Some emergencies are national (big natural or man-made disasters) and some are localised. EWF localisation is best served by an integrated network of FM, MW and SW transmitters, with FM used for highly localised events, FM and MW for regional issues, and all SW, MW and FM transmitters used for wider-reaching emergencies. MW transmitters can cover areas affected by disasters from outside the regions where the infrastructure might be badly affected, while unaffected areas can continue with regular programming. EWF will be activated by a national or regional government directing EWF signals to transmitters according to the required localisation.