A process for cooperative aerial inter-antenna beamforming for communication between (a) multiple moving platforms, each platform having an aerial antenna mounted thereon, such that the aerial antennas have variable positions and orientations over time, and (b) at least one user antenna mounted on user equipment having a lower altitude than the aerial antennas; the process involving a first beamforming operation which beamforming operation involves; transmitting data relating to the positions and orientations of the aerial antennas to a processing system, the processing system calculating and transmitting beamforming instructions to the aerial antennas, the aerial antennas thereby transmitting or receiving respective component signals for each user antenna, the component signals for each user antenna having essentially the same information content but differing in their phase and usually amplitude, so as to form a cooperative beam from the cooperative sum of the signals between the aerial antennas and the user antenna; carrying out a plurality of further beamforming operations, wherein the cooperative beam has essentially the same information content as that generated in the first beamforming operation, where by the further cooperative beams are directed to form a cluster of beams surrounding the first cooperative beam.