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Police radio. Police radio is a radio system used by police and other law enforcement agencies to communicate with one another. Police radio systems almost always use two-way radio systems to allow for communications between police officers and dispatchers . Most modern police radio systems are encrypted, and many jurisdictions have made ...
Wireless telegraphy or radiotelegraphy, commonly called CW ( continuous wave ), ICW (interrupted continuous wave) transmission, or on-off keying, and designated by the International Telecommunication Union as emission type A1A or A2A, is a radio communication method. It was transmitted by several different modulation methods during its history.
History of radio. The early history of radio is the history of technology that produces and uses radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy". Later radio history increasingly involves matters of ...
Signal strength and readability report. A signal strength and readability report is a standardized format for reporting the strength of the radio signal and the readability (quality) of the radiotelephone (voice) or radiotelegraph (Morse code) signal transmitted by another station as received at the reporting station's location and by their ...
Radiotelephony procedure (also on-air protocol and voice procedure) includes various techniques used to clarify, simplify and standardize spoken communications over two-way radios, in use by the armed forces, in civil aviation, police and fire dispatching systems, citizens' band radio (CB), and amateur radio . Voice procedure communications are ...
Wireless network technologies. Mobile radio telephone systems were mobile telephony systems that preceded modern cellular network technology. Since they were the predecessors of the first generation of cellular telephones, these systems are sometimes retroactively referred to as pre-cellular (or sometimes zero generation, that is, 0G) systems.
Radiotelephone. A radiotelephone (or radiophone ), abbreviated RT, [1] is a radio communication system for conducting a conversation; radiotelephony means telephony by radio. It is in contrast to radiotelegraphy, which is radio transmission of telegrams (messages), or television, transmission of moving pictures and sound.
The first use of a national emergency telephone number began in the United Kingdom in 1937 using the number 999, which continues to this day. [6] In the United States, the first 911 service was established by the Alabama Telephone Company and the first call was made in Haleyville, Alabama, in 1968 by Alabama Speaker of the House Rankin Fite and answered by U.S. Representative Tom Bevill.