A method of managing carrier aggregation for a multi-radio access technology (RAT) wireless transmitter/receiver unit (WTRU) is disclosed. The method may include: receiving, by the WRTU over a primary channel associated with a RAT of a first type, provisioning information for provisioning a supplementary channel associated with a RAT of a second type; establishing the supplementary channel associated with the RAT of the second type based on the received provisioning information; and wirelessly exchanging, by the WRTU, first data associated with a communication over the primary channel via the RAT of the first type, while wireless exchanging second data associated with the communication over the supplementary channel via the RAT of the second type.