TS24.501-g40 5 Elementary procedures for 5GS mobility management

5.1 Overview

5.1.1 General

The main function of the 5GS mobility management (5GMM) sublayer is to support the identification, security, mobility of a UE as well as generic message transport.

A further function of the 5GMM sublayer is to provide connection management services to the other sublayer(s).

5.1.2 Types of 5GMM procedures

Depending on how they can be initiated, three types of 5GMM procedures can be distinguished:

a) 5GMM common procedures

5GMM common procedure can always be initiated when the UE is in 5GMM-CONNECTED mode. The procedures belonging to this type are:

1) Initiated by the network:

i) network-initiated NAS transport;

ii) primary authentication and key agreement

iii) security mode control;

iv) generic UE configuration update

v) identification; and

vi) network slice-specific authentication and authorization;

2) Initiated by the UE:

UE-initiated NAS transport.

3) Initiated by the UE or the network and used to report certain error conditions detected upon receipt of 5GMM protocol data:

5GMM status.

b) 5GMM specific procedures:

At any time only one UE initiated 5GMM specific procedure can be running for each of the access network(s) that the UE is camping in. The procedures belonging to this type are:

1) Initiated by the UE and used e.g. to register to the network for 5GS services and establish a 5GMM context, to update the location/parameter(s) of the UE:

registration.

2) Initiated by the UE or the network and used to deregister from the network for 5GS services and to release a 5GMM context:

de-registration.

3) Initiated by the UE and used to deregister from the network for 5GS services and to release a 5GMM context:

eCall inactivity procedure.

c) 5GMM connection management procedures:

1) Initiated by the UE and used to establish a secure connection to the network or to request the resource reservation for sending data, or both:

service request.

The service request procedure can only be initiated if no UE initiated 5GMM specific procedure is ongoing for each of the access network(s) that the UE is camping in.

2) Initiated by the network and used to request the establishment of an N1 NAS signalling connection or to request re-establishment of user-plane resources for the PDU session(s) associated with 3GPP access or to request re-establishment of user-plane resources of the PDU session(s) associated with non-3GPP access over 3GPP access; not applicable for the non-3GPP access network:

paging.

3) Initiated by the network and used to request re-establishment of user-plane resources of the PDU session(s) associated with non-3GPP access over 3GPP access or to deliver 5GSM downlink signalling messages associated with non-3GPP access over 3GPP access, when the UE is in 5GMM-CONNECTED mode over 3GPP access and in 5GMM-IDLE mode over non-3GPP access; or

Initiated by the network and used to request re-establishment of user-plane resources of the PDU session(s) associated with 3GPP access over 3GPP access or to deliver downlink signalling associated with 3GPP access over 3GPP access, when the UE is in 5GMM-CONNECTED mode over non-3GPP access, and when the UE is in 5GMM-IDLE mode over 3GPP access and not in MICO mode:

notification.

3）ネットワークによって開始され、3GPPアクセス上の非3GPPアクセスに関連するPDUセッションのユーザープレーンリソースの再確立を要求するため、または3GPPアクセス上の非3GPPアクセスに関連する5GSMダウンリンクシグナリングメッセージを配信するために使用されます。 、UEが3GPPアクセスで5GMM-CONNECTEDモードで、非3GPPアクセスで5GMM-IDLEモードである場合。または  ネットワークによって開始され、UEが5GMMにあるときに、3GPPアクセスを介した3GPPアクセスに関連するPDUセッションのユーザープレーンリソースの再確立を要求するか、3GPPアクセスを介した3GPPアクセスに関連するダウンリンクシグナリングを配信するために使用されます非3GPPアクセス上のCONNECTEDモード、およびUEがMICOモードではなく、3GPPアクセス上の5GMM-IDLEモードにある場合：  通知。

NOTE 1: In NB-N1 mode, the UE NAS using 5GS services with control plane CIoT 5GS optimization can wait for the lower layers to complete the transmission of the previous UL NAS TRANSPORT messages carrying control plane user data before providing subsequent NAS messages. Other implementations are possible.

注1：NB-N1モードでは、コントロールプレーンCIoT 5GS最適化で5GSサービスを使用するUE NASは、下位レイヤーがコントロールプレーンユーザーデータを運ぶ以前のUL NAS TRANSPORTメッセージの送信を完了するのを待ってから、後続のNASメッセージを提供できます。他の実装が可能です

NOTE 2: When providing NAS messages to the lower layers for transmission, the UE NAS using 5GS services with control plane CIoT 5GS optimization can prioritize sending NAS signalling messages over the UL NAS TRANSPORT messages carrying control plane user data. How the UE performs this prioritization is implementation specific.

注2：制御プレーンCIoT 5GS最適化で5GSサービスを使用するUE NASが下位層にNASメッセージを提供する場合、制御プレーンのユーザーデータを運ぶUL NAS TRANSPORTメッセージよりもNASシグナリングメッセージの送信を優先できます。 UEがこの優先順位付けを実行する方法は、実装によって異なります。