Search results
Results from the WOW.Com Content Network
In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave ...
Radio broadcasting is the broadcasting of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based radio station, while in satellite radio the radio waves are broadcast by a satellite in Earth orbit.
The rapid spread of film in the 1920s and radio in the 1930s led to proposals to use it for distance education. [62] By 1938, at least 200 city school systems, 25 state boards of education, and many colleges and universities broadcast educational programs for public schools. [63] One line of thought was to use radio as a master teacher.
Broadcasting began with AM radio, which came into popular use around 1920 with the spread of vacuum tube radio transmitters and receivers. Before this, most implementations of electronic communication (early radio , telephone , and telegraph ) were one-to-one , with the message intended for a single recipient.
"HD Radio" allows each existing broadcast station to add additional "channels" in the US by transmitting a digital signal on both sides of its channel, just beyond their existing analog Frequency Modulation signal. The HD Radio signal occupies the 0.1 MHz that begins 0.1 MHz above and below the carrier frequency station.
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.
Annotated information flow diagram. An information flow diagram (IFD) is a diagram that shows how information is communicated (or "flows") from a source to a receiver or target (e.g. A→C), through some medium. [1]: 36–39 The medium acts as a bridge, a means of transmitting the information. Examples of media include word of mouth, radio ...
Spectrum management is a growing problem due to the growing number of spectrum uses. [6] Uses include: over-the-air broadcasting, (which started in 1920); government and research uses (which include defense, public safety—maritime, air, police—resource management, transport, and radio astronomy); commercial services to the public (including voice, data, home networking); and industrial ...