2013年1月6日星期日

About Two-Way Radios

2 way radios are radios which can receive and transmit, in contrast to broadcast receivers which can only receive. They are available in stationary, mobile and hand-held configurations. The hand-held versions of two-way radios are often called walkie-talkies. Cell phones are also considered two-way radios, as they can both transmit and receive data simultaneously.
History
The first two-way radio technology was available as early as 1907. In 1912, military and commercial ships were equipped with two-way radios. The first mobile two-way radios were introduced in 1923 in Australia by a Senior Constable of the Victorian Police. The first units were installed in Victorian police cars and took up the entire back seat. In 1933, the technology spread to the United States, where the Bayonne, New Jersey police department installed two-way radios into its police cars. They were also widely used amongst ground and air troops during World War II. Today, two-way radios are compact and easy to use for a variety of personal and commercial purposes.
Function
Two-way radios are used to facilitate contact between two or more parties when visibility or distance is an impeding factor. They are practical devices for staying connected to a group. Police and fire stations, security personnel and even soldiers in the military utilize two-way radios.

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