The Federal Network Agency has released the frequency range at 446 MHz for private mobile voice radio( PMR). It belongs to the non-public land mobile radio(nömL) and can be used free of license and charges.
The PMR standard provides for eight channels between 446.00625 MHz and 446.09375 MHz with a channel sp acing of 12.5 kHz. The permissible transmit power is 500 mW. In contrast, short range devices( SRD), which use the same frequency range, operate with a transmit power of only 10 mW. With these 500 mW, distances of up to 15 km can be bridged, depending on topological conditions. In terms of modulation techniques, the radio signals can be modulated in frequency and phase mod ulation.
For PMR, only mobile terminals with a permanently installed antenna are permitted. PMR systems can be used in professional radio and communicate between fixed and mobile stations as well as between mobile stations.
Users of PMR systems can be divided into three groups: Private mobile radio on community frequencies for trade, craft and commercial enterprises, private mobile radio for special customer groups such as local transport companies, public transport companies, cabs and rental cars, ship ports and airports, water and shipping authorities, vehicle fleets and many more, and thirdly, PMR systems for police and customs, federal border guards and fire departments, social services and disaster control.
Operators of PMR systems are the individual companies, which are allowed to operate the service in a regional area of about 15 km with an appropriate usage permit. The digital variant of PMR radio is Digital Mobile Radio( DMR).