2.4 Ghz Bandwidth utilization in crowded environments

[daguro]

I'm looking for information about bandwidth utilization in crowded environments, something like a sports stadium.

Has anyone at Nordic collected data on potential congestion in these enviroments?

[bjorn-spockeli]

I am afraid that we do not have any statistics on the scenario that you describe, but generally speaking, the BLE protocol has been designed to co-exist with other 2.4GHz devices like WLAN.

In an unconnected state, a BLE device will advertise on the BLE advertisement channels 37( 2402Mhz), 38 (2426MHz) and 39(2480MHz), that have been chosen in such a way that they fall in the gaps between the 3 most commonly used non-overlapping WLAN(802.11b) channels in the 2.4GHz, i.e. channel 1 ( 2412MHz), channel 6 (2437MHz) and channel 11(2462Mhz).

Two BLE devices in a connected state will hop through the remaining 37 channels (37 data channels + 3 advertisement channels = 40 in total) in order to avoid congestion. However, if you have several thousand devices within range of each other( e.g. 20-25m) then you will run into congestion issues.

Best regards

Bjørn