8.10 Relocation Cancel

25.4133GPPRelease 17TSUTRAN Iu interface Radio Access Network Application Part (RANAP) signalling

8.10.1 General

The purpose of the Relocation Cancel procedure is to enable a source RNC to cancel an ongoing relocation of SRNS. The Relocation Cancel procedure may be initiated by the source RNC during and after the Relocation Preparation procedure if either of the following conditions is fulfilled:

1. The source RNC has not yet initiated the execution of relocation of SRNS, neither via the Iur interface nor via the Uu interface.

2. After having initiated the execution of relocation of SRNS, the UE has returned to the source RNC by transmitting an RRC message which indicates that the UE considers the source RNC as its serving RNC.

The procedure shall be co-ordinated in all Iu signalling connections for which the Relocation Preparation procedure has been initiated. The procedure uses connection oriented signalling.

8.10.2 Successful Operation

Figure 11: Relocation Cancel procedure. Successful operation.

The RNC initiates the procedure by sending a RELOCATION CANCEL message to the CN. This message shall indicate the reason for cancelling the relocation of SRNS by the appropriate value of the Cause IE. Upon reception of a RELOCATION CANCEL message, the CN shall send a RELOCATION CANCEL ACKNOWLEDGE message to the source RNC.

Transmission and reception of a RELOCATION CANCEL ACKNOWLEDGE message terminate the procedure in the CN and in the source RNC respectively. After this, the source RNC does not have a prepared relocation for that Iu signalling connection.

Interactions with Relocation Preparation procedure:

Upon reception of a RELOCATION CANCEL message from the source RNC, the CN shall locally terminate the possibly ongoing Relocation Preparation procedure towards that RNC and abandon the relocation of SRNS.

If the source RNC receives a RELOCATION COMMAND message from the CN after the Relocation Cancel procedure is initiated, the source RNC shall ignore the received RELOCATION COMMAND message.

If the source RNC receives a RELOCATION PREPARATION FAILURE message from the CN after the Relocation Cancel procedure is initiated, then the source RNC shall terminate the ongoing Relocation Cancel procedure.

8.10.3 Unsuccessful Operation

Not applicable.

8.10.4 Abnormal Conditions

Not applicable.

8.10.5 Co-ordination of Two Iu Signalling Connections

If the Relocation Cancel procedure is to be initiated due to other reasons than reception of a RELOCATION PREPARATION FAILURE message, the Relocation Cancel procedure shall be initiated on all Iu signalling connections existing for the UE in which the Relocation Preparation procedure has not terminated unsuccessfully.