8.11 Location Reporting Procedures
36.4133GPPEvolved Universal Terrestrial Radio Access Network (E-UTRAN)Release 17S1 Application Protocol (S1AP)TS
8.11.1 Location Reporting Control
8.11.1.1 General
The purpose of Location Reporting Control procedure is to allow the MME to request the eNB to report where the UE is currently located. The procedure uses UE-associated signalling.
8.11.1.2 Successful Operation
Figure 8.11.1.2-1: Location Reporting Control procedure. Successful operation.
The MME initiates the procedure by sending a LOCATION REPORTING CONTROL message. On receipt of a LOCATION REPORTING CONTROL message, the eNB shall perform the requested location reporting control action for the UE.
The Request Type IE indicates to the eNB whether:
– to report directly;
– to report upon change of serving cell, or
– to stop reporting at change of serving cell.
If reporting upon change of serving cell is requested, the eNB shall report whenever the UE changes its serving cell to another cell belonging to the eNB.
If the Additional Location Information IE is included in the LOCATION REPORTING CONTROL message and set to "Include PSCell” then, if EN-DC is activated, the eNB shall include the current PSCell in the report. If a report upon change of serving cell is requested, the eNB shall provide the report also whenever the UE changes the PSCell, and when EN-DC is activated, as specified in TS 23.401 [11].
The Request Type IE also indicates what type of location information the eNB shall report. The location information is E-UTRAN CGI and TAI, or E-UTRAN CGI, PSCell and TAI.
8.11.1.3 Abnormal Conditions
Not applicable.
8.11.2 Location Report Failure Indication
8.11.2.1 General
The Location Report Failure Indication procedure is initiated by an eNB in order to inform the MME that a Location Reporting Control procedure has failed due to an interaction with a handover procedure. The procedure uses UE-associated signalling.
8.11.2.2 Successful Operation
Figure 8.11.2.2-1: Location Report Failure Indication procedure.
Upon reception of the LOCATION REPORT FAILURE INDICATION message the MME shall take appropriate actions based on the failure reason indicated by the Cause IE.
8.11.3 Location Report
8.11.3.1 General
The purpose of Location Report procedure is to provide the UE’s current location to the MME. The procedure uses UE-associated signalling.
8.11.3.2 Successful Operation
Figure 8.11.3.2-1: Location Report procedure. Successful operation.
The eNB initiates the procedure by generating a LOCATION REPORT message. The LOCATION REPORT message may be used as a response to a LOCATION REPORTING CONTROL message.
In case reporting at change of serving cell has been requested, the eNB shall send a LOCATION REPORT message whenever the information given to the EPC in any S1AP message is not anymore valid.
If the PSCell Information IE is included in the LOCATION REPORT message, then the MME may consider both E-UTRAN CGI IE and PSCell Information IE to determine the UE’s location.
8.11.3.3 Abnormal Conditions
Not applicable.