Police radio

Early portable radios were heavy and had short battery life, an issue that gradually disappeared as technology advanced.

[2] Modern police radio systems are often augmented by mobile data terminals to effectively manage units and assignments.

Prefectural police manage their own radio communications, which are officially limited to their respective jurisdictions but are capable of being used nationwide if necessary.

In Norway, it was historically legal for private citizens to listen to police radio frequencies.

However, this is no longer possible, as the Norwegian Police Service switched to "Nødnett", an encrypted radio system.

[12][13] The move from open analogue to the encrypted digital airwave system (TETRA) in the UK has made it practically impossible for civilians to listen to police radio.

The Federal Communications Commission assigns licenses to these entities in the public safety (PP and PX) allotments of the spectrum.

TETRA, the standard in many European countries as well as other places in the world, is virtually unused in the United States.