The difference between 20MHz and 40MHz can be imagined as the width of the road. The wider the width, the more data it can run, which in turn increases the speed. But the "road" of wireless networks is shared by everyone. As you occupy a wider road and run more data, it is more likely to collide with others. Once you collide, everyone will slow down, even slower than walking on narrow roads.
Originally, squeezing at 20MHz could allow 4 people to use it at the same time, but if you use 40MHz, you can only use it for 2 people at the same time. 5G Industrial Router
So the question of which one is better is not related to the size of your house, but most importantly, how many people are walking with you nearby. Using scanning software can easily see the occupancy of the surrounding frequency bands.siemens industrial wireless router
So, Beijing Broadband Connect suggests that if there aren't many people nearby using it, congratulations, use 40MHz to enjoy high-speed!
If there are many vehicles around, it is best to find a lane with fewer vehicles and use 20MHz instead. Wifi 5 Ceiling Wireless Ap team industries routing guide
In addition, 40MHz requires support from customer terminals, otherwise it will still fall back to 20MHz mode. Older phones and laptops, as well as cheaper smart home products, do not support 40MHz.telstra turbo industrial router
Moreover, the 2.4GHz total frequency band is very narrow, with a total of 14 channels. There are 13 channels in China, and some devices only support 11 channels. One WiFi occupies two channels and causes significant interference, so it is generally recommended to use 20MHz for 2.4GHz WiFi; 5GHz WiFi can be used at 80MHz or 40MHz. For bridging, it is recommended that both the main router and the bridging router use 2.4GHz WiFi, 20MHz mode, and the same channel.teltonika rut240 industrial lte router
