8.9 Position Activation

25.4533GPPRelease 17TSUTRAN Iupc interface Positioning Calculation Application Part (PCAP) signalling

8.9.1 General

The purpose of the Position Activation procedure is to enable the SAS to initiate a particular positioning method used for an individual positioning event. This procedure uses connection-oriented signalling.

8.9.2 Successful Operation

Figure 9c: Position Activation procedure, Successful Operation

The SAS initiates this procedure by sending a Position Activation Request message to the SRNC containing the required positioning method and any assistance data and instructions associated with that positioning method. The SRNC then sends a Position Activation Response message to the SAS confirming the requested action and providing any information required by the requested positioning method; e.g. UE channel information for the U-TDOA positioning method or A-GPS measurements for UE assisted A-GPS. In the POSITION ACTIVATION RESPONSE message, the SRNC should include either the UE Position Estimate Info IE, GPS Measurement Results IE, Cell-ID Measured Results Sets IE, OTDOA Measured Results Sets IE, UTDOA Group IE, GANSS Measurement Results IE, Required GPS Assistance Data IE, Required GANSS Assistance Data IE or the Additional Positioning Measured Results IE.

If the Positioning Method IE in a Position Activation Request message includes the GNSS Positioning Method IE indicating allowance of ‘GPS’ and any other GNSS (‘Galileo’, ‘SBAS’, ‘Modernized GPS’, ‘QZSS’, ‘GLONASS’, ‘BDS’), the SRNC may include both, the GPS Measurement Results IE and the GANSS Measurement Results IE, or both, the Required GPS Assistance Data IE or Required GANSS Assistance Data IE in the POSITION ACTIVATION RESPONSE message.

If the Positioning Method IE in a POSITION ACTIVATION REQUEST message includes the Additional Positioning Method IE, the SRNC may include the Additional PositioningMeasurement Results IE in the POSITION ACTIVATION RESPONSE message.

If the POSITION ACTIVATION REQUEST message contains periodic reporting information to start a periodic RNC positioning procedure (i.e., Amount of Reporting IE is included), the POSITION ACTIVATION RESPONSE message may be returned confirming the requested action and not including any measurements. In that case, all periodic measurement reports are conveyed using POSITION PERIODIC REPORT messages.

If the GPS Positioning Instructions IE or the GANSS Positioning Instructions IE is included in a POSITION ACTIVATION REQUEST message containing the Measurement Validity IE, the SRNC should include the Measurement Instructions Used IE in a POSITION ACTIVATION RESPONSE message if the Measurement Validity used by the SRNC is different from the Measurement Validity requested by the SAS.

If the GERAN IE is included in the Requested Cell-ID Measurements IE in the Cell-ID Positioning IE, the SRNC shall use it to determine the requested inter-RAT measurements.

If the POSITION ACTIVATION REQUEST message contains the Position Method IE with value "Cell ID", the Amount of Reporting IE shall not be included. If the POSITION ACTIVATION REQUEST message contains the Position Method IE with value “Cell ID” the Amount of Reporting IE shall not be included.

If the POSITION ACTIVATION REQUEST message contains the Position Method IE with value "Cell ID", the RNC may include the measurements requested in the Requested Cell-ID Measurements IE in the POSITION ACTIVATION RESPONSE message. If the RNC includes the measurements in the Requested Cell-ID Measurements IE it shall, if supported, do so for all cells (i.e. those in the active, monitored and detected sets) for which measurements are available from the UE. If both of the Round Trip Time Info IE and the Round Trip Time Info With Type 1 IE are included in the POSITION ACTIVATION RESPONSE message, the SAS shall use the Round Trip Time Info IE.

If the SRNC receives a new Position Activation Request message before it has responded to a previous non-periodic request, the SRNC should terminate all activity for the previous request, without sending any response to the initial request, and process the new request.

If the SRNC receives a new POSITION ACTIVATION REQUEST message for UE position measurement reporting using A-GPS or A-GANSS or OTDOA or Additional Positioning (periodic or non-periodic) while it is still performing activity for a previous A-GPS or A-GANSS or OTDOA or Additional Positioning periodic request, the SRNC should terminate all activity for the previous request, including terminating the periodic measurement reporting in the UE, and should process the new request.

If the SRNC receives a new POSITION ACTIVATION REQUEST message for Cell-ID or U-TDOA positioning while it is still performing activity for a previous A-GPS or A-GANSS or OTDOA or Additional Positioning periodic request (but after returning any POSITION ACTIVATION RESPONSE for this request), the SRNC may both continue with the previous request and process the new request.

If the GANSS Positioning IE is included in the POSITION ACTIVATION REQUEST message and contains the Requested Data Value IE:

– If the GANSS Generic Assistance Data IE, associated with a given GANSS, is included in the Requested Data Value IE, it shall contain a GANSS Real Time Integrity, GANSS Data Bit Assistance, DGANSS Corrections, GANSS Almanac and Satellite Health, GANSS Reference Measurement Information, GANSS UTC Model, GANSS Time Model, GANSS Navigation Model, GANSS Additional Time Models, GANSS Additional Navigation Models, GANSS Additional UTC Models, GANSS Auxiliary Information, DBDS Corrections, or BDS Ionospheric Grid Model IE.

– If the GANSS Generic Assistance Data IE does not contain the GANSS ID IE, the corresponding GANSS is "Galileo".

– The DGANSS Corrections IE contains one or several DGANSS Information IE(s), each of them associated with a GANSS Signal. A DGANSS Information IE for a particular GANSS that does not contain the GANSS Signal ID IE is by default associated with the default signal defined in TS 25.331 [4].

– The GANSS Real Time Integrity IE contains one or several Satellite Information IEs, each of them associated with a satellite and a GANSS Signal. A Satellite Information IE for a particular GANSS that does not contain the Bad GANSS Signal ID IE is by default associated with all the signals of the corresponding satellite (see OS SIS ICD [22], IS-GPS-200 [23], IS-GPS-705 [24], IS-GPS-800 [25], DTFA01-96-C-00025 [26], IS-QZSS [27], [28], BDS-SIS-ICD [33]).

– The GANSS Reference Measurement Information IE is associated with a GANSS Signal. A GANSS Reference Measurement Information IE for a particular GANSS that does not contain the GANSS Signal ID IE is by default associated with the default signal defined in TS 25.331 [4].

– The DBDS Corrections IE contains one or several DBDS Information IE(s), each of them associated with a BDS Signal. A DBDS Information IE that does not contain the BDS Signal ID IE is by default associated with the default signal defined in TS 25.331 [4].

If the RRC State included in the UTDOA Group IE is indicated as being CELL_DCH in the POSITION ACTIVATION RESPONSE message, [FDD – either the DCH Information IE or the E-DPCH Information IE][TDD – the DCH Information IE] should be included.

If the GANSS Measured Results IE is included in the POSITION ACTIVATION RESPONSE message and does not contain the GANSS Time ID IE, the SAS shall assume that the corresponding GANSS timing refers to the "Galileo" timing.

The GANSS Measured Results IE contains one or several GANSS Generic Measurement Information IEs, each of them associated with a given GANSS:

– If a GANSS Generic Measurement Information IE does not contain the GANSS ID IE, the SAS shall assume that the associated GANSS is "Galileo".

– If a GANSS Generic Measurement Information IE associated with a particular GANSS does not contain the GANSS Signal ID IE, the SAS shall assume the default value as defined in TS 25.331 [4].

– If a GANSS Generic Measurement Information IE does not contain the GANSS Code Phase Ambiguity IE and the GANSS Code Phase Ambiguity Extension IE, the SAS shall assume the value "1" (ms).

– If the GANSS Integer Code Phase IE and the GANSS Integer Code Phase Extension IE associated to a given satellite (identified by the Sat ID IE value) is not present within the GANSS Measurement Parameters IE, the SAS shall use the default "1" (ms) for the GANSS Code Phase Ambiguity value in order to compute the value of the Total Code Phase (as defined in TS 25.331 [4]) for the related satellite, whatever the value of the GANSS Code Phase Ambiguity IE.

If the OTDOA Measured Results Sets IE is included in the POSITION ACTIVATION RESPONSE message the SRNC should also include the OTDOA Reference Cell Info. The SAS shall use the cell identified in the OTDOA Reference Cell Info IE as reference cell for the measurements provided in the OTDOA Measured Results Info List IE.

If an optional Cell-ID IRAT Measured Results Sets IE is included in the POSITION ACTIVATION RESPONSE message, the SAS shall, if supported, use this value for the calculation of the UE Position Estimate in case of RFPM positioning method is used. The SAS may use this value for the calculation of the UE Position when any other methods are used.

8.9.3 Unsuccessful Operation

Figure 9d: Position Activation procedure, Unsuccessful Operation

When the SRNC is unable to accept a Position Activation Request message, the Position Activation Failure message should be sent to the SAS.

Typical cause values are:

– Processing Overload;

– Hardware Failure;

– O&M Intervention;

– Positioning Method Not Supported;

– Location Measurement Failure.

8.9.4 Abnormal Conditions

–