5 LCS charging principles and scenarios

32.2713GPPCharging managementLocation Services (LCS) chargingRelease 17Telecommunication managementTS

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

Editor’s note: Include a brief introduction statement saying that this clause contains the CDR and charging event types and their trigger conditions.

5.1 LCS charging principles

Charging information in the Service domain for LCS is collected for inter-operator charging purpose by the GMLC. The basic principle is that a network requesting location information may be charged by the network that provides the location information.

The GMLC shall collect the following charging information:

– Identity of the mobile subscriber to be located and of the entity requesting the location;

– Identity of the GMLC or PLMN serving the LCS Client;

– QoS Requested/Delivered: the charging information shall describe the quality of the location requested and delivered to the LCS client;

– Request Timestamp: the charging information shall record the date and time the location procedure was requested by the LCS client;

– Location services requested: the charging information shall describe the service types for which the LCS client is allowed to locate the particular UE;

– Usage of continuous/periodic tracking;

– Charging for Location Based Services (LBS): the charging information shall describe the service specific information in addition to the above location resource information.

The information listed above is captured for use cases in relation to:

– Mobile Originated Location Request;

– Mobile Terminated Location Request;

– Network Induced Location Request;

Refer to TS 23.271 [201] for further details on the above LCS transactions.

5.2 LCS offline charging scenarios

5.2.1 Basic principles

Editor’s note: TBD.

5.2.2 Rf message flows

Not applicable, as the separation of the CTF and CDF is not in the scope of the LCS charging standards. Refer to clause 4.2 for further information.

NOTE: Vendors may nevertheless implement a separate CTF and CDF for LCS charging. In this case, it is recommended that the approach chosen conforms to the principles and protocol applications specified in TS 32.299 [50].

5.2.3 CDR Generation

5.2.3.0 Introduction

Editor’s note: This clause shall also include the triggers of the CDR generation, the CDR types

The flows described in the present document specify the charging communications between the GMLC and the billing function for different charging scenarios. The LCS related messages associated with these charging scenarios are shown primarily for general information and to illustrate the charging triggers.

For the purpose of these examples, the following assumptions have been made:

– that the RAN location procedures are not depicted;

– that the CS and PS location procedures are not distinguished;

– that the LCS client has no privacy override capability;

– that the LCS charging procedures in the CS and the PS domains are not depicted

5.2.3.1 Mobile Originated Location Request (MO-LR)

MO-LR allows the UE to obtain its own geographical location or have its location information transferred to another LCS client. In this procedure, the R-GMLC, H-GMLC and V-GMLC are the same as no privacy checking is performed.

Figure 5.2.3.1.1 illustrates a MO-LR that allows a UE to request its own location.

Figure 5.2.3.1.1: Record trigger overview for MO-LR

1) The MSC (or SGSN) receives a Location Service Invoke from the UE.

2) The MSC (or SGSN) forwards the Location result to the GMLC by sending a MAP Subscriber Location Report.

3) The GMLC transfers the location information to the LCS client.

4) The LCS Client sends to the GMLC the Location Information ack message signalling the result.

5) The GMLC acknowledges the MAP Subscriber Location Report and the associated MO-LR CDR is processed as specified in TS 32.297 [52].

6) The MSC (or SGSN) returns a Service Response message to the UE carrying any location estimate requested by the UE.

The record trigger associated to the MO-LR is called ‘LCS GMLC Mobile Originated’ (LCS-GMO)

5.2.3.2 Mobile Terminated Location Request (MT-LR)

MT-LR allows an external LCS client to ask for the location of a mobile subscriber (target UE). Figure 5.2.3.2.1 illustrates a MT-LR scenario:

Figure 5.2.3.2.1: Record trigger overview for MT-LR

1. The external LCS client requests the location of a target UE from the R-GMLC.

2. The R-GMLC requests the H-GMLC address by sending a MAP Send Routing Info for LCS message to the home HLR/HSS of the target UE to be located.

3. The HLR/HSS returns a MAP Send Routing Info for LCS ack message that contains the H-GMLC address

4. The R-GMLC forwards the Location Service Request to the H-GMLC.

5. After performing privacy check, the H-GMLC requests the V-GMLC address by sending a MAP Send Routing Info for LCS message to the home HLR/HSS.

6. The HLR/HSS returns a MAP Send Routing Info for LCS ack message that contains the V-GMLC address.

7. The H-GMLC forwards the Location Service Request to the V-GMLC.

8. The V-GMLC forwards the Location request to the MSC or SGSN by sending a MAP Provider Subscriber Location Report.

9. After either a CS-MT-LR or PS-MT-LR was processed, the MSC or SGSN sends the acknowledgement of the MAP Provider Subscriber Location Report.

The associated LCS VGMT CDR is processed as specified in TS 32.297 [52].

10. The V-GMLC sends the location service response to the H-GMLC. After the H-GMLC has performed privacy check, the associated LCS HGMT CDR is processed as specified in TS 32.297 [52].

11. The H-GMLC sends the location service response to the R-GMLC and the associated LCS RGMT CDR is processed as specified in TS 32.297 [52].

12. The R-GMLC returns a Service Response message to the LCS client carrying any location estimate requested by the LCS client.

5.2.3.3 Network Induced Location Request (NI-LR)

NI-LR allows positioning for an emergency service call. Figure 5.2.3.3.1 illustrates a NI-LR scenario:

Figure 5.2.3.3.1: Record trigger overview for NI-LR

1. An emergency call procedure is initiated between the UE and the LCS client.

2. Positioning procedures are instigated.

3. The MSC (or SGSN) forwards the Location request to the GMLC by sending a MAP Subscriber Location Report.

4. The GMLC acknowledges the MAP Subscriber Location Report.

5. The GMLC transfers the location information to the LCS client and the associated LCS-GNI-CDR is processed as specified in TS 32.297 [52].

6. At some later time, the emergency services call is released.

5.2.4 Ga record transfer flows

Not applicable, as the separation of the CDF and CGF is not in the scope of the LCS charging standards.
Refer to clause 4.2 for further information.

NOTE: Vendors may nevertheless implement a separate CDF and CGF for LCS charging.
In this case, it is recommended that the approach chosen conforms to the principles and protocol applications specified in TS 32.295 [54].

5.2.5 B_L CDR file transfer

The integrated CGF of the GMLC transfers the CDR files to the BD as described in TS 32.297 [52]. In LCS, both fully qualified partial CDRs (FQPC) and reduced partial CDRs (RPC), as specified in TS 32.240 [1] may be supported on the Bl interface. In line with TS 32.240 [1], the support of FQPCs is mandatory, the support of RPCs is optional.
For further details on the Bl protocol application refer to TS 32.297 [52].

5.3 LCS online charging scenarios

5.3.0 General

LCS online charging uses the Debit / Reserve Units operation as specified in TS 32.299 [50].

5.3.1 Basic principles

Two cases for LCS online charging are distinguished:

– Immediate Event Charging (IEC); and

– event charging with unit reservation (ECUR).

In the case of IEC, granting units to the GMLC is performed in a single operation that also includes the deduction of the corresponding monetary units from the subscriber’s account. The charging process is controlled by the corresponding credit control request which is sent for a given credit control event.

In contrast, ECUR also includes the process of requesting, reserving units and releasing and returning unused units. The deduction of the corresponding monetary units then occurs upon conclusion of the ECUR transaction. In this case, the credit control request is used to control the credit control session.

The GMLC may apply either IEC, where Debit / Reserve Units Request[ event] messages are generated, or ECUR, using Debit / Reserve Units Request[ Initial, Update and Termina e]t. The decision whether to apply IEC or ECUR is based on the service and/or operator’s policy.

5.3.2 Ro message flows

5.3.2.0 General

The message flows described in the present document specify the charging communications between the GMLC and the Online Charging System (OCS) for different charging scenarios. The LCS messages associated with these charging scenarios are shown primarily for general information and to illustrate the charging triggers that are also used for LCS offline charging.

5.3.2.1 Mobile Originated Location Request (MO-LR)

Figure 5.3.2.1.1 shows the Debit Units operation that are required between GMLC and OCS during the MO-LR. In this scenario the UE is the party to charge for the Location Request.

Figure 5.3.2.1.1: LCS online charging scenario for MO-LR

5.3.2.2 Mobile Terminated Location Request (MT-LR)

Figure 5.3.2.2.1 shows the Debit Units operation that are required between GMLC and OCS during the MT-LR .

Figure 5.3.2.2.1: LCS online charging scenario for MT-LR