3GPP 23.501 v20.2.0 — the document's own text
5.9.2 Subscription Permanent Identifier
Taught in 7. Every name the system uses (The 5G system architecture, in depth), 4. Knowing who you are and where you are (The 5G system architecture, overview).
A globally unique 5G Subscription Permanent Identifier (SUPI) shall be allocated to each subscriber in the 5G System and provisioned in the UDM/UDR. The SUPI is used only inside 3GPP system and its privacy is specified in TS 33.501 [29].
The SUPI may contain:
- an IMSI as defined in TS 23.003 [19], or
- a network-specific identifier, used for private networks as defined in TS 22.261 [2].
- a GLI and an operator identifier of the 5GC operator, used for supporting FN-BRGs, as further described in TS 23.316 [84].
- a GCI and an operator identifier of the 5GC operator, used for supporting FN-CRGs and 5G-CRG, as further described in TS 23.316 [84].
A SUPI containing a network-specific identifier shall take the form of a Network Access Identifier (NAI) using the NAI RFC 7542 [20] based user identification as defined in TS 23.003 [19].
When UE needs to indicate its SUPI to the network (e.g. as part of the Registration procedure), the UE provides the SUPI in concealed form as defined in TS 23.003 [19].
In order to enable roaming scenarios, the SUPI shall contain the address of the home network (e.g. the MCC and MNC in the case of an IMSI based SUPI).
For interworking with the EPC, the SUPI allocated to the 3GPP UE shall always be based on an IMSI to enable the UE to present an IMSI to the EPC.
The usage of SUPI for W-5GAN is further specified in TS 23.316 [84].