Hi there!
We are currently evaluating a low-power BLE system for a safety-critical wearable application that must transmit immediate alerts to a nearby receiver or mobile device.
Our requirements are roughly:
– Range: stable communication at >70 m (open field) between two BLE devices, but often used also in an urban surrounding where the range should be at least around 30,
– Latency: alarm message delivery within <1 s
– Reliability: minimal packet loss or false-negatives, even in dynamic environments (body movement, multipath, partial obstruction, etc.)
We would appreciate your insight or thoughts on the following points:
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What is the realistic maximum reliable range for BLE (1M vs Coded PHY) in such scenarios?
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How stable is BLE signal transmission under moderate body shadowing or environmental attenuation (e.g. when one device is worn on the wrist)?
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Would you consider BLE sufficiently robust for a critical alert link, or would you recommend an alternative approach (e.g. proprietary 2.4 GHz, Sub-GHz, or hybrid)?
- Is there a specific Nordic chip which would you recommend for a safety-critical set up?
Many thanks in advance for your advice!
All the best,
Kai
Kai
