The present disclosure relates to a method performed by a network node for beamforming, to a network node and to a system including a network node. One aspect of the disclosure provides a method (900) comprising: obtaining (910), at the network node (800), information relating to a plurality of signals received or transmitted using a set of receiving beams or a set of transmitting beams of the network node (800), each individual beam of the set having a unique beam direction; determining a set of candidate beams for use by the network node (800) for synchronisation signal, SS, transmission or random access channel, RACH, detection; based on the obtained information, selecting one or more of the determined candidate beams; and using the selected one or more of the determined candidate beams for SS transmission or RACH detection by the network node (800).