Measuring RSSI on channel without connection or advertising package

[PhDi_1589426]

Hello,

I wanted to ask if it is possible to listen to a certain channel without beeing in a connection or receiving an advertising package?

I want to get the noise on this channel with the RSSI.

Thank you in advance

Philipp

[Anonymous]

Hi Philipp,

If you are scanning and receive an advertisement packet then you can get the RSSI value from the adv report on the central side.

CYBLE_GAPC_ADV_REPORT_T will have the rssi value of the device which sent the advertisement.

Thanks,

Ranjith

[PhDi_1589426]

Hi Ranjith,

as far as I know the RSSI is originally used by the central to determine if a channel is over crouded or not.

I thought that this means that the central is able to measure the noise on a channel.

I am interested in this because I want to increase the precision of positioning applications.

Can I listen to a channel to get the noise or is the RSSI allready filtered from noise?

If I use all 3 Channels for advertising, is the RSSI an average of all the channels?

This is a nice paper about this topic:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5750706/

Best regards

Philipp

[GyanC_36 · Accepted solution]

RSSI is a received signal strength indicator for the last received RF signal by the BLE radio sub system. It is not specific to central or peripheral role and does not give any explicit information about channel is noisy or not. Of course, if the environment is noisy , the signal strength will be degraded.

-Gyan