A method for estimating qualities of links between a transmitter and a receiver on respective carrier frequencies in a multi-carrier wireless communication system from measurements made during a scanning interval in which pilot signals may be transmitted from the transmitter to the receiver in a plurality of carrier-time bins, each carrier-time bin corresponding to a respective carrier frequency of the multi-carrier system and a respective time slot within the scanning interval, are provided. The method includes, during the scanning interval, making test measurements in less than all of the carrier-time bins, each test measurement comprising transmitting a respective signal from the transmitter to the receiver in a respective carrier-time bin and measuring a strength of the corresponding signal received by the receiver, and using the test measurements to determine at least one of: a value indicative of a predicted quality of a link between the transmitter and the receiver in a carrier-time bin of the scanning interval in which no test measurement is made during the scanning interval, and a value indicative of a predicted quality of a link between the transmitter and the receiver over a period of time within or equal to the scanning interval on a carrier frequency for which no test measurement is made in at least one carrier-time bin during said period of time.