6.3 Namf_MT Service API

29.5183GPP5G SystemAccess and Mobility Management ServicesRelease 17Stage 3TS

6.3.1 API URI

The Namf_MT shall use the Namf_MT API.

The API URI of the Namf_MT API shall be:

{apiRoot}/<apiName>/<apiVersion>/

The request URI used in HTTP requests from the NF service consumer towards the NF service producer shall have the Resource URI structure defined in clause 4.4.1 of 3GPP TS 29.501 [5], i.e.:

{apiRoot}/<apiName>/<apiVersion>/<apiSpecificResourceUriPart>

with the following components:

– The {apiRoot} shall be set as described in 3GPP TS 29.501 [5].

– The <apiName> shall be "namf-mt".

– The <apiVersion> shall be "v1".

– The <apiSpecificResourceUriPart> shall be set as described in clause 6.3.3.

6.3.2 Usage of HTTP

6.3.2.1 General

HTTP/2, as defined in IETF RFC 7540 [19], shall be used as specified in clause 5 of 3GPP TS 29.500 [4].

HTTP/2 shall be transported as specified in clause 5.3 of 3GPP TS 29.500 [4].

HTTP messages and bodies for the Namf_MT service shall comply with the OpenAPI [23] specification contained in Annex A.

6.3.2.2 HTTP standard headers

6.3.2.2.1 General

The usage of HTTP standard headers shall be supported as specified in clause 5.2.2 of 3GPP TS 29.500 [4].

6.3.2.2.2 Content type

The following content types shall be supported:

– JSON, as defined in IETF RFC 8259 [8], shall be used as content type of the HTTP bodies specified in the present specification as indicated in clause 5.4 of 3GPP TS 29.500 [4].

– The Problem Details JSON Object (IETF RFC 7807 [36]). The use of the Problem Details JSON object in a HTTP response body shall be signalled by the content type "application/problem+json".

6.3.2.3 HTTP custom headers

6.3.2.3.1 General

In this release of this specification, no custom headers specific to the Namf_MT service are defined. For 3GPP specific HTTP custom headers used across all service based interfaces, see clause 5.2.3 of 3GPP TS 29.500 [4].

6.3.3 Resources

6.3.3.1 Overview

Figure 6.3.3.1-1: Resource URI structure of the Namf_MT Service API

Table 6.3.3.1-1 provides an overview of the resources and applicable HTTP methods.

Table 6.3.3.1-1: Resources and methods overview

Resource name

Resource URI

HTTP method or custom operation

Description

ueReachInd

/ue-contexts/{ueContextId}/ue-reachind

PUT

Update the ueReachInd to UE Reachable

ueContext

/ue-contexts/{ueContextId}

GET

Map to following service operation:

– ProvideDomainSelectionInfo

ueContexts collection

/ue-contexts/enable-group-reachability

enable-group-reachability (POST)

Update the state of the list of UEs to CM-CONNECTED state

6.3.3.2 Resource: ueReachInd

6.3.3.2.1 Description

This resource represents the ueReachInd for a SUPI.

This resource is modelled as the Document resource archetype (see clause C.1 of 3GPP TS 29.501 [5]).

6.3.3.2.2 Resource Definition

Resource URI: {apiRoot}/namf-mt/<apiVersion>/ue-contexts/{ueContextId}/ue-reachind

This resource shall support the resource URI variables defined in table 6.3.3.2.2-1.

Table 6.3.3.2.2-1: Resource URI variables for this resource

Name

Data type

Definition

apiRoot

string

See clause 6.3.1

apiVersion

string

See clause 6.3.1.

ueContextId

Supi

Represents the Subscription Permanent Identifier (see 3GPP TS 23.501 [2] clause 5.9.2)
pattern: see pattern of type Supi in 3GPP TS 29.571 [6]

6.3.3.2.3 Resource Standard Methods
6.3.3.2.3.1 PUT

This method shall support the URI query parameters specified in table 6.3.3.2.3.1-1.

Table 6.3.3.2.3.1-1: URI query parameters supported by the PUT method on this resource

Name

Data type

P

Cardinality

Description

n/a

This method shall support the request data structures specified in table 6.3.3.2.3.1-2 and the response data structures and response codes specified in table 6.3.3.2.3.1-3.

Table 6.3.3.2.3.1-2: Data structures supported by the PUT Request Body on this resource

Data type

P

Cardinality

Description

EnableUeReachabilityReqData

M

1

Contain the State of the UE, the value shall be set to UE Reachable.

Table 6.3.3.2.3.1-3: Data structures supported by the PUT Response Body on this resource

Data type

P

Cardinality

Response

codes

Description

EnableUeReachabilityRspData

M

1

200 OK

Indicate the ueReachInd is updated to UE Reachable.

RedirectResponse

O

0..1

307 Temporary Redirect

When the related UE context is not fully available at the target NF Service Producer (e.g. AMF) during a planned maintenance case (e.g. AMF planned maintenance without UDSF case) the "cause" attribute may be used to include the following application error:

– NF_CONSUMER_REDIRECT_ONE_TXN

See table 6.3.7.3-1 for the description of these errors

The Location header of the response shall be set to the URI of the resource located on an alternative service instance within the same AMF or AMF (service) set to which the request is redirected.

If an SCP redirects the message to another SCP then the location header field shall contain the same URI or a different URI pointing to the endpoint of the NF service producer to which the request should be sent.

RedirectResponse

O

0..1

308 Permanent Redirect

Permanent redirection. The response shall include a Location header field containing a different URI, or the same URI if a request is redirected to the same target resource via a different SCP. In the former case, the URI shall be an alternative URI of the resource located on an alternative service instance within the same AMF or AMF (service) set.

ProblemDetailsEnableUeReachability

O

0..1

403 Forbidden

The "cause" attribute may be used to indicate one of the following application errors:

– UNABLE_TO_PAGE_UE

– UNSPECIFIED

– UE_IN_NON_ALLOWED_AREA

See table 6.3.7.3-1 for the description of this error.

ProblemDetails

O

0..1

404 Not Found

When the related UE is not found in the NF Service Producer (e.g. AMF) the "cause" attribute shall be set to:

– CONTEXT_NOT_FOUND

See table 6.3.7.3-1 for the description of these errors

ProblemDetails

O

0..1

409 Conflict

The "cause" attribute may be used to indicate the following application error:

– REJECTION_DUE_TO_PAGING_RESTRICTION

See table 6.3.7.3-1 for the description of this error.

ProblemDetails

O

0..1

503 Service Unavailable

The "cause" attribute may be used to indicate one of the errors defined in Table 5.2.7.2-1 of 3GPP TS 29.500 [4].

The HTTP header field "Retry-After" shall not be included in this scenario.

ProblemDetailsEnableUeReachability

O

0..1

504 Gateway Timeout

The "cause" attribute may be used to indicate one of the following application errors:

– UE_NOT_RESPONDING

See table 6.3.7.3-1 for the description of this error.

NOTE: The mandatory HTTP error status code for the PUT method listed in Table 5.2.7.1-1 of 3GPP TS 29.500 [4] also apply, with response body containing an object of ProblemDetails data type (see clause 5.2.7 of 3GPP TS 29.500 [4]).

Table 6.3.3.2.3.1-4: Headers supported by the 307 Response Code on this resource

Name

Data type

P

Cardinality

Description

Location

string

M

1

The URI of the resource located on an alternative service instance within the same AMF or AMF (service) set to which the request is redirected.

Or the same URI, if a request is redirected to the same target resource via a different SCP.

3gpp-Sbi-Target-Nf-Id

string

O

0..1

Identifier of the target NF (service) instance ID towards which the request is redirected

Table 6.3.3.2.3.1-5: Headers supported by the 308 Response Code on this resource

Name

Data type

P

Cardinality

Description

Location

string

M

1

An alternative URI of the resource located on an alternative service instance within the same AMF or AMF (service) set.

Or the same URI, if a request is redirected to the same target resource via a different SCP.

3gpp-Sbi-Target-Nf-Id

string

O

0..1

Identifier of the target NF (service) instance ID towards which the request is redirected

6.3.3.2.4 Resource Custom Operations

There is no custom operation supported on this resource.

6.3.3.3 Resource: ueContext

6.3.3.3.1 Description

This resource represents the UeContext for a UE.

This resource is modelled as the Document resource archetype (see clause C.1 of 3GPP TS 29.501 [5]).

6.3.3.3.2 Resource Definition

Resource URI: {apiRoot}/namf-mt/<apiVersion>/ue-contexts/{ueContextId}

This resource shall support the resource URI variables defined in table 6.3.3.3.2-1.

Table 6.3.3.3.2-1: Resource URI variables for this resource

Name

Data type

Definition

apiRoot

string

See clause 6.3.1

apiVersion

string

See clause 6.3.1.

ueContextId

Supi

Represents the Subscription Permanent Identifier (see 3GPP TS 23.501 [2] clause 5.9.2)
pattern: see pattern of type Supi in 3GPP TS 29.571 [6]

6.3.3.3.3 Resource Standard Methods
6.3.3.3.3.1 GET

This method shall support the URI query parameters specified in table 6.3.3.3.3.1-1.

Table 6.3.3.3.3.1-1: URI query parameters supported by the GET method on this resource

Name

Data type

P

Cardinality

Description

info-class

UeContextInfoClass

M

1

Indicates the class of the UE Context information elements to be fetched.

supported-features

SupportedFeatures

C

0..1

This IE shall be present if at least one optional feature defined in clause 6.3.8 is supported.

old-guami

Guami

C

0..1

This IE shall be present during an AMF planned removal procedure when the NF Service Consumer initiates a request towards the target AMF, for a UE associated to an AMF that is unavailable (see clause 5.21.2.2 of 3GPP TS 23.501 [2]).

This method shall support the request data structures specified in table 6.3.3.3.3.1-2 and the response data structures and response codes specified in table 6.3.3.3.3.1-3.

Table 6.3.3.3.3.1-2: Data structures supported by the GET Request Body on this resource

Data type

P

Cardinality

Description

n/a

Table 6.3.3.3.3.1-3: Data structures supported by the GET Response Body on this resource

Data type

P

Cardinality

Response

codes

Description

UeContextInfo

M

1

200 OK

This represents the operation is successful and request UE Context information is returned.

RedirectResponse

O

0..1

307 Temporary Redirect

When the related UE context is not fully available at the target NF Service Consumer (e.g. AMF) during a planned maintenance case (e.g. AMF planned maintenance without UDSF case) the "cause" attribute shall be set to:

– NF_CONSUMER_REDIRECT_ONE_TXN

See table 6.3.7.3-1 for the description of these errors

The Location header of the response shall be set to the URI of the resource located on an alternative service instance within the same AMF or AMF (service) set to which the request is redirected.

If an SCP redirects the message to another SCP then the location header field shall contain the same URI or a different URI pointing to the endpoint of the NF service producer to which the request should be sent.

RedirectResponse

O

0..1

308 Permanent Redirect

Permanent redirection. The response shall include a Location header field containing a different URI, or the same URI if a request is redirected to the same target resource via a different SCP. In the former case, the URI shall be an alternative URI of the resource located on an alternative service instance within the same AMF or AMF (service) set.

ProblemDetails

O

0..1

403 Forbidden

Indicates the operation has failed due to application error.

The "cause" attribute may be used to indicate one of the following application errors:

– UNABLE_TO_PAGE_UE

– UE_DEREGISTERED

– UNSPECIFIED

See table 6.3.7.3-1 for the description of these errors.

ProblemDetails

O

0..1

404 Not Found

Indicates the operation has failed due to application error.

The "cause" attribute may be used to indicate one of the following application errors:

– CONTEXT_NOT_FOUND

See table 6.3.7.3-1 for the description of these errors

ProblemDetails

O

0..1

409 Conflict

This indicates that the request could not be completed due to a temporary conflict with the current state of the target resource.

The cause attribute of the ProblemDetails structure shall be set to:

– TEMPORARY_REJECT_REGISTRATION_ONGOING, if there is an on-going registration procedure.

NOTE: The mandatory HTTP error status code for the GET method listed in Table 5.2.7.1-1 of 3GPP TS 29.500 [4] also apply, with response body containing an object of ProblemDetails data type (see clause 5.2.7 of 3GPP TS 29.500 [4]).

Table 6.3.3.3.3.1-4: Headers supported by the 307 Response Code on this resource

Name

Data type

P

Cardinality

Description

Location

string

M

1

The URI of the resource located on the target NF Service Consumer (e.g. AMF) to which the request is redirected.

Or the same URI, if a request is redirected to the same target resource via a different SCP.

3gpp-Sbi-Target-Nf-Id

string

O

0..1

Identifier of the target NF (service) instance ID towards which the request is redirected

Table 6.3.3.3.3.1-5: Headers supported by the 308 Response Code on this resource

Name

Data type

P

Cardinality

Description

Location

string

M

1

An alternative URI of the resource located on an alternative service instance within the same AMF or AMF (service) set.

Or the same URI, if a request is redirected to the same target resource via a different SCP.

3gpp-Sbi-Target-Nf-Id

string

O

0..1

Identifier of the target NF (service) instance ID towards which the request is redirected

6.3.3.3.4 Resource Custom Operations

There is no custom operation supported on this resource.

6.3.3.4 Resource: ueContexts collection

6.3.3.4.1 Description

This resource represents the collection of the individual UeContexts created in the AMF.

This resource is modelled as the Collection resource archetype (see clause C.2 of 3GPP TS 29.501 [5]).

6.3.3.4.2 Resource Definition

Resource URI: {apiRoot}/namf-mt/<apiVersion>/ue-contexts

This resource shall support the resource URI variables defined in table 6.3.3.4.2-1.

Table 6.3.3.4.2-1: Resource URI variables for this resource

Name

Data type

Definition

apiRoot

string

See clause 6.3.1

apiVersion

string

See clause 6.3.1.

6.3.3.4.3 Resource Standard Methods

There is no standard operation supported on this resource.

6.3.3.4.4 Resource Custom Operations
6.3.3.4.4.1 Overview

Table 6.3.3.4.4.1-1: Custom operations

Operation Name

Custom operation URI

Mapped HTTP method

Description

enable-group-reachability

/ue-contexts/enable-group-reachability

POST

Enable Group Reachability service operation

6.3.3.4.4.2 Operation: enable-group-reachability

6.3.3.4.4.2.1 Description

6.3.3.4.4.2.2 Operation Definition

This custom operation updates the state of the list of UEs to CM-CONNECTED state.

This operation shall support the request data structures specified in table 6.3.3.4.4.2.2-1 and the response data structure and response codes specified in table 6.3.3.4.4.2.2-2.

Table 6.3.3.4.4.2.2-1: Data structures supported by the POST Request Body on this resource

Data type

P

Cardinality

Description

EnableGroupReachabilityReqData

M

1

Contain the list of UEs involved in the MBS Session identified by the related TMGI.

Table 6.3.3.4.4.2.2-2: Data structures supported by the POST Response Body on this resource

Data type

P

Cardinality

Response

codes

Description

EnableGroupReachabilityRspData

M

1

200 OK

Successful response indicating the list of UEs in CM-CONNECTED state if any, and indicating the supported features.

RedirectResponse

O

0..1

307 Temporary Redirect

Temporary redirection. The response shall include a Location header field containing a different URI, or the same URI if a request is redirected to the same target resource via a different SCP. In the former case, the URI shall be an alternative URI of the resource located on an alternative service instance within the same AMF or AMF (service) set.

RedirectResponse

O

0..1

308 Permanent Redirect

Permanent redirection. The response shall include a Location header field containing a different URI, or the same URI if a request is redirected to the same target resource via a different SCP. In the former case, the URI shall be an alternative URI of the resource located on an alternative service instance within the same AMF or AMF (service) set.

ProblemDetails

O

0..1

404 Not Found

When none of the UEs in the list of UEs are found in the AMF, the "cause" attribute shall be set to:

– CONTEXT_NOT_FOUND

See table 6.3.7.3-1 for the description of these errors

ProblemDetails

O

0..1

503 Service Unavailable

The "cause" attribute may be used to indicate one of the errors defined in Table 5.2.7.2-1 of 3GPP TS 29.500 [4].

NOTE: The mandatory HTTP error status code for the POST method listed in Table 5.2.7.1-1 of 3GPP TS 29.500 [4] also apply, with response body containing an object of ProblemDetails data type (see clause 5.2.7 of 3GPP TS 29.500 [4]).

Table 6.3.3.4.4.2.2-3: Headers supported by the 307 Response Code on this resource

Name

Data type

P

Cardinality

Description

Location

string

M

1

The URI of the resource located on an alternative service instance within the same AMF or AMF (service) set to which the request is redirected.

Or the same URI, if a request is redirected to the same target resource via a different SCP.

3gpp-Sbi-Target-Nf-Id

string

O

0..1

Identifier of the target NF (service) instance ID towards which the request is redirected

Table 6.3.3.4.4.2.2-4: Headers supported by the 308 Response Code on this resource

Name

Data type

P

Cardinality

Description

Location

string

M

1

An alternative URI of the resource located on an alternative service instance within the same AMF or AMF (service) set.

Or the same URI, if a request is redirected to the same target resource via a different SCP.

3gpp-Sbi-Target-Nf-Id

string

O

0..1

Identifier of the target NF (service) instance ID towards which the request is redirected

6.3.4 Custom Operations without associated resources

There are no custom operations without associated resources supported on Namf_MT service.

6.3.5 Notifications

6.3.5.1 General

This clause specifies the notifications provided by the Namf_MT service.

Table 6.3.5.1-1: Notifications overview

Notification

Callback URI

HTTP method or custom operation

Description

(service operation)

UE Reachability Info Notify

{reachabilityNotifyUri}

POST

6.3.5.2 UE Reachability Info Notify

If a NF service consumer has implicitly subscribed to the UE Reachability Info Notify supported by Namf_MT service, the AMF shall deliver the notification to the call-back URI for the UE(s) which are reachable or do not respond to paging, following Subscribe/Notify mechanism defined in 3GPP TS 29.501 [5].

6.3.5.2.1 Notification Definition

Call-back URI: {callbackUri}

This callback URI shall be the "reachabilityNotifyUri" provided in the "EnableGroupReachabilityReqData" IE.

6.3.5.2.3 Notification Standard Methods
6.3.5.2.3.1 POST

This method shall support the request data structures specified in table 6.3.5.2.3.1-1 and the response data structures and response codes specified in table 6.3.5.2.3.1-2.

Table 6.3.5.2.3.1-2: Data structures supported by the POST Request Body

Data type

P

Cardinality

Description

ReachabilityNotificationData

M

1

Represents the notification to be delivered

Table 6.3.5.2.3.1-3: Data structures supported by the POST Response Body

Data type

P

Cardinality

Response

codes

Description

n/a

204 No Content

RedirectResponse

O

0..1

307 Temporary Redirect

Temporary redirection. The NF service consumer shall generate a Location header field containing a URI pointing to the endpoint of another NF service consumer to which the notification should be sent.

If an SCP redirects the message to another SCP then the location header field shall contain the same URI or a different URI pointing to the endpoint of the NF service consumer to which the notification should be sent.

RedirectResponse

O

0..1

308 Permanent Redirect

Permanent redirection. The NF service consumer shall generate a Location header field containing a URI pointing to the endpoint of another NF service consumer to which the notification should be sent.

If an SCP redirects the message to another SCP then the location header field shall contain the same URI or a different URI pointing to the endpoint of the NF service consumer to which the notification should be sent.

NOTE: The mandatory HTTP error status code for the POST method listed in Table 5.2.7.1-1 of 3GPP TS 29.500 [4] also apply, with response body containing an object of ProblemDetails data type (see clause 5.2.7 of 3GPP TS 29.500 [4]).

Table 6.3.5.2.3.1-4: Headers supported by the 307 Response Code on this resource

Name

Data type

P

Cardinality

Description

Location

string

M

1

A URI pointing to the endpoint of the NF service consumer to which the notification should be sent

3gpp-Sbi-Target-Nf-Id

string

O

0..1

Identifier of the target NF (service) instance ID towards which the request is redirected

Table 6.3.5.2.3.1-5: Headers supported by the 308 Response Code on this resource

Name

Data type

P

Cardinality

Description

Location

string

M

1

A URI pointing to the endpoint of the NF service consumer to which the notification should be sent

3gpp-Sbi-Target-Nf-Id

string

O

0..1

Identifier of the target NF (service) instance ID towards which the request is redirected

6.3.6 Data Model

6.3.6.1 General

This clause specifies the application data model supported by the API.

Table 6.3.6.3-1 specifies the data types defined for the Namf_MT service based interface protocol.

Table 6.3.6.3-1: Namf_MT specific Data Types

Data type

Clause defined

Description

EnableUeReachabilityReqData

6.3.6.2.2

Data within the Enable UE Reachability Request

EnableUeReachabilityRspData

6.3.6.2.3

Data within the Enable UE Reachability Response

UeContextInfo

6.3.6.2.4

Contains the UE Context Information

ProblemDetailsEnableUeReachability

6.3.6.2.5

Enable UE Reachability Error Detail

AdditionInfoEnableUeReachability

6.3.6.2.6

Additional information to be returned in EnableUeReachability error response.

EnableGroupReachabilityReqData

6.3.6.2.7

Data within the Enable Group Reachability Request

EnableGroupReachabilityRspData

6.3.6.2.8

Data within the Enable Group Reachability Response

UeInfo

6.3.6.2.9

list of UEs requested to be made reachable for the MBS Session

ReachabilityNotificationData

6.3.6.2.10

Data within the UE Reachability Info Notify

ReachableUeInfo

6.3.6.2.11

Contains the reachable UE Information

UeContextInfoClass

6.3.6.3.3

Indicates the UE Context information class

Table 6.3.6.3-2 specifies data types re-used by the Namf_MT service based interface protocol from other specifications, including a reference to their respective specifications and when needed, a short description of their use within the Namf_MT service based interface.

Table 6.3.6.3-2: Namf_MT re-used Data Types

Data type

Reference

Comments

ProblemDetails

3GPP TS 29.571 [6]

Common data type used in response bodies

supportedFeatures

3GPP TS 29.571 [6]

Supported Features

AccessType

3GPP TS 29.571 [6]

Access Type

RatType

3GPP TS 29.571 [6]

RAT Type

DurationSec

3GPP TS 29.571 [6]

RedirectResponse

3GPP TS 29.571 [6]

Response body of the redirect response message.

Supi

3GPP TS 29.571 [6]

SUPI

Tmgi

3GPP TS 29.571 [6]

TMGI

PduSessionId

3GPP TS 29.571 [6]

PDU Session Id

Uri

3GPP TS 29.571 [6]

URI

UserLocation

3GPP TS 29.571 [6]

User Location Information

MbsServiceAreaInfo

3GPP TS 29.571 [6]

MBS Service Area Information for a Location dependent MBS session

UeReachability

6.2.6.3.7

Describes the reachability of the UE

6.3.6.2 Structured data types

6.3.6.2.1 Introduction

Structured data types used in Namf_MT service are specified in this clause.

6.3.6.2.2 Type: EnableUeReachabilityReqData

Table 6.3.6.3.2-1: Definition of type EnableUeReachabilityReqData

Attribute name

Data type

P

Cardinality

Description

reachability

UeReachability

M

1

Indicates the desired reachability of the UE

supportedFeatures

SupportedFeatures

C

0..1

This IE shall be present if at least one optional feature defined in clause 6.3.8 is supported.

oldGuami

Guami

C

0..1

This IE shall be present during an AMF planned removal procedure when the NF Service Consumer initiates a request towards the target AMF, for a UE associated to an AMF that is unavailable (see clause 5.21.2.2 of 3GPP TS 23.501 [2]).

extBufSupport

boolean

C

0..1

This IE shall be present and set to "true", if the extended buffering is supported(see clauses 4.24.2 and clause 4.25.5 of 3GPP TS 23.502 [3]),

When present, the IE shall be set as following:

– true: the extended buffering is supported

– false (default): the extended buffering is not supported

6.3.6.2.3 Type: EnableUeReachabilityRspData

Table 6.3.6.2.3-1: Definition of type EnableUeReachabilityRspData

Attribute name

Data type

P

Cardinality

Description

reachability

UeReachability

M

1

Indicates the current reachability of the UE

supportedFeatures

SupportedFeatures

C

0..1

This IE shall be present if at least one optional feature defined in clause 6.3.8 is supported.

6.3.6.2.4 Type: UeContextInfo

Table 6.3.6.2.3-1: Definition of type UeContextInfo

Attribute name

Data type

P

Cardinality

Description

supportVoPS

boolean

C

0..1

This IE shall be present when following UE Context Information class are required:

– "TADS"

When present, this IE shall indicate whether or not IMS voice over PS Session is supported in the registration area (s) where the UE is currently registered in 3GPP access.

supportVoPSn3gpp

boolean

C

0..1

This IE shall be present when the UE is registered in WLAN non 3GPP access and the following UE Context Information class are required:

– "TADS"

When present, this IE shall indicate whether or not IMS voice over PS Session Supported Indication over non-3GPP access is supported in the WLAN where the UE is currently registered.

lastActTime

DateTime

C

0..1

This IE shall be present when following UE Context Information class are required:

– "TADS"

When present, this IE shall indicate the time stamp of the last radio contact with the UE.

accessType

AccessType

C

0..1

This IE shall be present when following UE Context Information class are required:

– "TADS"

When present, this IE shall indicate the current access type of the UE.

ratType

RatType

C

0..1

This IE shall be present when following UE Context Information class are required:

– "TADS"

When present, this IE shall indicate the current RAT type of the UE.

supportedFeatures

SupportedFeatures

C

0..1

This IE shall be present if at least one optional feature defined in clause 6.3.8 is supported.

6.3.6.2.5 Type: ProblemDetailsEnableUeReachability

Table 6.3.6.2.5-1: Definition of type ProblemDetailsEnableUeReachability as a list of to be combined data

Data type

Cardinality

Description

Applicability

ProblemDetails

1

Detail information of the problem

AdditionInfoEnableUeReachability

1

Additional information to be returned in error response.

6.3.6.2.6 Type: AdditionInfoEnableUeReachability

Table 6.3.6.2.6-1: Definition of type AdditionInfoEnableUeReachability

Attribute name

Data type

P

Cardinality

Description

maxWaitingTime

DurationSec

C

0..1

This IE shall contain the estimated maximum wait time (see clauses 4.24.2 and clause 4.25.5 of 3GPP 23.502 [3]).

6.3.6.2.7 Type: EnableGroupReachabilityReqData

Table 6.3.6.2.7-1: Definition of type EnableGroupReachabilityReqData

Attribute name

Data type

P

Cardinality

Description

ueList

array(UeInfo)

M

1..N

This IE shall indicate the list of UEs requested to be made reachable for the MBS Session and may indicate the PDU Session Id of the associated PDU Session for the UE(s).

tmgi

Tmgi

M

1

This IE shall Indicate the TMGI of the MBS session.

reachabilityNotifyUri

Uri

O

0..1

The callback URI on which UEReachabilityInfoNotify is reported.

mbsServiceAreaInfoList

array(MbsServiceAreaInfo)

O

1..N

List of MBS Service Area and related Area Session ID for location dependent content.

arp

Arp

O

0..1

This IE when present shall indicate the most demanding Allocation and Retention Priority of all MBS QoS Flow within the MBS session.

The AMF may use this IE for paging differentiation (see clause 6.12 of 3GPP TS 23.247 [55]).

5qi

5Qi

O

0..1

This IE when present shall indicate the most demanding 5QI of all MBS QoS Flow within the MBS session.

The AMF may use this IE for paging differentiation (see clause 6.12 of 3GPP TS 23.247 [55]).

supportedFeatures

SupportedFeatures

C

0..1

This IE shall be present if at least one optional feature defined in clause 6.3.8 is supported.

6.3.6.2.8 Type: EnableGroupReachabilityRspData

Table 6.3.6.2.8-1: Definition of type EnableGroupReachabilityRspData

Attribute name

Data type

P

Cardinality

Description

ueConnectedList

array(Supi)

C

1..N

This IE shall be present if there is at least one UE in the list of UEs received in the request that is already in CM-CONNECTED state. When present, this IE shall indicate the list of UEs in CM-CONNECTED state.

supportedFeatures

SupportedFeatures

C

0..1

This IE shall be present if at least one optional feature defined in clause 6.3.8 is supported.

6.3.6.2.9 Type: UeInfo

Table 6.3.6.2.9-1: Definition of type UeInfo

Attribute name

Data type

P

Cardinality

Description

ueList

array(Supi)

M

1..N

This IE shall indicate the list of UEs requested to be made reachable for the MBS Session.

pduSessionId

PduSessionId

O

0..1

Represents the identifier of the associated PDU Session for the UEs in ueList IE.

6.3.6.2.10 Type: ReachabilityNotificationData

Table 6.3.6.2.10-1: Definition of type ReachabilityNotificationData

Attribute name

Data type

P

Cardinality

Description

reachableUeList

array(ReachableUeInfo)

C

1..N

This IE shall indicate the list of reachable UEs.

unreachableUeList

array(Supi)

C

1..N

This IE shall Indicate the list of unreachable UEs.

6.3.6.2.11 Type: ReachableUeInfo

Table 6.3.6.2.11-1: Definition of type ReachableUeInfo

Attribute name

Data type

P

Cardinality

Description

ueList

array(Supi)

M

1..N

This IE shall indicate the list of reachable UEs.

userLocation

UserLocation

C

0..1

This IE shall Indicate the User Location of the reachable UEs.

6.3.6.3 Simple data types and enumerations

6.3.6.3.1 Introduction

This clause defines simple data types and enumerations that can be referenced from data structures defined in the previous clauses.

6.3.6.3.2 Simple data types

The simple data types defined in table 6.3.6.3.2-1 shall be supported.

Table 6.3.6.3.2-1: Simple data types

Type Name

Type Definition

Description

6.3.6.3.3 Enumeration: UeContextInfoClass

Table 6.3.6.3.3-1: Enumeration UeContextInfoClass

Enumeration value

Description

"TADS"

Defines the UE Context Information for Terminating Domain Selection for IMS Voice over PS.

6.3.6.4 Binary data

None.

6.3.7 Error Handling

6.3.7.1 General

HTTP error handling shall be supported as specified in clause 5.2.4 of 3GPP TS 29.500 [4].

6.3.7.2 Protocol Errors

Protocol Error Handling shall be supported as specified in clause 5.2.7 of 3GPP TS 29.500 [4].

6.3.7.3 Application Errors

The common application errors defined in the Table 5.2.7.2-1 in 3GPP TS 29.500 [4] may also be used for the Namf_MT service, and the following application errors listed in Table 6.3.7.3-1 are specific for the Namf_MT service.

Table 6.3.7.3-1: Application errors

Application Error

HTTP status code

Description

NF_CONSUMER_REDIRECT_ONE_TXN

307 Temporary Redirect

The request has been asked to be redirected to a specified target.

UNABLE_TO_PAGE_UE

403 Forbidden

AMF is unable page the UE, temporarily.

UE_IN_NON_ALLOWED_AREA

403 Forbidden

UE is currently in a non-allowed area and the service request is not for a regulatory prioritized service.

UE_DEREGISTERED

403 Forbidden

The user is in RM-DEREGISTERED state in the AMF.

UNSPECIFIED

403 Forbidden

The request is rejected due to unspecified reasons.

CONTEXT_NOT_FOUND

404 Not Found

The related UE is not found in the NF Service Consumer.

TEMPORARY_REJECT_REGISTRATION_ONGOING

409 Conflict

The request fails due to an on-going registration procedure.

REJECTION_DUE_TO_PAGING_RESTRICTION

409 Conflict

If Paging Restriction Information restrict the EnableUEReachability request from causing paging as defined in 3GPP TS 23.501 [2] clause 5.38.5 or if the UE rejects the paging as defined in 3GPP TS 23.501 [2] clause 5.38.4.

UE_NOT_RESPONDING

504 Gateway Timeout

UE is not responding to the request initiated by the network, e.g. Paging.

6.3.8 Feature Negotiation

The feature negotiation mechanism specified in clause 6.6 of 3GPP TS 29.500 [4] shall be used to negotiate the optional features applicable between the AMF and the NF Service Consumer, for the Namf_MT service, if any.

The NF Service Consumer shall indicate the optional features it supports for the Namf_MT service, if any, by including the supportedFeatures attribute in payload of the HTTP Request Message for following service operations:

– EnableUEReachability, as specified in clause 5.4.2.2;

– ProvideDomainSelectionInfo, as specified in clause 5.4.2.3;

– EnableGroupReachability, as specified in clause 5.4.2.4.

The AMF shall determine the supported features for the service operations as specified in clause 6.6 of 3GPP TS 29.500 [4] and shall indicate the supported features by including the supportedFeatures attribute in payload of the HTTP response for the service operation.

The syntax of the supportedFeatures attribute is defined in clause 5.2.2 of 3GPP TS 29.571 [6].

The following features are defined for the Namf_MT service.

Table 6.3.8-1: Features of supportedFeatures attribute used by Namf_MT service

Feature Number

Feature

M/O

Description

1

ES3XX

M

Extended Support of HTTP 307/308 redirection

An NF Service Consumer (e.g. SMSF) that supports this feature shall support handling of HTTP 307/308 redirection for any service operation of the Namf_MT service. An NF Service Consumer that does not support this feature does only support HTTP redirection as specified for 3GPP Release  15.

2

GRCAP

O

Group Reachability Capability

An AMF and SMF that supports this feature shall support the EnableGroupReachability and UEReachabilityInfoNotify service operations, as specified in clause 5.4.2.4 and clause 5.4.2.5.

Feature number: The order number of the feature within the supportedFeatures attribute (starting with 1).

Feature: A short name that can be used to refer to the bit and to the feature.

M/O: Defines if the implementation of the feature is mandatory ("M") or optional ("O").

Description: A clear textual description of the feature.

6.3.9 Security

As indicated in 3GPP TS 33.501 [27], the access to the Namf_MT API may be authorized by means of the OAuth2 protocol (see IETF RFC 6749 [28]), using the "Client Credentials" authorization grant, where the NRF (see 3GPP TS 29.510 [29]) plays the role of the authorization server.

If Oauth2 authorization is used, an NF Service Consumer, prior to consuming services offered by the Namf_MT API, shall obtain a "token" from the authorization server, by invoking the Access Token Request service, as described in 3GPP TS 29.510 [29], clause 5.4.2.2.

NOTE: When multiple NRFs are deployed in a network, the NRF used as authorization server is the same NRF that the NF Service Consumer used for discovering the Namf_MT service.

The Namf_MT API defines scopes for OAuth2 authorization as specified in 3GPP TS 33.501 [27]; it defines a single scope consisting on the name of the service (i.e., "namf-mt"), and it does not define any additional scopes at resource or operation level.

6.3.10 HTTP redirection

An HTTP request may be redirected to a different AMF service instance, within the same AMF or a different AMF of an AMF set, e.g. when an AMF service instance is part of an AMF (service) set or when using indirect communications (see 3GPP TS 29.500 [4]). See the ES3XX feature in clause 6.3.8.

An SCP that reselects a different AMF producer instance will return the NF Instance ID of the new AMF producer instance in the 3gpp-Sbi-Producer-Id header, as specified in clause 6.10.3.4 of 3GPP TS 29.500 [4].

If an AMF within an AMF set redirects a service request to a different AMF of the set using an 307 Temporary Redirect or 308 Permanent Redirect status code, the identity of the new AMF towards which the service request is redirected shall be indicated in the 3gpp-Sbi-Target-Nf-Id header of the 307 Temporary Redirect or 308 Permanent Redirect response as specified in clause 6.10.9.1 of 3GPP TS 29.500 [4].