来源:ACCA/CAT 发布时间:2012-02-04 ACCA/CAT视频 评论
为了帮助考生系统的复习ACCA考试全面的了解2011年ACCA考试的相关重点,小编特编辑汇总了2011年ACCA考试模拟试题,希望对您参加本次考试有所帮助!!
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
2011年ACCA/CAT历年真题
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