5.2.1 Network initiated location services operations

24.5713GPP5G System (5GS)Control plane Location Services (LCS) proceduresRelease 17Stage 3TS

5.2.1.1 Supplementary Services Location Notification

5.2.1.1.1 General

The supplementary services Location Notification operation enables the AMF to trigger the end-user notification verification process on the UE using NAS signalling. The supplementary services messages are transported using the DL NAS Transport message and the UL NAS Transport message defined in 3GPP TS 24.501 [3]. UE Location Privacy Indication information may be included in Location Notification Return Result to indicate whether subsequent LCS requests will be allowed or disallowed by the UE. Figure 5.2.1.1.1.1 illustrates an example of the NAS signalling transport applicable to a 5GC-MT-LR procedure for immediate or deferred location.

Figure 5.2.1.1.1.1: NAS signalling transport for Supplementary Services Location Notification

NOTE: The optional Additional Information IE of the DL/UL NAS Transport message is not used when the LCS Location Notification signalling is transported in the Payload container.

5.2.1.1.2 Normal operation

The network invokes a location notification procedure by sending a REGISTER message containing an LCS-LocationNotification invoke component to the UE as defined in 3GPP TS 24.080 [5]. This may be sent either to request verification for a 5GC-MT-LR or to notify the UE about an already authorized 5GC-MT-LR.

In case of privacy verification, the UE shall respond to the request by sending a RELEASE COMPLETE message containing the user’s response and optionally UE Location Privacy Indication information in a return result component (see figure 5.2.1.1.2.1).

If the timer T(LCSN) defined in 3GPP TS 24.080 [5] expires in the network before any response from the UE (e.g. due to no response from the user), the network shall interpret this by applying the default treatment defined in 3GPP TS 23.273 [2] (i.e. disallow location if barred by subscription or allow location if allowed by subscription).

In the case of location notification, the UE shall terminate the dialogue immediately by sending a RELEASE COMPLETE message containing a LocationNotification return result.

If the UE is unable to process the request received from the network, it shall return an error indication by sending a RELEASE COMPLETE message containing a return error component. Error values are specified in 3GPP TS 24.080 [5].

UE Network

REGISTER

<————————————————————————————————————————

Facility (Invoke = LCS-LocationNotification (notificationType, locationType, lcsClientExternalID, lcsClientName, lcsCodeword, lcsServiceTypeId, deferredLocationExt))

RELEASE COMPLETE

————————————————————————————————————————>

Facility (Return result = LCS-LocationNotification (verificationResponse, locationPrivacyIndication, validTimePeriod))

RELEASE COMPLETE

– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – ->

Facility (Return error (Error))

RELEASE COMPLETE

– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – ->

Facility (Reject (Invoke_problem))

RELEASE COMPLETE

<- – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –

Figure 5.2.1.1.2.1: Location Notification

5.2.1.2 Positioning Information Transport

The AMF sends an LPP message and an associated Correlation Identifier in the DL NAS Transport message (refer to 3GPP TS 24.501 [3] and 3GPP TS 23.273 [2] clause 6.11.1). Figure 5.2.1.2.1 illustrates an example of the NAS signalling transport for downlink LPP messages.

Figure 5.2.1.2.1: NAS signalling transport for downlink LPP messages

NOTE: If a scheduled location time is received in the LPP message, the UE in 5GMM-IDLE mode can initiate a service request procedure shortly before the scheduled location time.

5.2.1.3 Supplementary Services Periodic or Triggered Location

5.2.1.3.1 General

The supplementary services LCS PeriodicTriggered Invoke operation enables the LMF to initiate periodic or triggered location event reporting by a target UE as described in clause 6.3.1 of 3GPP TS 23.272 [2]. The supplementary services LCS PeriodicTriggered Invoke message is transferred to the target UE via the serving AMF in a DL NAS Transport message. A response from the target UE is similarly returned to the LMF via the serving AMF and is transferred to the AMF in an UL NAS Transport message. If the LCS PeriodicTriggered Invoke message in the Payload container IE of a DL NAS TRANSPORT message includes the deferred routing identifier, the UE shall include the deferred routing identifier in the Additional Information IE of a UL NAS TRANSPORT message during the subsequent procedures as specified in clause 5.2.2.

Figure 5.2.1.3.1.1 illustrates an example of the NAS signalling transport for initiation of periodic or triggered location,

Figure 5.2.1.3.1.1: NAS signalling transport for LCS PeriodicTriggered messages

NOTE: If a scheduled location time is received in the LCS PeriodicTriggered Invoke message, the UE in 5GMM-IDLE mode can initiate a service request procedure shortly before the scheduled location time.

5.2.1.3.2 Normal operation

The LMF sends a REGISTER message to the UE containing the supplementary services LCS PeriodicTriggered Invoke component as defined in 3GPP TS 24.080 [5]. The REGISTER message is transported to the UE via the serving AMF as described in figure 5.2.1.3.1.1.

If the UE can support the periodic or triggered location, the UE returns a RELEASE COMPLETE message to the LMF containing an LCS PeriodicTriggered return result. The RELEASE COMPLETE message is transported to the LMF via the serving AMF as described in figure 5.2.1.3.1.1.

If the UE is unable to process or support the request received from the network, it shall return an error indication by sending a RELEASE COMPLETE message containing a return error component or reject component. Error values are specified in 3GPP TS 24.080 [5].

Figure 5.2.1.3.2.1 illustrates the signalling for normal operation between the UE and the network.

UE Network

REGISTER

<————————————————————————————————————————

Facility (Invoke = LCS-PeriodicTriggered (referenceNumber, qos, periodicLocation, areaEventReporting, motionEventReporting, referenceNumberExt, h-gmlc-callBackUri, supportedGADShapes, deferredRoutingIdentifier, reportingAccessTypes, multiplePositioningProtocolPDUs, controlPlane-CIoT-5GS-Optimisation, scheduledLocTime))

RELEASE COMPLETE

————————————————————————————————————————>

Facility (Return result = LCS-PeriodicTriggered)

RELEASE COMPLETE

– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – ->

Facility (Return error (Error))

RELEASE COMPLETE

– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – ->

Facility (Reject (Invoke_problem))

RELEASE COMPLETE

<- – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –

Figure 5.2.1.3.2.1: Periodic or Triggered Location Invocation

5.2.1.4 Supplementary Services Cancel Deferred Location

5.2.1.4.1 General

The supplementary services Cancel Deferred Location operation enables the AMF to cancel ongoing periodic or triggered location in a target UE using NAS signalling as described in 3GPP TS 23.273 [2] clause 6.3.3. The supplementary services Cancel Deferred Location messages are transported using the DL NAS Transport message and the UL NAS Transport message defined in 3GPP TS 24.501 [3]. Figure 5.2.1.4.1-1 illustrates an example of the NAS signalling transport.

Figure 5.2.1.4.1.1: NAS signalling transport for Cancel Deferred Location

NOTE: The optional Additional Information IE of the DL/UL NAS Transport message is not used when the LCS CancelDeferredLocation signalling is transported in the Payload container.

5.2.1.4.2 Normal operation

The AMF invokes a cancel deferred location procedure by sending a REGISTER message containing an LCS-CancelDeferredLocation invoke component to the UE as defined in 3GPP TS 24.080 [5].

The UE shall terminate the ongoing periodic or triggered location if this can be identified from the information in the LCS-CancelDeferredLocation invoke component.

The UE shall then return a RELEASE COMPLETE message containing an LCS-CancelDeferredLocation return result component (see figure 5.2.1.4.2.1).

If the UE is unable to process the request received from the network or cannot identify the ongoing periodic or triggered location to be terminated, it shall return an error indication by sending a RELEASE COMPLETE message containing a return error component. Error values are specified in 3GPP TS 24.080 [5].

UE Network

REGISTER

<————————————————————————————————————————

Facility (Invoke = LCS-CancelDeferredLocation (referenceNumberExt, h-gmlc-callBackUri))

RELEASE COMPLETE

————————————————————————————————————————>

Facility (Return result = LCS-CancelDeferredLocation)

RELEASE COMPLETE

– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – ->

Facility (Return error (Error))

RELEASE COMPLETE

– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – ->

Facility (Reject (Invoke_problem))

RELEASE COMPLETE

<- – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –

Figure 5.2.1.4.2.1: Cancel Deferred Location