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.
The 2.4 GHz Part 15 band in the US allows spread-spectrum operation as long as the 50 dB bandwidth of the signal is within the range of 2,400–2,483.5 MHz[11] which fully encompasses channels 1 through 13.
[12] Channels 12 and 13 are nevertheless not normally used in order to avoid any potential interference in the adjacent restricted frequency band, 2,483.5–2,500 MHz,[13] which is subject to strict emission limits set out in 47 CFR § 15.205.
Network operators should consult their local authorities as these regulations may be out of date as they are subject to change at any time.
The consideration of spacing stems from both the basic bandwidth occupation (described above), which depends on the protocol, and from attenuation of interfering signals over distance.
The primary 20 MHz channel is used for signalling and backwards compatibility, the secondary is only used when sending data at full speed.
Except where noted, all information taken from Annex J of IEEE 802.11y-2008 This range is documented as only being allowed as a licensed band in the United States.
However, not in the original specification, under newer frequency allocations from the FCC, it falls under the 3.55–3.7 GHz Citizens Broadband Radio Service band.
[56] In 2010, the FCC further clarified the use of channels in the 5.470–5.725 GHz band to avoid interference with TDWR, a type of weather radar system.
[60] Since this is the German implementation of EU Rule 2005/513/EC, similar regulations must be expected throughout the European Union.
[citation needed] Japan's use of 10 and 20 MHz-wide 5 GHz wireless channels is codified by Association of Radio Industries and Businesses (ARIB) document STD-T71, Broadband Mobile Access Communication System (CSMA).
[64] Additional rule specifications relating to 40, 80, and 160 MHz channel allocation has been taken on by Japan's Ministry of Internal Affairs and Communications (MIC).
Indoor Wireless Data Network (WDN) equipment and devices shall not use external antenna.
[71] China MIIT expanded allowed channels as of 3 July 2017[update] to add U-NII-3, 5725–5850 MHz.
Standard-power access points are permitted indoors and outdoors at a maximum EIRP of 36 dBm in the U-NII-5 and U-NII-7 sub-bands with automatic frequency coordination (AFC).
To help ensure they are used only indoors, these types of access points are not permitted to be connectorized for external antennas, weather-resistant, or run on battery power.
[83]: 41 The FCC may issue a ruling in the future on a third class of very low power devices such as hotspots and short-range applications.
In November 2020, the Innovation, Science and Economic Development (ISED) of Canada published "Consultation on the Technical and Policy Framework for Licence-Exempt Use in the 6 GHz Band".
[84] They proposed to allow licence-exempt operations in the 6 GHz spectrum for three classes of radio local area networks (RLANs): For indoor and outdoor use.
ECC Decision (20)01 from 20 November 2020[85] allocated the frequency band from 5945 to 6425 MHz (corresponding almost to the US U-NII-5 band) for use by low-power indoor and very-low-power devices for Wireless Access Systems/Radio Local Area Networks (WAS/RLAN), with a portion specifically reserved for rail networks and intelligent transport systems.
[89] Further consideration is also being given to releasing the upper 6 GHz band (6425 to 7125 MHz) for WLAN use as well, although nothing has been officially proposed at this time.
In March 2024, it was reported that the ACMA had begun industry consultation to lay the ground work to release the upper 6Ghz bands in the near future.
[91] In September 2022, the Ministry of Internal Affairs and Communications announced amendments to the ministerial order and notices related to the Radio Act.
[94] On May 23, 2024, the Philippines' National Telecommunications Commission (NTC) is considering the use of 5925 MHz to 6425 MHz frequency bands indoors with an effective radiated power (ERP) not exceeding 250 mW and outdoors with an effective radiated power not exceeding 25 mW.