Content for  TS 24.257  Word version:  18.3.0

Upon receiving an HTTP POST request containing:

1. a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and
2. an application/vnd.3gpp.uae-info+xml MIME body with a <multi-USS-configuration-info> element,

the UAE-C:

1. shall store the received configuration information;
2. shall generate an HTTP 200 (OK) response according to RFC 9110. In the HTTP 200 (OK) response message, the UAE-C:
   1. shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and
   2. shall include an application/vnd.3gpp.uae-info+xml MIME body and in the <UAE-info> root element:
      1. shall include a <multi-USS configuration-info> element with a <result> child element set to the value "success" or "failure" indicating positive or negative result of reception and storing of the multi-USS configuration parameters; and
3. shall send the HTTP 200 (OK) response towards the UAE-S.

Upon receiving an HTTP POST request containing:

1. a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and
2. an application/vnd.3gpp.uae-info+xml MIME body with a <USS-change-info> element,

the UAE-C:

1. shall perform change of USS;
2. shall generate an HTTP 200 (OK) response according to RFC 9110. In the HTTP 200 (OK) response message, the UAE-C:
   1. shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and
   2. shall include an application/vnd.3gpp.uae-info+xml MIME body and in the <UAE-info> root element:
      1. shall include a <USS-change-info> element with a <result> child element set to the value "success" or "failure" indicating positive or negative result of reception and storing of the USS change parameters; and
3. shall send the HTTP 200 (OK) response towards the UAE-S.

Once the USS change is performed the UAE-C shall generate an HTTP POST request message according to RFC 9110. In the HTTP POST request message, the UAE-C:

1. shall include a Request-URI set to the URI corresponding to the identity of the UAE-S;
2. shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";
3. shall include an application/vnd.3gpp.uae-info+xml MIME body with a <USS-change-notification-info> element in the <UAE-info> root element which:
   1. shall include a <Reason> element to indicate reason for change of USS;
   2. shall include a <Target-USS-information> element set to an identifier of the new USS that the UAV has connected to (identified e.g. by FQDN); and
4. shall send the HTTP POST request message towards the UAE-S.

Upon receiving an application request from UAS application specific server (which can be the USS/UTM) to manage the multi-USS configuration for a UAS, the UAE-S shall generate an HTTP POST request message according to RFC 9110. In the HTTP POST request message, the UAE-S:

1. shall include a Request-URI set to the URI corresponding to the identity of the UAE-C;
2. shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";
3. shall include an application/vnd.3gpp.uae-info+xml MIME body with a <multi-USS-configuration-info> element in the <UAE-info> root element which:
   1. shall include a <UAS-id> element set to the identification of the UAS for which the multi-USS configuration request applies; and
   2. may include a <Multi-USS-policy-management-configuration> element that contains the Multi-USS policy management configuration information to be configured at the UAS which:
      1. shall include an <Allowed-USS> element indicating the USS that can be the target of a switch;
      2. shall include a <Serving-USS-information> element set to the serving USS identifier;
      3. shall include an <Additional-information-for-change-of-USS> element providing information about the serving USS, related with the switch to a particular target USS;
      4. shall include an <Area-for-change-of-USS> element indicating the area where the Multi-USS management request applies; and
4. shall send the HTTP POST request message towards the UAE-C.

Upon receiving an USS change request from UAS application specific server (which can be the USS/UTM) to manage the USS change for a UAS, the UAE-S shall generate an HTTP POST request message according to RFC 9110. In the HTTP POST request message, the UAE-S:

1. shall include a Request-URI set to the URI corresponding to the identity of the UAE-C;
2. shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";
3. shall include an application/vnd.3gpp.uae-info+xml MIME body with a <USS-change-request-info> element in the <UAE-info> root element which:
   1. shall include a <UASS-id> element set to the identification of the UAS application specific server for which the USS change request applies;
   2. shall include a <UAS-id> element set to the identification of the UAS for which the USS change request applies;
   3. shall include a <USS-change-authorization-information> element set to the authorization token to verify the request;
   4. shall include a <Target-USS> element set to the identification of the USS that is the target of a switch (identified e.g. by FQDN); and
   5. shall include a <Target-USS-info> element indicating the information of the target USS;
      1. shall include an <USS-endpoint> element indicating Endpoint information (e.g. URI, FQDN, IP address) used to communicate with the USS;
      2. may include a <USS-capabilities> element indicating the capabilities supported by the target USS;
      3. may include an <LUN-id> element set to the identity of the LUN where the serving/target USS belongs;
      4. may include an <List-of-USS-DNAI(s)> element indicating DNAI(s) associated with the target USS; and
4. shall send the HTTP POST request message towards the UAE-C.