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As Internet service diffuses, national and local governments are linking homes via fiber optic cable throughout the country. The incorporation of a technology called wavelength division multiplex makes feasible the transmission of broadcast-wave signals in addition to communications such as on the Internet, using a single fiber optic cable. This wavelength division multiplex technology is therefore a promising technology to complement broadcasting services via radio wave, such as those of digital terrestrial broadcasting transmissions.
Examinations are also underway on a scheme that will convert transmitted optical signals to millimeter waves, to accommodate areas or homes where the establishment of optical fiber proves difficult. |
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Wavelength division multiplex technology |
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Wavelength division multiplex technology multiplexes optical signals with different wavelengths for transmission over a single fiber optic cable. Individual wavelengths can be allotted to a broadcasting service or a communications service, to deliver them to homes via one cable. This system employs a total of three wavelengths, one for broadcast waves and two for Internet uplink/downlink communications.
The broadcast-wave signal is superimposed with a millimeter-wave carrier on the digital terrestrial broadcasting broadcast waves. Homes with an optical fiber connection can receive the digital terrestrial broadcasting signal by linking a home optical receiver to a fiber optic cable network. Where a cable connection is not feasible, it converts the transmitted optical broadcast-wave signal to millimeter-waves for transmission.
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Optical fiber cable network for broadcasting |
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The broadcast-wave signal is superimposed with a millimeter-wave carrier on the digital terrestrial broadcasting broadcast -waves. Homes with an optical fiber connection can receive the digital terrestrial broadcasting signal by linking a home optical receiver to a fiber optic cable network. Where a cable connection is not feasible, it converts the transmitted optical broadcast-wave signal to millimeter-waves for transmission.
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