8.1 Elementary procedures

36.4233GPPEvolved Universal Terrestrial Radio Access Network (E-UTRAN)Release 17TSX2 Application Protocol (X2AP)

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

In the following tables, all EPs are divided into Class 1 and Class 2 EPs.

Table 8.1-1: Class 1 Elementary Procedures

Elementary Procedure	Initiating Message	Successful Outcome	Unsuccessful Outcome
Elementary Procedure	Initiating Message	Response message	Response message
Handover Preparation	HANDOVER REQUEST	HANDOVER REQUEST ACKNOWLEDGE	HANDOVER PREPARATION FAILURE
Reset	RESET REQUEST	RESET RESPONSE
X2 Setup	X2 SETUP REQUEST	X2 SETUP RESPONSE	X2 SETUP FAILURE
eNB Configuration Update	ENB CONFIGURATION UPDATE	ENB CONFIGURATION UPDATE ACKNOWLEDGE	ENB CONFIGURATION UPDATE FAILURE
Resource Status Reporting Initiation	RESOURCE STATUS REQUEST	RESOURCE STATUS RESPONSE	RESOURCE STATUS FAILURE
Mobility Settings Change	MOBILITY CHANGE REQUEST	MOBILITY CHANGE ACKNOWLEDGE	MOBILITY CHANGE FAILURE
Cell Activation	CELL ACTIVATION REQUEST	CELL ACTIVATION RESPONSE	CELL ACTIVATION FAILURE
SeNB Addition Preparation	SENB ADDITION REQUEST	SENB ADDITION REQUEST ACKNOWLEDGE	SENB ADDITION REQUEST REJECT
MeNB initiated SeNB Modification Preparation	SENB MODIFICATION REQUEST	SENB MODIFICATION REQUEST ACKNOWLEDGE	SENB MODIFICATION REQUEST REJECT
SeNB initiated SeNB Modification	SENB MODIFICATION REQUIRED	SENB MODIFICATION CONFIRM	SENB MODIFICATION REFUSE
SeNB initiated SeNB Release	SENB RELEASE REQUIRED	SENB RELEASE CONFIRM
X2 Removal	X2 REMOVAL REQUEST	X2 REMOVAL RESPONSE	X2 REMOVAL FAILURE
Retrieve UE Context	RETRIEVE UE CONTEXT REQUEST	RETRIEVE UE CONTEXT RESPONSE	RETRIEVE UE CONTEXT FAILURE
SgNB Addition Preparation	SGNB ADDITION REQUEST	SGNB ADDITION REQUEST ACKNOWLEDGE	SGNB ADDITION REQUEST REJECT
MeNB initiated SgNB Modification Preparation	SGNB MODIFICATION REQUEST	SGNB MODIFICATION REQUEST ACKNOWLEDGE	SGNB MODIFICATION REQUEST REJECT
SgNB initiated SgNB Modification	SGNB MODIFICATION REQUIRED	SGNB MODIFICATION CONFIRM	SGNB MODIFICATION REFUSE
SgNB change	SGNB CHANGE REQUIRED	SGNB CHANGE CONFIRM	SGNB CHANGE REFUSE
MeNB initiated SgNB Release	SGNB RELEASE REQUEST	SGNB RELEASE REQUEST ACKNOWLEDGE	SGNB RELEASE REQUEST REJECT
SgNB initiated SgNB Release	SGNB RELEASE REQUIRED	SGNB RELEASE CONFIRM
EN-DC X2 Setup	EN-DC X2 SETUP REQUEST	EN-DC X2 SETUP RESPONSE	EN-DC X2 SETUP FAILURE
EN-DC Configuration Update	EN-DC CONFIGURATION UPDATE	EN-DC CONFIGURATION UPDATE ACKNOWLEDGE	EN-DC CONFIGURATION UPDATE FAILURE
EN-DC Cell Activation	EN-DC CELL ACTIVATION REQUEST	EN-DC CELL ACTIVATION RESPONSE	EN-DC CELL ACTIVATION FAILURE
E-UTRA – NR Cell Resource Coordination	E-UTRA – NR CELL RESOURCE COORDINATION REQUEST	E-UTRA – NR CELL RESOURCE COORDINATION RESPONSE
EN-DC X2 Removal	EN-DC X2 REMOVAL REQUEST	EN-DC X2 REMOVAL RESPONSE	EN-DC X2 REMOVAL FAILURE
EN-DC Resource Status Reporting Initiation	EN-DC RESOURCE STATUS REQUEST	EN-DC RESOURCE STATUS RESPONSE	EN-DC RESOURCE STATUS FAILURE
UE Radio Capability ID Mapping	UE RADIO CAPABILITY ID MAPPING REQUEST	UE RADIO CAPABILITY ID MAPPING RESPONSE

Table 8.1-2: Class 2 Elementary Procedures

Elementary Procedure	Initiating Message
Load Indication	LOAD INFORMATION
Handover Cancel	HANDOVER CANCEL
SN Status Transfer	SN STATUS TRANSFER
UE Context Release	UE CONTEXT RELEASE
Resource Status Reporting	RESOURCE STATUS UPDATE
Error Indication	ERROR INDICATION
Radio Link Failure Indication	RLF INDICATION
Handover Report	HANDOVER REPORT
X2 Release	X2 RELEASE
X2AP Message Transfer	X2AP MESSAGE TRANSFER
SeNB Reconfiguration Completion	SENB RECONFIGURATION COMPLETE
MeNB initiated SeNB Release	SENB RELEASE REQUEST
SeNB Counter Check	SENB COUNTER CHECK REQUEST
SgNB Reconfiguration Completion	SGNB RECONFIGURATION COMPLETE
SgNB Counter Check	SGNB COUNTER CHECK REQUEST
RRC Transfer	RRC TRANSFER
Secondary RAT Data Usage Report	SECONDARY RAT DATA USAGE REPORT
SgNB Activity Notification	SGNB ACTIVITY NOTIFICATION
Data Forwarding Address Indication	DATA FORWARDING ADDRESS INDICATION
gNB Status Indication	GNB STATUS INDICATION
EN-DC Configuration Transfer	EN-DC CONFIGURATION TRANSFER
Trace Start	TRACE START
Deactivate Trace	DEACTIVATE TRACE
Handover Success	HANDOVER SUCCESS
Conditional Handover Cancel	CONDITIONAL HANDOVER CANCEL
Early Status Transfer	EARLY STATUS TRANSFER
EN-DC Resource Status Reporting	EN-DC RESOURCE STATUS UPDATE
Cell Traffic Trace	CELL TRAFFIC TRACE
F1-C Traffic Transfer	F1-C TRAFFIC TRANSFER
Access and Mobility Indication	ACCESS AND MOBILITY INDICATION
Conditional PSCell Change Cancel	CONDITIONAL PSCELL CHANGE CANCEL