A method implemented in a wireless transmit/receive unit, WTRU, and directed to utilizing a cellular-based and wireless local area network, WLAN, based radio access technologies, RATs, to support aggregation of cellular and WLAN carriers, the method comprising: receiving, from a first radio access node utilizing the cellular-based RAT, a WLAN measurement object and reporting criteria for configuring an event for triggering a WLAN measurement report, wherein the WLAN measurement object comprises a first set of WLAN identifiers identifying a set of radio access nodes that utilize the WLAN-based RAT; detecting the configured event for triggering a WLAN measurement report; generating and sending the WLAN measurement report to the first radio access node, wherein the WLAN measurement report comprises a plurality of the first set of WLAN identifiers and a received signal strength indicator, RSSI, for each of the plurality of the first set of WLAN identifiers; receiving, from the first radio access node while in radio resource control, RRC, connected mode, a message comprising a second set of WLAN identifiers identifying a plurality of candidate radio access nodes that utilize the WLAN-based RAT, wherein the second set of WLAN identifiers corresponds to at least a subset of the reported plurality of WLAN identifiers; selecting one or more candidate radio access nodes of the plurality of candidate radio access nodes; attempting to connect to the selected one or more candidate radio access nodes for cellular and WLAN carrier aggregation; and on condition of WLAN connection failure: generating a connection status report; and sending the connection status report to the first radio access node. receiving, from a first radio access node utilizing the cellular-based RAT, a WLAN measurement object and reporting criteria for configuring an event for triggering a WLAN measurement report, wherein the WLAN measurement object comprises a first set of WLAN identifiers identifying a set of radio access nodes that utilize the WLAN-based RAT; detecting the configured event for triggering a WLAN measurement report; generating and sending the WLAN measurement report to the first radio access node, wherein the WLAN measurement report comprises a plurality of the first set of WLAN identifiers and a received signal strength indicator, RSSI, for each of the plurality of the first set of WLAN identifiers; receiving, from the first radio access node while in radio resource control, RRC, connected mode, a message comprising a second set of WLAN identifiers identifying a plurality of candidate radio access nodes that utilize the WLAN-based RAT, wherein the second set of WLAN identifiers corresponds to at least a subset of the reported plurality of WLAN identifiers; selecting one or more candidate radio access nodes of the plurality of candidate radio access nodes; attempting to connect to the selected one or more candidate radio access nodes for cellular and WLAN carrier aggregation; and on condition of WLAN connection failure: generating a connection status report; and sending the connection status report to the first radio access node. generating a connection status report; and sending the connection status report to the first radio access node.