A system comprising a central office, CO, said CO comprising: a plurality of intensity-modulation, IM, lasers each of which is configured to generate a separate optical data signal; a Butler matrix system coupled to the plurality of IM lasers comprising: a plurality of optical input ports provided correspondingly for the plurality of the IM lasers, Butler matrix components coupled to the plurality of the optical input ports, and a plurality of optical output ports coupled to the Butler matrix; wherein the Butler matrix is configured to generate a plurality of optical data signals comprising different phase shifts for beamforming of an optical data signal provided by one of the plurality of IM lasers; first wavelength-division multiplexers connected to the optical output ports of the Butler matrix system and configured to multiplex the plurality of optical data signals comprising different phase shifts to provide a serial optical data stream; the system also comprising: a fibre connected at one end of an amplifier coupled to the first wavelength-division multiplexers; second wavelength-division multiplexers connected to another end of the fibre and configured to demultiplex the serial optical data stream into the optical data signals comprising different phase shifts; detectors connected to the second wavelength-division multiplexers and configured to convert the demultiplexed optical data signals comprising different phase shifts into electrical data signals; and antennas configured to radiate the electrical data signals. a plurality of intensity-modulation, IM, lasers each of which is configured to generate a separate optical data signal; a Butler matrix system coupled to the plurality of IM lasers comprising: a plurality of optical input ports provided correspondingly for the plurality of the IM lasers, Butler matrix components coupled to the plurality of the optical input ports, and a plurality of optical output ports coupled to the Butler matrix; wherein the Butler matrix is configured to generate a plurality of optical data signals comprising different phase shifts for beamforming of an optical data signal provided by one of the plurality of IM lasers; first wavelength-division multiplexers connected to the optical output ports of the Butler matrix system and configured to multiplex the plurality of optical data signals comprising different phase shifts to provide a serial optical data stream; the system also comprising: a fibre connected at one end of an amplifier coupled to the first wavelength-division multiplexers; second wavelength-division multiplexers connected to another end of the fibre and configured to demultiplex the serial optical data stream into the optical data signals comprising different phase shifts; detectors connected to the second wavelength-division multiplexers and configured to convert the demultiplexed optical data signals comprising different phase shifts into electrical data signals; and antennas configured to radiate the electrical data signals. a plurality of optical input ports provided correspondingly for the plurality of the IM lasers, Butler matrix components coupled to the plurality of the optical input ports, and a plurality of optical output ports coupled to the Butler matrix; wherein the Butler matrix is configured to generate a plurality of optical data signals comprising different phase shifts for beamforming of an optical data signal provided by one of the plurality of IM lasers; first wavelength-division multiplexers connected to the optical output ports of the Butler matrix system and configured to multiplex the plurality of optical data signals comprising different phase shifts to provide a serial optical data stream; the system also comprising: a fibre connected at one end of an amplifier coupled to the first wavelength-division multiplexers; second wavelength-division multiplexers connected to another end of the fibre and configured to demultiplex the serial optical data stream into the optical data signals comprising different phase shifts; detectors connected to the second wavelength-division multiplexers and configured to convert the demultiplexed optical data signals comprising different phase shifts into electrical data signals; and antennas configured to radiate the electrical data signals. a fibre connected at one end of an amplifier coupled to the first wavelength-division multiplexers; second wavelength-division multiplexers connected to another end of the fibre and configured to demultiplex the serial optical data stream into the optical data signals comprising different phase shifts; detectors connected to the second wavelength-division multiplexers and configured to convert the demultiplexed optical data signals comprising different phase shifts into electrical data signals; and antennas configured to radiate the electrical data signals.