RF site survey — the independent pilot-preparation checklist.
A site survey done badly costs you 18 months of programme delivery. Done properly, it is the highest-leverage two days in any RTLS or RFID rollout. Here is exactly what to measure across UWB, RAIN RFID, BLE-AoA, LoRaWAN and Wi-Fi RTLS.
Why most site surveys fail on day 60, not day 1.
The default vendor survey runs at 09:00 in an empty bay against an architectural drawing. It produces a design that works at commissioning and starts failing six weeks later when the bay fills with racking, guarding, mezzanines and tooling.
Five failure modes account for most accuracy regression: anchor height drift, RF blockers introduced post-survey, multipath from metal and glass, line-of-sight gaps over the production day, and synchronisation timing. Every one is detectable in a properly-scoped survey.
The 12-point pre-survey checklist.
1. Site walkthrough at three different times of day — 06:00, 12:00, 16:00 minimum — capturing different shift states, door cycles and traffic patterns.
2. Floor-plan reconciliation against as-built. Every floor plan we have seen is wrong by 5%+.
3. Ceiling-height map at minimum every 10 m. Variations of 200 mm matter for UWB.
4. Floor surface material map — concrete with rebar, polished concrete, epoxy and raised floor affect RF reflection differently.
5. Metal-density and glass-partition map. Dominant multipath generators.
6. HVAC and ceiling utilities. Ducting, trays and sprinkler runs affect line-of-sight.
7. Mobile equipment cycle log — forklifts, AGVs, doors, presses.
8. Existing wireless interference scan — Wi-Fi, BLE, RFID, DECT, Zigbee, proprietary 433/868/915 MHz already on site.
9. Network topology map — PoE backbone, switch hop count, VLANs, time source.
10. Operations stakeholder interviews — what does the floor team need to see, where do they lose visibility today.
11. KPI baseline measurement — current WIP, search time, dock dwell, OEE.
12. Pre-agreed acceptance criteria. Pass/fail thresholds signed before scoping the pilot.
Per-technology specifics.
UWB: ceiling-height map, metal-density assessment, TDoA timing budget, multipath simulation against the as-built environment.
RAIN RFID: antenna geometry against dock-door geometry, dwell-time analysis, near-field shielding, conveyor integration timing.
BLE-AoA: Locator ceiling grid alignment, multi-antenna orientation, multipath-aware geometry, density vs ceiling height.
LoRaWAN: gateway placement against line-of-sight, rooftop or tower mount safety, lightning protection, GNSS-disciplined clock.
Wi-Fi RTLS: AP density (typically insufficient for RTLS), 802.11mc FTM support, network-refresh integration.
Frequently asked questions
How long does an RF site survey take?
Two to four weeks per site. Includes a one-day on-site walkthrough (multi-time-of-day), predictive RF modelling against the as-built environment, and the written design report with device-count justification and acceptance test plan.
Should the survey be done by the vendor or independently?
Vendor surveys produce vendor-friendly density designs. Independent surveys produce designs that pressure-test against your KPI. The 30–50% device count savings independent audits find are not visible to the vendor whose contract depends on the SLA buffer they specified.
What does the survey deliverable look like?
Predictive RF survey data, accuracy validation, network design, anchor/reader register with verified heights, multi-time-of-day data, photographs, sign-off pack for operations and IT/OT.
What if our site is too large for a full physical survey?
We run physical sampling at representative zones plus predictive modelling against the full as-built environment. Multi-site rollouts use hub-and-spoke surveys — one full physical survey at the reference site, predictive extrapolation.
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