8.20 Location Report

25.4133GPPRelease 17TSUTRAN Iu interface Radio Access Network Application Part (RANAP) signalling

8.20.1 General

The purpose of the Location Report procedure is to provide the UE’s location and optionally velocity information to the CN. The procedure uses connection oriented signalling.

8.20.2 Successful Operation

Figure 22: Location Report procedure. Successful operation.

The serving RNC 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. Also, when a user enters or leaves a classified zone set by O&M, e.g. a zone where a disaster has occurred, a LOCATION REPORT message including the Service Area of the UE in the Area Identity IE shall be sent to the CN. The Cause IE shall indicate the appropriate cause value to the CN, e.g. "User Restriction Start Indication" and "User Restriction End Indication". The CN shall react to the LOCATION REPORT message with CN vendor specific actions.

For this procedure, only Service Areas that are defined for the PS and CS domains shall be considered.

In case reporting at change of Service Area is requested by the CN, then the RNC shall issue a LOCATION REPORT message:

– whenever the information given in the previous LOCATION REPORT message or INITIAL UE MESSAGE message is not anymore valid.

– upon receipt of the first LOCATION REPORTING CONTROL message following a Relocation Resource Allocation procedure, with the Event IE included in the Request Type IE set to "Change of Service Area", as soon as SAI becomes available in the new SRNC and the relocation procedure has been successfully completed.

In case a Service Area is reported, the RNC shall include in the Area Identity IE of the LOCATION REPORT message a Service Area that includes at least one of the cells from which the UE is consuming radio resources.

In case the LOCATION REPORT message is sent as an answer to a request for a direct report, for periodic reporting or for reports at a change of Service Area, the Request Type IE from the LOCATION REPORTING CONTROL message shall be included.

If the LOCATION REPORT message is sent as an answer to a request for a direct report of Service Area and the current Service Area cannot be determined by the RNC, then the Area Identity IE shall be omitted and a cause value shall be included to indicate that the request could not be fulfilled, e.g. "Requested Information Not Available" or "Location Reporting Congestion". The RNC may also include the Last Known Service Area IE.

If the RNC cannot deliver the location information as requested by the CN, due to either the non-support of the requested event or the non-support of the requested report area, or if the RNC is currently not able to reach the UE, the RNC shall indicate the UE location to be "Undetermined" by omitting the Area Identity IE. A cause value shall instead be added to indicate the reason for the undetermined location, e.g. "Requested Request Type not supported", "Location Reporting Congestion" or "No Resource Available".

In case of periodic reporting is requested by the CN, the RNC shall issue the first LOCATION REPORT message one reporting interval as indicated in the Reporting Interval IE contained in the LOCATION REPORTING CONTROL message after reception of the LOCATION REPORTING CONTROL message and continue to send LOCATION REPORT messages one reporting interval after the previous LOCATION REPORT message until the desired amount of reports as given in the Reporting Amount IE has been attained, or until the periodic reporting is cancelled by the CN or aborted by the RNC. When no location estimate is available at the RNC when the reporting criteria are fulfilled (e.g., due to failure of a position method itself), the RNC shall indicate the UE location to be "Undetermined" by omitting the Area Identity IE. A cause value shall instead be added to indicate the reason for the undetermined location, e.g. "Periodic Location Information not Available".

If the Location Report procedure was triggered by a LOCATION REPORTING CONTROL message, which included a request to report a geographical area with a specific accuracy, the LOCATION REPORT message shall include:

– the Geographical Area IE within the Area Identity IE containing either a point with indicated uncertainty or a polygon or another type, which fulfils the requested accuracy, and

– the Accuracy Fulfilment Indicator IE with the value "requested accuracy fulfilled".

If the Location Report procedure was triggered by a LOCATION REPORTING CONTROL message, which included a request to report with a geographical area and whenever one of the geographic area shapes Ellipsoid point with uncertainty Ellipse IE, Ellipsoid point with altitude and uncertainty Ellipsoid IE or Ellipsoid Arc IE is reported, the Confidence IE shall indicate the probability that the UE is located within the uncertainty region of the shape. The value of the Confidence IE shall be in the interval of "1" to "100".

If any of the requested accuracy cannot be fulfilled, the LOCATION REPORT message shall include:

– the Geographical Area IE within the Area Identity IE containing either a point with indicated uncertainty or a polygon or another type, with the best possible accuracy, and

– the Accuracy Fulfilment Indicator IE with the value "requested accuracy not fulfilled".

If the Confidence IE received from the UE has value "0", the RNC shall consider the requested accuracy as not fulfilled and if the received position is reported or forwarded then the confidence and uncertainty shape shall not be included (i.e. either the Point IE or the Ellipsoid point with altitude IE shall be used).

If, on the other hand, no specific accuracy level was requested in the LOCATION REPORTING CONTROL message, the LOCATION REPORT message shall include the Geographical Area IE within the Area Identity IE, the reported Geographical Area IE may include an accuracy.

The LOCATION REPORT message shall also include, if available, the Position Data IE containing the positioning method (or list of positioning methods) used successfully to obtain the location estimate, together with the usage information.

The LOCATION REPORT message may also include, if available, the Barometric Pressure IE containing the uncompensated barometric pressure measured by the UE.

The LOCATION REPORT message may also include, if available, the Civic Address IE containing the location estimate for the UE expressed as a civic address.

If the Location Report procedure was triggered by a LOCATION REPORTING CONTROL message which included a request to report with a geographical area and in which the IncludeVelocity IE was set to "requested", the LOCATION REPORT message shall include a Velocity Estimate IE, if available and if the handling of velocity is supported by the RNC.

If the Location Report procedure was triggered by a LOCATION REPORTING CONTROL message, which included a request to report with a geographical area and in which the Client Type IE was not included, the RNC shall answer with the Point IE, or the Point With Uncertainty IE or the Polygon IE within the Geographical Area IE of the LOCATION REPORT message.

8.20.3 Abnormal Conditions

Not applicable.