目录
1. NG SETUP过程
1.1 NG SETUP定义
1.2 NG建立成功
1.3 NG建立失败
1.4 异常情况
2.NG SETUP信令结构
2.1 NG SETUP REQUEST结构
2.2 NG SETUP RESPONSE结构
2.3 NG SETUP FAILURE结构
1. NG SETUP过程1.1 NG SETUP定义
NGSetup过程用来交换NG-RAN节点和AMF在NG-C接口上正确互操作所需的应用程序级数据。该程序为TNL关联开始运行后触发的第一个NGAP程序。该过程使用非UE相关的信令。
此过程将擦除两个节点中的任何现有应用程序级配置数据,将其替换为接收到的数据,并清除NG-RAN节点上的AMF过载状态信息。如果NG-RAN节点和AMF不同意保留UE上下文,则此过程还会像NG重置过程一样重新初始化NGAP UE相关上下文,并擦除两个节点中的所有相关信令连接。
NGSETUP:成功运行
NG-RAN向AMF发送NG SETUP REQUEST消息来建立NG连接。AMF以NG SETUP RESPONSE消息进行响应。
如果NG SETUP REQUEST消息中Supported TA List字段包含的Configured TAC Indication设置为“true”,AMF可以考虑向此NG-RAN节点发送NG-C信令。
如果NG SETUP REQUEST消息中的UE Retention Information 设置为“ues-retained”,AMF将保留现有的UE上下文和信令连接,并将NG SETUP RESPONSE消息中的UE Retention Information 设置为“ues-retained”。
AMF应将Backup AMF Name包含在NG SETUP RESPONSE消息的Served GUAMI List中。如果NG-RAN支持的话,NG-RAN在执行AMF重选时,应先考虑Backup AMF Name所指示的AMF。
如果NG SETUP RESPONSE消息中包含有GUAMI Type,则NG-RAN节点应存储收到的值,将其用于进一步的AMF选择。
如果NG SETUP REQUEST消息中包含RAN Node Name,则AMF可以使用该Name作为NG-RAN节点的可读名称。
如果NG SETUP RESPONSE消息中包含AMF Name,则NG-RAN节点可以使用该Name作为AMF的可读名称。
如果NG SETUP REQUEST消息中包含NB-IoT Default Paging DRX,AMF应将其考虑在内进行寻呼。
如果NG SETUP REQUEST消息中包含RAT Information,AMF应按照TS 23.502【10】中的规定处理该信息。
1.3 NG建立失败NG设置:操作失败
如果AMF不能接受NG Setup,则回应NG SETUP FAILURE消息,并携带相应的原因值。
如果NG SETUP FAILURE消息包括Time to Wait,则NG-RAN节点至少应该等待所指示的时间,然后再向同一AMF重新启动NG Setup过程。
如果NG-RAN节点通过发送包括PLMN标识的NG SETUP REQUEST消息来启动该过程,并且AMF不识别由NG-RAN节点提供的PLMN,则AMF将以相应的原因值来拒绝NGSetup过程。
2.NG SETUP信令结构2.1 NG SETUP REQUEST结构IE/Group Name
Presence
Range
IE type and reference
Semantics description
Criticality
Assigned Criticality
Message Type
M
9.3.1.1
YES
reject
Global RAN Node ID
M
9.3.1.5
YES
reject
RAN NodeName
O
PrintableString
(SIZE(1..150, …))
YES
ignore
Supported TA List
1
Supported TAs in the NG-RAN node.
YES
reject
>Supported TA Item
1..<maxnoof
TACs>
-
>>TAC
M
9.3.3.10
Broadcast TAC
-
>>Broadcast PLMN List
1
-
>>>Broadcast PLMN Item
1..<maxnoof
BPLMNs>
-
>>>>PLMN Identity
M
9.3.3.5
Broadcast PLMN
-
>>>>TAI Slice Support List
M
Slice Support List
9.3.1.17
Supported S-NSSAIs per TAC, per PLMN or per SNPN.
-
>>>>NPN Support
O
9.3.3.44
If the NIDIE is included, it identifies a SNPN together with the PLMN IdentityIE.
YES
reject
>>>>Extended TAI Slice Support List
O
Extended Slice Support List
9.3.1.191
Additional Supported S-NSSAIs per TAC, per PLMN or per SNPN.
YES
reject
>>Configured TAC Indication
O
9.3.3.50
YES
ignore
>>RAT Information
O
9.3.1.125
RAT information associated with the TAC of the indicated PLMN(s).
YES
reject
Default Paging DRX
M
Paging DRX
9.3.1.90
YES
ignore
UE Retention Information
O
9.3.1.117
YES
ignore
NB-IoT Default Paging DRX
O
9.3.1.137
YES
ignore
Extended RAN Node Name
O
9.3.1.193
YES
ignore
IE/Group Name
Presence
Range
IE type and reference
Semantics description
Criticality
Assigned Criticality
Message Type
M
9.3.1.1
YES
reject
AMFName
M
9.3.3.21
YES
reject
Served GUAMI List
1
YES
reject
>Served GUAMI Item
1..<maxnoof
ServedGUAMIs>
-
>>GUAMI
M
9.3.3.3
-
>>Backup AMF Name
O
AMF Name
9.3.3.21
-
>>GUAMI Type
O
ENUMERATED (native, mapped, …)
YES
ignore
Relative AMF Capacity
M
9.3.1.32
YES
ignore
PLMN Support List
1
YES
reject
>PLMN Support Item
1..<maxnoof
PLMNs>
-
>>PLMN Identity
M
9.3.3.5
-
>>Slice Support List
M
9.3.1.17
Supported S-NSSAIs per PLMNor per SNPN.
-
>>NPN Support
O
9.3.3.44
If NIDIE is included, it identifies a SNPN together with the PLMN IdentityIE.
YES
reject
>>Extended Slice Support List
O
9.3.1.191
Additional Supported S-NSSAIs per PLMNor per SNPN.
YES
reject
>>Onboarding Support
O
ENUMERATED (true, ...)
Indication of onboarding support.
YES
ignore
Criticality Diagnostics
O
9.3.1.3
YES
ignore
UE Retention Information
O
9.3.1.117
YES
ignore
IAB Supported
O
ENUMERATED (true, ...)
Indication of support for IAB.
YES
ignore
Extended AMF Name
O
9.3.3.51
YES
ignore
Range bound
Explanation
maxnoofServedGUAMIs
Maximum no. of GUAMIs served by an AMF. Value is 256.
maxnoofPLMNs
Maximum no. of PLMNs per message. Value is 12.
IE/Group Name
Presence
Range
IE type and reference
Semantics description
Criticality
Assigned Criticality
Message Type
M
9.3.1.1
YES
reject
Cause
M
9.3.1.2
YES
ignore
Time to Wait
O
9.3.1.56
YES
ignore
Criticality Diagnostics
O
9.3.1.3
YES
ignore