- published: 05 May 2015
- views: 5491
There are two types of radio networks currently in use around the world: the one-to-many broadcast network commonly used for public information and mass media entertainment; and the two-way radio 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.
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 the range of coverage required by the jurisdiction or authority implementing the system: conventional wireless links in numerous frequency bands, fibre-optic links, or micro-wave 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.
Ronald Wilson Reagan (/ˈrɒnəld ˈwɪlsən ˈreɪɡən/; February 6, 1911 – June 5, 2004) was an American politician and actor, who served as the 40th President of the United States from 1981 to 1989. Prior to his presidency, he served as the 33rd Governor of California from 1967 to 1975, following a career as a Hollywood actor and union leader.
Raised in a poor family in small towns of Northern Illinois, Ronald Reagan graduated from Eureka College in 1932 and worked as a sports announcer on several regional radio stations. After moving to Hollywood in 1937, he became an actor and starred in a few major productions. Reagan was twice elected as President of the Screen Actors Guild, the labor union for actors, where he worked to root out Communist influence. In the 1950s, he moved into television and was a motivational speaker at General Electric factories. Having been a lifelong liberal Democrat, his views changed. He became a conservative and in 1962 switched to the Republican Party. In 1964, Reagan's speech, "A Time for Choosing," in support of Barry Goldwater's floundering presidential campaign, earned him national attention as a new conservative spokesman. Building a network of supporters, he was elected Governor of California in 1966. As governor, Reagan raised taxes, turned a state budget deficit to a surplus, challenged the protesters at the University of California, ordered National Guard troops in during a period of protest movements in 1969, and was re-elected in 1970. He twice ran unsuccessfully for the Republican nominations in 1968 and 1976; four years later, he easily won the nomination outright, going on to be elected the oldest President, defeating incumbent Jimmy Carter in 1980.