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The 800 MHz frequency band is a portion of the electromagnetic spectrum, or frequency band, that encompasses 790–862 MHz.. Being a part of the spectrum known as "UHF Bands IV and V" (i.e. 470 MHz to 862 MHz) it was allocated by the ITU to Broadcasting as the primary user in Region 1 and was used for analogue television broadcasting before changing to digital terrestrial television in many ...
(MHz) Common name Subset of band Uplink [C 2] (MHz) Downlink [C 3] (MHz) Duplex spacing (MHz) Channel bandwidths (MHz) Notes 6 FDD 800 UMTS 800 5, 19, 26 830 – 840 875 – 885 45 5, 10 9 FDD 1800 UMTS 1700 3 1749.9 – 1784.9 1844.9 – 1879.9 95 5, 10 10 FDD 1700 Extended AWS 66 1710 – 1770 2110 – 2170 400 5, 10, 15, 20 22 FDD 3500 C ...
In 2004 the FCC developed a new band plan where narrowband operations are provided in 806–816 and 851–861 MHz ranges while wideband operations are allowed in 817–824 MHz and 862–869 MHz separated from narrowband services by a 1 MHz wide guard band. [6] The wideband services part of the SMR band was called ESMR (Enhanced SMR).
The idea to give each band a number, in which the number is the logarithm of the approximate geometric mean of the upper and lower band limits in Hz, originated with B. C. Fleming-Williams, who suggested it in a letter to the editor of Wireless Engineer in 1942. For example, the approximate geometric mean of band 7 is 10 MHz, or 10 7 Hz. [14]
Many GSM phones support three bands (900/1,800/1,900 MHz or 850/1,800/1,900 MHz) or four bands (850/900/1,800/1,900 MHz), and are usually referred to as tri-band and quad-band phones, or world phones; with such a phone one can travel internationally and use the same handset. This portability is not as extensive with IS-95 phones, however, as IS ...
As a more recent example the Apple iPhone 5 and iPhone 4S support quad-band GSM at 850/900/1800/1900 MHz, quad-band UMTS/HSDPA/HSUPA at 850/900/1900/2100 MHz, and dual-band CDMA EV-DO Rev. An at 800/1900 MHz, for a total of 'six' different frequencies (though at most four in a single mode).
During World War II, the frequencies originally assigned as channels 13 to 18 were appropriated by the U.S. military, which still uses them to this day. It was also decided to move the allocation for FM radio from the 42-50 MHz band to a larger 88-106 MHz band (later extended to the current 88-108 MHz FM band).
This page was last edited on 4 November 2023, at 10:12 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.