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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.
Wi-Fi (/ˈwaɪfaɪ/)[1][a] is a family of wireless network protocols based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio waves. These are the most widely used computer networks, used globally in home and small ...
- Limits
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The frequency boundaries of the radio spectrum are a matter of convention in physics and are somewhat arbitrary. Since radio waves are the lowest frequency category of electromagnetic waves, there is no lower limit to the frequency of radio waves. Radio waves are defined by the ITU as: "electromagnetic waves of frequencies arbitrarilylower than 300...
A radio band is a small frequency band (a contiguous section of the range of the radio spectrum) in which channelsare usually used or set aside for the same purpose. To prevent interference and allow for efficient use of the radio spectrum, similar services are allocated in bands. For example, broadcasting, mobile radio, or navigation devices, will...
Broadcasting
Broadcast frequencies: 1. Longwave AM Radio= 148.5 kHz – 283.5 kHz (LF) 2. Mediumwave AM Radio= 520 kHz – 1700 kHz (MF) 3. Shortwave AM Radio= 3 MHz – 30 MHz (HF) Designations for television and FM radio broadcast frequencies vary between countries, see Television channel frequencies and FM broadcast band. Since VHF and UHF frequencies are desirable for many uses in urban areas, in North America some parts of the former television broadcasting band have been reassigned to cellular phone and v...
Air band
Airband refers to VHF frequencies 108 to 137 MHz, used for navigation and voice communication with aircraft. Trans-oceanic aircraft also carry HFradio and satellite transceivers.
Marine band
The greatest incentive for development of radio was the need to communicate with ships out of visual range of shore. From the very early days of radio, large oceangoing vessels carried powerful long-wave and medium-wave transmitters. High-frequency allocations are still designated for ships, although satellite systems have taken over some of the safety applications previously served by 500 kHz and other frequencies. 2182 kHzis a medium-wave frequency still used for marine emergency communicat...
ITU-R Recommendation V.431: Nomenclature of the frequency and wavelength bands used in telecommunications. International Telecommunication Union, Geneva.IEEE Standard 521-2002: Standard Letter Designations for Radar-Frequency BandsAFR 55-44/AR 105-86/OPNAVINST 3430.9A/MCO 3430.1, 27 October 1964 superseded by AFR 55-44/AR 105-86/OPNAVINST 3430.1A/MCO 3430.1A, 6 December 1978: Performing Electronic Countermeasures in the Unit...RF and microwave filter. Radio frequency (RF) and microwave filters represent a class of electronic filter, designed to operate on signals in the megahertz to gigahertz frequency ranges ( medium frequency to extremely high frequency ). This frequency range is the range used by most broadcast radio, television, wireless communication (cellphones ...
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limited to 2.5 milliwatts, giving it a very short range of up to 10 metres (33 ft).
See media help. The International Radiotelephony Spelling Alphabet or simply Radiotelephony Spelling Alphabet, commonly known as the NATO phonetic alphabet, is the most widely used set of clear-code words for communicating the letters of the Roman alphabet. Technically a radiotelephonic spelling alphabet, it goes by various names, including ...
Information and communications technology ( ICT) is an extensional term for information technology (IT) that stresses the role of unified communications [1] and the integration of telecommunications ( telephone lines and wireless signals) and computers, as well as necessary enterprise software, middleware, storage and audiovisual, that enable ...
