How many channels are available for the 5 ghz band?

What's the Difference - 2.4GHz vs. 5GHz Wireless?

Wireless technology for industrial applications has been a key factor in the success of the Industrial Internet of Things (IIoT). The rapidly deployable technology has given companies the ability to extend networking communications in areas where traditional wiring may be too expensive or not possible and has allowed for the introduction of new types of technology. This combination has led to increased productivity and expanded services, in a safer more efficient manner.

Primary Wi-Fi Signals

The IEEE 802.11 wireless communication standards we use today for industrial wireless routers have three different frequencies or bandwidths - 2.4GHz, 5Ghz, and in the near future 6Ghz. It is a good idea to have a basic understanding of how these frequencies operate to ensure you get the most out of your enterprise or operational wireless network.

Wireless Basics

All wireless communications operate using channels to transmit and receive data. These channels have a specified width (measured in megahertz) which determine the speed data can be sent and received. The width of these channels can be aggregated to increase speed and throughput of the data. However, by aggregating channel width you will reduce the channels available for use.

Wireless bandwidth is partly dependent on channel width and frequency. As a rule of thumb, the higher the frequency, the wider the channel, the faster your bandwidth speeds will be.

Characteristics of a Wireless Wave

2.4GHz, 5GHz, and 6GHz are wireless frequencies based on electromagnetic spectrum wavelengths. Each wavelength has its own characteristics for each frequency. The 2.4GHz wavelength is long and dense, making it a great choice for long distances or in areas with lots of obstructions and great for penetrating floors, drywall, concrete or steal. 5GHz has a shorter wavelength making it ideal for high-speed applications in open areas where obstructions are limited. 6GHz, is set to be the fastest of the three frequencies but we will have to wait and see.

Difference Between 2.4GHz and 5GHz

The 2.4GHz wireless spectrum consists of 14 channels, however, not all channels are available for use. Different countries have different regulation bodies that control which channels can be used. In North America, the FCC regulation permits the use of only channels 1 - 11, while channels 12 - 14 are not permitted.

The 11 available channels are 20MHz wide with a 5MHz of spacing between them. The 5MHz spacing causes channel overlapping which leads to poor connectivity and undesirable results. For these reasons, in North America, it is considered a best practice method to use only use channels 1,6,and 11 - the three non-overlapping channels. You can arrogate 2 x 20Mhz channels into 1 x 40Mhz channel for increased throughput, but this option restricts channel availability and is not recommended.

2.4Ghz supports IEEE 802.11b /g /n networking protocols. Each of these protocols use 20MHz channels, with the exception of 802.11n which can be used for both 20 and 40MHz channels.

The 5GHz spectrum uses 24 non-overlapping channels divided in four different sections UNII-1, UNII-2, UNII-2 extended, UNII-3, and ISM. Each section has its own recommended uses and restrictions. Each channel is also 20Mhz wide with 20MHz of space separating the channels.

5GHz uses a variety of channel widths allowing 20MHz, 40MHz, 80MHz, and 160MHz, unlike 2.4GHz which allows for only two channels widths (20Mhz & 40Mhz). The 5GHz also supports the IEEE 802.11a /n /ac networking protocols. The higher frequency combined with ultrawide channel width plus the latest 802.11ac standard makes 5GHz ideal for high-speed wireless networking.

However, there is a downside to the 5GHz spectrum. The higher frequency also means it is less susceptible to obstacles and has a shorter distance span between the transmitter and receiver.

Is 2.4GHz or 5GHz Wireless Better?

Applications that require higher bandwidth speeds should take advantage of the 5GHz wireless spectrum. 2.4GHz falls short of the speeds that 5GHz offers. However, if you require connectivity between two points at longer distances and speed is not an issue, or if you have legacy equipment that requires wireless connectivity or have large obstacles in between your transmitter and receiver then 2.4GHz would be your best choice.

If you’ve ever tinkered with your router, then there’s a good chance you did it to change the Wi-Fi channel because your Internet was too slow or perhaps because you’d read somewhere that Channel “X” (just an example; there isn’t a real Channel X) is the perfect one, free from other people and signal interference.

But now that most routers are shipping with the ability to transmit signals across 5GHz frequencies rather than just the lowly 2.4GHz, a big question that keeps coming up is “What’s the best 5GHz channel?” As with the 2.4GHz channels, there is no universal answer; it depends on the amount of people around you using the same channel and outside signal interference, among other things, but there are a few more things to consider if your router’s on the faster 5GHz frequency and to check for the best Wi-Fi channel for 5GHz connections.

There Are More Channels at 5 GHz

When you go into your router settings on a 5GHz frequency, you’ll see that you have quite a few more channels to pick from. The higher the channel, the higher the frequency, going up in increments of 5MHz per channel. This technically means the higher the frequency, the more data that can be carried on it in less time, but it’s not quite as simple as that, so before you just go and select the highest possible channel on your Wi-Fi router, there are a few things to consider.

At 5GHz there are four “Bands” available, each containing a bunch of Wi-Fi channels. Here’s an image to give you an idea. (The “ISM band is reserved for industrial, scientific, and medical use.) The first band, UNII-1, is designed mainly for domestic use, as from Unii-2 upwards, your router needs to have DFS (dynamic frequency selection) and TPC (transmit power control) built in, which will automatically adjust the channel and power output of your router so that it doesn’t interfere with military, radar, weather station signals, and so on.

Log in to your router, and you’ll be able to see which 5GHz channels are available to you. The 5GHz channels generally don’t overlap (unlike many of the 2.4GHz ones), because in many countries contiguous channels are “bonded” to have a higher bandwidth. This means that on your router you may see that the channels are all four numbers apart. There are 23 non-overlapping channels at 5GHz, as opposed to just three at 2.4GHz, making each channel equally good when it comes to not having interference from other channels.

Other Considerations

Sometimes, it also depends on the type of router you have. For instance, some newer routers, such as those supporting Wi-Fi 6, only have a dual-band mode. The router automatically assigns you either 2.4GHz or 5.0GHz based on current traffic, distance from the router, and interference. It may also mean you have to choose channels for both. However, these routers typically do an amazing job of choosing the right channel for your needs.

In this case, you’ll need to select a 2.4GHz channel as well. Ideally, 1, 6, and 11 are best, and you don’t have to deal with overlapping issues.

With Wi-Fi 6, there’s also the possibility of 6GHz, though that’s not really a thing just yet. However, once it is, this will add even more frequency space, making the need to manually choose channels unnecessary.

So Which Is the Best 5GHz Channel?

There is no universal best Wi-Fi channel for 5GHz frequencies, but there are ways to find out which one’s best for you. Download a Wi-Fi analyzer app, such as WiFiInfoView or WiFi Commander on PC, iStumbler or AirRadar on Mac, or WiFiAnalyzer for Android, then take a look at what the channel situation is in your area.

Are there a lot of people on the same channel as you? That could be slowing you down. If you’re using WiFiAnalyzer, tap the menu icon at the top left, then “Channel Rating,” and tap “5 GHZ” at the top of the screen. This will rate your channel based on the power of your signal, congestion and interference.

The higher channel numbers, operating at higher frequencies, tend to be used by radar, weather stations, and the military. If that happens while you’re using your Wi-Fi, then your signal may be bumped to another frequency. This shouldn’t be an issue, though it can cause momentary interference as your channel gets switched. There are also some old phone models that still operate at the higher frequencies/channels, though the likelihood of this affecting your signal is very small.

With all that said, perhaps it’s best to stick to the channels in the first “Band” I talked about earlier (36, 40, 44, 48), as these are designated for domestic use and are least likely to get interference from exterior factors. As these tend to be the “default” channels, there will be more people using them, which is why you should use a Wi-Fi checker to find which ones are least congested while offering you the best signal.

It’s important to note that if others in the area make changes, you may find your best current Wi-Fi channel for 5GHz needs to change too. If you start experiencing issues, consider analyzing your connection again and changing to another channel.

Wrapping Up

One of the big perks of 5G is that channel overlap is a virtual non-issue, so pretty much any channel you decide to use won’t be affected by it. With the amount of channels available, leaving your router on “Auto” is likely to place you on the best Wi-Fi channel for 5GHz at that moment. Should that not work, then the above tools and tips should guide you to the 5GHz channel that will make the most of your swanky modern router.

If you start to have issues with your router, try these troubleshooting steps to quickly get better connections.

Image: Wikimedia Commons/Abhi25t

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