Modifications for PCF-initiated UE Not Reachable State

This section describes about the UE not reachable state activities in the PCF-initiated modification call flow procedure.

The following figure describes the Modifications for PCF-initiated UE Not Reachable State.

Call Flow for the Modifications for PCF-initiated UE Not Reachable State
Call Flow Description for the Modifications for PCF-initiated UE Not Reachable State

Step

Description

1

The PCF sends the SMF Policy Association Modification Request to the SMF.

It’s an interchangeable action as it also receives the same message from the SMF.

2

The SMF sends the Namf Comm N1N2MessageTransfer Request to the AMF.

It’s an interchangeable action as it also receives the same message from the AMF.

3

The AMF sends the PDU Session Resource Modify Request to the RAN.

Note

During this step, the gNB performs the paging activities as the UE isn’t reachable.

4

The RAN sends the PDU Session Resource Modify Response Unsuccessful message to the AMF.

It also includes the failure cause ue-in-rrc-inactive-state-not-reachable message.

5

The AMF sends the Nsmf PDUSession UpdateSMContext (N2SMlnfo) response message to the SMF.

It’s an interchangeable action as it also receives the same message from the SMF.

6

The SMF sends the failed report SM Policy Association Modification (rule failure report) message to the PCF.

It’s an interchangeable action as it also receives the same message from the PCF.