Search results
Results from the WOW.Com Content Network
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.
A radio band is a small frequency band (a contiguous section of the range of the radio spectrum) in which channels are usually used or set aside for the same purpose. To prevent interference and allow for efficient use of the radio spectrum, similar services are allocated in bands.
A trunked radio system is a two-way radio system that uses a control channel to automatically assign frequency channels to groups of user radios. In a traditional half-duplex land mobile radio system a group of users (a talkgroup ) with mobile and portable two-way radios communicate over a single shared radio channel, with one user at a time ...
Several hand-held Project 25 radios used around the world. Project 25 (P25 or APCO-25) is a suite of standards for interoperable digital two-way radio products. P25 was developed by public safety professionals in North America and has gained acceptance for public safety, security, public service, and commercial applications worldwide. [1]
The International Telecommunication Union defines frequency allocation as being of "a given frequency band for the purpose of its use by one or more terrestrial or space radiocommunication services or the radio astronomy service under specified conditions". [2] Frequency allocation is also a special term, used in national frequency ...
The network is a digital 9600 bps Project 25 (commonly referred to as P25 or APCO-25) Phase 2 trunked radio system operating in the UHF band between 403 MHz and 430 MHz in 12.5 kHz steps. [7] End user equipment is supplied mostly by Motorola , and consists primarily of Motorola APX series mobiles and portables two-way radios (although Benelec ...
Frequencies are reserved for Public Safety and for Industrial users. The 900 MHz band (935-940 MHz) is available solely for Industrial users. Finally, Public Safety entities are allotted an exclusive band of frequencies at 758-806 MHz. Low band has longer range capability, but requires mobile antennas as long as nine feet (2.7 m) tall.
The Radio Regulations of the International Telecommunication Union allow amateur radio operations in the frequency range 1,240–1,300 MHz, and amateur satellite up-links are allowed in the range 1,260–1,270 MHz. This is known as the 23-centimeter band by radio amateurs and as the L-band by AMSAT.