A method comprising: transmitting , from a base station to a user equipment, UE, , measurement configuration information via a licensed frequency band, wherein the measurement configuration information is information to instruct the UE to perform measurements on an unlicensed frequency band; performing measurements , at the UE , on the unlicensed frequency band in response to receiving the measurement configuration information from the base station , wherein the measurements include at least a measurement of Received Signal Strength Indicator, RSSI, values of the unlicensed frequency band ; determining if the RSSI values are beyond a first threshold; transmitting , from the UE to the base station , measurement results, wherein the measurement results include the RSSI values and a result of the determination; receiving , at the base station , the measurement results from the UE ; assigning , at the base station , resources of the unlicensed frequency band for communication with the UE ; transmitting , from the base station to the UE , resource information indicating the resources of the unlicensed frequency band for communication between the base station and the UE , based on the measurement results; transmitting, from the base station to the UE, information specifying either a first mode or a second mode, based on the measurement results; wherein in the first mode the UE performs a first monitoring of the unlicensed frequency band to determine whether the unlicensed frequency band is in use; and wherein in the second mode the UE performs a second monitoring of the unlicensed frequency band to determine whether the unlicensed frequency band is in use, the second monitoring being a reduced monitoring compared to the first monitoring. transmitting , from a base station to a user equipment, UE, , measurement configuration information via a licensed frequency band, wherein the measurement configuration information is information to instruct the UE to perform measurements on an unlicensed frequency band; performing measurements , at the UE , on the unlicensed frequency band in response to receiving the measurement configuration information from the base station , wherein the measurements include at least a measurement of Received Signal Strength Indicator, RSSI, values of the unlicensed frequency band ; determining if the RSSI values are beyond a first threshold; transmitting , from the UE to the base station , measurement results, wherein the measurement results include the RSSI values and a result of the determination; receiving , at the base station , the measurement results from the UE ; assigning , at the base station , resources of the unlicensed frequency band for communication with the UE ; transmitting , from the base station to the UE , resource information indicating the resources of the unlicensed frequency band for communication between the base station and the UE , based on the measurement results; transmitting, from the base station to the UE, information specifying either a first mode or a second mode, based on the measurement results; wherein in the first mode the UE performs a first monitoring of the unlicensed frequency band to determine whether the unlicensed frequency band is in use; and wherein in the second mode the UE performs a second monitoring of the unlicensed frequency band to determine whether the unlicensed frequency band is in use, the second monitoring being a reduced monitoring compared to the first monitoring. <EOS>