A wireless transmit/receive unit (WTRU) and a method for use by the WTRU for transmitting a radio resource control (RRC) message to a first base station, the RRC message including WTRU capability information, receiving and processing configuration information from a second base station, the configuration information being received after the second base station has received a WTRU information transfer message from a network controller, the WTRU information transfer message including uplink physical channel support information, frequency division duplex (FDD) and time division duplex (TDD) parameters including TDD specific parameters, hybrid automatic repeat request (HARQ) information, supported modulation scheme information, and shared channel information, and sending transmissions to the second base station in accordance with the received configuration information.