17 Location procedures
24.2823GPPMission Critical Data (MCData) signalling controlProtocol specificationRelease 18TS
17.1 General
If the participating MCData function needs to obtain location information, the participating MCData function configures the MCData client upon successful MCData service authorization. The configuration contains information the MCData client uses to set up filter criteria for when the MCData client shall send location reports to the participating MCData function.
The participating MCData function can also explicitly request the MCData client to send a location report.
The MCData client will, based on the received configuration or when explicitly requested, send location reports.
The location information can be used by the participating MCData function to determine whether to use MBMS bearers or not.
17.2 Participating MCData function location procedures
17.2.1 General
The participating MCData function has procedures to:
– configure the location reporting at the UE;
– request the UE to report the location of the UE; and
– receive a location information report from the UE.
17.2.2 Location reporting configuration
The participating MCData function may configure the location reporting in the MCData client by generating a SIP MESSAGE request in accordance with 3GPP TS 24.229 [5] and IETF RFC 3428 [6]. The participating MCData function:
1) shall include a Request-URI set to the URI from MCData service authorization corresponding to the MCData ID of the MCData user;
2) shall include an Accept-Contact header field with the media feature tag g.3gpp.icsi-ref set to the value "urn:urn-7:3gpp-service.ims.icsi.mcdata" along with parameters "require" and "explicit" in accordance with IETF RFC 3841 [8];
3) shall include an application/vnd.3gpp.mcdata-info+xml MIME body with an <mcdata-request-uri> element containing the MCData ID of the MCData user to receive the configuration;
4) shall include an application/vnd.3gpp.mcdata-location-info+xml MIME body with the <Configuration> element contained in the <location-info> root element set to the desired configuration;
5) shall include the TriggerId attribute where defined for the sub-elements defining the trigger criterion;
6) shall include the public service identity of the participating MCData function in the P-Asserted-Identity header field;
7) shall include a P-Asserted-Service header field with the value "urn:urn-7:3gpp-service.ims.icsi.mcdata"; and
8) shall send the SIP MESSAGE request as specified in 3GPP TS 24.229 [5].
17.2.3 Location information request
If the participating MCData function needs to request the MCData client to report its location, the participating MCData functions shall generate a SIP MESSAGE request in accordance with 3GPP TS 24.229 [5] and IETF RFC 3428 [6]. The participating MCData function:
1) shall include a Request-URI set to the URI from MCData service authorization corresponding to the MCData ID of the MCData user;
2) shall include an Accept-Contact header field with the media feature tag g.3gpp.icsi-ref set to the value "urn:urn-7:3gpp-service.ims.icsi.mcdata" along with parameters "require" and "explicit" in accordance with IETF RFC 3841 [8];
3) shall include an application/vnd.3gpp.mcdata-info+xml MIME body with an <mcdata-request-uri> element containing the MCData ID of the MCData user;
4) shall include an application/vnd.3gpp.mcdata-location-info+xml MIME body with a <Request> element contained in the <location-info> root element;
5) shall include a P-Asserted-Service header field with the value "urn:urn-7:3gpp-service.ims.icsi.mcdata"; and
6) shall send the SIP MESSAGE request as specified in 3GPP TS 24.229 [5].
17.2.4 Location information report
If the participating MCData function receives a SIP request containing:
1) a Content-Type header field set to "application/vnd.3gpp.mcdata-location-info+xml"; and
2) an application/vnd.3gpp.mcdata-location-info+xml MIME body with a <Report> element included in the <location-info> root element;
then the participating MCData function shall authorise the location report based on the MCData ID received. If the MCData user is authorised to send a location report the participating MCData function:
1) shall use the location information as needed;
2) shall follow the procedure of clause 6.3.7.1.7, if the MCData client has entered into or exited from a group geographic area; and
3) shall follow the procedure of clause 6.3.7.1.6, if the MCData client has entered into or exited from an emergency alert area.
NOTE: The <Report> element contains the event triggering identity in the location information report from the UE, and can contain location information.
17.2.5 Abnormal cases
Upon receipt of a SIP request:
1) where the P-Asserted-Identity identifies a public user identity not associated with an MCData user served by the participating MCData function; or
2) with a MIME body with Content-Type header field set to "application/vnd.3gpp.mcdata-info+xml" and with a <mcdata-request-URI> element containing an MCData ID that identifies an MCData user served by the participating MCData function;
then, when the SIP request contains:
1) an Accept-Contact header field with the g.3gpp.mcdata media feature tag;
2) an Accept-Contact header field with the g.3gpp.icsi-ref media-feature tag with the value of "urn:urn-7:3gpp-service.ims.icsi.mcdata"; and
3) an application/vnd.3gpp.mcdata-location-info+xml MIME body containing a <Request> element or a <Configuration> element;
the participating MCData function shall remove the application/vnd.3gpp.mcdata-location-info+xml MIME body when sending a SIP request.
17.3 MCData client location procedures
17.3.1 General
The MCData client sends a location report when one of the trigger criteria is fulfilled or when it receives a request from the participating MCData function to send a location report. To send the location report the MCData client can use an appropriate SIP message that it needs to send for other reasons, or it can include the location report in a SIP MESSAGE request.
To send a location report, the MCData client includes in the SIP MESSAGE request an application/vnd.3gpp.mcdata-location-info+xml MIME body as specified in clause D.4. The MCData client populates the elements in accordance with its reporting configuration. Further location information may also be included in the P-Access-Network-Info header field.
17.3.2 Location reporting configuration
Upon receiving a SIP MESSAGE request containing:
1) an Accept-Contact header field with the media feature tag g.3gpp.icsi-ref set to the value "urn:urn-7:3gpp-service.ims.icsi.mcdata";
2) a Content-Type header field set to "application/vnd.3gpp.mcdata-location-info+xml"; and
3) an application/vnd.3gpp.mcdata-location-info+xml MIME body with a <Configuration> root element included in the <location-info> root element;
the MCData client:
1) shall store the contents of the <Configuration> elements;
2) shall set the location reporting triggers accordingly; and
3) shall start the minimumReportInterval timer.
17.3.3 Location information request
Upon receiving a SIP MESSAGE request containing:
1) an Accept-Contact header field with the media feature tag g.3gpp.icsi-ref set to the value "urn:urn-7:3gpp-service.ims.icsi.mcdata";
2) a Content-Type header field set to "application/vnd.3gpp.mcdata-location-info+xml"; and
3) an application/vnd.3gpp.mcdata-location-info+xml MIME body with a <Request> element included in the <location-info> root element;
the MCData client:
1) shall send a location report as specified in clause 17.3.4; and
2) shall reset the minimumReportInterval timer.
17.3.4 Location information report
17.3.4.1 Report triggering
If a location reporting trigger fires, the MCData client checks if the minimumReportInterval timer is running. If the timer is running the MCData client waits until the timer expires. When the minimumReportInterval timer expires, the MCData client:
1) shall, if any of the reporting triggers are still true, send a location information report as specified in clause 17.3.4.2.
If the MCData client receives a location information request as specified in clause 17.3.3, the MCData client shall send a location report as specified in clause 17.3.4.2.
17.3.4.2 Sending location information report
If the MCData client needs to send a SIP request anyway (i.e. for reasons other than explicit location reporting request or the firing of a configured location trigger), the MCData client:
1) shall include an application/vnd.3gpp.mcdata-location-info+xml MIME body and in the <location-info> root element the MCData client shall include:
a) a <Report> element and, if the Report was triggered by a location request, include the <ReportID> attribute set to the value of the <RequestID> attribute in the received Request;
b) <TriggerId> child elements, if triggers have fired, where each element is set to the value of the <Trigger-Id> attribute associated with the triggers that have fired; and
c) the location reporting elements corresponding to the triggers that have fired, if at least one trigger has fired;
2) shall set the minimumReportInterval timer to the minimumReportInterval time and start the timer; and
3) shall reset all triggers.
If the MCData client does not need to send a SIP request for reasons other than explicit location reporting request or the firing of a configured location trigger, the MCData client shall generate a SIP MESSAGE request in accordance with 3GPP TS 24.229 [5] and IETF RFC 3428 [6]. The MCData client;
1) shall include in the Request-URI, the SIP URI received in the P-Asserted-Identity header field in the received SIP MESSAGE request for location report configuration;
2) shall include a Content-Type header field set to "application/vnd.3gpp.mcdata-location-info+xml";
3) shall include an application/vnd.3gpp.mcdata-location-info+xml MIME body and in the <location-info> root element include:
a) a <Report> element and if the Report was triggered by a location request include the <ReportID> attribute set to the value of the <RequestID> attribute in the received Request;
b) <TriggerId> child elements, if triggers have fired, where each element is set to the value of the <Trigger-Id> attribute associated with the triggers that have fired; and
c) the location reporting elements corresponding to the triggers that have fired, if at least one trigger has fired;
4) shall include an Accept-Contact header field with the media feature tag g.3gpp.mcdata along with parameters "require" and "explicit" in accordance with IETF RFC 3841 [8];
5) shall set the minimumReportInterval timer to the minimumReportInterval time and start the timer;
6) shall reset all triggers; and
7) shall send the SIP MESSAGE request as specified in 3GPP TS 24.229 [5].