6 UAE procedures

24.2573GPPProtocol aspectsRelease 17Stage 3TSUncrewed Aerial System (UAS) Application Enabler (UAE) layer

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

6.1 General

6.2 Communications between UAVs within a geographical area using unicast Uu

6.2.1 Client procedure

6.2.1.1 Sending of a UAV application message

In order to send a UAV application message, the UAE-C shall generate an HTTP POST request message according to procedures specified in IETF RFC 7231 [5]. In the HTTP POST request message, the UAE-C:

a) shall set the Request-URI to the URI received in the UAE client UE configuration document via the SCM-S;

b) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";

c) shall include an application/vnd.3gpp.uae-info+xml MIME body and in the <UAV-application-message-info> element in the <UAE-info> root element:

1) shall include a <UAV-id> element set to the identity of the UAV which requests the sending of the UAV application message;

2) shall include an <application-defined-proximity-range-info> element to indicate the range information over which the UAV application message is to be sent; and

3) shall include an <application-payload> element set to the application payload that is to be delivered to the other UAVs; and

NOTE: The application payload is provided by the UAS application specific client and its contents are out of scope of 3GPP.

d) shall send the HTTP POST request message towards the UAE-S.

6.2.1.2 Reception of a UAV application message

Upon receiving an HTTP POST request containing:

a) a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

b) an application/vnd.3gpp.uae-info+xml MIME body with a <UAV-application-message-info> element in the <UAE-info> root element;

the UAE-C:

a) shall store the received <application-payload> information included in the <UAV-application-message-info> element; and

b) shall generate an HTTP 200 (OK) response according to IETF RFC 7231 [5] and send the HTTP 200 (OK) response towards the UAE-S.

6.2.2 Server procedure

6.2.2.1 Reception of a UAV application message

Upon receiving an HTTP POST request containing:

a) a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

b) an application/vnd.3gpp.uae-info+xml MIME body with a <UAV-application-message-info> element in the <UAE-info> root element;

the UAE-S:

a) shall obtain the other UAV(s) information in the location of the UAV based on the range information indicated in the <application-defined-proximity-range-info> element from the SLM-S as specified in 3GPP TS 24.545 [7];

b) shall send the received <application-payload> information to each of the UAV obtained from step a) via unicast Uu channel as specified in clause 6.2.2.2;

c) shall generate an HTTP 200 (OK) response according to IETF RFC 7231 [5] and in the HTTP 200 (OK) response:

1) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

2) may include an application/vnd.3gpp.uae-info+xml MIME body with a <UAV-application-message-info> with an <acknowledgement> child element in the <UAE-info> root element to indicate the acknowledgement of communications between UAVs within a geographical area; and

NOTE: The geographical area is from the perspective of the UAV initiating the communication with other UAVs.

d) shall send the HTTP 200 (OK) response towards the UAE-C.

6.2.2.2 Sending of a UAV application message

In order to send a UAV application message received from a UAV as specified in clause 6.2.2.1 to each of the UAV within a geographical area of the UAV initiating the communication with other UAVs, the UAE-S shall generate an HTTP POST request message according to procedures specified in IETF RFC 7231 [5]. In the HTTP POST request message, the UAE-S:

a) shall set the Request-URI to the URI corresponding to the identity of the UAE-C of UAV obtained in clause 6.2.2.1;

b) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";

c) shall include an application/vnd.3gpp.uae-info+xml MIME body and in the <UAV-application-message-info> element in the <UAE-info> root element:

1) shall include a <UAV-id> element set to the identity of the UAV which requests the sending of the UAV application message; and

2) shall include an <application-payload> element set to the application payload that needs to be delivered to the other UAVs; and

d) shall send the HTTP POST request message towards the UAE-C.

6.3 C2 Communication mode selection and switching

6.3.1 Client procedure

6.3.1.1 C2 communication modes configuration procedure

Upon receiving an HTTP POST request containing:

a) a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

b) an application/vnd.3gpp.uae-info+xml MIME body with a <c2-modes-switching-configuration-info> element,

the UAE-C:

a) shall store the received configuration information;

b) shall generate an HTTP 200 (OK) response according to IETF RFC 7231 [5]. 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:

i) shall include a <c2-modes-switching-configuration-info> element with a <result> child element set to the value "positive" or "negative" indicating positive or negative result of reception and storing of the communication mode configuration parameters; and

c) shall send the HTTP 200 (OK) response towards the UAE-S.

6.3.1.2 C2 communication mode selection by UAE Client procedure

UAE Clients (UAV and UAV-C) select a primary and secondary C2 communication mode based on C2 communication mode configuration, then the UAE-C shall generate an HTTP POST request according to IETF RFC 7231 [5]. In the HTTP POST request message, the UAE-C:

a) shall set the Request-URI to the URI received in the UAE client UE configuration document via the SCM-S;

b) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";

c) shall include an application/vnd.3gpp.uae-info+xml MIME body with a <C2-communication-mode-notification-info> element in the <UAE-info> root element which:

1) shall include a <UAS-id> element set to the identifier of the UAS;

2) shall include a <selected-primary-C2-communication-mode> element indicating the selected primary C2 communication mode; and

3) may include a <selected-secondary-C2-communication-mode> element indicating the selected secondary C2 communication mode; and

d) shall send the HTTP POST request towards the UAE-S.

6.3.1.3 UAE-layer assisted dynamic C2 mode switching procedure

Upon detecting a condition for switching C2 communication mode based on local conditions (e.g. using the C2 communication mode switching policy) or based on a command from the UAS application specific server, the UAE-C shall generate an HTTP POST request according to IETF RFC 7231 [5]. In the HTTP POST request message, the UAE-C:

a) shall set the Request-URI to the URI corresponding to the identity of the UAE-S;

b) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";

c) shall include an application/vnd.3gpp.uae-info+xml MIME body with a <C2-related-trigger-event-report> element in the <UAE-info> root element which shall include:

1) a <UAE-client-id> element set to the identifier of the UAE client which indicates the QoS downgrade; and

2) an <application-QoS-related-event> element including the expected or actual application QoS/QoE parameters which were changed (i.e. latency, throughput, reliability, jitter); and

d) shall send the HTTP POST request towards the UAE-S.

Upon receiving an HTTP 200 (OK) message containing:

a) a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

b) an application/vnd.3gpp.uae-info+xml MIME body with a <C2-operation-mode-switching> element,

the UAE-C may start C2 communication using the indicated C2 communication mode included in the <C2-operation-mode-switching-requirement> child element and generate an HTTP POST request according to IETF RFC 7231 [5]. In the HTTP POST request message, the UAE-C:

a) shall set the Request-URI to the URI corresponding to the identity of the UAE-S;

b) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";

c) shall include an application/vnd.3gpp.uae-info+xml MIME body with a <C2-operation-mode-switching-performed> element in the <UAE-info> root element which shall include a <result> child element set to the value "positive" or "negative" indicating positive or negative result of the reception; and

d) shall send the HTTP POST request towards the UAE-S.

6.3.2 Server procedure

6.3.2.1 C2 communication modes configuration procedure

Upon receiving an application request from UAS application specific server (which can be the USS/UTM) to manage the C2 operation modes (direct, network-assisted) of C2 communication for a UAS, the UAE-S shall generate an HTTP POST request message according to IETF RFC 7231 [5]. In the HTTP POST request message, the UAE-S:

a) shall include a Request-URI set to the URI corresponding to the identity of the UAE-C;

b) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";

c) shall include an application/vnd.3gpp.uae-info+xml MIME body with a <c2- communication-modes-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 C2 QoS management request applies; and

2) may include a <C2-operation-mode-management-configuration> element which:

i) shall include a <C2-operation mode-management-requirement> element set to the identification of the type of the C2 mode switching to be supported by the UAE server;

ii) shall include an <allowed-C2-communication-modes> element indicating the type of the C2 mode switching;

iii) shall include a <primary-C2-communication-mode> element indicating the primary type of the C2 mode switching;

iv) may include a <secondary-C2-communication-mode> element indicating the secondary type of the C2 mode switching; and

v) shall include a <policy-of –C2-switching> element set to the parameters for C2 switching; and

d) shall send the HTTP POST request message towards the UAE-C.

6.3.2.2 C2 communication mode selection by UAE Client

Upon receiving an HTTP POST request containing:

a) a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

b) an application/vnd.3gpp.uae-info+xml MIME body with a <C2-communication-mode-notification-info> element,

the UAE-S shall store the C2 communication modes and links information received in the <C2-communication-mode-notification-info> element and then forward the C2 communication modes and links information to the UAS application specific server and upon receiving a C2 communication mode notification acknowledgement from the UAS application specific server, the UAE-S shall generate an HTTP 200 (OK) response according to IETF RFC 7231 [5]. In the HTTP 200 (OK) response message, the UAE-S:

a) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

b) shall include an application/vnd.3gpp.uae-info+xml MIME body and in the <UAE-info> root element:

1) shall include a <C2-communication-mode-notification-info> element with an <acknowledgement> child element indicating the acknowledgement of selected C2 communication mode(s); and

c) shall send the HTTP 200 (OK) message towards the UAE-C.

6.3.2.3 UAE-layer assisted dynamic C2 mode switching

Upon receiving an HTTP POST request containing:

a) a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

b) an application/vnd.3gpp.uae-info+xml MIME body with a <C2-related-trigger-event-report> element,

the UAE-S:

a) shall obtain a location report for the UAE-C by the SLM-S;

b) shall determine the switching of the C2 mode from direct to network assisted or vice versa or to USS/UTM navigated;

c) if the switching of the C2 mode is from direct to network assisted or vice versa, may send a C2 mode switching confirmation request to the UAS application specific server;

d) if the switching of the C2 mode is from direct to USS/UTM navigated, shall send a C2 mode switching confirmation request to the UAS application specific server; and

e) the UAE-S shall generate an HTTP 200 (OK) response according to IETF RFC 7231 [5]. In the HTTP 200 (OK) response message, the UAE-S:

NOTE: If the UAE-S has sent a C2 mode switching confirmation request to the UAS application specific server, the UAE-S shall wait and receive from the UAS application specific server a C2 mode switching confirmation response and then generate the HTTP 200 (OK) response message.

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 <C2-operation-mode-switching> element in the <UAE-info> root element which:

i) shall include a <UAE-server-id> element set to the identifier of the UAE server which instructs the UAS to apply the C2 mode switching;

ii) shall include a <C2-operation-mode-switching-requirement> element indicating the type of the C2 mode switching to be applied;

iii) may include a <time-validity> element set to the time validity for the C2 switching requirement; and

iv) may include a <geographical-area> element indicating the area for which the C2 switching applies; and

4) shall send the HTTP 200 (OK) message towards the UAE-C.

6.4 UAS UE registration

6.4.1 Client procedure

Upon receiving a request from a UAV application to register for receiving UAV application messages from the UAS application specific server, the UAE-C shall generate an HTTP POST request message according to procedures specified in IETF RFC 7231 [5]. In the HTTP POST request message, the UAE-C:

a) shall set the Request-URI to the URI received in the UAE client UE configuration document via the SCM-S;

NOTE 1: The provision of the UAE-S information in the UAE client UE configuration document via the SCM-S is out of scope of 3GPP.

b) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";

c) shall include an application/vnd.3gpp.uae-info+xml MIME body and in the <registration-info> element in the <UAE-info> root element:

1) shall include a <UAV-id> element set to the identity of the UAV which initiates the UAS UE registration procedure;

2) may include a <UAS-UE-information> element set to the related information (e.g. UAS UE IP address) the UAS UE needs to provide to the UAE-S; and

3) may include a <proposed-registration-lifetime> element set to the time during which the UAS UE wants to stay registered to the UAE-S for receiving UAV application messages from the UAS application specific server; and

NOTE 2: If the <proposed-registration-lifetime> element is not included in the <registration-info> element, the registration lifetime is valid until the explicit UAS UE deregistration is performed as specified in clause 6.5.

d) shall send the HTTP POST request message towards the UAE-S.

6.4.2 Server procedure

Upon receiving an HTTP POST request containing:

a) a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

b) an application/vnd.3gpp.uae-info+xml MIME body with a <registration-info> element in the <UAE-info> root element;

the UAE-S:

a) shall store the received registration information for the UAE-C;

b) shall generate an HTTP 200 (OK) response according to IETF RFC 7231 [5] and in the HTTP 200 (OK) response:

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 <registration-info> element in the <UAE-info> root element:

i) shall include a <result> element set to the value "success" or "failure" indicating success or failure of the UAS UE registration; and

ii) may include a <registration-lifetime> element set to the time during which the UAS UE can stay registered to the UAE-S for receiving UAV application messages from the UAS application specific server; and

c) shall send the HTTP 200 (OK) response towards the UAE-C.

6.5 UAS UE de-registration

6.5.1 Client procedure

Upon receiving a request from a UAV application to de-register for receiving UAV application messages from the UAS application specific server, the UAE-C shall generate an HTTP POST request message according to procedures specified in IETF RFC 7231 [5]. In the HTTP POST request message, the UAE-C:

a) shall set the Request-URI to the URI of the UAE-S for which the UAS UE has successfully registered (see clause 6.4);

b) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";

c) shall include an application/vnd.3gpp.uae-info+xml MIME body and in the <de-registration-info> element in the <UAE-info> root element:

1) shall include a <UAV-id> element set to the identity of the UAV which initiates the UAS UE de-registration procedure; and

d) shall send the HTTP POST request message towards the UAE-S.

6.5.2 Server procedure

Upon receiving an HTTP POST request containing:

a) a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

b) an application/vnd.3gpp.uae-info+xml MIME body with a <de-registration-info> element in the <UAE-info> root element;

the UAE-S:

a) shall remove the stored UAS UE information for the UAE-C;

b) shall generate an HTTP 200 (OK) response according to IETF RFC 7231 [5] and in the HTTP 200 (OK) response:

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 <de-registration-info> element in the <UAE-info> root element:

i) shall include a <result> element set to the value "success" or "failure" indicating success or failure of the UAS UE de-registration; and

c) shall send the HTTP 200 (OK) response towards the UAE-C.

6.6 UAS UE registration update

6.6.1 Client procedure

Upon receiving a request from a UAV application, if the UAE-C needs to update the registration for receiving UAV application messages from the UAS application specific server, the UAE-C shall generate an HTTP POST request message according to procedures specified in IETF RFC 7231 [5]. In the HTTP POST request message, the UAE-C:

a) shall set the Request-URI to the URI of the UAE-S for which the UAS UE has successfully registered (see clause 6.4);

b) shall include a Content-Type header field set to "application/vnd.3gpp.uae-info+xml";

c) shall include an application/vnd.3gpp.uae-info+xml MIME body and in the <registration-info> element in the <UAE-info> root element:

1) shall include a <UAV-id> element set to the identity of the UAV which initiates the UAS UE registration update procedure;

2) shall include a <UAS-UE-information> element set to the related information (e.g. UAS UE IP address) the UAS UE needs to update; and

NOTE: If the <proposed-registration-lifetime> element is not included in the <registration-info> element, the registration lifetime is not updated.

d) shall send the HTTP POST request message towards the UAE-S.

6.6.2 Server procedure

Upon receiving an HTTP POST request containing:

a) a Content-Type header field set to "application/vnd.3gpp.uae-info+xml"; and

b) an application/vnd.3gpp.uae-info+xml MIME body with a <registration-info> element in the <UAE-info> root element;

the UAE-S:

a) shall update the stored registration information with the received registration information for the UAE-C;

b) shall generate an HTTP 200 (OK) response according to IETF RFC 7231 [5] and in the HTTP 200 (OK) response:

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 <registration-info> element in the <UAE-info> root element:

i) shall include a <result> element set to the value "success" or "failure" indicating success or failure of the UAS UE registration update; and

c) shall send the HTTP 200 (OK) response towards the UAE-C.