Patent ID: 9031039
Filing Date: 2015-05-12
Classification: H04B,H04W

Abstract:
1. A method of performing a handover procedure by a donor base station (BS) in a wireless communication system, the method comprising: receiving a handover indicator, which indicates desire for a handover but does not indicate a type of the handover, from a relay node (RN) through a second X2 interface between the RN and the donor BS; determining the type of the handover according to whether a first X2 interface between the donor BS and a target BS is available or not; if it is determined that the first X2 interface between the donor BS and the target BS is available, transmitting an X2 handover request message to the target BS via the first X2 interface; if it is determined that the first X2 interface between the donor BS and the target BS is not available, transmitting an S1 handover required message to a mobility management entity (MME); and transmitting a handover response message to the RN, wherein the handover response message is a handover request admission message if the handover to the target BS is available, and wherein the handover response message is a handover preparation failure message if the handover to the target BS is not available.