The Difference Between Good and Great Wi-Fi

Wi-Fi is ubiquitous but performance is not. We’ve all visited somewhere where the Wi-Fi is bad, maybe it was a hotel room, an airport or maybe even in your workplace. When the Wi-Fi is bad it’s very obvious for the user, internet browsing is slow, applications don’t work as they should, and the general experience is poor.

What about when the Wi-Fi is not performing as well as it could but is “good enough”, is this acceptable and does it warrant time to improve it?

This article explores the difference between good and great Wi-Fi and asks the questions if we can settle for good enough.

Wi-Fi won’t go down without a fight

Wi-Fi is an exceptionally robust technology; it is designed to keep you connected even when conditions aren’t quite optimal. Wi-Fi has always had to contend with other devices using the unlicensed spectrum. There is a plethora of devices that use the same frequencies as Wi-Fi. These devices, other Wi-Fi networks and even sometime our own Wi-Fi networks can be the cause of performance degradation. For these reasons the Institute of Electrical and Electronics Engineers (the creators of Wi-Fi) designed Wi-Fi with robust contention mechanisms to keep thing moving even when there are issues. Moreover Wi-Fi 7 introduces more technologies like Multi-RU Puncturing to make Wi-Fi even more resilient!

All good Wi-Fi engineers will know the frustration of recommending against a certain practice, only to be told that it still works when their advice is not followed. The truth is that it likely does still work because of the robust nature of Wi-Fi but is likely not working at its optimal.

If you place APs above ceiling tiles or in hallways it will reduce the signal strength. Using excessively wide channels or overlapping channels will cause more retries. Broadcasting a large number of SSID or using a low minimum bitrate will increase airtime. But none of these will stop Wi-Fi from working, it just simply degrades performance.

Your Wi-Fi might not but perfect, but does it matter?

If your Wi-Fi is working, should you care that your Wi-Fi is not at its best? It depends on the importance of the Wi-Fi network. There are some networks where Wi-Fi isn’t very important, maybe the Wi-Fi connections only used for employee personal devices or provided as a best effort free service. But there are many networks and at increasing number that heavily rely on Wi-Fi for processing orders, picking stock, conducting meetings and many other important tasks. For these networks it is imperative that Wi-Fi works and works well.

Moreover, what is good enough today may not be good enough for tomorrow. More and more devices are coming into networks daily, and as more applications move to the cloud, so does the requirement to send more data over the network.

Knowing how your Wi-Fi is performing, and its available scope for increasing density and throughput should be a known entity. As this is crucial to form correct decision regarding your IT strategy. It can also highlight issues before they arise. For example, are certain APs experiencing an overly high number of concurrent client connections or are any channels suffering from high channel utilisation. These metrics can help you identify issues before they become issues, but unless you actively seek out this information, it won’t be obvious. So, when Wi-Fi is a critical part of the business, always recommend regular health checks.

A good analogy is servicing a car, servicing a car minimises the risk of failures. Why shouldn’t we take the same proactive approach with Wi-Fi?

So, how do I go from good to great Wi-Fi?

There is no one size fits all solution here and there are no shortcuts either. You must first start with an assessment of your current Wi-Fi setup. This can take part in two forms a wireless survey this validates the RF environment, which includes everything from signal strength, neighbouring Wi-Fi networks and RF interference. Second is an audit of the configuration of your current Wi-Fi setup. Is the Wi-Fi infrastructure up to date with the latest firmware version and how is each SSID and radio configured. This will give you a baseline that you can compare against industry best practices.

The below lists serves as a guide for best practices, however as already mentioned there is no one size fits all so it is strongly recommended to conduct your own research that will determine what is possible and the best practices for your networks requirements and goals.

• Primary Signal Strength should be equal or greater than -67dBm
• Secondary Signal Strength should be equal or greater than -67dBm
• Reduce 2.4GHz channel overlap should be no more than 3 Access Points
• Reduce 5GHz and 6GHz channel overlap should be no more than 1 Access Point
• Use 20MHz wide channel for 2.4GHz
• Use 20MHz wide channels for 5GHz and only use 40MHz if you can avoid co-channel interference
• Use 20/40MHz wide channels for Europe and 80MHz wide channels for USA
• Minimum Bit Rate on 2.4GHz should equal 11Mbps or greater
• Minimum Bit Rate on 5GHz and 6GHz should equal 12Mbps or greater
• Use channel 1, 6 and 11 only on 2.4GHz
• Avoid using channel 144 and 165 on 5GHz if client devices don’t support it
• Channel utilisation should not regularly exceed 50%
• Transmit power should match the least capable most important device and generally not exceed 17dBm
• SSID count should remain as low as possible, ideally not more than 4 on a single radio
• Avoid the use of hidden SSIDs
• Use WPA3 when possible, if necessary, fall back to WPA2
• Enable Client Isolation on guest networks
• Enable 802.11k and 802.11r
• Avoid the use of transmit beamforming
• Enable AP Background Scanning alongside RRM
• RRM should be tightly controlled to use of unwanted transmit powers or channels
• All APs should be serviced with appropriate PoE standard (varies per AP)
• All APs should be connected with at least a 1Gbps wired connection
• Avoid meshing
• Wi-Fi infrastructure should be running the stable firmware release

Achieving every item on the above list may not be possible and may not be necessary depending on the requirements of your network. But this can act as a good guide to make necessary improvements to your Wi-Fi network moving you from good to great Wi-Fi. It is also important to stress that this review of Wi-Fi performance should be regularly undertaken, configuration changes over time, a build layout can also change with walls added and removed or the use of a room changing, and newer firmware is always forthcoming.

With the ever-increasing reliance on Wi-Fi for critical operations it is important that we optimise our Wi-Fi networks to ensure their reliability and performance and implementing regular audits of the Wi-Fi will also help ensure great Wi-Fi stays great.