Wifi 7 Bands

[Christopher]

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. The standards allow for channels to be bonded together into wider channels for faster throughput.

802.11ah operates in sub-gigahertz unlicensed bands. Each world region supports different sub-bands, and the channels number depends on the starting frequency on the sub-band it belongs to. Therefore there is no global channels numbering plan, and the channels numbers are incompatible between world regions (and even between sub-bands of a same world region).

14 channels are designated in the 2.4 GHz range, spaced 5 MHz apart from each other except for a 12 MHz space before channel 14.[2] The abbreviation F0 designates each channel's fundamental frequency.

.mw-parser-output .citationword-wrap:break-word.mw-parser-output .citation:targetbackground-color:rgba(0,127,255,0.133)^A In the 2.4 GHz bands bonded 40 MHz channels are uniquely named by the primary and secondary 20 MHz channels, e.g. 9+13. In the 5 GHz bands they are denoted by the center of the wider band and the primary 20 MHz channel e.g. 42[40]

Nations apply their own RF emission regulations to the allowable channels, allowed users and maximum power levels within these frequency ranges. Network operators should consult their local authorities as these regulations may be out of date as they are subject to change at any time. Most of the world will allow the first thirteen channels in the spectrum.

Interference happens when two networks try to operate in the same band, or when their bands overlap. The two modulation methods used have different characteristics of band usage and therefore occupy different widths:

While overlapping frequencies can be configured at a location and will usually work, it can cause interference resulting in slowdowns, sometimes severe, particularly in heavy use. Certain subsets of frequencies can be used simultaneously at any one location without interference (see diagrams for typical allocations). 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. In the worst case, using every fourth or fifth channel by leaving three or four channels clear between used channels causes minimal interference, and narrower spacing still can be used at further distances.[18][19] The "interference" is usually not actual bit-errors, but the wireless transmitters making space for each other. Interference resulting in bit-error is rare.[19] The requirement of the standard is for a transmitter to yield when it decodes another at a level of 3 dB above the noise floor,[20] or when the non-decoded noise level is higher than a threshold Pth which, for Wi-Fi 5 and earlier, is between -76 and -80 dBm.[19]

The division into 5 MHz channels consumes all eight possible channel numbers, and so (unlike other bands) it is not possible to infer the width of a channel from its number. Instead each wider channel shares its channel number with the 5 MHz channel just above its mid frequency:

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).[68] 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).[69]

In the Philippines, the National Telecommunications Commission (NTC) allows the use of 5150 MHz to 5350 MHz and 5470 MHz to 5850 MHz frequency bands indoors with an effective radiated power (ERP) not exceeding 250 mW. Indoor Wireless Data Network (WDN) equipment and devices shall not use external antenna. All outdoor equipment/radio station whether for private WDN or public WDN shall be covered by appropriate permits and licenses required under existing rules and regulations.[73]

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".[87] They proposed to allow licence-exempt operations in the 6 GHz spectrum for three classes of radio local area networks (RLANs):

ECC Decision (20)01 from 20 November 2020[88] allocated the frequency band from 5925 to 6425 MHz (corresponding 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]

Since July 2020, the UK's Ofcom permitted unlicensed use of the lower 6 GHz band (5925 to 6425 MHz, corresponding to the US U-NII-5 band) by Low Power indoor and Very Low Power indoor and mobile Outdoor devices.[90][91]

In December 2022, Russian State Commission for Radio Frequencies authorised 6 GHz operation for low-power indoor (LPI) use with transmitter power control (TPC) limited to maximum EIRP of 200 mW and maximum PSD of 10 mW/MHz, and very low power (VLP) indoor and mobile outdoor use with maximum EIRP of 25 mW and maximum PSD of 1.3 mW/MHz.[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.[96]

Wireless interface really looks like wired interface once connected. I mean when you're done with authentication, your wireless connection will emulates a wired connection, and you should "see" the network as you were connected with a wire on the router.

On this router, there is an option to prevent client to client communication connected on the same wireless interface, named Set AP isolated in the Wireless>Professional tab (reference).

Yes... The key to remember here, at least in this instance, is that the WiFi connection is just layers 1 & 2 connection to the network regardless of the band involved, meaning in layman's terms it is taking the place of a wired Ethernet connection. To the rest of the devices in the network, it is just another node. The fact it is wired or wireless is not relevant. The actual IP connection at layer 3 and all higher layers are identical to a wired client.

Unless some other factor is involved (like AP Isolation), all nodes, both wired and wireless, are on the same network, meaning the rules of them communicating with each other are the same regardless of the underlying connection.

Yes that will work, since they're both connecting to the same IP subnet. (I assume) The wifi bands are comparable to having two different types of cables, for instance one being a cat.5e and another being cat.6 - both devices will connect to the same ip subnet but with different connection speeds.

The Chromecast will work better on the less congested 5 GHz band. In order to make it use that band you must set it up (in peer-to-peer mode, not via the router) with a device (phone, tablet) that uses the same 5 GHz band at that time. Later you can mix WiFi bands, just not during the setup.

But ignoring everything else and only replying to your question, it doesn't matter if you are connected to 2.4 GHz or 5 GHz since you are connecting to the same access point you will be able to communicate with other hosts which are connected with different broadcast frequency.

Now, since cracking just one of the two means that the attacker would gain access to my network anyways without needing the other one, are there any reasons why I should set a different password for each band?

Sure there is! In the absence of a "guest" SSID feature on your router, use one of the bands for guests/visitors, and the other band for private use. That way you can regularly change the password for the guest/visitor WiFi without disrupting connectivity on your own devices.

Two passwords instead of one means the attack surface is doubled. I don't think it would benefit you in any way to secure your bands with different passwords. Having two passwords instead of one means that if one gets leaked or known, the other may be compromised as well. The only reason I can think of to do this is if you have a situation where you want to let one group use one band, and another use the other. That way you would provide them with different access credentials, but for personal use, it is not recommended.

I have an HP Spectre x360 15t with Intel Dual Band Wireless-AC 8265 and I seem to have trouble maintaining a stable wireless connection when I move further away from the wifi router. I use a tri-band Linksys router supporting 2.4 and 5 Ghz bands. The problem occurs when I move from the living room, which is close to the router and gets a strong 5Ghz signal, to my office which is further away from the router. My house is no very large but I'd guess it's about 50 feet from the office to the router. In the office, the laptop will start using a 2.4Ghz band and have a good signal. No problem. Then, for reasons I haven't determined, will switch to the 5Ghz band and the signal quality drops dramatically. After some time, it might decide to switch back again. This is causing drops, slowness, etc. and is quite frustrating. I am using the same SSID on each band and I understand the device will try to use the best connection, but it should always be using the 2.4Ghz band in my opinion and never get confused. Is there a way to ensure its using the right band without having different SSIDs?

I have multiple routers in my home (to handle issues between multiple stories rather than distance) and initially I set them up so that the same SSIDs were used by both (though, in my case, it was one SSID for 2.4GHz and another for 5.0GHz). What I found is that this caused confusion in my portable devices (both laptop and Samsung phone) and it would stick with a connection rather than switch to a better one when I moved around. I found that reconfiguring with separate SSIDs alleviated this confusion.

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