Provided are a wireless transmit/receive unit, a Node-B and a method.In one embodiment, a radio network controller (RNC) initiates an inter-Node-B soft handover. A wireless transmit/receive unit (WTRU) establishes communication connections with a plurality of Node-Bs. A particular one of the Node-Bs is designated as being a primary Node-B, and each of other Node-Bs are designated as being a non-primary Node-B. The RNC informs all of the Node-Bs that the particular Node-B is a primary Node-B. The primary Node-B schedules EU transmission and performs ACK/NACK during soft handover. In another embodiment, the RNC initiates a hard handover for a WTRU connected to a source Node-B. The RNC sends an activation timer to the source Node-B to set the time for handover. As many previously negatively acknowledged (NACKed) data packets as possible are prioritized for retransmission in the source Node-B before the activation timer expires.