Amateur and hobbyist
Amateur radio • Amateur radio repeater • Citizens' band radio • Family Radio Service
General Mobile Radio Service • Mobile rig • Multi-Use Radio Service • PMR446 • UHF CB (Australia) A two-way radio is simply a radio that can both transmit and receive (a transceiver). ... Amateur radio station with modern solid-state transceiver featuring LCD display and DSP capabilities Amateur radio, often called ham radio, is a hobby that uses various types of radio broadcasting equipment to communicate with other radio amateurs for public service, recreation and self-training. ... An amateur radio repeater is an electronic device that receives a weak or low-level amateur radio signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. ... A typical CB base station. ... The Family Radio Service is an improved walkie talkie system authorized in the United States. ... GMRS capable handheld radio The General Mobile Radio Service (GMRS) is a land-mobile UHF radio service in the United States available for short-distance two-way communications to facilitate the activities of an adult individual who possesses a valid GMRS license, as well his or her immediate family members... Mobile surveillance camera watching over passengers in a taxicab A mobile rig (or automobile rig) is a class of communications system that is midway between a base station (building-mounted) and portable (body mounted). ... The Multi-Use Radio Service (MURS) is a small two-way radio service consisting of five frequencies in the VHF spectrum. ... Alan 456r PMR446 (Personal Mobile Radio, 446 MHz) is a radio frequency part of the UHF range that is open without licensing for personal usage in most members of the European Union. ... UHF CB is a licence-free citizens band radio service authorised by the government of Australia in the UHF 477MHz band. ...

Aviation (aeronautical mobile)
Air traffic control • Aircraft emergency frequency • Airband • Mandatory frequency airport • Single Frequency Approach • UNICOM Air Traffic Control Towers (ATCTs) at Amsterdams Schiphol Airport Air traffic control (ATC) is a service provided by ground-based controllers who direct aircraft on the ground and in the air. ... The aircraft emergency frequency is a frequency used on the aircraft radio band reserved for emergency communications for aircraft in distress. ... An airport with a mandatory frequency (MF), mandatory traffic advisory frequency (MTAF) or air/ground radio (A/G) is an airport which does not have a control tower but still requires arriving and departing airport to communicate with other aircraft or a radio operator on a published frequency. ... In aviation, a Single Frequency Approach (SFA) is a service for a military single-piloted turbojet aircraft to use a single UHF frequency during their landing approach. ... UNICOM, or UNiversal Integrated COMmunication, is an air-ground communication facility operated by a private agency to provide private advisory station (PAS) service at uncontrolled aerodromes and airports with no Air Traffic Services (ATS) air-ground communication facility. ...

Land-based commercial and government mobile
Business band • Base station • Mobile radio • Professional Mobile Radio • Radio repeater • Specialized Mobile Radio • Trunked radio system • Walkie talkie The business band is the name used by US scanner hobbyists who listen to Federal Communications Commission licensees using Industrial/Business pool frequencies. ... The term base station can be used in the context of land surveying, wireless computer networking, and wireless communications. ... This article is about professional equipment. ... Professional Mobile Radio (also known as Private Mobile Radio (PMR) in the UK and Land Mobile Radio (LMR) in North America) are field radio communications systems which use portable, mobile, base station, and dispatch console radios and are sometimes based on such standards as MPT1327, TETRA and APCO 25 which... A Radio Repeater is a combination of a radio receiver and a radio transmitter that receives a weak or low-level signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. ... The Specialized Mobile Radio system (SMR) is a conventional two-way radio system, or trunked radio system, operated by a service in the 800 or 900 Mhz bands. ... A trunked radio system is a radio system used to maximize available capacity in a two-way radio system, usually UHF. Groups of users are given a logical talkgroup to share for their communications, rather than a dedicated radio frequency. ... Recreational, toy and amateur radio walkie talkies A Picture of two Walkie Talkies. ...

Marine (shipboard)
2182 kHz • Coast radio station • Marine VHF radio • Maritime mobile amateur radio The radio frequency of 2182 kilohertz (kHz) is the international calling and distress frequency for voice maritime communication (radio telephony) on the marine MF bands. ... Coast radio station is a maritime radio station situated on shore which monitores radio distress frequencies and relays ship-to-ship and ship-to-land communications. ... Portable VHF radio set Marine VHF radio is installed on all large ships and most motorized small craft. ... Most countries amateur radio licences allow licensed operators to install and use radio transmission equipment while at sea. ...

Signaling / Selective calling
CTCSS • Dual-tone multi-frequency • D-STAR • MDC-1200 • Push to talk • Quik Call I • Quik Call II • Selcall In a conventional, analog two-way radio system, a standard radio has noise squelch or carrier squelch which allows a radio to receive all transmissions on a channel. ... In telecommunications, squelch is a circuit function that acts to suppress the audio (or video) output of a receiver. ... This article does not cite any references or sources. ... D-STAR (Digital Smart Technologies for Amateur Radio) is a digital voice and data protocol specification developed for use in amateur radio. ... MDC, also known as MDC-1200 and MDC-600, is a low-speed Motorola two-way radio data system using audio frequency shift keying, (AFSK). ... Push-to-Talk (PTT), also known as Press-to-Transmit, is a method of conversing on half-duplex communication lines, including two-way radio, using a momentary button to switch from voice reception mode to transmit mode. ... Quik-Call I, also known as 2+2, is a selective calling method originally used in one-way paging receivers. ... Selcall (selective calling) is a type of squelch protocol used in radio communications systems, in which transmissions are preceded by a brief burst of sequential audio tones. ...

System elements and principles
Antenna • Audio level compression • Automatic vehicle location • Call sign • CAD • DC remote • Dispatch • Fade margin • Link budget • Rayleigh fading • Tone remote • Voice procedure • Voting (diversity combining) A Yagi-Uda beam antenna Short Wave Curtain Antenna (Moosbrunn, Austria) A building rooftop supporting numerous dish and sectored mobile telecommunications antennas (Doncaster, Victoria, Australia) An antenna is a transducer designed to transmit or receive radio waves which are a class of electromagnetic waves. ... Audio level compression, also called dynamic range compression, volume compression, compression, limiting, or DRC (often seen in DVD player settings) is a process that manipulates the dynamic range of an audio signal. ... Automatic vehicle location is a means for determining the location of a vehicle and transmitting this information to a point where it can be used. ... Call sign can refer to different types of call signs: Airline call sign Aviator call sign Cosmonaut call sign Radio and television call signs Tactical call sign, also known as a tactical designator See also: International Callsign Allocations, Maritime Mobile Service Identity This is a disambiguation page — a navigational... The CAD system of a fire department on a busy day. ... A current loop describes two different electrical signalling schemes. ... Dispatch is a procedure for assigning customers to taxicabs, couriers, emergency services, and other mobile units. ... In telecommunication, the term fade margin (fading margin) has the following meanings: A design allowance that provides for sufficient system gain or sensitivity to accommodate expected fading, for the purpose of ensuring that the required quality of service is maintained. ... A link budget is the accounting of all of the gains and losses from the transmitter, through the medium (free space, cable, waveguide, fiber, etc. ... Rayleigh fading is a statistical model for the effect of a propagation environment on a radio signal, such as that used by wireless devices. ... A Motorola T-1300 series remote control is built in a telephone housing. ... Voice procedure includes various techniques used to clarify, simplify and standardize spoken communications over two-way radios, in use by the military, in civil aviation, police and fire dispatching systems, citizens band radio (CB), etc. ... Diversity Combining is the technique applied to combine the multiple received signals of a diversity reception device into a single improved signal. ...