Police radio

radio operator Before police radio systems were first implemented, police officers assigned to their beat could only communicate with police command using telephone booths, call boxes, police boxes, or physical meetings. Calling for help or signaling other officers could only be done by shouting, using a whistle, or hitting things to make sounds. This meant that properly calling for assistance, reporting an incident or arrest, being dispatched to handle a crime, or requesting police resources was only possible if the officer reached a telephone or call box. The first police radio systems were implemented in Detroit in 1928, when the Detroit Police Department set up a one-way radio system to broadcast crime information to police cars. The first two-way police radio system was implemented by the Bayonne, New Jersey police in 1933. The FCC briefly prohibited police radio communications in 1934, but rescinded their decision in 1935. Due to their cost and size, early police radio systems were only used in police cars and buildings; officers on foot patrol still had to rely on telephones and call boxes. Portable radios introduced in the 1960s made radio communications widely accessible to all officers. Early portable radios were heavy and had short battery life, an issue that gradually disappeared as technology advanced. Modern police radio systems are often augmented by mobile data terminals to effectively manage units and assignments. Police radio systems historically used public radio frequencies, and listening to them was, for the most part, legal. Most modern police radio systems switched to encrypted radio systems in the 1990s and 2000s to prevent eavesdroppers from listening in. ==By country==

, Germany Canada In Canada, the Radiocommunication Act states that it is illegal to intercept private radio communications with the intent to divulge or use any information obtained in the interception. This applies to any attempts to listen to emergency services radios and police radios. Additionally, there are prohibitions on certain radio scanner devices. Germany In Germany, it is illegal for private citizens to listen to police radio, even if it is unintentional. Offenders can be punished with up to two years in prison or a fine. Japan In Japan, police radio communication regulation is managed by the National Police Agency. Prefectural police manage their own radio communications, which are officially limited to their respective jurisdictions but are capable of being used nationwide if necessary. Individual officers communicate with radio operators in nearby police stations, while police vehicles communicate with their prefectural police's communications command centers, located at prefectural police headquarters. with trials commencing in 1931, and the results published in a 1933–1934 series of articles. It is an offence under the Wireless Telegraphy Act 2006 to listen to police radio in the UK. 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. United States In the United States, police departments, sheriff's departments, and state police often run their own systems in parallel, presenting interoperability problems. The Federal Communications Commission assigns licenses to these entities in the public safety (PP and PX) allotments of the spectrum. These include allocations in the lower portion of the VHF spectrum (around 39–45 MHz), highly susceptible to "skip" interference but still used by state highway patrols; the VHF "hi-band", from 150–160 MHz; and various UHF bands. Many systems still use conventional FM transmissions for most traffic; others are trunked analog or digital systems. Recently, there has been a move towards digital trunked systems, especially those based around the public-safety standard Project 25 format set by the Association of Public-Safety Communications Officials-International. A minority of other police radio systems, the largest examples being the Milwaukee Police Department and Pennsylvania State Police, use the incompatible OpenSky format. TETRA, the standard in many European countries as well as other places in the world, is virtually unused in the United States. Some states operate statewide radio networks with varying levels of participation from police on the county and city levels: • Idaho: Idaho Cooperative Agencies Wireless Interoperable Network (ICAWIN) • Illinois: StarCom21 • Louisiana: Louisiana Wireless Information Network (LWIN) • Michigan: State of Michigan Public Safety Communications System (MPSCS) • Minnesota: Allied Radio Matrix for Emergency Response (ARMER) • Montana: Montana Public Safety Communications System • North Carolina: VIPER • Ohio: Multi-agency communications system (MARCS) • South Carolina: Palmetto 800 • Wisconsin: Wisconsin Interoperable System for Communications (WISCOM) It is generally legal in the United States to listen to unencrypted police communications, though some states and municipalities prohibit carrying receivers within vehicles. == See also ==