To prevent from overloading, the Semtech SX12xx-chipset has an AGC (Automatic Gain Control) that can reduce the LNA-gain if enabled. This will result in lower RSSI- and SNR-values.
If no AGC is used, the LNA-gain can be controlled by LnaGain Setting. This gain can be reduced in steps of 6dB by firmware. This will result in lower RSSI- and SNR-values too.
I donât understand this fully,
Will AGC reduces Transmission Power in Node?, I checked Loramac code, and AGC is on default setting.
Is AGC also works in Gateway, and will reduces gatewayâs receiving sensitivity and so nodeâs data is unable to reach to gateway
Thats exactly my point. The AGC or LNAgain is able to reduce the sensitivity of the gateway.
The AGC works for the receive-path of the node or the gateway. AGC does not influence the transmit -path.
Means Suddenly RSSI and SNR decreased of nodes, issue is not from Nodeâs side?
The first thing I would do, is to look at the gateways. But nothing is impossible, if the power of the nodes was reduced by ADR they should come back after a certain time.
If you have an outdoor -antenna, connect your SDR-receiver to this antenna and look whatâs going on ± 20 MHz.
we are on conclusion that it is RF interface issue of Mobile network, any advice about it?
That is why you should stick to the regulating authorities regulations. You donât stick to it someone gets upset.
Like FUP or running 100âs of nodes on TTN as a commercial entity, sooner or late someone is not happy.
Ask them to turn it off, complain to regulating authorities.
Add a band filter tuned to the LoRaWAN frequencies between the gateway and the antenna.
In IN865, there is no duty cycle restrictions, So how to complain authorities about this, and RF noise is not from other Lorawan devices, It is from 4G or 5G bands.
You need to contact the regulators for your country âŠ
Youâve asked someone who lives in South Africa how to complain to the Indian authorities about the RF noise you think is coming from mobile comms?
His reference to LoRaWAN was in regard to your skirting around the regulations on TTN.
Yes, TTN and to the mobile 4G/5G.
The mobile network suppliers equipment should also comply to the regulating authorities regulations. Their filters should limit there RF bleed into other bands as not to cause interference.
By the way, where are your gateways?
With the help of RF analyzer, we found that noise power in that place is about -60.
One of the Dutch telecom providers also has a LoRaWAN network. The gateways are co-located with mobile sites and those use a frequency band close to the LoRaWAN allocated ones. Iâve been told when they started deploying they had to add special filters to the kerlink carrier grade gateways because of the interference of the mobile communication. So find a party with good RF skill, explain your issue and ask them to propose a solution.
If the interference overlaps the ISM band @Johan_Scheepersâs advice to engage with the regulator is the best way forward.
We (the TTN community) are not going to (be able to) resolve this for you. The advice you got is all we can do,
Thanks for this useful advice.
can Band pass Filter, help in bettering of SNR values?
A bandpass-filter might help, but depending on the signals you want to mute, a simple dielectric bandpass wonât do the job.
imho you need a cavity-filter with a stop-band attenuation of 30dB or more. It will be much more expensive than a dielectric filter.
It might do, you really need to try it.
This:
might be a suitable bandpass.
Is that standard Lego spacing or Duplo sized?