Sources of high frequency fields

Numerous technologies use high frequency (HF) electromagnetic fields: Every day life cannot be imagined without broadcasting and television, cordless phones increase comfort when phoning indoors and in the garden, babies are monitored in their rooms using baby monitors, computers are linked to each other and to peripheral devices by using Wireless LAN (WLAN) and Bluetooth and recently ultrawideband (UWB) technologies, police and fire brigades use their own radio network for communication.