One room has full signal, the next room has none, and the person at the far desk keeps complaining that video calls freeze. Wi-Fi dead zones are very common in offices, shops and factories, and buying a stronger router rarely fixes them. The real fix is to understand why the signal drops and to place access points properly. This guide explains the causes and gives a practical step-by-step plan.
Why dead zones happen
- Distance: Wi-Fi signal gets weaker with every meter.
- Building materials: thick concrete, brick, metal doors, metal shelves and elevators absorb or reflect the signal. Low-emissivity (coated) glass and mirrors can also block it.
- A single router in a corner: the signal has to cover the whole floor from one edge.
- Interference: neighbouring networks, microwave ovens, cordless phones and other devices on the same channel.
- Too many devices on one access point: the signal is there but the speed is poor.
- Weak client devices: an old laptop or phone cannot reach as far as the access point can.
Step 1: Measure before you change anything
Walk through the office with a Wi-Fi analyzer app on your phone (for example a free app for Android) or a PC tool such as NetSpot. Note the signal strength in each room. Signal is shown in dBm, and values closer to zero are better:
| Signal | What it means |
|---|---|
| -30 to -50 dBm | Excellent |
| -50 to -67 dBm | Good, fine for video calls and streaming |
| -67 to -75 dBm | Fair, may be slow or unstable |
| Weaker than -75 dBm | Poor, dead zone for practical use |
Sketch a simple floor plan and write the readings on it. This is your before picture and it will help you place access points later.
Step 2: Place the access point in the right spot
- Mount it high, on a ceiling or high on a wall, with a clear view of the room.
- Put it in the middle of the area it must cover, not in a corner or behind a cabinet.
- Keep it away from metal cabinets, thick walls, microwaves and large fish tanks or water pipes.
- Do not hide it in a closed rack or inside a drawer.
- Aim for one access point per area or a few rooms instead of one for the whole building.
Step 3: Choose the right channels and bands
- 2.4 GHz reaches farther but is slower and crowded. If you use it, stick to channels 1, 6 and 11, which do not overlap.
- 5 GHz is faster and less crowded, but the signal does not pass through walls as well. It is best when access points are close to users.
- Give nearby access points different channels so they do not compete with each other.
- Do not set the transmit power to maximum on every access point. Very high power on all of them causes interference, and phones keep sticking to a far access point instead of moving to the nearest one.
Step 4: Use wired access points, not repeaters
A Wi-Fi repeater receives and resends the signal on the same channel, which roughly halves the speed. It can fix a small gap at home, but in an office it is a weak solution.
The best method is to connect extra access points with Ethernet cable to the main switch (a wired backhaul). Power them with PoE if possible, which gives you power and data over a single cable and makes ceiling installation easy.
Step 5: Wired access points vs mesh
| Option | Good for | Limit |
|---|---|---|
| Wired access points with a controller or same SSID | Offices, shops, factories | Needs cabling |
| Mesh with wired backhaul | Medium offices when you can run some cables | Costs more than basic routers |
| Wireless mesh only | Homes and small spaces | Speed drops with every wireless hop |
Use the same network name (SSID) and password on all access points so devices can move between them. If your equipment supports it, enable fast roaming features (802.11k, 802.11v and 802.11r).
Step 6: Special tips for factories, warehouses and glass buildings
- Metal racks, machinery and large glass panels reflect and block the signal. Place access points above racks and give each aisle or section its own coverage.
- Use access points with external or directional antennas where long open areas need coverage.
- Test again after goods are stored, because full shelves change the signal.
- Avoid running the Wi-Fi cable or PoE next to heavy power cables.
Step 7: Test again
Walk the same route with your analyzer app and compare. Check that the weak rooms now show at least -67 dBm, and run a speed test in the former dead zones. Also test roaming by making a call while walking from one area to another.
Quick checklist
- Measure the signal in every room.
- Mark dead zones on a floor plan.
- Add wired access points in the middle of those areas.
- Set different channels and moderate power.
- Use one SSID everywhere.
- Re-test and keep the map for the future.
FAQ
Is a repeater or an access point better? An access point connected by cable is better. A repeater cuts speed and adds delay.
Which is better, 2.4 GHz or 5 GHz? 2.4 GHz covers a wider area, 5 GHz is faster. Most offices use both, with 5 GHz access points placed close enough to users.
How many access points do I need? It depends on walls, users and devices. As a rough start, one access point per 100 to 150 square meters of open office, and more where walls or many users are present. Always verify by measuring.
Does a higher price always mean better coverage? No. Placement, channel planning and wiring matter more than the brand.
Related reading: IP Address Conflict in the Office: How to Find and Fix It | Network Printer Shows Offline: 7 Fixes That Work | How to Set Up Hikvision DVR Remote View on Your Mobile
Leave A Comment