Key takeaways:
Wi-Fi technology continues to improve and adapt as more connected equipment comes onto the scene. Homes, offices, retail establishments, universities, hospitals, and a range of other settings are now packed full of devices looking for a wireless connection. And it can be difficult to sustain all these connections, much less prioritize them.
Because of the traffic, congestion occurs. To meet these challenges, new standards have been introduced, devices have been improved, and Wi-Fi engineers employ dedicated techniques to chase better Wi-Fi performance for clients.
Band steering is not a part of these new standards. It is a proprietary tactic used to alleviate 2.4 GHz congestion. First, let’s walk through what dual-band access points are, followed by exploring how they use band steering to help Wi-Fi performance.
For years, there have been two unlicensed bands of frequency that Wi-Fi devices can use—2.4 GHz and 5 GHz. Access points (APs) transmit signals on these bands to user devices so they can connect to the internet.
Dual-band access points can simultaneously transmit on both the 2.4 and 5 GHz bands. Modern networks commonly use these APs to support newer devices and provide significantly more capacity.
Both bands are often necessary because the 2.4 GHz frequency is used by a lot of wireless gadgets, including those within the Internet of Things (IoT). This means that beyond smartphones and laptops, equipment like baby monitors, garage door openers, smartwatches, and even microwaves are using that same frequency.
In addition, very old routers and specific devices can only connect on the 2.4 GHz frequency. It has a longer reach than 5 GHz, but it's more vulnerable to interference because there are so many more users of the band.
Band steering encourages a client to attach to 5 GHz instead of 2.4 GHz. The 5 GHz band is less congested and has a higher capacity.
Why? It’s because the 2.4 GHz band has only three non-overlapping 20 MHz channels: 1, 6, and 11; the remaining ones overlap. And to achieve the desired data rates and speeds, there has to be a certain channel width. This means that there’s not a lot of room within those three channels to sustain the needed traffic, and they fill up fast.
Thus, it helps to steer people to the 5 GHz band when possible, where there are 24 non-overlapping 20 MHz channels. Connections are spread out, and users get faster Wi-Fi.
Band steering works by speeding delaying probe responses in 2.4 GHz. So, when a client comes along, it will probe in both bands and get a 5 GHz response first, increasing the likelihood it will connect in 5 GHz.
However, the way clients react to band steering is unpredictable, and it can cause undesirable results. Remember, band steering is proprietary; it’s not part of the 802.11 standard, so clients don’t have a standardized way of reacting to it. Some clients will still try to associate on the 2.4 GHz band, perhaps because they received a beacon from the AP in the band, and delaying probe responses to them can cause connectivity issues. These issues may repeat every time the client roams to another AP. So, band steering can have a negative impact on client connectivity because of this and other ways clients react.
When a WLAN has an undesirable balance of clients between the bands, the first thing to look at is the RF design. Make sure that the 5 GHz signal is at least 6 dB louder than the 2.4 GHz signal in most coverage areas. This can be accomplished by disabling 2.4 GHz radios that are providing redundant coverage (which will also reduce CCI), limiting the maximum Tx power an AP can use in 2.4 GHz, and also limiting the minimum Tx power an AP can use in the 5 GHz band.
With 7SIGNAL’s platform, you gain visibility into open channels, along with many more performance metrics. And just like driving on a highway, you can switch over to a channel for better service when you see an open lane.
Our solutions deliver unparalleled insight into end users’ digital experiences and provide actionable data to solve problems in real-time. 7SIGNAL’s wireless experience monitoring platform watches and tests Wi-Fi performance continuously from the device perspective. This reporting enables faster, better-informed solutions to congestion and many other issues, including the proper use of band steering.
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7SIGNAL® is the leader in wireless experience monitoring, providing insight into wireless networks and control over Wi-Fi performance so businesses and organizations can thrive. Our cloud-based wireless network monitoring platform continually tests and measures Wi-Fi performance at the edges of the network, enabling fast solutions to digital experience issues and stronger connections for mission-critical users, devices, and applications. Learn more at www.7signal.com.