Thursday, 9th January 2020 Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum (radio waves), in a one-to-many model. Over the air broadcasting is usually associated with radio and television, though in recent years, both radio and television transmissions have begun to be distributed by cable (cable television). The receiving parties may include the general public or a relatively small subset; the point is that anyone with the appropriate receiving technology and equipment (e.g., a radio or television set) can receive the signal. Transmission of radio and television programs from a radio or television station to home receivers by radio waves is referred to as "over the air" (OTA) or terrestrial broadcasting and in most countries requires a broadcasting license. Transmissions using a wire or cable, like cable television (which also retransmits OTA stations with their consent), are also considered broadcasts but do not necessarily require a license (though in some countries, a license is required). In the 2000s, transmissions of television and radio programs via streaming digital technology have increasingly been referred to as broadcasting as well. Digital audio or video is transmitted as a series of binary bits. Like a dam holding back water in a stream, broadcast equipment stores up a backlog, or cache, of data. Then, if there are dropouts in transmission, there’s a sufficient supply to maintain the signal without interruption. Some services buffer more than others, explaining the discrepancy between digital radio and digital TV. Radio broadcasting involves audio signals sent through the air as radio waves from a transmitter, picked up by an antenna and sent to a receiver. Radio stations can be linked in radio networks to broadcast common radio programs, either in broadcast syndication, simulcast or subchannels. Television broadcasting (telecast) is an extension of radio to include video signals. A television transmitter is a transmitter that is used for terrestrial (over-the-air) television broadcasting. It is an electronic device that radiates radio waves that carry a video signal representing moving images, along with a synchronized audio channel, which is received by television receivers belonging to a public audience, which display the image on a screen. Television transmitters must be licensed by governments, and are restricted to a certain frequency channel and power level. They transmit on frequency channels in the VHF and UHF bands. Since radio waves of these frequencies travel by line of sight, they are limited by the horizon to reception distances of 40-60 miles depending on the height of transmitter station. Television transmitters use one of two different technologies: analog, in which the picture and sound are transmitted by analog signals modulated onto the radio carrier wave, and digital in which the picture and sound are transmitted by digital signals. The original television technology, analog television, began to be replaced in a transition beginning in 2006 in many countries with digital television (DTV) systems. These transmit pictures in a new format called HDTV (high definition television) which has higher resolution and a wider screen aspect ratio than analog. DTV makes more efficient use of scarce radio spectrum bandwidth, as several DTV channels can be transmitted in the same bandwidth as a single analog channel. In both analog and digital television, different countries use several incompatible modulation standards to add the video and audio signals to the radio carrier wave, https://en.wikipedia.org/wiki/Broadcasting https://en.wikipedia.org/wiki/Television_transmitter https://www.sciencefocus.com/science/why-do-live-events-transmit-faster-to-my-digital-radio-than-my-tv/
