A method of controlling the Equivalent Isotropic Radiated Power (EIRP) emitted from an array of antenna elements (14a - 14g) to a maximum allowed level at an access point of a wireless communication network, the access point being configured to form a plurality of MU-MIMO beams (6, 7, 8) by applying a weightset for a beamforming weights matrix to a plurality of signal streams, to form a respective MU-MIMO beam to transmit simultaneously within a timeslot of a time frame sequence different payload data to each respective one of an identified group of subscriber modules, the respective beam forming a null to each subscriber module of the group other than the respective one, the method comprising: providing the array of antenna elements, respective transmit chains for each antenna element and a combiner network as parts of an integrated unit arranged to impede changing of the spacing of the antenna elements by an operator to maintain a predetermined configuration of the antenna array, each respective transmit chain being connected to the antenna array using printed conductors and without the use of coaxial cable connectors, and the circuit design and physical layout of radio frequency transmission paths being the same for each antenna element; periodically, as part of the time frame sequence, calibrating transmission phase and gain of a respective transmit chain (13a - 13n) for each antenna element by generating an OFDM test symbol for each transmit chain, each respective OFDM test symbol comprising a respective set of sounding tones, combining signals from each transmit chain into a combined channel, receiving a combined OFDM symbol in the combined channel, and calibrating each transmit chain based on determining the transmission amplitude and phase for each transmit chain from the combined symbol or a series of combined symbols; providing a polar radiation model for an antenna element of the array; determining a weightset for the beamforming weights matrix subject to a constraint that a maximum total EIRP for the plurality of beams in combination in any azimuth direction is maintained within the maximum allowed level, wherein said determining is based at least on a spatial separation of the antenna elements, the polar radiation model and the calibrated transmission phase and gain of each respective transmit chain; and using the determined weightset to transmit the plurality of MU-MIMO beams within the timeslot of the time frame sequence to give a total EIRP above an EIRP level that would result if the conducted power to each antenna element were limited such that, if the maximum possible array gain were applied, the maximum allowed EIRP would not be exceeded. providing the array of antenna elements, respective transmit chains for each antenna element and a combiner network as parts of an integrated unit arranged to impede changing of the spacing of the antenna elements by an operator to maintain a predetermined configuration of the antenna array, each respective transmit chain being connected to the antenna array using printed conductors and without the use of coaxial cable connectors, and the circuit design and physical layout of radio frequency transmission paths being the same for each antenna element; periodically, as part of the time frame sequence, calibrating transmission phase and gain of a respective transmit chain (13a - 13n) for each antenna element by generating an OFDM test symbol for each transmit chain, each respective OFDM test symbol comprising a respective set of sounding tones, combining signals from each transmit chain into a combined channel, receiving a combined OFDM symbol in the combined channel, and calibrating each transmit chain based on determining the transmission amplitude and phase for each transmit chain from the combined symbol or a series of combined symbols; providing a polar radiation model for an antenna element of the array; determining a weightset for the beamforming weights matrix subject to a constraint that a maximum total EIRP for the plurality of beams in combination in any azimuth direction is maintained within the maximum allowed level, wherein said determining is based at least on a spatial separation of the antenna elements, the polar radiation model and the calibrated transmission phase and gain of each respective transmit chain; and using the determined weightset to transmit the plurality of MU-MIMO beams within the timeslot of the time frame sequence to give a total EIRP above an EIRP level that would result if the conducted power to each antenna element were limited such that, if the maximum possible array gain were applied, the maximum allowed EIRP would not be exceeded.