“Band IV”的意思、由来-开放百科全书

Sources differ on the exact frequency range of the band. For example, the Swiss Federal Office of Communications,^[1] the Broadcast engineer's reference book^[2] and Ericsson India Ltd^[3] all define the range of Band IV from 470 to 582 MHz. An EICTA paper^[4] defines the range as 474 to 602 MHz, whilst the BBC define the range as 470 to 614 MHz.^[5] Band IV is primarily used for analogue and digital (DVB-T, ATSC and ISDB) television broadcasting, as well as services intended for mobile devices such as DVB-H.

Television

Australia

In Australia UHF channel allocations are 7 MHz wide. Band IV includes channels 28 to 35, with base frequencies of 529.5 MHz to 578.5 MHz. More details are available on the television frequencies page.

New Zealand

In New Zealand UHF channel allocations are 8 MHz wide. Band IV includes channels 25 to 35, with base frequencies of 506.0 MHz to 586.0 MHz. More details are available on the television frequencies page.

United Kingdom

In the UK, Band IV allocations are 8 MHz wide, traditionally consisting of 14 channels from UHF 21 to 34 inclusive. However, in the mid-1990s the squeezing of analogue Channel 5 broadcasts into the existing national terrestrial TV transmitter network effectively closed a gap between bands IV and V, which was previously reserved for radar applications and home consumer devices. This stretched the practical definition of Band IV in the UK to cover 18 channels from UHF 21 to 38 inclusive.^[6] Aerials of the group A type cover this band.^[7]

The following table covers the most inclusive definition of Band IV in the UK. Rows with a yellow background indicate channels which were not traditionally (before the mid-1990s) considered part of Band IV for TV broadcasting purposes and may not be considered part of the band in other countries (e.g. Switzerland^[1]).

References

1. ^¹²{{cite web|url=http://www.ofcomnet.ch/cgi-bin/rir.pl?id=0201;nb=52|title=Frequency characteristics and radio parameters|date=2009-01-01|accessdate=2009-05-17|publisher=Swiss Federal Office of Communications}}
2. ^¹{{cite book|title=Broadcast engineer's reference book|last=Tozer|first=Edwin Paul J.|authorlink=Edwin Paul J. Tozer|year=2004|publisher=Focal Press|isbn=0-240-51908-6|page=166|url=https://books.google.com/books?id=DL73f4vFeEwC&pg=PA166&lpg=PA166&source=bl&ots=9-fiFnLpJj&hl=en&oi=book_result&ct=result&resnum=10 |accessdate=2009-05-17}}
3. ^¹{{cite web|url=http://google.com/search?q=cache:9Ksg79GNnzQJ:www.iete.org/index1_files/IETEWorkshop13-03-09/ArifkhanUHF%2520Band%2520IETE%2520v2.ppt&cd=1&hl=en&ct=clnk&gl=uk|title=700 MHz: Spectrum Issues|year=2009|accessdate=2009-05-17|publisher=Ericsson India Ltd}}
4. ^¹{{cite web|url=http://www.ero.dk/60E93E59-F20F-4B60-8BDB-FA0EEB6E4BA3?frames=no& |title=TECHNICAL ASPECTS IN SPECTRUM ALLOCATION FOR DVB-UMTS CONVERGENCE TERMINALS |year=2003 |accessdate=2009-05-17 |publisher=DVB-UMTS Group and EICTA |deadurl=yes |archiveurl=https://web.archive.org/web/20070606225438/http://www.ero.dk/60E93E59-F20F-4B60-8BDB-FA0EEB6E4BA3?frames=no& |archivedate=June 6, 2007 }}
5. ^¹{{cite web|url=http://www.bbc.co.uk/reception/info/pdf/factsheet_tvaerials.pdf|title=Television aerials factsheet|accessdate=2012-07-07|publisher=British Broadcasting Corporation}}
6. ^{{cite web|url=http://www.digitalspy.co.uk/terrestrial/tuning/|title=UHF channel and frequency guide|accessdate=2007-05-17|publisher=Digital Spy Limited| archiveurl= https://web.archive.org/web/20070518172927/http://www.digitalspy.co.uk/terrestrial/tuning/| archivedate= 18 May 2007 | deadurl= no}}
7. ^{{cite web|url=http://www.aerialsandtv.com/aerials.html#aerialgroups|title=Aerial Groups / Widebands|accessdate=2009-05-17|publisher=A.T.V. (Aerials and Television)| archiveurl= https://web.archive.org/web/20090423063325/http://www.aerialsandtv.com/aerials.html| archivedate= 23 April 2009 | deadurl= no}}