Hubbry Logo
search
logo
1694519

Mobile radio

logo
Community Hub0 Subscribers
Write something...
Be the first to start a discussion here.
Be the first to start a discussion here.
See all
Mobile radio

Mobile radio or mobiles refer to wireless communications systems and devices which are based on radio frequencies (using commonly UHF or VHF frequencies), and where the path of communications is movable on either end. There are a variety of views about what constitutes mobile equipment. For US licensing purposes, mobiles may include hand-carried, (sometimes called portable), equipment. An obsolete term is radiophone.

A sales person or radio repair shop would understand the word mobile to mean vehicle-mounted: a transmitter-receiver (transceiver) used for radio communications from a vehicle. Mobile radios are mounted to a motor vehicle usually with the microphone and control panel in reach of the driver. In the US, such a device is typically powered by the host vehicle's 12 Volt electrical system.

Some mobile radios are mounted in aircraft (aeronautical mobile), shipboard (maritime mobile), on motorcycles, or railroad locomotives. Power may vary with each platform. For example, a mobile radio installed in a locomotive would run off of 72 or 30 Volt DC power. A large ship with 117 V AC power might have a base station mounted on the ship's bridge.

According to article 1.67 of the ITU, a mobile radio is "A station in the mobile service intended to be used while in motion or during halts at unspecified points."

The distinction between radiotelephones and two-way radio is becoming blurred as the two technologies merge.[citation needed] The backbone or infrastructure supporting the system defines which category or taxonomy applies. A parallel to this concept is the convergence of computing and telephones.

Radiotelephones are full-duplex (simultaneous talk and listen), circuit switched, and primarily communicate with telephones connected to the public switched telephone network.[citation needed] The connection sets up based on the user dialing.[citation needed] The connection is taken down when the end button is pressed. They run on telephony-based infrastructure such as AMPS or GSM.[citation needed]

Two-way radio is primarily a dispatch[citation needed] tool intended to communicate in simplex or half-duplex modes using push-to-talk, and primarily intended to communicate with other radios rather than telephones. These systems run on push-to-talk-based infrastructure such as Nextel's iDEN, Specialized Mobile Radio (SMR), MPT-1327, Enhanced Specialized Mobile Radio (ESMR) or conventional two-way systems. Certain modern two-way radio systems may have full-duplex telephone capability.

Early users of mobile radio equipment included transportation and government. These systems used one-way broadcasting instead of two-way conversations. Railroads used medium frequency range (MF) communications (similar to the AM broadcast band) to improve safety. Instead of hanging out of a locomotive cab and grabbing train orders while rolling past a station, voice communications with rolling trains became possible. Radios linked the caboose with the locomotive cab. Early police radio systems were initially one way using MF frequencies above the AM broadcast band, (1.7 MHz). Some early systems talked back to dispatch on a 30-50 MHz link, (called crossband).

See all
User Avatar
No comments yet.