4.1.4 Signalling deactivation

32.4223GPPRelease 17Subscriber and equipment traceTelecommunication managementTrace control and configuration managementTS

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

4.1.4.1 General

4.1.4.1.1 General signalling deactivation mechanisms for UMTS and EPS

In Signalling deactivation, the Trace Deactivation shall always be carried out from the Core Network EM only [EM (PS), EM (CS), EM(EPC) and EM (HSS) are generally considered to be in the Core Network. A Core Network EM can be any of these or their combinations]. In case of home subscriber trace (i.e. in the HPLMN) the Trace Session deactivation shall go to the HSS, MSC Server/VLR, SGSN or MME. In case of foreign subscriber trace (i.e. the HPLMN operator wishes to deactivate tracing on foreign subscribers roaming in his PLMN) the Trace Session deactivation shall go the MSC Server/VLR SGSN or MME. The Management System shall deactivate the Trace Session in the same NE where it activated the Trace Session.

When an HSS receives a Trace Session deactivation from its Management system, it shall deactivate the active Trace Session corresponding to the Trace Reference received in the deactivation message. The HSS shall delete all trace control and configuration parameters associated with this Trace Session. If a Trace Recording Session is active at the time of receiving a Trace Session deactivation message from the EM, the HSS may choose to continue the Trace Recording Session till it ends gracefully or may stop it immediately. In all cases, the HSS shall deactivate the requested Trace Session immediately at the end of the Trace Recording Session.

4.1.4.1.2 General signalling deactivation mechanisms for 5GS

In 5GS the signaling trace deactivation utilizes the Services Based Management Architecture (SBMA) defined in TS 28.533 [48]. The 5GC NE Trace Control and Configuration parameters are removed via interaction between Provisioning MnS (see definitions in TS 28.532 [47]) consumer and Provisioning MnS producer. Figure 4.1.4.1.2-1 below illustrates the 5GS signaling deactivation where the role of a Provisioning MnS producer is played by the 5GC NE and the role of a Provisioning MnS consumer is played by the Management System. The 5GC NE shall propagate the deactivation to in the entire network. Detailed signalling deactivation mechanisms are specified for 5GC in clause 4.1.4.11 and for NG-RAN in clause 4.1.4.12.

Figure 4.1.4.1.2-1: Overview of signaling deactivation for 5GS

4.1.4.2 UTRAN deactivation mechanisms

When RNC receives the CN_DEACTIVATE_TRACE message it shall deactivate the Trace Session for the indicated Trace Reference in the CN_DEACTIVATE_TRACE message. In case of simultaneous CS/PS connections, the trace session for the indicated Trace Reference shall be closed upon reception of the CN DEACTIVATE TRACE message from any of the CN domain, whether it was the one which initiated trace session activation or not.

The Trace Session is also deactivated in the RNC when the Iu connection to the Core Network is released.

If CN_INVOKE_TRACE message is received for only one Iu connection (either CS or PS) the Trace Session shall be deactivated in the RNC when the IU_RELEASE_COMMAND message is received from the Core Network for that Iu connection where the CN_INVOKE_TRACE message is sent.

The following figure shows this behaviour:

Figure 4.1.4.2.1: Trace session deactivation (Signalling) in UTRAN 1

If CN_INVOKE_TRACE message is received by the RNC for both Iu-CS and Iu-PS connection with the same Trace Reference number than the Trace Session shall not be deactivated in the RNC when any of the Iu connection is released (when the first IU_RELEASE_COMMAND message is received). The Trace Session shall be deactivated when the second Iu connection is released (the second IU_RELEASE_COMMAND message is received). The following figure shows the situation.

Figure 4.1.4.2.2: Trace session deactivation (Signalling) in UTRAN 2

Interaction with Soft-handover

The Trace Session should be deactivated in a Drift RNC when the DRNC receives the IUR_DEACTIVATE_TRACE message or the Iur connection is released.

When an RNC deactivates a Trace Session the Trace Recording Session shall also be stopped at the same time.

NOTE: In RNC the Trace Session and the Trace Recording Session always the same.

4.1.4.3 PS Domain deactivation mechanisms

When an HSS receives a Trace Session deactivation from the Management System it shall send a MAP_DEACTIVATE_TRACE_MODE message to the SGSN.

When the SGSN receives a MAP_DEACTIVATE_TRACE_MODE message it shall deactivate the Trace Session identified by the Trace Reference received in the MAP_DEACTIVATE_TRACE_MODE message.

If a Trace Recording Session is active at the time of receiving a deactivation message (in SGSN it is the MAP-DEACTIVATE_TRACE_MODE, in GGSN it is the GTP Update PDP Context Request or the Update MBMS Context Request, in BM-SC it is the Diameter Gmb STR message), the SGSN and/or the GGSN and/or the BM-SC may choose to continue the Trace Recording Session till it ends gracefully or may stop it immediately. In all cases, the SGSN/GGSN/BM-SC shall deactivate the requested Trace Session immediately at the end of the Trace Recording Session. When the SGSN deactivates the Trace Session, it shall delete all trace control and configuration parameters associated with the corresponding Trace Session.

If SGSN deactivates the Trace Session during the Trace Recording Session, the SGSN should deactivate the trace to the RNC by using the CN_DEACTIVATE_TRACE RANAP message and should deactivate the trace to the GGSN by sending the GTP Update PDP Context Request or the Update MBMS Context Request message with Trace Activity Control set to Trace Deactivation.

If the GGSN deactivates the Trace Session during the Trace Recording Session, the GGSN should deactivate the trace to the BM-SC (by sending a Diameter Gmb STR message).

4.1.4.4 CS Domain deactivation mechanisms

When an HSS receives Trace Session deactivation from the Management System it shall send a MAP_DEACTIVATE_TRACE_MODE message to the MSC Server.

When the MSC Server receives a MAP_DEACTIVATE_TRACE_MODE message it shall deactivate the Trace Session identified by the Trace Reference received in the MAP_DEACTIVATE_TRACE_MODE message.

If a Trace Recording Session is active at the time of receiving a MAP_DEACTIVATE_TRACE_MODE message from the HSS, the MSC Server may choose to continue the Trace Recording Session till it ends gracefully or may stop it immediately. In all cases, the MSC Server shall deactivate the requested Trace Session immediately at the end of the Trace Recording Session. When the MSC Server deactivates the Trace Session it shall delete all trace control and configuration parameters associated with the corresponding Trace Session. .

If MSC Server deactivates the Trace Session during a Trace Recording Session, it should deactivate the trace to the RNC by sending the CN_DEACTIVATE_TRACE RANAP message and should deactivate the trace to the MGW.

4.1.4.5 Void

4.1.4.6 Service Level Trace in IMS deactivation mechanisms

4.1.4.6.1 General

When an IMS NE (i.e. S/I/P-CSCF, AS, HSS, MRF, MGCF, BGCF) receives Trace Session deactivation the Trace Session, as identified by the Trace Reference, shall be deactivated.

If a Trace Recording Session(s) within the Trace session is active at the time of receiving a Trace Session deactivation, the IMS NE may stop the trace recording session(s) immediately or it may choose to continue the Trace Recording Session(s) till the session(s) ends gracefully (e.g. the SIP session ends after a specific period of time, or upon completion of a SIP session and the reception of a SIP BYE).

In all cases, the IMS NE shall deactivate the requested Trace Session immediately at the end of the Trace Recording Session(s). When the IMS NE deactivates the Trace Session, it shall delete all associated trace control and configuration parameters associated with that Trace Session.

4.1.4.6.2 Trace session deactivation at an IMS NE

4.1.4.6.2.1 Trace session deactivation propagated by EM

Trace Session deactivation may be initiated from the Core Network EM only [EM (UE), and EM (HSS)]. The same EM that initiated Trace Session activation shall initiate a Trace Session deactivation in the same Network Element (NE).

When Trace Session deactivation is required for a registered home subscriber in the home IM CN SS, Trace Session deactivation shall go to the UE and the HSS. The HSS shall propagate the Trace Session deactivation to the S-CSCF, I-CSCF, and the AS. The S-CSCF and I-CSCF shall propagate the Trace Session deactivation to the P-CSCF. The Trace Session deactivation shall be propagated to the MRF, MGCF and BGCF via the S-CSCF.

When Trace deactivation is required for a registered home subscriber in a visited IM CN SS, Trace Session deactivation shall go to the UE and the HSS. The HSS shall propagate the Trace Session deactivation to the S-CSCF, I-CSCF and the AS.

Depending on whether the I-CSCF had previously propagated a Trace Session Activation to the P-CSCF serving the UE (see subclause 4.1.2.9.2) where Trace is to be initiated the I-CSCF may propagate the Trace Session deactivation to the P-CSCF.

4.1.4.6.2.2 Trace session deactivation following a Triggering event

An Active Trace Session may be deactivated at an IMS NE following the detection of a Stop Triggering Event, e.g. Trace Session expiry time.

In the case where there is one or more active Trace Recording Sessions, the IMS NE shall deactivate the Trace Session immediately following the detection of a Stop Triggering Event associated for each of the Trace Recording Session(s), e.g. following the detection of SIP final response or a SIP Request Failure.

When the IMS NE deactivates the Trace Session Stop Triggering Event, it shall delete all associated trace control and configuration parameters associated with that Trace Session.

4.1.4.6.2.3 Trace session deactivation initiated directly by an EM

When required, an active Trace Session at an IMS NE may be deactivated directly by its EM. The Management based Trace Session deactivation mechanism (see clause 4.1.1) shall be used for this purpose.

4.1.4.6.3 Trace session deactivation at the UE

The EM (UE) and the interactions between the EM (UE) and the UE shall be achieved using OMA Device Management [18].

Figure 4.1.4.6.3.1 illustrates the sending of Trace Session Deactivation from the Device Management Server (DMS) to a UE.

Figure 4.1.4.6.3.1: Trace session deactivation at a UE

Trace Session deactivation shall be initiated from the Device Management Server (DMS). The same DMS that initiated Trace Session activation shall initiate a Trace Session deactivation in the same UE (Step 1).

When a UE receives Trace Session Deactivation as part of the received management operation from its DMS (Step 2) it may deactivate the Trace Session (Step 3).

If a Trace Recording Session(s) within the Trace session is active at the time of receiving a Trace Session deactivation, the UE may stop the trace recording session(s) immediately (see note), or it may choose to continue the Trace Recording Session(s) until the session(s) end gracefully (e.g. the SIP session ends after a specific period of time, or upon completion of a SIP session and the reception of a SIP BYE).

NOTE: When the Trace session is stopped the UE may deactivate or delete its management operation.

4.1.4.7 EPC deactivation mechanisms

When an HSS receives a Trace Session Deactivation from the Management System it shall send an S6a-Delete Subscriber Data Request message to the MME at which the UE is currently registered if MME is included in the NE types for Tracing, via the S6a interface to remove the "trace data" from subscription data (see 3GPP TS 29.272[26]). The HSS shall deactivate trace if trace is active at the HSS.

When the MME receives the S6a-Delete Subscriber Data Request message to remove the "trace data" from subscription data (see 3GPP TS 29.272 [26]) or the Trace Session is deactivated directly from the EM it shall deactivate the Trace Session identified by the Trace Reference.

If the UE was registered to the HSS by an MME via the S6a interface, (i.e. the user is attached to a 3GPP access network), the Trace Session shall be deactivated to the MME via the S6a interface.

If the user was registered by a AAA server via the SWx interface (i.e. the user is attached to a non-3GPP network) the HSS shall send the Trace Session deactivation request with a push profile request.

The AAA server shall examine the received user profile and if it detects that the Trace Session shall be deactivated, it shall initiate a re-authorization procedure towards the PDN GW. The Trace Session is deactivated in the PDN GW by using this re-authorization procedure.

When the PDN GW receives the updated authorization data with trace information that represents Trace Session deactivation request, it shall deactivate the Trace Session identified by the Trace Reference.

The following figure illustrates the Trace Session deactivation when the user is attached to a non-3GPP access network for DSMIPv6 on S2c or PMIP on S2a/S2b.

Figure 4.1.4.7.1: Trace Session deactivation in case UE attached from non-3GPP access network for DSMIPv6 on S2c or PMIP on S2a/S2b

The AAA server shall examine the received user profile and if it detects that the Trace Session shall be deactivated, it shall initiate a re-authorization procedure towards the ePDG.
The ePDG shall examine the received information from the AAA and if it detects that the Trace Session shall be deactivated (see 3GPP TS 29.273 [22]), it shall initiate a trace deactivation procedure towards the PDN GW (see 3GPP TS 29.274 [34]).

When the PDN GW receives the data with trace information that represents Trace Session deactivation request, it shall deactivate the Trace Session identified by the Trace Reference.

Figure 4.1.4.7.2: Trace Session deactivation in case UE attached from non-3GPP access network for GTP based S2b interface

If a Trace Recording Session is active at the time of receiving a deactivation message, the MME may choose to continue the Trace Recording Session until it ends gracefully or may stop it immediately. In all cases, the MME shall deactivate the requested Trace Session immediately at the end of the Trace Recording Session. When the MME deactivates the Trace Session, it shall delete all trace control and configuration parameters associated with the corresponding Trace Session.

If MME deactivates the Trace Session during the Trace Recording Session, the MME should deactivate the trace at the eNB by sending the S1-Deactivate Trace message to the eNodeB via the S1 interface and should deactivate the trace at the SGW by sending an S11-Trace Session Deactivation message to the SGW via the S11 interface. The message sent by MME shall include the Trace Reference to identify the Trace Session that is to be deactivated.

When SGW receives an S11-Trace Session Deactivation message from the MME, the SGW may choose to continue the Trace Recording Session until it ends gracefully or may stop it immediately. In all cases, the SGW shall deactivate the requested Trace Session immediately at the end of the Trace Recording Session. If SGW deactivates the Trace Session during the Trace Recording Session, the SGW should deactivate the trace at the PDN GW by sending the S5-Trace Session Deactivation message to the PGW via the GTP based S5 interface. In case of PMIP based S5 interface the SGW should deactivate the trace to the PDN GW using PCC signalling, i.e. by sending a Trace Deactivation message to the PCRF and PCRF forwards the trace deactivation message to the PDN GW [29].When the SGW deactivates the Trace Session, it shall delete all trace control and configuration parameters associated with the corresponding Trace Session.

When PGW receives an S5-Trace Session Deactivation message from the SGW, or S2b-Trace Session Deactivation message from the ePDG, or it receives the Trace Session Deactivation message from PCRF in case of PMIP based S5, the PDN GW may choose to continue the Trace Recording Session until it ends gracefully or may stop it immediately. In all cases, the PDN GW shall deactivate the requested Trace Session immediately at the end of the Trace Recording Session. When the PDN GW deactivates the Trace Session, it shall delete all trace control and configuration parameters associated with the corresponding Trace Session.

When a Trace Session Deactivation message is sent on any interface the Trace Reference that identifies the Trace Session shall be included to the Trace Session Deactivation message.

4.1.4.8 E-UTRAN deactivation mechanisms

There are two different events that deactivate a Trace Session:

1) When eNB receives the S1- Deactivate Trace message it shall deactivate the Trace Session for the indicated Trace Reference.

2) When the eNB releases the UE context the Trace Recording Session shall be stopped and the Trace Session is deactivated at the eNB.

4.1.4.9 EPC deactivation mechanisms for MDT

When the MME receives a Trace Session Deactivation request for an MDT Trace Session of a UE, it shall act according to the following.

In case of an immediate MDT trace session and the UE being in connected mode, the MME shall send trace session deactivation toward the eNodeB. The eNodeB shall deactivate the corresponding MDT RRC measurements in the UE and shall discard the given trace session context.

In case of an immediate MDT trace session and the UE being in idle mode, the MME shall silently discard the stored trace session context.

Note: Signaling based deactivation does not apply for logged MDT or Logged MBSFN MDT trace sessions, the logged MDT and Logged MBSFN MDT trace session terminates when logging duration expires.

4.1.4.10 Deactivation mechanisms at UE for MDT

The UE shall discard a logged MDT or Logged MBSFN MDT trace session when logging duration expires and shall indicate the availability of logged measurement results to the network next time it enters connected mode.

4.1.4.11 5GC deactivation mechanisms

Figure 4.1.4.11.1 illustrates the signaling Trace Session deactivation procedure in 5GC:

Figure 4.1.4.11.1: Trace deactivation in 5GC procedure

1. Management system deactivates Trace Session to the UDM.

2. UDM sends Nudm_SDM_Notification to AMF with the trace deactivation information (see clause 5.2.3.3.3 of 3GPP TS 23.502 [41]).

3. AMF deactivates the Trace Session according to the received information.

4. AMF sends the DEACTIVATE TRACE message over NG interface (N2 interface from the 5GC perspective)

5. NG-RAN node deactivates the Trace Session according to the received information received from the AMF. This step is part of NG-RAN signaling trace deactivation – see clause 4.1.2.12 for more details.

6. AMF sends the Nsmf_PDUSession_UpdateSMContext request to the SMF

7. SMF deactivates the Trace Session according to the received information.

8. SMF performs Session Management Policy Modification with PCF (see step 7 in clause 4.3.3.2 of 3GPP TS 23.502 [41]) and provides the trace deactivation information to the PCF.

9. PCF deactivates the Trace Session according to the received information.

10 SMF performs N4 Session Modification with UPF (see step 10 in clause 4.3.3.2 of 3GPP TS 23.502 [41]) and provides the trace deactivation information to the UPF.

11. UPF deactivates the Trace Session according to the received information.

Figure 4.1.4.11.2 illustrates the signaling Trace Session deactivation procedure in 5GC where UDM notifies SMF about trace deactivation directly:

Figure 4.1.4.11.2: Trace deactivation in 5GC procedure (with UDM to SMF notification)

1. Management system deactivates Trace Session to the UDM.

2. UDM sends Nudm_SDM_Notification to AMF with the trace deactivation information (see clause 5.2.3.3.3 of 3GPP TS 23.502 [41]).

3. AMF deactivates the Trace Session according to the received information.

4. AMF sends the DEACTIVATE TRACE message over NG interface (N2 interface from the 5GC perspective)

6. UDM sends Nudm_SDM_Notification to SMF with the trace deactivation information (see clause 5.2.3.3.3 of 3GPP TS 23.502 [41]).

7. SMF deactivates the Trace Session according to the received information.

8. SMF performs Session Management Policy Modification with PCF (see step 7 in clause 4.3.3.2 of 3GPP TS 23.502 [41]) and provides the trace deactivation information to the PCF.

9. PCF deactivates the Trace Session according to the received information.

10 SMF performs N4 Session Modification with UPF (see step 10 in clause 4.3.3.2 of 3GPP TS 23.502 [41]) and provides the trace deactivation information to the UPF.

11. UPF deactivates the Trace Session according to the received information.

4.1.4.12 NG-RAN deactivation mechanisms

There are two different events that deactivate a Trace Session:

1. When NG-RAN node receives the DEACTIVATE TRACE message using NG interface, it shall deactivate the Trace Session for the indicated Trace Reference.

2. When the NG-RAN node releases the UE context the Trace Recording Session shall be stopped and the Trace Session is deactivated at the NG-RAN node.

If the NG-RAN node is not able to deactivate the trace session due to ongoing handover of the UE to another NG-RAN node, the NG-RAN node shall inform the AMF with the TRACE FAILURE INDICATION message using NG interface.

In case of an immediate MDT trace session and the UE being in connected mode in a split architecture, the AMF shall send DEACTIVATE TRACE message using NG interface toward the gNB-CU-CP. The gNB-CU-CP shall send trace session deactivation towards gNB-CU-UP and/or gNodeB-DU if the trace sessions in the gNB-CU-UP and/or gNB-DU have been activated by the gNB-CU-CP. The gNB-CU-CP shall also deactivate the corresponding MDT RRC measurements in the UE and shall discard the given trace session context.

Note: Signaling based deactivation does not apply for logged MDT trace sessions. The logged MDT trace session terminates when logging duration expires.

4.1.4.13 5GC deactivation mechanisms for MDT

When the AMF receives a Trace Session Deactivation request for an MDT Trace Session of a UE, it shall act according to the following.

In case of an immediate MDT trace session and the UE being in connected mode, the AMF shall send trace session deactivation toward the eNB/gNB. The eNB/gNB shall deactivate the corresponding MDT RRC measurements in the UE and shall discard the given trace session context.

In case of an immediate MDT trace session and the UE being in idle mode, the AMF shall silently discard the stored trace session context.

In case of an immediate MDT trace session and the UE being in inactive state, the AMF that is aware of inactive state shall silently discard the stored trace session context.

Note: Signaling based deactivation does not apply for logged MDT or Logged MBSFN MDT trace sessions. The logged MDT and Logged MBSFN MDT trace session terminates when logging duration expires.