[5g NR] ng setup of ngap protocol

Catalog

1. NG SETUP The process

1.1 NG SETUP Definition

1.2 NG Build success

1.3 NG Establish a failure

1.4 Abnormal situation

2.NG SETUP Signaling structure

2.1 NG SETUP REQUEST structure

2.2 NG SETUP RESPONSE structure

2.3 NG SETUP FAILURE structure

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1. NG SETUP The process

1.1 NG SETUP Definition

NG Setup Procedures are used to exchange NG-RAN Nodes and AMF stay NG-C Application level data required for proper interoperability on the interface . The procedure is TNL The first... Triggered after the association starts running NGAP Program . This process uses non UE Related signaling .

This process erases any existing application level configuration data in both nodes , Replace it with the received data , And get rid of NG-RAN nodes AMF Overload status information . If NG-RAN Nodes and AMF Do not agree to keep UE Context , Then the process will be like NG Reinitialize as in the reset process NGAP UE Relevant context , And erase all relevant signaling connections in the two nodes .
 

1.2 NG Build success

NG SETUP： Running successfully

 NG-RAN towards AMF send out NG SETUP REQUEST Message to establish NG Connect .AMF With NG SETUP RESPONSE The message responds .

If NG SETUP REQUEST In the news Supported TA List Field contains Configured TAC Indication Set to “true”,AMF You can consider this NG-RAN The node sends NG-C Signaling .

If NG SETUP REQUEST In the news UE Retention Information Set to “ues-retained”,AMF The existing UE Context and signaling connections , And will NG SETUP RESPONSE In the news UE Retention Information Set to “ues-retained”.

AMF Should be Backup AMF Name Included in NG SETUP RESPONSE News Served GUAMI List in . If NG-RAN Words of support ,NG-RAN In execution AMF When reselection , Consider first Backup AMF Name Indicated by AMF.

If NG SETUP RESPONSE The message contains GUAMI Type, be NG-RAN The node should store the received value , Use it for further AMF choice .

If NG SETUP REQUEST The message contains RAN Node Name, be AMF You can use the Name As NG-RAN Readable name of the node .

If NG SETUP RESPONSE The message contains AMF Name, be NG-RAN Nodes can use this Name As AMF The readable name of .

If NG SETUP REQUEST The message contains NB-IoT Default Paging DRX,AMF This should be taken into account for paging .

If NG SETUP REQUEST The message contains RAT Information,AMF Should be in accordance with the TS 23.502【10】 The information is processed as specified in .

1.3 NG Establish a failure

 NG Set up ： operation failed

If AMF Can't accept NG Setup, Response NG SETUP FAILURE news , And carry the corresponding reason value .

If NG SETUP FAILURE The news includes Time to Wait, be NG-RAN The node should wait at least for the indicated time , And then to the same AMF Restart NG Setup The process .

1.4 Abnormal situation

If NG-RAN Nodes include by sending PLMN Identification of the NG SETUP REQUEST Message to start the process , also AMF Not recognized by NG-RAN Nodes provide PLMN, be AMF Will reject with the corresponding reason value NGSetup The process .

2.NG SETUP Signaling structure

2.1 NG SETUP REQUEST structure

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 Node Name	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 NID IE is included, it identifies a SNPN together with the PLMN Identity IE.	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

2.2 NG SETUP RESPONSE structure

IE/Group Name	Presence	Range	IE type and reference	Semantics description	Criticality	Assigned Criticality
Message Type	M		9.3.1.1		YES	reject
AMF Name	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 PLMN or per SNPN.	-
>>NPN Support	O		9.3.3.44	If NID IE is included, it identifies a SNPN together with the PLMN Identity IE.	YES	reject
>>Extended Slice Support List	O		9.3.1.191	Additional Supported S-NSSAIs per PLMN or 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.

2.3 NG SETUP FAILURE structure

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