If everything works fine downstairs but the upstairs office is a coin flip, you almost certainly have a coverage problem, not a speed one. Here's the 5-minute diagnostic.
Step 1 — measure where it's bad
Stand where it's slow with your phone or laptop. Open a speed test. Note three numbers:
| Metric | Good | Borderline | Bad |
|---|---|---|---|
| Download | > 50 Mbps | 10–50 Mbps | < 10 Mbps |
| Upload | > 10 Mbps | 3–10 Mbps | < 3 Mbps |
| Ping to 1.1.1.1 | < 20 ms | 20–60 ms | > 60 ms |
Now walk closer to the access point (AP). Repeat. If the numbers jump dramatically as you approach, it's coverage.
Step 2 — check signal strength
On macOS:
# Hold ⌥ and click the Wi-Fi icon, or run:
/System/Library/PrivateFrameworks/Apple80211.framework/Versions/A/Resources/airport -I
Look at the agrCtlRSSI value. Anything below -70 dBm is the source of your trouble. -65 to -55 dBm is healthy.
On Windows:
netsh wlan show interfaces | findstr Signal
Step 3 — fix itt
In order of effort:
- Move the AP to a more central location, away from the metal filing cabinet you put it next to. (We do this on a quarter of customer site visits.)
- Add a wired AP upstairs. Best fix; cleanest performance. Needs an Ethernet run and an AP — your account manager can scope this.
- Powerline + AP — Ethernet over the mains wiring. Works in modern installations; flaky in older buildings with metal junction boxes.
- Mesh — last resort. Cheap and visible-looking, but throughput halves at every "hop". Better than nothing for a single dead spot.
Avoid Wi-Fi repeaters / extenders. They double your channel usage and reduce total throughput. If a sales person at PC World is pushing one, walk away.
When to call us
If the dBm reading is fine but the speed is still bad — that's not coverage, that's interference, channel congestion or a backhaul issue. Open a ticket and we'll come and do a proper survey.