Content for &nbsp; TS 23.558 &nbsp; Word version:&nbsp; 19.5.0

The EAS sends an AC information subscription request to the EES. The request may contain filters to retrieve information about particular ACs e.g. AC profile parameters or parameter ranges to be matched, specific UE Identifiers, location ranges, etc.

Upon receiving the request from the EAS, the EES performs an authorization check to verify whether the EAS has authorization to perform the operation. The EES determines the matching AC information corresponding to the filter provided and composes a result. The EES stores the subscription information for future processing.

Figure 8.6.4.2.3-1: AC information notification

The EES sends an AC information subscription response to the EAS with the result composed in step 2.

8.6.4.2.3 Notify p. 138

Figure 8.6.4.2.3-1 illustrates the AC information notification procedure between the EES and the EAS.

Pre-conditions:

The EAS subscribed for AC information at the EES.

Reproduction of 3GPP TS 23.558, Fig. 8.6.4.2.3-1: AC information notification

The EES is triggered for AC information updates, e.g. it receives an EEC registration request, it determines if it matches the filter provided by the EAS, e.g. if the AC Geographical Service Area is included in the EAS provided Geographical Service Area.

Figure 8.6.4.2.4-1: AC information subscription update

The EES sends an AC information notification to the EAS.

8.6.4.2.4 Subscription update p. 138

Figure 8.6.4.2.4-1 illustrates the AC information subscription update procedure between the EAS and the EES.

Pre-conditions:

The EAS has subscribed for AC information as described in clause 8.6.4.2.2.

Reproduction of 3GPP TS 23.558, Fig. 8.6.4.2.4-1: AC information subscription update

The EAS sends an AC information subscription update request to the EES. The request may contain updated filters to retrieve information about particular ACs e.g. AC profile parameters or parameter ranges to be matched, specific UE Identifiers, location ranges, etc.

Upon receiving the request from the EAS, the EES performs an authorization check to verify whether the EAS has authorization to perform the operation. If authorized, the EES updates the stored subscription information.

Figure 8.6.4.2.5-1: AC information unsubscribe

The EES sends an AC information subscription update response to the EAS.

8.6.4.2.5 Unsubscribe p. 139

Figure 8.6.4.2.5-1 illustrates the AC information unsubscribe procedure between the EAS and the EES.

Pre-conditions:

The EAS has subscribed for AC information as described in clause 8.6.4.2.2.

Reproduction of 3GPP TS 23.558, Fig. 8.6.4.2.5-1: AC information unsubscribe

The EAS sends an AC information unsubscribe request to the EES.

Upon receiving the request from the EAS, the EES performs an authorization check to verify whether the EAS has authorization to perform the operation. If authorized, the EES cancels the subscription as requested in step 1.

Table 8.6.4.3.2-1: AC information subscription request

The EES sends an AC information unsubscribe response to the EAS.

8.6.4.3 Information flows p. 139

8.6.4.3.1 General p. 139

Void

8.6.4.3.2 AC information subscription request p. 139

Table 8.6.4.3.2-1 describes the information flow for an AC information subscription request from the EAS to the EES.

Information element	Status	Description
EASID	M	The identifier of the EAS.
Security credentials	M	Security credentials of the EAS.
Subscription type	M	Choice of "One time" or "Event based" determining the type of processing requested.
Notification Target Address	M	The Notification Target Address (e.g. URL) where the notifications destined for the EAS should be sent to.
Filters	O	List of characteristics for discovery purposes, as detailed in Table 8.6.4.3.2-2.
Event conditions	O	Parameters indicating notification event conditions e.g. number of notifications instances, subscription timeout, etc.
Trigger parameters	O	Parameters indicating notification triggering conditions e.g. EEC registration, EAS discovery.

Table 8.6.4.3.2-2: Filters

Information element	Status	Description
ACID(s)	O	List of identities of AC(s) to be matched
UE ID(s)	O	List of UE identifiers to be matched
AC Type(s)	O	List of categories or types of ACs (e.g. V2X) to be matched
ECSP ID(s)	O	Identifier(s) for the ECSP associated with the EEC.
Operation Schedule	O	EAS operation schedule (e.g. time windows) to be matched
Geographical Service Area	O	EAS service area for identifying UEs with matching expected geographical location(s) (e.g. route). This geographic information can express a geographic point, polygon, route, signalling map, or waypoint set.
Topological Service Area	O	EAS service area for identifying UEs with matching expected topological location(s). See possible formats in Table 8.2.7-1.
Maximum AC Service KPIs (NOTE)	O	Maximum value for identifying the ACs to be matched. Both Minimum required AC Service KPIs and Expected AC Service KPIs from the AC Profiles provided during registration (Table 8.4.2.3.2-1) and/or discovery subscription (Table 8.5.3.4-1) need to be lower than this value.
Min AC Service KPIs (NOTE)	O	Minimum value for identifying the ACs to be matched. Both Minimum required AC Service KPIs and Expected AC Service KPIs from the AC Profiles provided during registration (Table 8.4.2.3.2-1) and/or discovery subscription (Table 8.5.3.4-1) need to be greater than this value.
UE location(s)	O	List of locations (e.g. routes) of the UE(s) for which the request applies
EAS bundle indication	O	Indicator for identifying ACs which include EAS bundle information in the AC Profile and the EAS bundle includes the requesting EAS. If Bundle ID or EAS bundle requirements filters are not included, the presence of this IE signifies that all ACs which include EAS bundle information in the AC Profile match.
> Bundle ID	O	A bundle ID as described in clause 7.2.10 for identifying ACs with EAS bundle information in the AC Profile and with matching bundle EAS identification information.
> Bundle type	O	Type of the EAS bundle as described in clause 7.2.10.
> EAS bundle requirements	O	Bundle requirements (as described in clause 8.2.10) for identifying ACs with EAS bundle information in the AC Profile and with matching bundle requirements.
> Partial EAS bundle determination	O	Indicator for identifying ACs which include EAS bundle information in the AC Profile but for which only an EAS subset has been determined by EES.
NOTE: Maximum and minimum AC Service KPIs values may be provided for any IEs from Table 8.2.3-1.

8.6.4.3.3 AC information subscription response p. 141

Table 8.6.4.3.3-1 describes the information flow for the AC information subscription response from EAS to the EES.

Table 8.6.4.3.3-1: AC information subscription response

Information element	Status	Description
Successful response	O	Indicates that the subscription request was successful.
> Subscription ID	M	Subscription identifier corresponding to the subscription.
Failure response	O	Indicates that the subscription request failed.
> Cause	O	Indicates the cause of subscription request failure

8.6.4.3.4 AC information notification p. 142

Table 8.6.4.3.4-1 describes the information flow for an AC information notification from the EES to the EAS.

Table 8.6.4.3.4-1: AC information notification

Information element	Status	Description
Subscription Identifier	M	Subscription identifier for which the notification is generated.
List of clients	O	List of clients matched based on the given filtering criteria, with elements listed below
>AC Profile(s)	M	Profiles of ACs as described in Table 8.2.2-1.
>UE ID(s)	O	UE identifier for the UE hosting the AC
>UE location(s)	O	UE location for the UE hosting the AC

8.6.4.3.5 AC information subscription update request p. 142

Table 8.6.4.3.5-1 describes the information flow for an AC information subscription update request from the EAS to the EES.

Table 8.6.4.3.5-1: AC information subscription update request

Information element	Status	Description
Security credentials	M	Security credentials of the EAS.
Subscription ID	M	Subscription identifier corresponding to the subscription.
Filter	O	List of characteristics for discovery purposes, as detailed in Table 8.6.4.3.2-2.
Event conditions	O	Parameters indicating notification event conditions e.g. number of notifications instances, subscription timeout, etc.
Trigger parameters	O	Parameters indicating notification triggering conditions e.g. EEC registration, EAS discovery.

8.6.4.3.6 AC information subscription update response p. 142

Table 8.6.4.3.6-1 describes the information flow for the AC information subscription update response from EAS to the EES.

Table 8.6.4.3.6-1: AC information subscription update response

Information element	Status	Description
Successful response	O	Indicates that the subscription update request was successful.
Failure response	O	Indicates that the subscription update request failed.
> Cause	O	Indicates the cause of subscription update request failure

8.6.4.3.7 AC information unsubscribe request p. 143

Table 8.6.4.3.7-1 describes the information flow for an AC information unsubscribe request from the EAS to the EES.

Table 8.6.4.3.7-1: AC information unsubscribe request

Information element	Status	Description
Security credentials	M	Security credentials of the EAS
Subscription Identifier	M	Subscription identifier for the corresponding subscription request.

8.6.4.3.8 AC information unsubscribe response p. 143

Table 8.6.4.3.8-1 describes the information flow for the AC information unsubscribe response from EAS to the EES.

Table 8.6.4.3.8-1: AC information unsubscribe response

Information element	Status	Description
Successful response	O	Indicates that the unsubscribe request was successful.
Failure response	O	Indicates that the unsubscribe request failed.
> Cause	O	Indicates the cause of unsubscribe request failure

8.6.4.4 APIs p. 143

8.6.4.4.1 General p. 143

Table 8.6.4.4.1-1 illustrates the API for AC information exposure.

Table 8.6.4.4.1-1: Eees_AppClientInformation API

API Name	API Operations	Operation Semantics	Consumer(s)
Eees_AppClientInformation	Subscribe	Subscribe/ Notify	EAS
	Notify
	UpdateSubscription
	Unsubscribe

8.6.4.4.2 Eees_AppClientInformation_Subscribe operation p. 143

API operation name:

Eees_AppClientInformation_subscribe

Description:

The consumer subscribes to receive an AC information.

Inputs:

See clause 8.6.4.3.2.

Outputs:

See clause 8.6.4.3.3.

See clause 8.6.4.2.2 for details of usage of this operation.

8.6.4.4.3 Eees_AppClientInformation_Notify operation p. 143

API operation name:

Eees_AppClientInformation_Notify

Description:

The consumer is notified of an event by the EES.

Inputs:

See clause 8.6.4.3.4.

Outputs:

None.

See clause 8.6.4.2.3 for details of usage of this operation.

8.6.4.4.4 Eees_AppClientInformation_UpdateSubscription operation p. 144

API operation name:

Eees_AppClientInformation_UpdateSubscription

Description:

The consumer updates an existing subscription for AC information.

Inputs:

See clause 8.6.4.3.5.

Outputs:

See clause 8.6.4.3.6.

See clause 8.6.4.2.4 for details of usage of this operation.

8.6.4.4.5 Eees_AppClientInformation_Unsubscribe operation p. 144

API operation name:

Eees_AppClientInformation_Unsubscribe

Description:

The consumer unsubscribes for the previously subscribed events.

Inputs:

See clause 8.6.4.3.7.

Outputs:

See clause 8.6.4.3.8.

See clause 8.6.4.2.5 for details of usage of this operation.

8.6.5 UE Identifier API p. 144

8.6.5.1 General p. 144

EES exposes UE Identifier API to the EAS and EEC in order to provide an identifier uniquely identifying a UE. This API is used by an EAS or EEC to obtain the identifier of the UE if the EAS or EEC does not have it (e.g. hasn't already cached). This identifier, called UE ID and defined in clause 7.2.6, is used by the EAS to invoke capability APIs specific to UEs over EDGE-3 and/or EDGE-7 depending on the UE ID type.

The EAS's direct invocation of the UE Identifier API of the EES may result in UE ID not found response (e.g. if the NATed UE's public IPv4 address can't be resolved by the core network). Under such circumstances, the EAS may choose to signal its AC to trigger the UE ID query onto the EEC over EDGE-5 (see clause 8.14.2.6). In turn, the EEC would invoke the EES's UE Identifier API using the UE's CN assigned IP addresses (i.e. IPv4 and/or IPv6) which should result in return of the UE ID to the EEC and from thereon to the AC and the EAS.

8.6.5.2 Procedure p. 144

Figure 8.6.5.2-1 illustrates the interactions between the EES and the EAS or EEC.

Pre-conditions:

The EAS or EEC is authorized to discover and to use UE Identifier API provided by the EES.
When the EEC is used to invoke the UE Identifier API with the UE IPv6 address as the input parameter, the UE IPv6 address may or may not be NATed. If NATed however, the IPv6 may not be reused (i.e. assigned to more than one UE simultaneously). If the EEC already has the UE ID (GPSI as per clause 7.2.6), and it needs the Edge UE ID to share with an AC/EAS, this procedure can still be used to retrieve Edge UE ID.

Reproduction of 3GPP TS 23.558, Fig. 8.6.5.2-1: UE Identifier API

Figure 8.6.5.2-1: UE Identifier API

The EAS or EEC invokes UE Identifier API exposed by the EES. If it is the EAS invoking the API and it recognizes that the UE's IP address is a public IP address, i.e., the UE is behind a NAT, the Port Number and associated IP address should be included in user information.

The EES uses the received user information in the step 1 (e.g. IP address) and obtains the UE identifier by interacting with NEF as specified in clause 4.15.10 of TS 23.502. If it is the EEC invoking the API with only UE IP address, it shall be interpreted by EES that EEC is requesting the UE ID for interaction with EES (hence EES shall use its own AF Identifier towards NEF and consequently the UE ID is EES specific). When the EES needs to interact with the NEF's Nnef_UEId_Get (seeclause 4.15.10 of TS 23.502 "AF specific UE ID retrieval") as per EAS request, the EES may use either its own AF Identifier or EASID as AF Identifier instead of its own AF Identifier.