release the call;
• Continue the call processing with modified information.

Following the CAMEL processing of the incoming call request procedure it shall be possible for the CSE to initiate a call release at any moment of the call. To use this procedure:

• The originating VPLMN shall have reported an initial service event to the CSE and be waiting for instructions from the CSE, or
• The CSE shall be waiting for the report of a subsequent service event (with "Type of monitoring" set to control).

The purpose of this procedure is to manage an outgoing call set-up at the time when the called party is alerted. If the CSE has activated this service event for this call and the called party alert event occurs the IPLMN/VPLMN shall:

• Suspend call processing, notify the CSE and await further instructions, or
• Notify the CSE and continue call processing.

The following information shall be provided to the CSE:

• Event met;
• The party in the call for which the event is reported (only called party applicable);
• Type of monitoring.

If the IPLMN/VPLMN reports the alerting event to the CSE, the location information of the MS shall be provided to the CSE. When the IPLMN/VPLMN has made contact with the CSE, the CSE shall be able to instruct the IPLMN/VPLMN to act as described below:

• Perform charging activities;
• Activate subsequent control service events for the call. The CSE shall have the possibility to send the following information:
  • The service event which shall be detected and reported:
    • Calling party abandon;
    • Unsuccessful call establishment. In the case of no answer the CSE may provide a no answer timer;
    • Call disconnection;
    • Mid call event (DTMF); The CSE shall specify the digit string(s) for which the instruction is valid. The arming and detection of the mid call event shall be limited to the VPLMN;
    • Change of Position. The CSE may specify notification criteria. The arming and detection of the Change of Position event shall be limited to the VPLMN;
    • Called party connection
    • Change of basic service.
  • The party in the call for which the event shall be detected and reported;
  • The type of monitoring (control or notification).
• Order in-band user interaction with the calling party.

There shall be no restriction regarding the order of the above instructions or the number of times each of the above instructions can be repeated. Once the CSE has concluded issuing the above instructions, it shall issue the following instruction:

• Continue the call processing.

When the CSE instructs the VPLMN to arm the change of position event it may specify a list of up to 10 criteria against which the change of position shall be matched. The VPLMN shall report the event when the subscriber's location information changes and one of the criteria is met. Each element of the list of criteria contains either:

• the identifier of a location which the subscriber enters or leaves. It is specified as one of the following:
• cell global id;
• location area id;
• service area id

or one of the following types of handover:

• "inter-system handover";
• "inter-PLMN handover";
• "inter-MSC hand over".

If more then one criterion is met, then only one change of position event shall be reported to the CSE. If this list of criteria is not included in the instruction, the criteria upon any change of position shall be regarded as fulfilled. It shall be possible for the CSE to instruct the VPLMN to re-arm the change of position event when it is encountered. If the CSE has activated this service event for the served subscriber and a change of position event occurs (as determined by the criteria for the change of position procedure being satisfied) the VPLMN shall:

• Notify the CSE and continue call processing.

The following information shall be provided to the CSE:

• Event met;
• Type of monitoring;
• Event specific data:
  • Location information.
• Charge result if charging supervision is provided.

When the VPLMN has made contact with the CSE, the CSE shall be able to instruct the VPLMN to act as described below:

• Perform charging activities;
• Activate other control service events for the call. The CSE shall have the possibility to send the following information:
  • The service event which shall be detected and reported:
    • Change of position. The CSE may specify notification criteria.
  • The party in the call for which the event shall be detected and reported;
  • The type of monitoring (notification);
  • Order in-band user interaction.

There shall be no restriction regarding the order of the above instructions or the number of times each of the above instructions can be repeated.

When the CSE has instructed the IPLMN/VPLMN to arm the change of basic service event, the IPLMN/VPLMN shall report the event when the basic service changes. It shall be possible for the CSE to instruct the IPLMN/VPLMN to re-arm the change of basic service event when it is encountered. The CSE may arm this event in the various phases of the call (as specified in this specification)- however the IPLMN/VPLMN reports the basic service changes in the active phase of the call only. If the CSE has activated this service event for the served subscriber and a change of basic service event occurs the IPLMN/VPLMN shall:

• Notify the CSE and continue call processing.

The following information shall be provided to the CSE:

• Event met;
• Type of monitoring;
• Event specific data;
• Basic service:
• Charge result if charging supervision is provided:

When the IPLMN/VPLMN has made contact with the CSE, the CSE shall be able to instruct the IPLMN/VPLMN to act as described below:

• Perform charging activities;
• Activate other control service events for the call. The CSE shall have the possibility to send the following information:
• The service event which shall be detected and reported:
  • Change of basic service.
• The party in the call for which the event shall be detected and reported;
• The type of monitoring (notification).

There shall be no restriction regarding the order of the above instructions or the number of times each of the above instructions can be repeated.