Understanding Wi-Fi bands is vital to understanding when to use 20 MHz versus 40 MHz versus 80 MHz channel widths. It's also an important prerequisite to understanding WiFi channels and channel width. The two main Wi-Fi bands are 2.4 GHz and 5 GHz. These Wi-Fi bands are then split into channels for wireless devices to communicate on. In theory, 40Mhz has twice the channel bandwidth compared to 20Mhz, and the theoretical data transmission rate is also twice as high; However, from a practical application perspective, setting a higher bandwidth has a greater chance of conflicting with surrounding WiFi signals, which can affect the actual data transmission rate. Blog Cisco When and How to Use 20mhz vs 40mhz vs 80mhz When and How to Use 20mhz vs 40mhz vs 80mhz The word network is a simple word of seven letters, but is it that simple? Let's take a broader look to understand it rightly. If putting it simply, whenever we think of or talk about some inter-connected stuff or location, we refer it as a network. 20Mhz. -----. 20MHz is the most common Wi-Fi bandwidth as most users still opt to use 2.4GHz radios. 40Mhz. -----. In an environment with less congestion where a higher data throughput is required, using the 40MHz channel can be a good idea as it still offers 12 non-overlapping channels on 5GHz. 80Mhz. -----. There are only 13 20MHz channels in 2.4GHz, which quickly become congested due to many devices that, in turn, generate interferences. Thus, it's practically impossible to connect to 40MHz channels in that frequency band. Guys you can view my previous speed tests on 20MHz bandwidth here:-1) https://youtu.be/NfJIW_UQkKU .

difference between 20mhz and 40mhz bandwidth