4.4 Handling of MDT Trace sessions at handover for Immediate MDT in UTRAN and E-UTRAN

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

The eNB/RNC shall activate the Immediate MDT in the UE if the area based selection conditions are satisfied or not in the target cell after a handover that is made over X2 or S1 (or over Iur or Iu in case of UMTS). If the management based selection conditions are not satisfied in the handover target cell, the eNB/ RNC may deactivate the Immediate MDT in the UE. The trace sessions and trace recording sessions are not visible for the UE.

In case of signalling based trace activation , the eNB/RNC shall propagate the Trace Session parameters together with the MDT specific parameters to the target cell regardless of whether the source or target cell is part of the configured area scope in case of an Intra-PLMN handover over X2 or S1 (or Iur or Iu in case of UMTS).

In case of UTRAN the RNC shall propagate the Trace Session of the UE to the target cell in case of a handover over Iur or Iu. Any trace recording session shall be maintained, stopped or started in the target cell according to the evaluation of the selection criteria.

For LTE, the MDT configuration received by signalling based trace messages for a specific UE will propagate during intra-PLMN handover, and may propagate during inter-PLMN handover if the Signalling Based MDT PLMN List is available and includes the target PLMN. This behaviour applies also for MDT configuration that includes area scope, regardless of whether the source or target cell is part of the configured area scope.

For UMTS, the MDT configuration received by signalling based trace messages for a specific UE will continue during intra-PLMN handover, and may continue during inter-PLMN handover if the Signalling Based MDT PLMN List is available and includes the target PLMN, except for the case of SRNS relocation. In the case of SRNS relocation, MDT may be reactivated by the Core Network following a successful relocation.

For signalling based MDT configuration , when a UE that has been configured with MDT hands over to another eNB (i.e., in connected mode) and the Signalling Based MDT PLMN List conditions mentioned above are satisfied:

– with an X2 handover: the MDT configuraiton shall be passed to the eNB in the X2 handover request for continuity of MDT data collection . The new eNB shall stop the MDT collection if the new conditions are not within the criteria for MDT data collection.

– with an S1 handover and with no MME relocation: with S1 handover the MME shall ensure the MDT configuration is sent to the new eNB.

– with an S1 handover and with MME relocation: MDT configuration shall be passed on to the new MME on MME relocation. During inter-MME handover, the MME shall propagate the MDT configuration parameters to the target MME within an S10- Forward Relocation Request message as part of inter-MME handover procedures. The new MME shall save the information as part of the UE context and forward the MDT configuration to the new eNB.

The following MDT configuration shall be passed during handovers (Either intra-eNB, inter-eNB or inter-MME HO):

– Trace Reference

– Trace Recording Session Reference

– Area Scope

– List of Measurements

– Report Amount

– Reporting Trigger

– Event Threshold

– Report Interval

– TCE IP Address

– Job Type

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

– Positioning Method

– Collection Period for RRM Measurements LTE (present only if M3 measurement is 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).

– MDT PLMN List

Note that at the same time not all the parameters can be present. The conditions are described in clause 5.10 of the present document.