It shall be possible to mark for a subscriber that a notification shall be sent to the CSE when the VPLMN has completed the processing of any one or more of the following mobility events:

• For a CS subscriber:
  • Location area update of MS to a different VLR service area;
  • Location area update of MS within the same VLR service area;
  • MS-initiated detach (e.g. MS switched off);
  • Network initiated detach (periodic location update of MS failed);
  • Attach of MS (e.g.MS switched on, successful location update after network initiated detach);
• For a GPRS subscriber:
  • Routeing area update of MS to a different SGSN service area;
  • Routeing area update of MS within the same SGSN service area;
  • MS-initiated detach (e.g. MS switched off);
  • Network initiated detach;
  • Network initiated transfer to "MS not reachable for paging" (periodic routeing area update of MS failed);
  • Attach of MS (e.g. MS switched on, successful routeing area update after network initiated detach.

The notification shall contain the following information if available:

• Event met;
• Service Key;
• IMSI;
• Basic MSISDN;
• Location information;
• LSA identity;
• CAMEL phases supported at the VPLMN.

It shall be possible to mark for a subscriber that a notification shall be sent to the CSE when any of the following subscriber data are changed as a result of a request from any entity except the CSE to which the notification shall be sent:

• CF SS data;
• CB SS data;
• CLIP SS data;
• CLIR SS data
• CW SS data;
• CH SS data;
• ECT SS data;
• ODB data;
• CAMEL subscription information.

One ore more CSEs may be defined to which the notification shall be sent.

It shall be possible to mark for a subscriber that a notification shall be sent to the CSE when any of the following supplementary services are invoked:

• ECT;
• CD;
• MPTY;
• CCBS.

It shall be possible for the CSE (as part of an OSS, including special handling of mobile terminating calls) to interrogate the HLR for information about a particular subscriber, for which it is entitled to do so (e.g. the subscriber belongs to the same HPLMN as the CSE). This may be information from the list below:

• Subscriber status;
• Location information (see clause 22);
• IMEI (with software version);
• MS class (only in the CS domain);
• GPRS MS class (only in the PS domain);
• Call Forwarding SS data;
• Call Barring SS data;
• Calling Line Identification Presentation SS data;
• Calling Line Identification Restriction SS data;
• Call Wait SS data;
• Call Hold SS data;
• Explicit Call Transfer SS data;
• Operator Determined Barring data;
• CAMEL Subscription Information;
• CAMEL phases supported at the VPLMN.

The CSE shall indicate in the request for subscriber information whether the information is requested from the HPLMN, the VPLMN in the circuit switched domain or the VPLMN in the packet switched domain. The HPLMN shall have the possibility to reject any interrogation from any CSE.

It shall be possible for the CSE to modify user data for a particular subscriber, for which it is entitled to do so (e.g. the subscriber belongs to the same HPLMN as the CSE). This shall be data from the list below:

• Call Forwarding SS data;
• Call Barring SS data;
• Calling Line Identification Presentation SS data;
• Calling Line Identification Restriction SS data;
• Call Wait SS data;
• Call Hold SS data;
• Explicit Call Transfer SS data;
• Operator Determined Barring data;
• Activation/Deactivation of CAMEL Subscription Information.

The HPLMN shall have the possibility to reject any request for modification from any CSE.

As a part of the following procedures, it shall be possible for the CSE to order the playing of announcements or tones to the calling subscriber:

• The call set-up request procedure;
• The unsuccessful call establishment procedure;
• The call disconnection procedure;
• The incoming call request procedure;
• The called party alert reporting procedure.

In the active phase of the call leg and in the mid-call procedure it shall be possible for the CSE to play tones and/or announcements to any held party or the group as specified in clauses 5, 6, 8 and 24. It shall be possible to play tones efficiently using local tone generators. The HPLMN operator is responsible for the administration of announcements. If there is an appropriate bilateral agreement the VPLMN operator may also administer announcements.

As a part of the call set-up request procedure, unsuccessful call establishment procedure, call disconnection procedure and incoming call request procedure it shall be possible for the CSE to order voice prompting and information collection to the calling subscriber. It shall not be possible to collect information from the user as part of the originating CAMEL handling for a forwarded call. In the active phase of the call leg and in the mid-call procedure it shall be possible for the CSE to order voice prompting and information collection towards any held party as specified in clauses 5, 6, 8 and 24.

It shall be possible for the CSE to initiate the sending of a USSD message to the served subscriber at any time. It shall be possible for the CSE to receive a served subscriber initiated USSD message at any time (see TS 22.030 and TS 22.090).

If the subscriber is provisioned with a CAMEL based service and a contact exists between the VPLMN and the CSE, the CSE shall be able to send e-values for the Advice of Charge supplementary service. Those e-values represent the charge applicable to the CPH configuration. For the purpose of charge indication on the MS even when one (or more) tariff switch occurs during the call, the CSE may send several sets of e-values to the VPLMN, which will transmit them in sequence to the Mobile Station of the served subscriber. Before the call is answered, the CSE may send either one set or two sets of e-values:

• If one set is sent, then the set of e-values is applicable from the beginning of the call, that is from the time any call leg is answered;
• If two sets are sent, then:
  • A tariff switch time after which the second set becomes valid must also be sent;
  • If any call leg is answered before the tariff switch time expires, then the first set of e-values is applicable from the beginning of the call and the second set of e-values is stored for future use;
  • If any call leg is answered after the tariff switch time expires, then the first set of e-values is discarded and the second set of e-values is applicable from the beginning of the call.

During the call, the CSE may send a new set of e-values either to be transmitted directly to the mobile station or to be stored until the next tariff switch is reached. The tariff switch time is sent together with the new set of e values. When the tariff switch time is reached, the stored set of e-values is sent immediately to the mobile station. CSE controlled e-values are not applicable to Trunk Originated CAMEL services.

The CSE shall be able at one or several active service events to download free-format charging information to be transparently output to the call record available at the IPLMN/VPLMN depending on the call scenario. The CSE can download free-format charging information for each call leg separately.

It shall be possible for the CSE to request from the VPLMN/IPLMN a call information report to be delivered at the termination of the call leg. The report shall contain call duration and release cause. The CSE can request a report for each call leg of the CPH configuration.

The purpose of this procedure is to allow the CSE to monitor and influence the call duration for each call leg independently of the other call legs in the CPH configuration. A change in the CPH configuration may result in a revision of the maximum call period duration for the altered call leg. If the subscriber is provisioned with a CAMEL based service and a contact between the IPLMN/VPLMN and the CSE exists, the CSE shall be able to instruct the IPLMN/VPLMN, at the beginning of the call or during the monitoring of the call, to act as described below:

1. Receive a maximum call period duration from the CSE for a call leg;
2. Receive a switch time after which the next tariff switch applies for a call leg;
3. Receive sets of e-values for the served subscriber (for the purpose of AoC controlled by the CSE).

The following combinations of the instructions are allowed:

• (a) or (a and b) or (a and c) or (b and c) or (a and b and c) or (c).

In the above combinations it shall be possible for the CSE to instruct multiple values of (a) and/or (b).In case (a) the CSE shall be able to instruct the IPLMN/VPLMN how to proceed when the maximum call period duration has expired, i.e. release the call leg or allow the call leg to continue. In both cases, a charging report shall be sent to the CSE. The CSE shall also be able to instruct the IPLMN/VPLMN to play a tone before the maximum call period duration is expired. The CSE shall be able to instruct the IPLMN/VPLMN to begin playing of an audible tone to the served subscriber at anytime before the maximum call period time is expired. The tone to be played shall consist of up to three audible bursts. A burst shall consist of a single tone, or a sequence of two tones, or a sequence of three tones. A normal speech path connecting all parties in the call shall be established between bursts. The CSE shall be able to instruct the IPLMN/VPLMN:

• The time before the maximum call period time expires when tone playing shall start;
• The number of bursts to be played (1, 2 or 3);
• The time interval between bursts (maximum 120 seconds);
• The number of tones in each burst (1, 2 or 3);
• The duration of the tone in a burst;
• The pause between the tone in a burst.

When the instruction sent by the CSE is received at the IPLMN/VPLMN as a result of the call set up request procedure before the call is established, the IPLMN/VPLMN shall immediately set the reference point for the next tariff switch, if available. When a call leg is answered, the IPLMN/VPLMN shall:

• Start the timer for the first call period for that leg;
• Send e-values, if available:
  • If one set of e-parameters were received from the CSE, then the set of e-values is applicable from the beginning of the call, that is from the time the first call leg is answered;
  • If two sets of e-parameters were received from the CSE, then:
    • A tariff switch time when the second set becomes valid must be also sent;
    • The first set of e-values is applicable from the beginning of the call (that is from the time the first call leg is answered) except in the case where the tariff switch time occurs before the first call leg is answered, in which case the second set of e-values is applicable at the beginning of the call.

When the reference point for the tariff switch is reached, the stored set of e-values is sent immediately to the mobile station, if available. When the end of a call period is reached, the IPLMN/VPLMN shall report to the CSE:

• If no tariff switch has occurred since the call leg was answered or since the call was modified by a CPH procedure:
  • Report the elapsed time since the call leg was answered or modified by a CPH procedure to the CSE;
• If a tariff switch has occurred since the call leg was answered or since the call was modified by a CPH procedure:
  • Report the elapsed time since the last tariff switch has applied;
  • Report the elapsed time from when the call leg was answered or modified by a CPH procedure or from when the previous tariff switch occurred to the time when the most recent tariff switch occurred.

When the IPLMN/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 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);
  • 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).

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.

At the end of a call period and after the relevant information was sent to the CSE, the IPLMN/VPLMN may receive instructions applicable to for the next call period for the call leg:

• The timing of the new call period shall start as soon as the previous call period is ended;
• The timing since the call leg was answered or the last tariff switch occurred shall keep on running;
• If the instruction contains an indication for a new tariff switch during the call period, the IPLMN/VPLMN shall set the reference point for the next tariff switch and store the new set of e-values, if available.

When the reference point for the tariff switch is reached, the stored set of e-values (if available) is sent immediately to the mobile station. When the call leg is released, the IPLMN/VPLMN shall report to the CSE:

• If no tariff switch has occurred since the call leg was answered or since the call was modified by a CPH procedure:
  • The elapsed time since the call leg was answered or modifiied by a CPH procedure.
• If a tariff switch has occurred since the call leg was answered or since the call was modified by a CPH procedure:
  • The elapsed time since the last tariff switch occurred,
  • The elapsed time from when the call leg was answered or modified by a CPH procedure or from when the previous tariff switch occurred to the time when the most recent tariff switch occurred.

In addition, the report to the CSE shall always contain an indication of whether the call leg is active or held. The following figure explains the division of a call leg into separate call periods and shows which information is sent and when from the IPLMN/VPLMN to the CSE.

• Reference Point 1: when the call leg is answered, tariff 1 applies
• Reference Point 2: the point in time when tariff 2 applies
• Reference Point 3: the point in time when tariff 3 applies
• A call period is a certain time part of an ongoing call. The duration of a call period is limited by the granted time from the CSE.
• Timers indicating the maximum duration (or granted time) for the call periods are called Tx (x is the number of the call period).
• Timers indicating the duration until the next tariff applies are called TSx (x is the number of the tariff).
• Timers indicating the elapsed time in a certain tariff are called TSxy (x is the number of the tariff and y is the elapsed time since the previous reference point).
• When a call period is ended, the elapsed time in each tariff is reported to the CSE.

At the end of the call period any timer indicating the duration until the next tariff switch for this call leg is discarded. If the report is not confirmed by the CSE within a specified time, the IPLMN/VPLMN shall release the call leg. The procedure may be repeated sequentially, i.e. when a report is sent to the CSE, the CSE may instruct the IPLMN/VPLMN to monitor the call for a further period.