Hello,
I have done some other experiments by adding a gradually increasing attenuation (from 50 dB to 125 dB) using an attenuator directly connected to an End-Node SMA port (the antenna is connected at the SMA port after the attenuator), but at the receiving side of the Multitech AP I was not able to see a significant degradation of the RSSI:
-for 50 dB attenuation, the RSSI measured by the GW varies between -69 and -71
-for 60 dB attenuation, the RSSI measured by the GW varies between -70 and -72
-for 70 dB attenuation, the RSSI measured by the GW varies between -73 and -75
-for 90 dB attenuation, the RSSI measured by the GW varies between -73 and -74
Hence the RSSI does not seem to reflect the gradual decrease of the signal’s amplitude.
Note that tests have been redone assuming a possible leakage RF signal from the board by wrapping the end-node in aluminum foil on a grounded metallic suface.
-for 70 dB attenuation, the RSSI measured by the GW varies between -104 and -105.
-for 90 dB attenuation, the RSSI measured by the GW varies between -104 and -107.
-for 125 dB attenuation, the RSSI measured by the GW varies between -102 and -107.
So I have several questions:
1) Is the RSSI scaled between some extreme values (for example: below a signal level of X dBm, the RSSI will always be equal to a minmum value; and for a signal measured above Y dBm, the RSSI will be set to its maximum value) ?
2) At what level is the RSSI being measured (Radio level or after some processing) ?
3) At what level is the SNR being measured ?
4) what is the sensitivity of the multitech AP ?
Thanks a lot,
Kind regards