A method is provided in a base station having multiple directional antenna elements each providing a corresponding radio coverage lobe to identify which subset of the lobes covers a user terminal. The base station is a picocell base station. A user terminal is positioned within the coverage area of the base station. A subset of the lobes is selected. The base station applies for a period an adjusted signal power in respect of the selected subset of the lobes. The signal power is detected and information dependent upon the detected pilot signal power is provided. The base station uses said information to determine whether or not the user terminal is located in the selected subset of lobes. A sub-group of the subset of lobes is then selected and a corresponding determination is made whether or not the user terminal is located in the selected sub-group.