When a data burst to be transmitted on the uScell arrives in the eNB buffer 701, the eNB starts LBT 706 on the unlicensed carrier. After determining that the carrier is free 708, the eNB starts transmitting 712 a reserving transmission on the unlicensed carrier to effectively reserve the unlicensed carrier frequency. The reserving transmission is made to ensure that other devices sensing the carrier detect that the carrier is occupied by the eNB. It also prepares an activation command 710 for transmission on the PCell to the UE. When the eNB is ready to transmit the activation command (e.g., after a one or two subframe delay for internal processing, two subframe delay shown in the figure), it transmits the activation command 710 on the Pcell. The UE, after receiving the activation command 710, transitions to an unlicensed carrier frequency receive activated state A from its deactivated unlicensed carrier receive state D. The UE may need a few subframes (e.g., 1 or 2 subframes, 1 subframe shown in the figure) to make this transition 714. Once the UE is in activated state, the eNB schedules data (using PDSCH) to the UE. After transmitting for a few subframes (e.g., 5 subframes shown in the figure), the eNB stops transmission and reinitiates LBT 715 on the unlicensed carrier to satisfy DCT requirements. After the carrier is determined to be free 716, the eNB reinitiates PDSCH transmission to the UE. This process is continued till the data burst transmission is complete.