When the Wi-Fi drops in the boardroom or crawls at the far end of the office, the usual response is to buy another access point and put it where the complaints are. Sometimes that helps. Often it changes nothing, and now and then it makes the whole network worse. Wi-Fi problems are usually design problems, and more hardware does not fix a design.
Why more access points can make it worse
Wi-Fi is a shared medium. On any one channel, only one device can transmit at a time, and everything else on that channel within earshot has to wait its turn. That includes other access points.
If you add an access point on the same channel as one it can hear, the two do not double your capacity. They take turns, along with every laptop and phone connected to either one. This is called co-channel interference, and it is the most common reason a network with plenty of access points still feels slow.
Turning the power up does not help either. A phone decides for itself when to switch access points, and if it can still hear a loud one from across the building, it will cling to it instead of moving to the one overhead. There is also a mismatch: an access point at high power can reach a phone that is too weak to answer back clearly. The phone shows full bars and still performs badly.
Placement comes first
Where an access point sits matters more than how many you have. They work best mounted on the ceiling, in the open, in the rooms where people actually work.
The common mistakes are easy to spot. Access points lined up along a hallway hear each other perfectly down the corridor while their signal has to push through walls to reach anyone. Units hidden above ceiling tiles, tucked in a closet, or sitting on top of a metal cabinet lose much of their signal before it gets anywhere useful.
Building materials decide how far a signal travels. Drywall barely slows it. Concrete, brick, metal, elevator shafts, foil-backed insulation and energy-efficient coated glass can stop it almost entirely.
Coverage is only half of it. A boardroom or training room where twenty people open laptops at once needs capacity, not just signal, and may deserve its own access point even though a neighbouring one reaches it.
Channels and bands: 2.4, 5 and 6 GHz
Each band behaves differently, and a good design uses them deliberately.
- 2.4 GHz travels furthest and passes through walls best, but it has only three channels that do not overlap (1, 6 and 11). It is crowded with neighbouring networks, Bluetooth and microwave ovens. In an office with more than a few access points it is often turned down or switched off on some of them.
- 5 GHz has many more channels and a shorter reach, which makes it much easier to keep neighbouring access points from overlapping. Some of its channels are shared with radar, and an access point must leave them if it detects radar.
- 6 GHz, used by Wi-Fi 6E and Wi-Fi 7 equipment, offers a large amount of clean spectrum. Only newer devices can use it, and its range is shorter again.
Channel width matters too. A wide channel produces an impressive number on a speed test with one laptop, but it uses up several channels' worth of spectrum. In an office with many access points, narrower channels usually give everyone a better and steadier connection.
What a site survey tells you
A site survey replaces guessing with measurement. It usually has three parts.
A predictive design models the space on a floor plan, with wall materials entered, to estimate how many access points are needed and where they should go. An on-site survey measures what is really there: signal levels in each area, noise, neighbouring networks and sources of interference. A validation walk after installation confirms the network performs as designed.
What you get is a map of coverage, a list of access point locations, and a channel and power plan. Quite often the finding is that the office does not need more access points. It needs the ones it has moved, retuned, or in some cases reduced.
Check the wiring and switches behind it
An access point is only as good as the cable and switch behind it. Each one should have its own cable run back to a network switch. Current access points often have ports faster than 1 gigabit, which is why Cat6A is the usual recommendation for new runs to ceiling locations.
Power is the other half. Access points are powered through the network cable using PoE, and newer models need more power than older switches supply. An access point on an underpowered port may start up with some of its radios or features switched off, without anyone noticing. The switch also has a total power budget, and adding access points can exceed it.
It is worth ruling out the rest of the network as well. Plug a laptop in with a cable and test. If it is slow on the wire, the problem is the internet connection, the firewall, or something else upstream, and no amount of Wi-Fi work will fix it.
Uninexus designs and installs office Wi-Fi with proper site surveys, and we do the cabling and switching behind it too. If your office has dead spots or drops calls on Vancouver Island, the Lower Mainland or the Sunshine Coast, let us know what you are seeing and we can work out where the real problem is.