Antenna apparatus for operating as a base station in a wireless network, comprising: a rotatable antenna assembly configured to employ a transmission beam pattern selected from a plurality of transmission beam patterns; a controller to rotate the rotatable antenna assembly in order to alter an azimuth direction of the rotatable antenna assembly; the controller being configured, during a configuration mode, to perform a sweep operation in order to rotate the rotatable antenna assembly to each of multiple selected azimuth directions; quality metric determination circuitry to determine, for each selected azimuth direction, a link quality metric for each of a plurality of wireless terminals based on communication between the plurality of wireless terminals and the base station whilst the rotatable antenna assembly is at that selected azimuth direction; and transmission beam determination circuitry to determine, from the link quality metrics determined for the plurality of wireless terminals at each selected azimuth direction, both an output transmission beam pattern from said plurality of transmission beam patterns, and an output azimuth direction; for a subsequent communication with the plurality of wireless terminals, the controller being arranged to rotate the rotatable antenna apparatus to said output azimuth direction and the rotatable antenna assembly being arranged to employ said output transmission beam pattern; wherein the transmission beam determination circuitry is configured to perform a harmonic mean operation using as inputs the link quality metrics determined for the plurality of wireless terminals at each selected azimuth direction and the plurality of transmission beam patterns, in order to determine the output azimuth direction and the output transmission beam pattern. a rotatable antenna assembly configured to employ a transmission beam pattern selected from a plurality of transmission beam patterns; a controller to rotate the rotatable antenna assembly in order to alter an azimuth direction of the rotatable antenna assembly; the controller being configured, during a configuration mode, to perform a sweep operation in order to rotate the rotatable antenna assembly to each of multiple selected azimuth directions; quality metric determination circuitry to determine, for each selected azimuth direction, a link quality metric for each of a plurality of wireless terminals based on communication between the plurality of wireless terminals and the base station whilst the rotatable antenna assembly is at that selected azimuth direction; and transmission beam determination circuitry to determine, from the link quality metrics determined for the plurality of wireless terminals at each selected azimuth direction, both an output transmission beam pattern from said plurality of transmission beam patterns, and an output azimuth direction; for a subsequent communication with the plurality of wireless terminals, the controller being arranged to rotate the rotatable antenna apparatus to said output azimuth direction and the rotatable antenna assembly being arranged to employ said output transmission beam pattern; wherein the transmission beam determination circuitry is configured to perform a harmonic mean operation using as inputs the link quality metrics determined for the plurality of wireless terminals at each selected azimuth direction and the plurality of transmission beam patterns, in order to determine the output azimuth direction and the output transmission beam pattern.