The present invention relates to a method in an RBS of a wireless network, for supporting HO of a UE in a served cell. The method comprises pre-allocating resources for HO of the UE to a target cell candidate. The pre-allocated resources comprise a dedicated preamble for the target cell candidate. The method also comprises receiving a measurement report from the UE triggering a HO and comprising a list of neighbor cells, determining if a cell in the list of neighbor cells corresponds to one of the at least one target cell candidates, and when they correspond transmitting a HO command to the UE comprising the dedicated preamble for the target. The present invention also relates to a corresponding method in the target RBS and to the serving and target RBS themselves.