2013特许公认会计师考试模拟试题

时间:2013-12-12 15:16:00   来源:无忧考网     [字体: ]
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