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      ACCA考試必做練習(xí)題1

      考試網(wǎng)  [ 2016年4月16日 ] 【

        ALLOCATION OF FREQUENCIES IN THE RADIO SPECTRUM

        In the United States the National Telecommunications and Information Administration (NTIA) has responsibility for assigning each portion of the

        radio spectrum (9 kHz to 300 GHz) for different uses. These assignments must be compatible with the rules of the International Telecommunications

        Union (ITU), to which the United States is bound by treaty. The current assignments are given in a wall chart (Reference 1) and may also be found

        on the NTIA web site (Reference 2). The list below summarizes the broad features of the spectrum allocation, with particular attention to those sections

        of scientific interest. The references should be consulted for details of the allocations in the frequency bands listed here, which in some cases are quite

        complex.

        REFERENCES

        1. United States Frequency Allocations, 1996 Spectrum Wall Chart, Stock No. 003-000-00652-2, U. S. Government Printing Office, P. O. Box

        371954, Pittsburgh, PA 15250-7954.

        2. http://www.ntia.doc.gov/osmhome/allochrt.html

        Frequency range Allocation

        9 - 19.95 kHz Maritime communication, navigation

        19.95 - 20.05 kHz Standard frequency and time signal (also at 60 kHz and 2.5, 5, 10, 15, 20, 25 MHz)

        20.05 - 535 kHz Maritime and aeronautical communication, navigation

        535 - 1605 kHz AM radio broadcasting

        1605 - 3500 kHz Mobile communication and navigation, amateur radio (1800-1900 kHz)

        3.5 - 4.0 MHz Amateur radio

        4.0 - 5.95 MHz Mobile communication

        5.95 - 13.36 MHz Mobile communication, amateur, short-wave broadcasting

        13.36 - 13.41 MHz Radioastronomy

        13.41 - 25.55 MHz Mobile communication, amateur, short-wave broadcasting

        25.55 - 25.67 MHz Radioastronomy

        25.67 - 37.5 MHz Mobile communication, amateur, short-wave broadcasting

        37.5 -38.25 MHz Radioastronomy

        38.25 - 50.0 MHz Mobile communication

        50.0 - 54.0 MHz Amateur

        54.0 - 72.0 MHz TV channels 2-4

        72.0 - 73.0 MHz Mobile communication

        73.0 - 74.6 MHz Radioastronomy

        74.6 - 76.0 MHz Mobile communication

        76.0 - 88.0 MHz TV channels 5-6

        88.0 - 108.0 MHz FM radio broadcasting

        108.0 - 118.0 MHz Aeronautical navigation

        118.0 - 174.0 MHz Mobile communication, space research, meteorological satellites

        174.0 - 216.0 MHz TV channels 7-13

        216.0 - 400.05 MHz Mobile communication

        400.05 - 400.15 MHz Standard frequency and time satellite (also 20 and 25 GHz)

        400.15 - 406.1 MHz Meteorological aids (radiosonde)

        406.1 - 410.0 MHz Radioastronomy

        410.0 - 470.0 MHz Mobile communication, amateur

        470.0 - 512.0 MHz TV channels 14-20

        512.0 - 608.0 MHz TV channels 21-36

        608.0 - 614.0 MHz Radioastronomy

        614.0 - 806.0 MHz TV channels 38-69

        806 -1400 MHz Mobile communication, navigation

        1400 - 1427 MHz Radioastronomy, space research

        1427 - 1660 MHz Various navigation and satellite applications

        1660 - 1710 MHz Radioastronomy, space research, meteorology

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