Before You Buy Another Black Box: A Small-Business Wi-Fi Reality Check

There is a particular kind of optimism that arrives when the Wi-Fi drops in the stockroom. Someone says the router is old. Someone else suggests a mesh kit from a weekend advert. By Friday there are three more boxes on the ceiling and the meeting room still cannot hold a Teams call.

Wi-Fi problems in small UK offices rarely look like a shortage of boxes. They look like a traffic jam, a badly placed access point, a switch that cannot power what is plugged into it, or a guest network that has quietly become the main network. Buying more kit before you understand which one you have is an expensive way to add interference.

More boxes, more problems

Wi-Fi is radio, and radio does not care how much you spent. Add an access point in the wrong place and you can increase co-channel interference, confuse devices that cling to a distant signal, and make roaming worse. In a small premises with brick walls, metal racking, a fridge, a till and a neighbouring unit running its own kit, the answer is often placement and channel planning, not another black box.

Start with a walk and a floor plan

Before anyone reaches for a purchase order, walk the building with a floor plan and a flask of tea. Mark the places where people actually use devices: desks, the stockroom, the meeting room, the kitchen, the loading bay. Test at 9am and again at 2pm, because a warehouse at lunchtime is a different radio environment from a warehouse at opening time.

Use a free analyser on a phone or laptop. You are looking for three things: signal strength, channel overlap and the difference between 2.4GHz and 5GHz. As a rough guide, minus 67 dBm is comfortable for general work, minus 75 dBm is marginal, and anything weaker is where video calls start to sulk. Do not trust the little bars on a laptop. They are a mood indicator, not a survey.

While you walk, note what is between the device and the access point. Metal shelving, mirrors, thick walls, filing cabinets and even a large water tank can block or bend the signal. An access point hidden in a cupboard or above a metal ceiling tile is not doing the job it was bought for.

Channels are the invisible traffic jam

In the 2.4GHz band there are really only three non-overlapping channels: 1, 6 and 11. If every access point is set to channel 6 because that is the default, they will all talk over each other. Set 2.4GHz to 20MHz and space the channels out. In the 5GHz band there are more channels, but walls eat the signal faster, so do not crank the power to compensate. Lower power and better placement usually beat a shouting match.

If you have a controller or a cloud-managed system, use it to check the channel plan. If you do not, log into each access point and write down what it is doing. Turn off legacy speeds if you still can, and enable band steering if the kit supports it properly. The aim is to let devices choose 5GHz when they are close and fall back to 2.4GHz when they are not.

Placement beats power

An access point should be central to the area it serves, mounted below the ceiling rather than above it, and clear of metal. Do not put it next to a microwave, a fridge or a stack of stock boxes. If the stockroom is a metal-lined box, no amount of extra power will fix it. You may need an access point inside the room or a cabled connection to a device that does not move.

PoE and cabling: the unglamorous limits

Power over Ethernet is brilliant until the budget runs out. Check the PoE budget on the switch, not just the number of ports. A cheap switch may have eight ports but only enough power for two access points. Check whether the access point needs 802.3af or 802.3at, and whether the cable run is under the 100-metre limit. A long, cheap cable run with a dodgy crimp will cause problems that look like Wi-Fi faults.

If you need a new cable drop into a ceiling void, that is a cabling job. Trailing a patch lead through a wall and calling it a day is how you create an intermittent fault that takes three visits to find.

Separate the guests from the gadgets

Guest Wi-Fi and business traffic on the same network is a common small-business shortcut. So is putting the smart fridge, the printer and the doorbell on the staff network because it was easier. Both shortcuts cause trouble: guests compete for bandwidth, IoT devices broadcast chatter, and a compromised gadget has a direct route to your files.

A simple guest SSID on its own VLAN is usually enough for a small office. Put IoT devices on a separate SSID too, especially if they only need 2.4GHz. Keep staff devices on the main network. Do not over-engineer this with five VLANs and a dissertation; one guest network and one IoT network will solve most of the problem.

When to stop adding boxes and call a cabler

Stop buying access points when the survey shows overlap, bad placement or a weak signal caused by the building. Stop when the switch has no PoE headroom, when you need new ceiling drops, or when the premises has listed-building rules, asbestos ceilings or a landlord who controls the comms cupboard. At that point, a proper cabler and a network engineer will save you more than another mesh kit costs.

A sensible order of work

1. Walk the site and mark the real dead spots.
2. Check channels, power and firmware on the existing kit.
3. Move access points out of cupboards and away from metal.
4. Separate guest and IoT traffic.
5. Check the PoE budget and cable runs.
6. Add an access point only where the survey says it is needed.
7. Call a cabler for structured cabling and ceiling drops.

After any change, test the things people actually do: a Teams call in the meeting room, a scanner in the stockroom, a laptop at the far desk. Wi-Fi that looks fine on a speed test can still fall over when everyone returns from lunch. Fix the radio and the cabling first. The extra black box can wait.