There are two types of radio network currently in use around the world: the one-to-many ( simplex communication ) broadcast network commonly used for public information and mass-media entertainment, and the two-way radio ( duplex communication ) type used more commonly for public safety and public services such as police , fire, taxicabs , and delivery services. Cell phones are able to send and receive simultaneously by using two different frequencies at the same time. Many of the same components and much of the same basic technology applies to all three.
10-752: The Saga Radio Group was a British radio network owned and operated by Saga Services Ltd , and aimed at an audience aged 50 and over. The first Saga station was launched in the West Midlands on 16 October 2001 and was subsequently followed by two others based in the East Midlands and Glasgow . The network won a fourth licence for the north east in 2006, but was sold in December of that year to Guardian Media Group , which decided to re-launch Saga along with its Smooth FM stations as Smooth Radio . All Saga stations were closed on Friday 23 March 2007, and Smooth Radio
20-434: A concept called trunking is commonly used to achieve better efficiency of radio spectrum use and provide very wide-ranging coverage with no switching of channels required by the mobile radio user as it roams throughout the system coverage. Trunking of two-way radio is identical to the concept used for cellular phone systems where each fixed and mobile radio is specifically identified to the system controller and its operation
30-590: A variety of networks. Radio networks rose rapidly with the growth of regular broadcasting of radio to home listeners in the 1920s. This growth took various paths in different places. In Britain the BBC was developed with public funding , in the form of a broadcast receiver license , and a broadcasting monopoly in its early decades. In contrast, in the United States various competing commercial broadcasting networks arose funded by advertising revenue. In that instance,
40-533: Is a term used in signal processing and mixed-signal system design to describe a series of signal-conditioning electronic components that receive input (data acquired from sampling either real-time phenomena or from stored data) sequentially, with the output of one portion of the chain supplying input to the next. Signal chains are often used in signal processing applications to gather and process data or to apply system controls based on analysis of real-time phenomena. This definition comes from common usage in
50-540: Is switched by the controller. The broadcast type of radio network is a network system which distributes programming to multiple stations simultaneously, or slightly delayed, for the purpose of extending total coverage beyond the limits of a single broadcast signal. The resulting expanded audience for radio programming or information essentially applies the benefits of mass-production to the broadcasting enterprise. A radio network has two sales departments, one to package and sell programs to radio stations, and one to sell
60-508: The audience of those programs to advertisers. Most radio networks also produce much of their programming. Originally, radio networks owned some or all of the stations that broadcast the network's radio format programming. Presently however, there are many networks that do not own any stations and only produce and/or distribute programming. Similarly station ownership does not always indicate network affiliation. A company might own stations in several different markets and purchase programming from
70-434: The range of coverage required by the jurisdiction or authority implementing the system: conventional wireless links in numerous frequency bands, fibre-optic links, or microwave links. In all of these cases the signals are typically backhauled to a central switch of some type where the radio message is processed and resent (repeated) to all transmitter sites where it is required to be heard. In contemporary two-way radio systems
80-537: The same corporation that owned or operated the network often manufactured and marketed the listener's radio. Major technical challenges to be overcome when distributing programs over long distances are maintaining signal quality and managing the number of switching/relay points in the signal chain . Early on, programs were sent to remote stations (either owned or affiliated) by various methods, including leased telephone lines, pre-recorded gramophone records and audio tape. The world's first all-radio, non-wireline network
90-596: Was claimed to be the Rural Radio Network , a group of six upstate New York FM stations that began operation in June 1948. Terrestrial microwave relay, a technology later introduced to link stations, has been largely supplanted by coaxial cable , fiber , and satellite , which usually offer superior cost-benefit ratios. Many early radio networks evolved into Television networks . Signal chain (signal processing chain) Signal chain , or signal-processing chain
100-703: Was launched the following Monday. Stations in the Saga network; Radio network The two-way type of radio network shares many of the same technologies and components as the broadcast-type radio network but is generally set up with fixed broadcast points ( transmitters ) with co-located receivers and mobile receivers/transmitters or transceivers . In this way both the fixed and mobile radio units can communicate with each other over broad geographic regions ranging in size from small single cities to entire states/provinces or countries. There are many ways in which multiple fixed transmit/receive sites can be interconnected to achieve
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