The 5G System supports a registration procedure with AMF re-allocation. As described in TS 23.502
, this procedure is used when the initial AMF is unable to serve the UE. In which case, the NAS message received from the UE is rerouted to another target AMF either directly over the AMF-to-AMF interface i.e. N14, or via RAN. In the present document only the indirect reroute via RAN is considered.
The present document aims at addressing the case for the indirect reroute procedure for UE registration. The intention is to enable deployment scenarios with stricter slice isolation requirements on the core network, for example where the AMFs are unable to communicate with each other.
The aim of the present document is to:
Collect the potential requirements related to the AMF re-allocation procedure.
Study the potential enhancements to the security mechanisms in order to fulfil the requirements for the AMF re-allocation.
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
: "Vocabulary for 3GPP Specifications".
: "Procedures for the 5G System (5GS)".
: "Security architecture and procedures for 5G System".
: "Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3".
: "NG-RAN; NG Application Protocol (NGAP)".
For the purposes of the present document, the terms given in TR 21.905
and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905
For the purposes of the present document, the abbreviations given in TR 21.905
and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905