On site communications are essential at events, both for controlling the public via public address systems and for keeping in contact with essential members of the organisational team during the actual event.
Radio communication is excellent for large events covering extensive sites; however, organisers should be aware that there are limitations on their use, due to geographical location or more simply if caused by the undisciplined user who insists on talking over other transmissions.
There are also a number of technical considerations to be made, e.g. two channel systems or multi-channel systems and special headsets for communications inside entertainment marquees where it may be difficult to receive or hear communications over the sound of on-stage public address or stage gear. Consider also earpiece reception for staff/stewards/helpers in the front line. Innocent messages overheard by the public, if misheard or misinterpreted can cause panic. Priority talk-through arrangements for key posts, e.g. Safety Officer and Event Co-ordinator for dealing with emergencies is essential.
A link into the public address system is also an essential feature in controlling the behaviour of the public through public announcements.