WiFi runs in three frequency bands: 2.4, 5 and 6 GHz. Lower frequencies travel further and through walls more easily, while higher frequencies offer far more channels and cleaner airspace. Most enterprise networks today rely on 5 GHz as the workhorse, add 6 GHz for newer devices, and keep 2.4 GHz for older or simpler equipment.
The three bands at a glance
| 2.4 GHz | 5 GHz | 6 GHz | |
|---|---|---|---|
| Range and wall penetration | Best | Moderate | Shortest |
| Non-overlapping channels | Three at 20 MHz | Many, some with DFS rules | The most, with room for wide channels |
| Interference | Heavy: WiFi and non-WiFi | Moderate | Lowest, for now |
| Device support | Almost universal | Very wide | WiFi 6E and WiFi 7 devices only |
The two trade-offs pull in opposite directions. The same access point reaches furthest at 2.4 GHz and least far at 6 GHz, while the room available for separate channels runs the other way.
2.4 GHz
The 2.4 GHz band has the longest range and the widest device support. Nearly every WiFi device ever made can use it, including many sensors, building controls, printers and older industrial equipment.
Its weaknesses are serious, though. There are only three non-overlapping 20 MHz channels in North America (1, 6 and 11), so access points in a dense building inevitably overlap. The band is also shared with microwave ovens, Bluetooth and many other devices, and because signals travel so far, neighbouring networks are heard from a long way off. The result is a crowded, noisy band with limited capacity.
In enterprise design, 2.4 GHz is usually kept for devices that need it, often with some access points' 2.4 GHz radios turned off or set to low power to limit overlap.
5 GHz
The 5 GHz band is the backbone of most enterprise WiFi. It offers many more channels than 2.4 GHz, so access points can be placed closer together without competing, and it carries far less non-WiFi interference.
Some 5 GHz channels require dynamic frequency selection (DFS), meaning access points must listen for radar and leave a channel if they detect it. DFS channels add useful capacity, but near airports or weather radar they can cause sudden channel changes, and some client devices do not support them. Signals at 5 GHz lose more strength through walls than 2.4 GHz, which is one reason enterprise networks use more access points placed closer to users.
6 GHz
Canada has opened the 6 GHz band for licence-exempt WiFi use. It adds a large amount of new spectrum, enough for many wide channels, and it is available only to newer WiFi 6E and WiFi 7 devices, so there is no crowd of legacy devices slowing it down. Security is stronger too: 6 GHz networks require WPA3.
The trade-offs are range and device support. 6 GHz signals do not reach as far or pass through walls as easily as 5 GHz, so coverage from the same access point is smaller. Only newer phones, laptops and tablets can use it, and many specialized devices such as scanners, medical equipment and building sensors will not support it for some time. Power limits and the rules for indoor and outdoor use are set by Innovation, Science and Economic Development Canada (ISED); check current rules and equipment certification during design.
How to choose
Most buildings do not choose one band; they decide what each band is for.
- Start from the devices. List the devices that must work, especially specialized ones, and which bands they support. A warehouse full of older scanners needs a solid 2.4 or 5 GHz design regardless of what new laptops can do.
- Design coverage for the most important band. In most new designs that is 5 GHz, with 6 GHz coverage checked separately since its cells are smaller.
- Limit 2.4 GHz overlap. Do not run every 2.4 GHz radio at full power just because it is available.
- Use band steering carefully. Encouraging capable devices onto 5 or 6 GHz frees 2.4 GHz for the devices that need it, but aggressive steering can cause connection problems for some clients.
- Plan for 6 GHz now. Even if few devices use it today, access points installed now will be in service for years. See WiFi 6, 6E and 7 explained.
A worked example: giving each band a job
Consider a mid-sized office with staff laptops, WiFi desk phones and handsets, a mix of personal phones, wireless printers, and a set of 2.4 GHz-only environmental sensors installed by the building operator.
- 5 GHz is designed as the primary band. Coverage and roaming are planned for the voice handsets, which only support 5 GHz, so this band gets the strictest targets.
- 6 GHz is enabled on the new access points for the laptops and phones that support it. Its smaller cells are checked separately, and the design accepts that some corners are served by 5 GHz instead.
- 2.4 GHz is kept for the sensors and printers, on channels 1, 6 and 11 at low power, with the radio turned off on some access points so the band does not overlap itself.
The result is that each device class lands on the band best suited to it, and the busy 5 GHz band is not shared with slow legacy devices.
Before you rely on 6 GHz
- Confirm which of your laptops, phones and tablets actually support 6 GHz, and which operating system versions are needed.
- Check that your security settings suit 6 GHz, which requires WPA3, and plan for devices that cannot use it.
- Confirm that the access points are certified for use in Canada and configured for the correct country.
- Survey 6 GHz coverage separately; its cells are smaller and walls affect it more.
- Make sure switches and Power over Ethernet can support the newer access points at full capability.
Check each band on its own. Coverage that looks good at 2.4 GHz can have gaps at 5 and 6 GHz from the same access points. Design and survey each band separately.
How ehZee can help
We design networks around the devices you actually rely on, deciding what each band is for and how channels and power are planned across all three. Our WiFi design and build service includes band and channel planning and a validation survey for each band. For the channel side, read WiFi channel planning.
Common questions
Should we turn 2.4 GHz off completely?
Only if you are sure nothing needs it. Many building systems, printers and specialized devices still rely on 2.4 GHz. It is more common to reduce 2.4 GHz radios and power than to remove the band.
Do we need new access points to use 6 GHz?
Yes. Using 6 GHz requires WiFi 6E or WiFi 7 access points and client devices that support the band.
Can one network name cover all three bands?
Often, yes. One complication is that 6 GHz requires WPA3, so devices that cannot use WPA3 may need to stay on a network name served only on the lower bands, or the network may use a transition setting. Plan this with the security design.
Why does my device connect on 2.4 GHz when 5 GHz is available?
Devices choose based on their own logic, often preferring the strongest signal. Because 2.4 GHz travels further, it can look stronger. Network design and band steering settings can help.