Author. On 5/23/2017 at 10:28 PM, CyberneticTitan said: In general, If 2.4Ghz -> 20Mhz. If 5Ghz -> 40Mhz. If you're fairly wirelessly isolated and you have modern devices, go for 40Mhz. My WiFi modem doesn't support 5GHz, however we are wirelessly isolated (at the moment, the three SSID's that are showing are all from our house) and our devices
20 MHz in 5 GHz lets you use channel 165 which generally is unused. I didn't realize this was a thing. I will consider testing it out for sure. That is a good tradeoff if the WiFi is your limiting factor. You really should try your normal activities wired to see if things improve. If you are maxing your upload wired will have the same problem.
The 5G frequency band plans are much more complex, as the frequency spectrum for sub-6 GHz 5G spans 450 MHz to 6 GHz, and millimeter-wave 5G frequencies span 24.250 GHz to 52.600 GHz, and also include unlicensed spectrum. Additionally, there may be 5G spectrum in the 5925 to 7150 MHz range and 64 GHz to 86 GHz range.
2.4 GHz WiFi 频段示意图. 2.4 GHz 频段范围内有每隔 5 MHz 分隔的频道14个（除了第14頻道与第13頻道相隔了 12 MHz）。 40 MHz 频段可以由两个相邻 20 MHz 频段组成。取决于哪个频带是主（控制）频带，哪个频带是从（扩展）频带，路由器可能会显示成 1+5、5+1、9+13、13+9。
5 Ghz Wi-Fi: When to Use 40 MHz. Use 40 MHz to strike a balance between minimizing interference and maximizing throughput. 40 MHz offers more throughput than 20 MHz. It still leaves room for a dozen or so non-overlapping channels. This enables you to improve performance relative to 20 MHz and without risking the interference associated with 80 MHz.
The differences in terms of range in the 5ghz band are insignificant. The lower end, the UNI-II band (channels 36, 40, 44, and 48) because they are "lower" than the UNI-IIExt band channels, will "travel" farther.but again, the differences are insiginificant in the grand scheme of things, and the better comparison is between the 2.4ghz band and the 5 ghz channels and obviously, the 2.4ghz
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difference between 20mhz and 40mhz wifi
