An apparatus, method and computer program product for: receiving (305) information relating to a power level of a radio beam received by an antenna array, analysing (310) a radio beam power profile associated with the antenna array, determining (315), based on the radio beam power profile, a characteristic of a radio channel, calculating (320), based on the characteristic, an optimum radio beam gain of the antenna array, and estimating (325) a link budget based on the optimum radio beam gain of the antenna array and the information relating to the power level of the radio beam received by the antenna array.