The brief
IT wanted to know whether to rip and replace or add APs. Teachers reported freezes in the hall during exams and in the older science block. A previous installer had heatmaps that were all green at -70 dBm and called it done. Green at -70 dBm is not a Chromebook design.
We ran a passive on-site survey against the associated SSID, plus a spectrum pass for Bluetooth speakers, wireless presentation kits and neighbouring houses on 2.4 GHz.
What we measured
Walk paths covered every classroom, stairwell, corridor and the hall at empty and (with the school’s permission) a rehearsal with ~400 devices. We looked at RSSI, SNR, associated APs, channel overlap and estimated airtime, not just colour.
The hall had two APs on the stage wall. At the back of the floor, clients still showed bars and still could not complete a Teams call: SNR collapsed and retries ate the channel. The science block had APs in corridors; Victorian walls meant classrooms were secondary coverage only. Roaming between blocks used a single sticky 2.4 GHz SSID.
What we recommended
- Hall: APs in the roof void looking down, not on the stage, with 5 GHz as the exam SSID.
- Science: APs in the teaching rooms, lower 2.4 GHz power, disable sticky band steering that parked iPads on 2.4 GHz.
- Minimum design target of about -67 dBm primary coverage in teaching spaces, with a documented secondary AP.
- A short prep list for holidays so the next validation can be done without a full school day.
Result
The school added APs in the rooms that actually needed them rather than another corridor unit. Exam-day tickets dropped. We handed over heatmaps, a channel plan and an .esx file the MSP could reopen in Ekahau.
We survey schools and universities across the South of England and nationwide. Multi-academy trusts can book a block of sites.