15 Charging Activities

22.0783GPPCustomised Applications for Mobile network Enhanced Logic (CAMEL)Release 17Service descriptionStage 1TS

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

The following general principles are valid for CAMEL based charging aspects:

– Calls may be divided into call periods for the purpose of controlling the call duration;

– The management and the control of tariff switches is under the responsibility of the HPLMN. There may be a tariff switch for the CSE control of e-values and separate tariff switches for the control of call duration (which apply per call leg).The time at which these tariff switches apply may differ or the CSE control of e-values and for the control of the call duration.;

– The tariff switch time is indicated to the network in the form of a time relative to the reception of the instruction.

In a CPH configuration, the following procedures shall apply per call party:

– Inclusion in charging records of information received from the CSE (subclause 15.2);

– Support of additional charging information to the CSE (subclause 15.3);

– CSE control of call duration (subclause 15.4).

The e values sent by the CSE are reported only to the served subscriber and only if this subscriber is connected to the CPH configuration (subclause 15.1).

15.1 CSE controlled e-values

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.

15.2 Inclusion in charging records of information received from the CSE

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.

15.3 Support of additional charging information to the CSE

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.

15.4 CSE control of call duration

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:

a) Receive a maximum call period duration from the CSE for a call leg;

b) Receive a switch time after which the next tariff switch applies for a call leg;

c) 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.

Figure 1: CSE control of call duration

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.