Understanding of Wi-fi bands

To choose the right channel bandwidth, a person should know the wi-fi band; only then can they analyze how much channel bandwidth is available and how they can effectively use it without any interference (distortion).

2.4GHz and 5 GHz bands are available for wi-fi.

2.4 GHz Wi-Fi band: In the 2.4 GHz band, the available bandwidth is 100 MHz, with a range of 2.4-2.5 GHz (2400-2500MHz). So, the total available bandwidth is 100 MHz, so the channel width is also allocated accordingly so that there is no overlapping between channels. If we allocate 20 MHz channels, then we can allocate 4 channels only if we make more than 4; otherwise, there will be overlap between the channels, and at the time of transmission, interference will take place.

5 GHz Wi-fi band: The 5 GHz band covers a range of 5725-5875 MHz, so we have a total bandwidth of 150 MHz. Unlicensed National Information Infrastructure (UNII) widens this 150 MHz band up to 750 MHz. So, as in the 5GHz band, we have more channel bandwidth; here, we can allocate more channels, so you can understand that the number of channels mainly depends on available bandwidth. Here, we have a total bandwidth of 750 MHz, so we can allocate more channels.

2.4GHz and 5GHz: Which is to use?

If you want long-distance coverage and high-speed connection, both things at the same time, then you should use both 2.4 and 5GHz bands.

5GHz is faster: The 5GHz band provides higher upload and download speeds than the 2.4 GHz band. Also, here you can create more channels without any overlap. For high-speed gaming applications and high-quality video streaming, the 5GHz band is a good choice. However, it doesn’t provide reachability across the walls. 

 2.4 GHz provides high reachability: The 2.4 GHz band frequencies are good at passing through solid objects. In simple words, it covers more distance than the 5 GHz wi-fi band.

You can use both: By using dual-band routers, you can implement 2.4 GHz and 5 GHz at the same time. Dual-band routers allow some devices to use the 2.4 GHz band and some devices to use the 5GHz band.

What is wi-fi channel width?

Channel width is the difference between the lower frequency and the higher frequency. Here, lower frequency means the starting frequency of the channel, and higher frequency means the last frequency of that channel.

20 MHz and 40 MHz: what is the difference?

1. The main difference between 20 MHz and 40 MHz is the channel width difference. 20 MHz and 40 MHz both represent the channel width; 20 MHz means the channel is 20 MHz wide, and 40 MHz means the channel is 40 MHz wide.

2. 40 MHz channel has a higher throughput than the 20 MHz channel.

3. All wi-fi clients support 20 MHz channel bandwidth, so there is no compatibility issue. While other channels (40 MHz, 80 MHz), all devices don’t support these channels, so there may be a compatibility issue.

4. 20 MHz channels are referred to as the narrow channel or narrow bandwidth channel, while 40 MHz and 80 MHz channels are referred to as wideband channels.

What is a dual-band wi-fi router?

Nowadays, dual-band routers are very common; these routers support both 2.4 and 5 GHz wi-fi bands. So, this way, by using a dual-band router, you can take advantage of both bands. The 5 GHz band will provide you with low interference and high internet speed, while the 2.4 GHz band will provide you with more reachability.

When to use 20 MHz, 40MHz, and 80 MHz

We have discussed all the things that you should know to make a decision on which channel bandwidth we should use. Now, come back to our main point, and let’s understand when to use which channel?

2.4 GHz Wi-Fi: For 2.4 GHz, a 20 MHz channel width is the right choice. As in this band, we have only 100 MHz bandwidth, if we go for 40 MHz or 80 MHz, then the number of channels is 2 or 1, respectively. By using a 20 MHz channel width, we can make 4 channels without overlapping.

5 GHz Wi-Fi: For 5 GHz, a 40 MHz channel width is the right choice. There are other conditions, too, in which you can use 20 MHz or 80 MHz.

5 GHz Wi-fi: When to use 20 MHz: Channel width choice is mainly dependent on the application. When there is a requirement for more channels, we use a 20MHz channel. In a high-density populated area and where interference is the main concern, 20 MHz is the right choice.

5 GHz Wi-Fi: when to use 40 MHz: When we require minimizing interference and more throughput, in that case, we use 40 MHz because 40MHz provides more throughput than 20 MHz.

5 GHz Wi-Fi: when to use 80 MHz: We use 80 MHz when interference is not a big issue, or the wi-fi client is close to the router, but we need more throughput.

How to automate Wi-Fi channel and width selection

Channel width choice is mainly dependent on the application. When there is a requirement for more channels, we use a 20MHz channel. In a high-density populated area, where interference is the main concern, 20 MHz is the right choice.

Wrapping Up:

This way, you can understand that throughput and interference are two important parameters on the basis that the channel width is selected. In short, when we need more throughput, we go for higher channel bandwidth (40 or 80 MHz), and when interference is the main concern and we need more channels in that case we use a smaller channel width (20 MHz). There are some secondary parameters too- number of channels, speed, and more distance coverage.