8.5 X2AP Message Transfer

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

8.5.1 General

The purpose of the X2AP Message Transfer procedure is to allow indirect transport of an X2AP message (except the X2AP MESSAGE TRANSFER message) between two eNBs and to allow an eNB to perform registration.

8.5.2 Successful Operation

Figure 8.5.2-1: X2AP Message Transfer, successful operation

eNB₁ initiates the procedure by sending the X2AP MESSAGE TRANSFER message to eNB₂.

Upon the reception of X2 MESSAGE TRANSFER message the target eNB may:

– Retrieve the X2AP message included in the X2AP Message IE;

– Consider the target eNB ID contained in the Target eNB ID IE, included in the RNL Header IE, as the destination for the X2AP message signaled in the X2AP Message IE;

– Consider the source eNB ID contained in the Source eNB ID IE, included in the RNL Header IE, as the source of the X2AP message signaled in the X2AP Message IE.

In case the included RNL Header IE does not contain the Target eNB ID IE, the receiving eNB shall consider the eNB ID included in the Source eNB ID IE as the eNB ID corresponding to the TNL address(es) of the sender and update its internal information.

8.5.3 Unsuccessful Operation

Not Applicable.

8.5.4 Abnormal Condition

Not Applicable.