切片选择过程-核心网5GC业务流程培训课件-17

切片选择过程 AMF NSSF UE NR AMF UE在AS和NAS层携带请求的NSSAI，其中包含多个S-NSSAI，请求NSSAI要么来自配置的NSSAI，要么之前保存的允许NSSAI，如果没有配置NSSAI，或者允许NSSAI，UE不能携带请求NSSAI 根据请求NSSAI选择一个AMF，如果NR不能根据NSSAI选出一个AMF，他将NAS消息发给默认AMF集 AMF从UDM获取用户的签约S-NSSAI信息，校验用户请求NSSAI是否符合签约切片信息 如果UE没有包括请求的NSSAI，或者与签约不匹配时，AMF查询NSSF，携带请求NSSAI，与归属NSSAI映射关系，签约S-NSSAI，PLMN ID，以及UE的TA 校验用户请求NSSAI中每个S-NSSAI是否符合签约切片信息 如果UE没有包括请求的NSSAI，选择签约中默认S-NSSAI 选择服务UE的网络实例，NSI ID 当多个网络实例都可以选择时，NSSF可以推迟选择切片实例，等后续触发 确定目标AMF set 确定允许的NSSAI，以及切片实例可用性信息 如果允许S-NSSAI到签约S-NSSAI的映射 也可以确定用于选择该切片其他NF的NRF 如果不能服务UE，通过重路由消息，发给其他AMF * PPT学习交流 * * When the AMF selected by the AN receives the UE Registration request: - As part of the Registration procedure described in TS 23.502 [3], clause 4.2.2.2.2, the AMF may query the UDM to retrieve UE subscription information including the Subscribed S-NSSAIs. - The AMF verifies whether the S-NSSAI(s) in the Requested NSSAI are permitted based on the Subscribed S-NSSAIs (to identify the Subscribed S-NSSAIs the AMF may use the mapping to the S-NSSAI(s) of the Configured NSSAI for the HPLMN provided by the UE, in the NAS message, for each S-NSSAI of the Requested NSSAI). - When the UE context in the AMF does not yet include an Allowed NSSAI for the corresponding Access Type, the AMF queries the NSSF (see (B) below for subsequent handling), except in the case when, based on configuration in this AMF, the AMF is allowed to determine whether it can serve the UE (see (A) below for subsequent handling). The address of the NSSF is locally configured in the AMF. NOTE 1: The configuration in the AMF depends on operator's policy. - When the UE context in the AMF already includes an Allowed NSSAI for the corresponding Access Type, based on the configuration for this AMF, the AMF may be allowed to determine whether it can serve the UE (see (A) below for subsequent handling). NOTE 2: The configuration in the AMF depends on the operator's policy. (A) Depending on fulfilling the configuration as described above, the AMF m