4.1.1 Management activation

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

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

4.1.1.1 General

4.1.1.1.1 General management activation mechanisms for UMTS and EPS

In Management activation, the Trace Control and Configuration parameters are sent directly to the concerned NE by its management system in UMTS or EPS (by its EM). This NE shall not propagate the received data to any other NE’s – whether or not it is involved in the actual recording of the call.

Once the parameters have been provided, the NE looks for the IMSI or IMEI (IMEISV) passing through it. If it does not have them, these shall be provided to the NE (that performs the trace recording) as part of traffic signalling by the CN.

The following figure represents the management based trace functionality within a PLMN. The figure represents a typical PLMN network. A dotted arrow with "Trace Parameter Configuration" represents the availability of the management based trace functionality at the EM for that domain.

NOTE: There is no propagation of trace parameters in management based trace activation.

Figure 4.1.1.1.1: Overview of management activation for an UMTS system

If the NE failed to activate the Trace Session, a Trace failure notification shall be sent to the TCE, and the Trace failure notification has the the same parameters as the notification notifyTraceRecordingSessionFailure defined in 3GPP TS 32.442 [24], the Trace failure notification file XML schema is defined in Annex A.

4.1.1.1.2 General management activation mechanisms for 5GS

In 5GS the management trace activation utilizes the Services Based Management Architecture (SBMA) defined in TS 28.533 [48]. The NE is configured with Trace Control and Configuration parameters via interaction between Provisioning MnS (see definitions in TS 28.532 [47]) consumer and Provisioning MnS producer. Figure 4.1.1.1.2-1 below illustrates the 5GS management activation where the role of a Provisioning MnS producer is played by the NE and the role of a Provisioning MnS consumer is played by the Management System. The configured NE shall not propagate the received Trace Control and Configuration parameters to any other NE’s – whether or not it is involved in the actual recording of the call.

Figure 4.1.1.1.2-1: Overview of management activation for 5GS

Once configured with Trace Control and Configuration parameters, the NE shall activate the Trace Session. If the NE failed to activate the Trace Session in a file-based reporting case, a Trace failure notification shall be sent to the TCE. XML based encoding of the Trace failure notification file is defined in Annex A. Administrative messages can also be used if the NE failed to activate a Trace Session, or if there are errors for an ongoing session, and are included in the trace data. An example of an administrative message is the Trace Recording Session Not Started administrative message (see TS 32.423 [3]).

4.1.1.2 UTRAN activation mechanisms

When an RNC receives Trace Session activation from the EM it shall start a Trace Session. The trace control and configuration parameters of the Trace Session are received in Trace Session activation from the EM. The RNC shall not forward these trace control and configuration parameters to other nodes. The received trace control and configuration parameters shall be saved and used to determine when and how to start a Trace Recording Session. (Starting a Trace Recording Session is described in subclause 4.2.2.1). A Trace Session may be requested for a limited geographical area.

Since a RNC has visibility of an IMSI, it can start an IMSI Trace all by itself when a Trace session is requested for an IMSI or a list of IMSI’s. However, a RNC does not have visibility of the IMEI(SV). Hence, when a Trace session is requested for an IMEI(SV) or a list of IMEI(SV), the RNC shall send the requested IMEI(SV) / list of IMEI(SV)s in an ‘Uplink Information Exchange Request’ message to the interacting MSC Server(s) and SGSN(s). The MSC Servers and SGSNs shall store the requested IMEI(SV)s per RNC. For each subscriber/UE activity the MSC Servers and SGSNs shall request IMEI(SV), if it is not already provided. For each subscriber/UE activity the MSC server/SGSN shall check whether a trace request is active in an RNC for the IMEI(SV). If a match is found, the MSC Server/SGSN shall inform the RNC about the IMEI(SV) in CN Invoke Trace, so that the RNC can trace the control signalling according to the trace control and configuration parameters that are received from its EM.

If an Inter-MSC SRNS Relocation or an Inter-SGSN SRNS relocation occurs, the anchor MSC Server or source SGSN shall transfer the IMSI and IMEI(SV) for the subscriber/UE activity to the non anchor MSC Server or target SGSN. The non anchor MSC Server/target SGSN shall check whether it has received a trace request from the target RNC for the transferred IMEI(SV). If a match is found on the IMEI(SV) in the non anchor MSC Server/target SGSN, the MSC Server/SGSN shall inform the RNC about the IMEI(SV) in the CN Invoke Trace. The IMSI shall be transferred from the non anchor MSC Server/target SGSN to the target RNC in Relocation Request. The RNC can then trace the subscriber/UE activity according to the trace control and configuration parameters that are received from its EM.

4.1.1.2a UTRAN activation mechanisms for management-based MDT data collections without IMSI/IMEI(SV) selection

In case of management based MDT data collection, the UE selection should be done in the radio network at RNC based on the input information received from OAM, like device capability information and area scope. In this case there is no IMSI, IMEI(SV) selection.

The following figure shows an example scenario how the MDT configuration is done utilising the cell traffic trace functionality:

Figure 4.1.1.2a.1: Example formanagement based MDT activation in UTRAN

1) The EM sends a Trace Session activation request to the RNC. This request includes the parameters for configuring MDT data collection:

– Area Scope where the MDT data should be collected: list of UTRAN cells. Routing Area or Location Area should be converted to UTRAN cells.

– Job Type

– List of Measurements

– Reporting Trigger (only in case of Immediate MDT)

– Report Interval (only in case of Immediate MDT)

– Report Amount (only in case of Immediate MDT)

– Event Threshold (Only in case of Immediate MDT)

– Logging Interval (Only in case of Logged MDT)

– Logging Duration (Only in case of Logged MDT)

– Trace Reference

– TCE IP Address

– Anonymization of MDT Data.

– Measurement Quantity

– Measurement Period UMTS (Only in case of Immediate MDT and if either of the measurements M6, M7 is requested in the list of measurement parameter).

– Collection Period for RRM Measurements UMTS (present only if any of M4 or M5 measurements are requested).

– Positioning Method

2) When RNC receives the Trace Session activation request from its EM, it shall start a Trace Session and should save the parameters associated to the Trace Session.

3) Void.

4) RNC shall select the suitable UEs for MDT data collection. The selection is based on the area received from the EM and the area where UE is roaming, user consent information received from the core network (As described in clause 4.6.2 of the present document).If the user is not in the specified area or if the Management Based MDT Allowed IE is not received from the Core Network (which indicates lacking user consent)the UE shall not be selected by the RNC for MDT data collection. During UE selection , the RNC shall take into account also the UE capability (MDT capability) when it selects UE for logged MDT configuration. If the UE does not support logged MDT the UE shall not be selected. The RNC should also start the Data Volume measurement if it is requested in the MDT configuration.

5) RNC shall activate the MDT functionality to the selected UEs. As part of this operation the RNC shall allocate a Trace Recording Session Reference and send at least the following configuration information to the UE in case of Logged MDT:

– Trace Reference

– Trace Recording Session Reference

– TCE Id (The value signalled as IP address of TCE from the EM is mapped to a TCE Id, using a configured mapping in the RNC)

– Logging Interval

– Logging Duration

– Absolute time reference

– Area Scope where the MDT data should be collected: list of UTRAN cells/RA/LA

In case of Immediate MDT only the measurements and their parameters needs to be sent to the UE:

– List of Measurements

– Reporting Trigger

– Report Interval

– Report Amount

– Event Threshold (only if event based reporting is configured in reporting trigger)

6) When UE receives the MDT activation it shall start the MDT functionality based on the received configuration parameters. The MDT related measurements are reported to the RNC via RRC signalling. In case of Logged MDT the MDT reporting is done when the network requests the log. The MDT log is requested if UE’s rPLMN matches the PLMN where TCE used to collect MDT data resides (e.g. RNC’s primary PLMN) by sending the UEInformationRequest message. The MDT log is sent by the UE in the UEInformationResponse message. If the MDT anonymization requires the IMEI-TAC in the MDT record, RNC shall send the Trace Recording Session Reference, Trace Reference, serving Cell Identifier (containing serving cell PLMN and Cell ID, for immediate MDT only), TCE IP Address and IMSI in the UPLINK INFORMATION EXCHANGE REQUEST message to the SGSN/MSC Server via Iu connection. When SGSN/MSC Server receives this Iu signalling message containing the Trace Recording Session Reference, Trace Reference, TCE IP A ddress, IMSI, the SGSN/MSC Server shall look up the corresponding equipment identities (IMEI (SV)) of the given IMSI from its database, and send the IMEI-TAC together with the Trace Recording Session Reference and Trace Reference to the TCE, as described in section 4.7 of the present document. For logged MDT, SGSN/MSC Server shall send the IMEI-TAC together with the Trace Recording Session Reference, Trace Reference to the TCE.

For immediate MDT, RNC shall include the serving cell identifier in the UPLINK INFORMATION EXCHANGE REQUEST message.

The UE should report the Trace Reference, Trace Recording Session Reference and TCE Id together with the MDT reports to the network in case of Logged MDT.

7) When RNC receives the MDT report from the UE the RNC shall compare the Trace PLMN (PLMN portion of Trace Reference) with the PLMN where TCE used to collect MDT data resides (e.g. its primary PLMN). In case of a match, for immediate MDT, it shall capture it and put the UE’s serving cell CGI together with the MDT report from the UE to the trace record. In case of a match, for logged MDT, the RNC shall capture it and put it to the trace record. Otherwise it shall discard the MDT report.

NOTE: For management based Immediate MDT, TRSR may be duplicated among different RNCs when multiple cells are selected as the area scope for the same MDT job. In this case, the combination of TRSR and the UE’s serving cell CGI in the MDT report can uniquely identify one trace recording session.

8) The Trace Records shall be forwarded to the Trace Collection Entity indicated in the MDT report received from the UE in case of Logged MDT. The RNC translates the TCE Id received from the UE to the TCE IP Address before it forwards the measurement records to the TCE. (The address translation is done by using configured mapping in the RNC.) The RNC shall not provide the IMSI in the MDT.

The Immediate MDT measurement configuration is deleted in the UE together with the RRC context when entering idle mode.

The Logged MDT trace session is preserved in the UE until the duration time of the trace session expires, including also multiple idle periods interrupted by idle-connected-idle state transitions.

The Logged MDT trace session context of the UE is stored in the network as long as the trace session is active, including also the periods when the UE is in connected state.

EM shall validate that the MCC and MNC in the Trace Reference is the same as the PLMN supported by all the RNCs specified in the area scope. If the RNC receives a request with a PLMN in the TraceReference that does not match any PLMN in its list, it shall ignore the request.

4.1.1.3 PS Domain activation mechanisms

When a SGSN, GGSN or BM-SC receives Trace Session activation from the EM it shall start a Trace Session. The trace control and configuration parameters of the Trace Session are received in the Trace Session activation from the EM. The SGSN/GGSN/BM-SC shall not forward these trace control and configuration parameters to other nodes. The received trace control and configuration parameters shall be saved and used to determine when and how to start a Trace Recording Session. (Starting a Trace Recording Session is described in subclause 4.2.2.2).

4.1.1.4 CS Domain activation mechanisms

When a MSC Server receives Trace Session activation from the EM it shall start a Trace Session. The trace control and configuration parameters of the Trace Session are received in the Trace Session activation from the EM. The MSC Server shall not forward these trace control and configuration parameters to other nodes. The received trace control and configuration parameters shall be saved and used to determine when and how to start a Trace Recording Session. (Starting a Trace Recording Session is described in subclause 4.2.2.3).

4.1.1.5 IP Multimedia Subsystem activation mechanisms

When a S-CSCF/P-CSCF receives Trace Session activation from EM, the S-CSCF/P-CSCF shall start a Trace Session. The Trace control and configuration parameters of the Trace Session, received from EM in the Trace Session activation, shall be saved. The Trace control and configuration parameters define when the S-CSCF and P-CSCF shall start and stop a Trace Recording Session.

The following figure illustrates the Trace Session activation in S-CSCF and in P-CSCF in case of Management based activation.

Figure 4.1.1.5.1: Trace Session activation in IMS

4.1.1.6 E-UTRAN activation mechanisms

In E-UTRAN the Management Based Trace Activation can be fulfilled with the E-UTRAN Cell Traffic trace functionality. In this case the Trace Session Activation is done to one or a list E-UTRAN cells within one eNodeB, where Trace Session is activated.

The following trace control and configuration parameters of the Trace Session are received by eNodeB in the Trace Session activation message from the EM:

– Trace Reference

– Trace Depth

– Trace Target: list of E-UTRAN cells

– List of Interfaces for eNB

– Trace Collection Entity IP Address

When eNodeB receives the Trace Session Activation message from the EM for a given or a list of E-UTRAN cell(s) the eNodeB shall start a Trace Session for the given or list of E-UTRAN cell(s).

4.1.1.6a E-UTRAN activation mechanisms for management based MDT data collections without IMSI/IMEI(SV) selection

For management based MDT data collection with no IMSI/IMEI(SV) criteria, the UE selection can be done in the radio network at eNB based on the input information received from EM and the user consent information stored in the eNB. This mechanism works for the following OAM input parameters:

– Area information only

The following figure summarizes the flow how the MDT configuration is done utilising the cell traffic trace functionality for this scenario:

Figure 4.1.1.6a.1: Example formanagement based MDT activation in E-UTRAN

0) Whenever the eNB receives the Management based MDT allowed IE in Initial Context Setup Request or in Handover Request message, it shall save it for possible later usage.

1) The EM sends a Trace Session activation request to the eNB. This request includes the parameters for configuring UE measurements:

– Job Type

– Area Scope where the UE measurements should be collected: list of E-UTRAN cells. Tracking Area should be converted to E-UTRAN cell.

– List of Measurements

– Reporting Trigger

– Report Interval

– Report Amount

– Event Threshold

– Logging Interval

– Logging Duration

– Trace Reference

– TCE IP Address

– Anonymization of MDT Data.

– Measurement Period LTE (if either of the measurements M4, M5 is requested)

– Collection Period for RRM Measurements LTE (present only if M3 measurements are requested).

– Collection Period M6 in LTE (present only if any of M6 measurements (DL or UL) is requested).

– Collection Period M7 in LTE (present only if any of M7 measurements (DL or UL)is requested).

– Positioning Method

– MDT PLMN List

Note that at the same time not all the parameters can be present. The criteria for which parameters are present are described in clause 5 of the present document.

2) When eNB receives the Trace Session activation request from its EM, it shall start a Trace Session and should save the parameters associated to the Trace Session.

3) eNB shall select the suitable UEs for MDT data collection. The selection is based on the area received from the EM and the area where UE islocated, user consent information received from the core network as part of the Management Based MDT Allowed IE (As described in section in 4.6. of this document).If the user is not in the specified area or if the Management Based MDT Allowed IE is not present in the UE context the UE shall not be selected by the eNB for MDT data collection. During UE selection, the eNB shall take into account also the UE capability (MDT capability) when it selects UE for logged MDT configuration. If the UE does not support logged MDT the UE shall not be selected.
If M4 or M5 measurements are requested in the MDT configuration, eNB should start the measurement according to the received configuration. Details of the measurements are defined in TS 36.314 [56].

4) eNB shall activate the MDT functionality to the selected UEs. When eNB selects a UE it shall take into account the availability of Management Based MDT Allowed IE in the user context and the area scope parameter received in MDT configuration (Trace Session activation). Detailed description about user consent handling and how it is provided to the eNB is described in section 4.6.2. If there is no Management Based MDT Allowed IE in the user context or the user is outside the area scope defined in the MDT configuration, the UE shall not be selected for MDT data collection. The eNB shall assign Trace Recording Session Reference corresponding to the selected UE. The eNB shall send at least the following configuration information to the UE in case of Logged MDT:

– Trace Reference

– Trace Recording Session Reference

– TCE Id (The value signalled as IP address of TCE from the EM is mapped to a TCE Id, using a configured mapping in the eNB)

– Logging Interval

– Logging Duration

– Absolute time reference

– Area Scope where the UE measurements should be collected: list of E-UTRAN cells/TA.

– MDT PLMN List

NOTE: For UEs currently being in idle mode and camping in the cell the logged MDT configuration cannot be sent. These UEs may be configured when they initiate some activity (e.g., Service Request or Tracking Area Update) at next time.

In case of Immediate MDT the following parameters shall be sent to the UE:

– List of Measurements

– Reporting Trigger

– Report Interval

– Report Amount

– Event Threshold

Note that at the same time not all the parameters can be present. Conditions of the parameters are described in clause 5 of the present document.

If positioning method indicates GNSS positioning, eNB should activate the GNSS module of the UE via RRC as specified in TS 36.331 [32]. If positioning method indicates E-Cell ID positioning, the eNB should collect the UE reported UE Rx-Tx time difference measurements as specified in TS 36.331[32] measurement procedures, as well as, any available eNB measured eNB Rx-Tx time differenc, Angle of Arrival measurements as specified in TS 36.214 [38] and capture it in MDT trace record.

If Reporting Trigger parameter indicates that all configured RRM measurement trigger should be reported in MDT, then eNB should ask the UE to provide the "best effort" location information together with the measurement reporting by setting the includeLocationInfo IE in all RRC measurement reporting configurations.

5) When UE receives the MDT activation it shall start the MDT functionality based on the received configuration parameters.

6) The eNodeB shall not retrieve MDT report from the UE if UE’s rPLMN does not match the PLMN where TCE used to collect MDT data resides (e.g. eNodeB’s primary PLMN). When the eNodeB receives the MDT report from UE, the eNodeB shall get the Trace Recording Session Reference, Trace Reference and TCE Id from the report, and compare the Trace PLMN (PLMN portion of Trace Reference) with the PLMN where TCE used to collect MDT data resides (e.g. its primary PLMN) and discard MDT report in case of a mismatch. Otherwise if the MDT anonymization requires the IMEI-TAC in the MDT record eNodeB shall send the Trace Recording Session Reference, Trace Reference, serving cell CGI, and TCE IP Address in the CELL TRAFFIC TRACE message to the MME via the S1 connection. When MME receives this S1 signalling message containing the Trace Recording Session Reference , Trace Reference, serving cell CGI, and the Privacy Indicator (that shall be set to Logged MDT or Immediate MDT depending on the configured Job Type) if so indicated in the privacy indicator, the MME shall look up the subscriber identities (IMEI (SV)) of the given call from its database, and send the IMEI-TAC together with the Trace Recording Session Reference and Trace Reference and for immediate MDT also the serving cell CGI to the TCE, as described in section 4.7 of the present document. For logged MDT, MME will send the IMEI-TAC together with the Trace Recording Session Reference, Trace Reference to the TCE.

NOTE: For management based Immediate MDT, TRSR may be duplicated among different eNodeBs when multiple cells are selected as the area scope for the same MDT job. In this case, the combination of TRSR and the UE’s serving cell CGI in the MDT report can uniquely identify one trace recording session.

7) For Immediate MDT when the eNB receives the MDT report from the UE in the RRC message the eNB shall capture it and put the UE’s serving cell CGI together with the MDT report from the UE to the trace record. A UE configured to perform Logged MDT measurements in IDLE indicates the availability of MDT measurements, by means of a one bit indicator, in RRCConnectionSetupComplete message during connection establishment as specified in [2]. The eNB can decide to retrieve the logged measurements based on this indication by sending the UEInformationRequest message to the UE. The UE can answer with the collected MDT logs in UEInformationResponse message.

8) The eNB shall forward the Trace Records to the Trace Collection Entity (TCE). In case of logged MDT, the TCE Id is indicated in the MDT report is translated to the actual IP address of the TCE by the eNB before it forwards the measurement records. (The address translation is using configured mapping in the eNB.) In case of immediate MDT, the IP address of the TCE is indicated for the eNB in the trace configuration.

The Immediate MDT measurement configuration is deleted in the UE together with the RRC context when entering idle mode.

The Logged MDT trace session is preserved in the UE until the duration time of the trace session expires, including also multiple idle periods interrupted by idle-connected-idle state transitions.

The Logged MDT trace session context of the UE is stored in the network as long as the trace session is active, including also the periods when the UE is in connected state.

EM shall validate that the MCC and MNC specified in the Trace Reference is the same as the PLMN supported by all the cells specified in the area scope. If the eNodeB receives a request with a PLMN in the TraceReference that does not match any PLMN in its list, it shall ignore the request.

4.1.1.6b E-UTRAN activation mechanisms for management-based Logged MBSFN MDT data collections without IMSI/IMEI(SV) selection

For management-based Logged MBSFN MDT data collection with no IMSI/IMEI(SV) criteria, the UE selection can be done in the radio network at eNB based on the input information received from EM, the device capability (MDT capable and UEs capable of logging Measurements for MBSFN) and the user consent information stored in the eNB. This mechanism works for the following OAM input parameters:

– Area Information

– MBSFN Area List

The following figure summarizes the flow how the Logged MBSFN MDT configuration is done utilising the cell traffic trace functionality for this scenario:

Figure 4.1.1.6b.1: Example for management-based MBSFN Logged MDT activation in E-UTRAN

0) Whenever the eNB receives the Management based MDT allowed IE in Initial Context Setup Request or in Handover Request message, it shall save it for possible later usage.

1) The EM sends a Trace Session activation request to the eNB. This request includes the parameters for configuring UE measurements:

– Job Type – Logged MBSFN MDT

– Area Scope where the UE measurements should be collected: list of E-UTRAN cells. Tracking Area, should be converted to E-UTRAN cell.

– Logging Interval

– Logging Duration

– Trace Reference

– TCE IP Address

– Anonymization of MDT Data.

– MDT PLMN List

– MBSFN Area List (applicable if Job Type is Logged MBSFN MDT)

NOTE: The criteria for which parameters are present are described in clause 5 of the present document.

2) When eNB receives the Trace Session activation request from its EM, it shall start a Trace Session and should save the parameters associated to the Trace Session.

3) eNB shall select the suitable UEs for MDT data collection. The selection is based user consent information received from the core network as part of the Management Based MDT Allowed IE (As described in section in 4.6. of this document).If the Management Based MDT Allowed IE is not present in the UE context the UE shall not be selected by the eNB for MDT data collection. During UE selection, the eNB shall take into account also the UE capability (MDT capability and MBSFN logging capability). If the UE does not support MBSFN logging capability the UE shall not be selected for Logged MBSFN MDT.

4) eNB shall activate the Logged MBSFN MDT functionality to the selected UEs. The eNB shall assign Trace Recording Session Reference corresponding to the selected UE. The eNB shall send at least the following configuration information to the UE in case of Logged MDT or Logged MBSFN MDT:

– Trace Reference

– Trace Recording Session Reference

– TCE Id (The value signalled as IP address of TCE from the EM is mapped to a TCE Id, using a configured mapping in the eNB)

– Logging Interval

– Logging Duration

– Absolute time reference

– Area Scope where the UE measurements should be collected: list of E-UTRAN cells/TA

– MDT PLMN List

– MBSFN Area List

NOTE: For UEs currently being in idle mode and camping in the cell the logged MBSFN MDT configuration cannot be sent. These UEs may be configured when they initiate some activity (e.g., Service Request or Tracking Area Update) at next time.

NOTE: Conditions of the parameters are described in clause 5 of the present document.

5) When UE receives the MDT activation it shall start the MDT functionality based on the received configuration parameters.

6) The eNodeB shall not retrieve MDT report from the UE if UE’s rPLMN does not match the PLMN where TCE used to collect MDT data resides (e.g. eNodeB’s primary PLMN). When the eNodeB receives the MDT report from UE, the eNodeB shall get the Trace Recording Session Reference, Trace Reference and TCE Id from the report, and compare the Trace PLMN (PLMN portion of Trace Reference) with the PLMN where TCE used to collect MDT data resides (e.g. its primary PLMN) and discard MDT report in case of a mismatch. Otherwise if the MDT anonymization requires the IMEI-TAC in the MDT record eNodeB shall send the Trace Recording Session Reference, Trace Reference, serving cell CGI, and TCE IP Address in the CELL TRAFFIC TRACE message to the MME via the S1 connection. When MME receives this S1 signalling message containing the Trace Recording Session Reference , Trace Reference, serving cell CGI, and the Privacy Indicator (that shall be set to Logged MDT – for ) if so indicated in the privacy indicator, the MME shall look up the subscriber identities (IMEI (SV)) of the given call from its database, and send the IMEI-TAC together with the Trace Recording Session Reference and Trace Reference to the TCE.

NOTE: For management-based Immediate MDT, TRSR may be duplicated among different eNodeBs when multiple cells are selected as the area scope for the same MDT job. In this case, the combination of TRSR and the UE’s serving cell CGI in the MDT report can uniquely identify one trace recording session.

7) A UE configured to perform Logged MBSFN MDT in IDLE or CONNECTED mode (when MBMS service is available) indicates the availability of MDT measurements, by means of a one bit indicator, in RRCConnectionSetupComplete message during connection establishment as specified in [2]. The eNB can decide to retrieve the logged measurements based on this indication by sending the UEInformationRequest message to the UE. The UE can answer with the collected MDT logs in UEInformationResponse message.

8) The TCE Id indicated in the MDT report is translated to the actual IP address of the TCE by the eNB before it forwards the measurement records. (The address translation is using configured mapping in the eNB.)

The Logged MBSFN MDT session is preserved in the UE until the duration time of the trace session expires, including also multiple idle periods interrupted by idle-connected-idle state transitions.

The Logged MBSFN MDT trace session context of the UE is stored in the network as long as the trace session is active, while UE is in idle or connected state.

4.1.1.7 EPC Domain activation mechanisms

When a MME, SGW or PGW receives Trace Session activation from the EM, it shall start a Trace Session. The following trace control and configuration parameters of the Trace Session are received in the Trace Session activation from the EM:

– Trace Target: IMSI or IMEISV

– Trace Reference

– Triggering Events for this network element

– Trace Depth

– List of Interfaces for this network element

– Trace Collection Entity IP Address

The MME, SGW or PGW shall not forward these trace control and configuration parameters to other nodes. The received trace control and configuration parameters shall be saved and used to determine when and how to start a Trace Recording Session. (Starting a Trace Recording Session is described in subclause 4.2.2.6).

4.1.1.8 5GC Domain activation mechanisms

When an AF, AMF, AUSF, NEF, NRF, NSSF, PCF, SMF, SMSF, UPF or UDM receives Trace Session activation from the management function, it shall start a Trace Session. The following trace control and configuration parameters of the Trace Session are received in the Trace Session activation from the management function:

– Trace Target: SUPI or IMEISV.

– Trace Reference.

– Triggering Events for this network element.

– Trace Depth.

– List of Interfaces for this network element.

– Trace Collection Entity IP Address for the file-based trace reporting or Trace Reporting Consumer URI for the streaming trace reporting.

The AF, AMF, AUSF, NEF, NRF, NSSF, PCF, SMF, SMSF, UPF or UDM shall not forward these trace control and configuration parameters to other nodes. The received trace control and configuration parameters shall be saved and used to determine when and how to start a Trace Recording Session. (Starting a Trace Recording Session is described in subclause 4.2.2.9).

4.1.1.9 NG-RAN activation mechanisms

4.1.1.9.1 General

In NG-RAN the Management Based Trace Activation can be fulfilled with the NG-RAN Cell Traffic trace functionality. In this case the Trace Session Activation is done to one or a list NG-RAN cells within one NG-RAN node, where Trace Session is activated.

The following trace control and configuration parameters of the Trace Session are received by NG-RAN node in the Trace Session activation message from the management system:

– Trace Reference.

– Trace Depth.

– Trace Target: NG-RAN cells list.

– List of Interfaces for NG-RAN node.

– Trace Collection Entity IP Address for the file-based trace reporting or Trace Reporting Consumer URI for the streaming trace reporting.

When NG-RAN node receives the Trace Session Activation message from the management system for a given or a list of NG-RAN cell(s) the NG-RAN node shall start a Trace Session for the given or list of NG-RAN cell(s).

4.1.1.9.2 NG-RAN activation mechanisms for management based MDT data collections without IMSI/IMEI(SV)/SUPI selection in the case of non-split architecture

For management based MDT data collection with no IMSI/IMEI(SV)/SUPI criteria in the case of non-split architecture, the UE selection can be done in the radio network at gNB based on the input information received from management system and the user consent information stored in the gNB. This mechanism works for the following OAM input parameters:

– Area information only

The following figure summarizes the flow as an example how the MDT configuration is done utilising the cell traffic trace functionality for this scenario:

Figure 4.1.1.9.2.1: Example for management based MDT activation in NG-RAN in the case of non-split architecture

Whenever the gNB receives the Management based MDT allowed IE in Initial Context Setup Request or in Handover Request message, it shall save it for possible later usage.

1) The management system sends a Trace Session activation request to the gNB. This request includes the parameters for configuring UE measurements:

– Job Type.

– Area Scope where the UE measurements should be collected: list of NG-RAN cells. Tracking Area should be converted to NG-RAN cell.

– List of Measurements.

– Reporting Trigger.

– Report Interval.

– Report Amount.

– Event Threshold.

– Logging Interval.

– Logging Duration.

– Trace Reference.

– TCE IP Address.

– Anonymization of MDT Data.

– Collection Period for RRM Measurements NR (present only if any of M4 or M5 measurements are requested).

– Collection Period M6 in NR (present only if any of M6 measurements (DL or UL) is requested).

– Collection Period M7 in NR (present only if any of M7 measurements (DL or UL)is requested).

– Positioning Method.

– MDT PLMN List.

– Report Type for Logged MDT (periodical logged or event-triggered measurement) for logged MDT only.

– Event Threshold, Hysteresis and Time to Trigger (present only if L1 event is configured for logged MDT)

– Event List for Event Triggered Measurement for logged MDT only.

– Area Configuration for Neighbouring Cells for logged MDT only.

– Sensor Information for logged MDT and immediate MDT.

– Excess packet delay thresholds (present only if M6 measurements are requested).

Note that at the same time not all the parameters can be present. The criteria for which parameters are present are described in clause 5 of the present document.

2) When gNB receives the Trace Session activation request from its management system, it shall start a Trace Session and should save the parameters associated to the Trace Session.

3) gNB shall select the suitable UEs for MDT data collection. The selection is based on the area received from the management system and the area where UE is located, user consent information received from the core network as part of the Management based MDT PLMN List IE (As described in section in 4.9.2 of this document). If the user is not in the specified area or if the Management based MDT PLMN List IE is not present in the UE context the UE shall not be selected by the gNB for MDT data collection. During UE selection, the gNB shall take into account also the UE capability (MDT capability) when it selects UE for logged MDT configuration. If the UE does not support logged MDT, the UE shall not be selected.
If M4 or M5 measurements are requested in the MDT configuration, gNB should start the measurement according to the received configuration. Details of the measurements are defined in TS 38.314 [50].

4) gNB shall activate the MDT functionality to the selected UEs. When gNB selects a UE, it shall take into account the availability of Management based MDT PLMN List IE in the user context and the area scope parameter received in MDT configuration (Trace Session activation). Detailed description about user consent handling and how it is provided to the gNB is described in section 4.9.2. If there is no Management based MDT PLMN List IE in the user context or the user is outside the area scope defined in the MDT configuration, the UE shall not be selected for MDT data collection. The gNB shall assign Trace Recording Session Reference corresponding to the selected UE. The gNB shall send at least the following configuration information to the UE in case of Logged MDT:

– Trace Reference

– Trace Recording Session Reference

– TCE Id (The value signalled as IP address of TCE from the EM is mapped to a TCE Id, using a configured mapping in the gNB)

– Logging Interval

– Logging Duration

– Absolute time reference

– Area Scope where the UE measurements should be collected: list of NG-RAN cells/TA.

– MDT PLMN List

NOTE: For UEs currently being in idle or inactive mode and camping in the cell the logged MDT configuration cannot be sent. These UEs may be configured when they initiate some activity (e.g., Service Request or Tracking Area Update) at next time.

In case of Immediate MDT, the following parameters shall be sent to the UE:

– List of Measurements

– Reporting Trigger

– Report Interval

– Report Amount

– Event Threshold

– Excess packet delay thresholds (present only if M6 UL measurements are requested)

Note that at the same time not all the parameters can be present. Conditions of the parameters are described in clause 5 of the present document.

gNB performs necessary actions (e.g. activates GNSS module of the UE, enables and collects certain positioning measurements) specified in TS 38.305 [xx] according to the value of Positioning Method (see clause 5.10.19) received in the Trace configuration. gNB captures location information and/or positioning measurements in the MDT trace record.

If Reporting Trigger parameter indicates that all configured RRM measurement trigger should be reported in MDT, then gNB should ask the UE to provide the "best effort" location information together with the measurement reporting by setting the includeCommonLocationInfo IE in all RRC measurement reporting configurations.

5) When UE receives the MDT activation it shall start the MDT functionality based on the received configuration parameters.

6) The gNB shall not retrieve MDT report from the UE if UE’s rPLMN does not match the PLMN where TCE used to collect MDT data resides (e.g. gNB’s primary PLMN). When the gNB receives the MDT report from UE, the gNB shall get the Trace Recording Session Reference, Trace Reference and TCE Id from the report, and compare the Trace PLMN (PLMN portion of Trace Reference) with the PLMN where TCE used to collect MDT data resides (e.g. its primary PLMN) and discard MDT report in case of a mismatch. Otherwise if the MDT anonymization requires the IMEI-TAC in the MDT record gNB shall send the Trace Recording Session Reference, Trace Reference, serving cell CGI, and TCE IP Address in the CELL TRAFFIC TRACE message to the AMF via the NG connection. When AMF receives this NG signalling message containing the Trace Recording Session Reference, Trace Reference, serving cell CGI, and the Privacy Indicator (that shall be set to Logged MDT or Immediate MDT depending on the configured Job Type) if so indicated in the privacy indicator, the AMF shall look up the subscriber identities (IMEI(SV)) of the given call from its database, and send the IMEI-TAC together with the Trace Recording Session Reference and Trace Reference and for immediate MDT also the serving cell CGI to the TCE, as described in section 4.7 of the present document. For logged MDT, AMF will send the IMEI-TAC together with the Trace Recording Session Reference, Trace Reference to the TCE.

NOTE: For management based Immediate MDT, TRSR may be duplicated among different gNBs when multiple cells are selected as the area scope for the same MDT job. In this case, the combination of TRSR and the UE’s serving cell CGI in the MDT report can uniquely identify one trace recording session.

7) For Immediate MDT when the gNB receives the MDT report from the UE in the RRC message the gNB shall capture it and put the UE’s serving cell CGI together with the MDT report from the UE to the trace record. A UE configured to perform Logged MDT measurements in IDLE or INACTIVE indicates the availability of MDT measurements, by means of a one-bit indicator, in RRCConnectionSetupComplete message during connection establishment as specified in 3GPP TS 32.421 [2]. The gNB can decide to retrieve the logged measurements based on this indication by sending the UEInformationRequest message to the UE. The UE can answer with the collected MDT logs in UEInformationResponse message.

8) The gNB shall forward the Trace Records to the Trace Collection Entity (TCE). In case of logged MDT, the TCE Id is indicated in the MDT report is translated to the actual IP address of the TCE by the gNB before it forwards the measurement records. (The address translation is using configured mapping in the gNB.) In case of immediate MDT, the IP address of the TCE is indicated for the gNB in the trace configuration.

The Immediate MDT measurement configuration is deleted in the UE together with the RRC context when entering idle or inactive mode.

The Logged MDT trace session is preserved in the UE until the duration time of the trace session expires, including also multiple idle or inactive periods interrupted by various state transistions such as idle-connected-idlestate transitions.

The Logged MDT trace session context of the UE is stored in the network as long as the trace session is active, including also the periods when the UE is in connected state.

Management system shall validate that the MCC and MNC specified in the Trace Reference is the same as the PLMN supported by all the cells specified in the area scope. If the gNB receives a request with a PLMN in the TraceReference that does not match any PLMN in its list, it shall ignore the request.

4.1.1.9.3 NG-RAN activation mechanisms for management based MDT data collections without IMSI/IMEI(SV)/SUPI selection in the case of split RAN architecture

For management based MDT data collection with no IMSI/IMEI(SV)/SUPI criteria in the case of split RAN architecture, the UE selection can be done in the radio network at gNB-CU-CP, gNB-CU-UP and gNB-DU based on the input information received from management system and the user consent information stored in the gNB-CU-CP, gNB-CU-UP, gNB-DU. The area scope as optional parameter is needed to apply this mechanism.

The following figure summarizes an example of the flow how the MDT configuration for gNB-CU-CP is done utilising the cell traffic trace functionality for this scenario:

Figure 4.1.1.9.3.1: Example for management based MDT activation for gNB-CU-CP in NG-RAN in the case of split architecture

In the case of split RAN architecture, the management system may send the MDT activation directly to gNB-CU-CP, gNB-DU, or gNB-CU-UP. If a gNB-CU-CP receives a management based MDT activation, it may propagate the MDT configuration to gNB-DUs and/or gNB-CU-UPs over F1 and E1 in case that the activation involves measurements collected by multiple nodes under the same gNB-CU-CP control in split RAN architecture.

The overall description for management-based MDT activation in a split architecture is defined in TS 38.401 [44].