Wireless networks include a number of different technologies. In this video, you’ll learn about wireless frequencies and channels, band steering, and regulatory impacts.
We’ve become so accustomed to wireless networks being available that we often forget that there’s a lot of work that happens behind the scenes to create these wireless connections. This work is done primarily by the Institute of Electrical and Electronics Engineers, or the IEEE. There’s a committee in the IEEE called the 802.11 committee, and that is the committee that focuses on creating worldwide standards for wireless networking.
In the past, we’ve referred to the standards name to be able to describe the network. For example, we’ll describe 802.11ac, 802.11ax, or 802.11be. The IEEE committee realized that these numbers and letters combinations weren’t very appealing for most people, so they’ve also assigned separate names that are a little easier to keep track of. For example, 802.11ac is Wi-Fi 5, 802.11ax is Wi-Fi 6 and Wi-Fi 63, the extended version of Wi-Fi 6, and 802.11be is also called Wi-Fi 7.
As additional major releases of the 802.11 wireless standards are released, they will also increment those Wi-Fi numbers. So in the future, we should see Wi-Fi 8, Wi-Fi 9, and so on.
There are a number of technologies used by 802.11 wireless networking. And the first is the frequencies that are in use. 802.11 commonly uses 2.4 gigahertz, 5 gigahertz, and 6 gigahertz frequency ranges. Sometimes there’s a combination of those. You may have an access point that supports both 2.4 and 5 gigahertz, and some access points may support all of those frequencies at the same time.
Instead of having to memorize individual frequency numbers, the IEEE has created groupings of these frequencies known as channels. These channels help us easily understand what frequencies we may be using. For example, on this access point, we’re using both the 2.4 gigahertz range and the 5 gigahertz range. The 2.4 gigahertz range is using channel 6, which is centered on 2.437 gigahertz, and the 5 gigahertz band is using channel 44, which is centered on 5.220 gigahertz.
You can see that referring to this as channel 6 is much faster and more efficient than saying that this particular access point is centered on 2.437 gigahertz.
The amount of frequency that we use is referred to as the wireless bandwidth. And when I say that channel 6 is centered on 2.437 gigahertz, there’s actually more frequencies that we’re using for that single channel. Different frequency bands have different sizes of bandwidths that can be used, but it’s very common to see 20 megahertz, 40 megahertz, 80 megahertz, and 160 megahertz bandwidths.
Here’s a diagram that shows the 2.4 gigahertz range, the 5 gigahertz range, and the 6 gigahertz range that’s used by 802.11 wireless networks. We’ll start with the 2.4 gigahertz spectrum. You can see there are three nonoverlapping channels in that particular range, and it’s using the 20 megahertz bandwidth to describe those three channels.
Next is the 5 gigahertz spectrum. And you can see there are many more frequencies available in the 5 gigahertz range. You’ll also notice that we might use different bandwidths depending on the access point that we’re using. So we might use anywhere from 20 megahertz to 160 megahertz. And you can see the ranges that are available for those particular frequencies. And in the 6 gigahertz range, we have even more frequencies available, giving us options to be able to transmit and use these wireless networks without conflicting with other wireless networks that might be nearby.
As you can tell, there are many frequencies available to choose from for your wireless networks, but not every frequency is going to be the best one to use. There may be differences in the environment where you happen to be where one frequency might work better than the other, or there may be other access points that are already using certain frequencies. You might also be using older devices that aren’t able to communicate on the 5 or 6 gigahertz ranges and may only be able to communicate on 2.4 gigahertz frequencies.
But if you have a modern wireless device, you might have options. Your phone, for example, may be able to support two or more different types of frequencies. It just needs to be able to choose the optimal frequency for where you happen to be. Your access points can be set up with a feature known as band steering. This allows you to specify how the users might be able to use the frequencies in the best possible way.
For example, you might have a user that has a mobile phone, and that phone can support either a 2.4 gigahertz connection or a 5 gigahertz connection. And you might have access points that also support both of those frequencies. So which frequency does your phone choose when it’s connecting to that access point? If band steering is not configured in the access point, the device will simply use the one that has the best possible signal.
Sometimes that best signal will provide you with the best throughput, but that’s not always the case. And you may find that you get better throughput using a different frequency, even though that frequency may not be the one that has the strongest signal. If band steering is turned on, the administrator of the access point can determine what frequency a user will choose if they have a choice. For example, if a user is connecting to an access point with band steering enabled and that device can support either 2.4 gigahertz or 5 gigahertz, you can force it or steer it into using the 5 gigahertz frequencies by default.
One of the challenges with these wireless networks is that each country makes its own decisions about how this wireless bandwidth is to be used. For example, in the United States, we have the Federal Communications Commission, and they are responsible for managing all of the frequency allocations in the US. Of course, the FCC can’t control how other countries manage their frequencies, but they do work very closely with other countries around the world to make sure that everyone is properly managing these very important frequencies.
Another challenge with this is that we are coming up with new technologies and new ways to use these frequencies all the time, and we sometimes have to make sure that different services can use similar frequencies without any type of conflict.
The popularity of these wireless networks has almost required that all of these countries work together to come up with standards that everyone can agree on. A good example of these organizations working together can be found in the 802.11h standard. This adds a number of interoperability features to 802.11 wireless networks so that you can have many different wireless networks in one area but still allow all of those networks to work together.
There are a series of guidelines for wireless communications that are published by the International Telecommunications Union. The ITU provides a worldwide approach to managing these many different wireless technologies. One of the things that is included in these standards is called DFS. This is Dynamic Frequency Selection. This allows our wireless access points to use frequencies that are not going to conflict with other access points that may already be operating.
This is one of the reasons that when you turn on your wireless access point today that you don’t have to manually configure any of the wireless settings inside of that device. It automatically looks at the frequencies that are in use and chooses a series of frequencies for you that are not going to conflict with anything that may already be operating. And if something does change with the wireless environment and your access point needs to change its channel, it will tell all of the devices on that network to also move along with the access point.
Another interoperable feature is TPC, or the Transmit Power Control. Traditionally, we’ve set the power that we would use for these wireless networks on our clients. But TPC puts the transmit power control in the hands of the access point. This means that the access point can tell a client to use less power to be able to communicate over this wireless network. This means that we can have many devices communicating at their optimal power level without having any type of conflict with other third-party services.