A first method (and related first apparatus) includes transmitting, in a handover request message, an indication of a first protocol version; a second method (and related second apparatus) includes receiving, in the handover request message, the indication, deciding, based on the received indication and a second protocol version, on a value of an information element included in a handover request acknowledgement message to be transmitted, the information element indicating usage of a first or second signaling schemes, and transmitting the handover request acknowledgement message including the information element; and in the first method receiving the handover request acknowledgement message including the information element; and a third method (and related third apparatus) including receiving the handover command message including the information element, and configuring according to one of the first and second signaling schemes indicated by the information element.