Radio is very important part of information technology
and it is very popular and important source of information, news, education and
entertainment. Radio is working through the radiation, wireless transmission,
of electromagnetic signals in the atmosphere or free space. Radio waves can
carry information, such as sound, by systematically changing, modulating, some
property of the radiated waves, such as their amplitude, frequency, phase, or
pulse width. When radio waves strike an electrical conductor, the oscillating
fields induce an alternating current in the conductor. The information in the
waves can be extracted and transformed back into its original form. Radio
systems need a transmitter to modulate, change, some property of the energy
produced to impress a signal on it, for example using amplitude modulation,
angle modulation, which can be frequency modulation or phase modulation. Radio
systems also need an antenna to convert electric currents into radio waves, and
vice versa. An antenna can be used for both transmitting and receiving. The
electrical resonance of tuned circuits in radios allow individual stations to
be selected. The electromagnetic wave is intercepted by a tuned receiving
antenna. A radio receiver receives its input from an antenna and converts it
into a form usable for the consumer, such as sound, pictures, digital data,
measurement values, navigational positions. A band is a small section of the
spectrum of radio communication frequencies, in which channels are usually used
or set aside for the same purpose and Radio frequencies occupy the range from a
3 kHz to 300 GHz, although commercially important uses of radio use only a
small part of this spectrum and Different parts of the radio spectrum are
allocated for different radio transmission technologies and applications. In
some cases, parts of the radio spectrum is sold or licensed to operators of
private radio transmission services, for example, cellular telephone operators
or broadcast television stations. Ranges of allocated frequencies are often
referred to by their provisioned use, for example, cellular spectrum or
television spectrum. An antenna is an electrical device which converts electric
currents into radio waves, and vice versa. It is usually used with a radio
transmitter or radio receiver. In transmission, a radio transmitter supplies an
electric current oscillating at radio frequency to the antenna's terminals, and
the antenna radiates the energy from the current as electromagnetic waves,
radio waves. In reception, an antenna intercepts some of the power of an
electromagnetic wave in order to produce a tiny voltage at its terminals, that is applied to a receiver to be
amplified. Some antennas can be used for both transmitting and receiving, even
simultaneously, depending on the connected equipment. Once generated,
electromagnetic waves travel through space either directly, or have their path
altered by reflection, refraction or diffraction. The intensity of the waves
diminishes due to geometric dispersion some energy may also be absorbed by the
intervening medium in some cases. Noise will generally alter the desired
signal; this electromagnetic interference comes from natural sources, as well
as from artificial sources such as other transmitters and accidental radiators.
A radio communication system sends signals by radio. Types of radio
communication systems deployed depend on technology, standards, regulations,
radio spectrum allocation, user requirements, service positioning, and
investment. The radio equipment involved in communication systems includes a
transmitter and a receiver, each having an antenna and appropriate terminal
equipment such as a microphone at the transmitter and a loudspeaker at the
receiver in the case of a voice-communication system. A radio communication
system may send information only one way. For example, in broadcasting a single
transmitter sends signals to many receivers. Two stations may take turns
sending and receiving, using a single radio frequency; this is called, simplex.
By using two radio frequencies, two stations may continuously and concurrently
send and receive signals, this is called duplex operation. Internet radio is an
audio service transmitted via the Internet. Broadcasting on the Internet is
usually referred to as webcasting since it is not transmitted broadly through
wireless means. Internet radio involves streaming media, presenting listeners
with a continuous stream of audio that typically cannot be paused or replayed,
much like traditional broadcast media; in this respect, it is distinct from on
demand file serving. Internet radio is also distinct from podcasting, which
involves downloading rather than streaming. Internet radio services offer news,
sports, talk, and various genres of music every format that is available on
traditional broadcast radio stations. Many Internet radio services are
associated with a corresponding traditional, terrestrial, radio station or
radio network, although low start-up and ongoing costs have allowed a
substantial proliferation of independent Internet only radio stations. Internet
radio services are usually accessible from anywhere in the world with a
suitable internet connection available. Streaming technology is used to
distribute Internet radio, typically using a lossy audio codec and Streaming
audio formats include MP3, Ogg Vorbis, Windows Media Audio, RealAudio, and HE-
AAC. Audio data is continuously transmitted serially, streamed, over the local
network or internet in TCP or UDP packets, then reassembled at the receiver and
played a second or two later. The delay is called lag, and is introduced at
several stages of digital audio broadcasting. An Internet radio device, also
called network music player is a hardware device that is capable of receiving
and playing streamed media from either Internet radio stations or a home
network and Network music players usually have Broadband connection, an
Ethernet or Wi-Fi network interface, with TCP/IP support for access to the
Internet USB port, where the user can connect an external MP3 player like iPod
or external hard drive for MP3 files LCD display, remote control Built-in
amplifier, speaker, or AUX-out port, that can be used to connect to a HiFi or
similar audio device. internet radio player software. These let you play live
internet radio from multiple internet radio stations around the world easily.
All these internet radio player software are completely free and can be
downloaded to Windows PC and These software offer various features, like, gives
you access to numerous internet radio stations around the world, arrange the internet
radio stations according to genre, arranged the radio stations in a
alphabetical manner, record internet radio, display internet radio stations
country wise, stream live internet radio from multiple radio stations all over
the world, supports WMA, WAV, OGG, MP1, MP2, MP3, MP4 and AAC audio formats and
listening radio is very famous in around globe. Radio set an electronic
receiver that detects and demodulates and amplifies transmitted signals and a
different kind radio sets are available in the market including digital and
manual radio sets.
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