X2AP的HANDOVER CANCEL过程是从『____』发送给『____』用来取消一个正在进行的切换。( The HANDOVE

X2AP的HANDOVER CANCEL过程是从『____』发送给『____』用来取消一个正在进行的切换。( The HANDOVER CANCEL process of X2AP is ransmitted from『____』to『____』.)