Search results
Results from the WOW.Com Content Network
Channel spacing, also known as bandwidth [citation needed], is a term used in radio frequency planning. It describes the frequency difference between adjacent allocations in a frequency plan . Channels for mediumwave radio stations, for example are allocated in internationally agreed steps of 9 or 10 kHz : 10 kHz in ITU Region 2 (the Americas ...
An FM radio receiver's tuner spans a limited range of frequencies. A government agency (such as the Federal Communications Commission in the United States) may apportion the regionally available bandwidth to broadcast license holders so that their signals do not mutually interfere. In this context, bandwidth is also known as channel spacing.
Frequency deviation is used in FM radio to describe the difference between the minimum or maximum extent of a frequency modulated signal, and the nominal center or carrier frequency. The term is sometimes mistakenly used as synonymous with frequency drift , which is an unintended offset of an oscillator from its nominal frequency.
The original allocation of channels consisted of only channels 1 to 28 with 50 kHz spacing between channels, and the second frequency for full-duplex operation 4.6 MHz higher. Improvements in radio technology later meant that the channel spacing could be reduced to 25 kHz with channels 60 to 88 interspersed between the original channels.
The rules for second-adjacent-channel spacing do not apply for stations licensed before 1964. In 2017, Brazil laid the groundwork to reclaim channels 5 and 6 (76.1–87.5 MHz) for sound broadcasting use and required new radio receivers to be able to tune into the new extended band (Portuguese: faixa estendida, abbreviated eFM).
First restricted to 68–73 MHz with 100 kHz channel spacing, then in the 1970s eventually expanded to 65.84–74.00 MHz with 30 kHz channel spacing. [46] The use of FM for domestic radio encouraged listeners to acquire cheap FM-only receivers and so reduced the number able to listen to longer-range AM foreign broadcasters.
TETRA uses different channel spacing compared to GSM systems. The standard is 25 kHz spacing and the center frequency of each channel may be offset in a number of fashions such as ±12.5 kHz or even ±6.25 kHz. This makes it more tricky to correlate the ARFCN strictly to a pair of frequencies, you need to know the specifics of the system.
Wireless LAN (WLAN) channels are frequently accessed using IEEE 802.11 protocols. The 802.11 standard provides several radio frequency bands for use in Wi-Fi communications, each divided into a multitude of channels numbered at 5 MHz spacing (except in the 45/60 GHz band, where they are 0.54/1.08/2.16 GHz apart) between the centre frequency of the channel.