Is GSM-850 band affect Lorawan IN865 band?
From RTL-SDR module Analysis in Area.
Can it impact on 865 to 867 mhz?
In India there are some areas where 5G started, Can 5G effect, IN865 Lorawan Band?
You could get a totally different device - perhaps just an off the shelf device - and deploy it to see what happens - then you’ll be able to differentiate between environmental or firmware issues.
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Perhaps check which providers acquired licenses to use the band and contact them? The ISM band should not be impacted by 5G.
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IIRC the L-A consulted widely and selected a slightly lower range band than e.g.other EU868Mhz bands specifically to avoid such an issue and to squeeze in between avoiding mutual interference or need for expensive narrow band or steep roll off filters etc. you might reach out to the L-A to ask if they have started to accurate instances of poor implementation that might be indicative of a problem?
The often used dielectric bandpass-filter from Taoglas has an attenuation of only abt. 10dB at these frequencies.
Strong signals a few MHz under or above 868MHz can lead to an overload of the receiver-circuit. The receiver becomes deaf.
Request to explain this in more details.
Every receiver has a signal-range it can handle, the difference between the lowest detectable signal and the highest signal it can withstand without distortion. This is called dynamic -range.
The signal a receiver sees at its input doesn’t only consist of the signal you want to receive (in-band), but it is a sum of all signals (voltages) comming from the antenna. If the out-band signals are very strong, they will overload the receiver-input.
Therefore you need means for selectivity to keep the out-band signals away from the receiver-input. The first part of this selection-chain can be the antenna, the second part are filters like the Taoglas dielectric bandpass-filters.
If you look at the datasheet of this bandpass-filters eg. DBP868UA you will see, that the attenuation of out-band signals that are only a few MHz away is rather low.
This is the reason why a receiver can become deaf because of out-band signals.
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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.
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I don’t 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 gateway’s receiving sensitivity and so node’s data is unable to reach to gateway
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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 Node’s 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 what’s 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 don’t stick to it someone gets upset.
Like FUP or running 100’s 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.
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Add a band filter tuned to the LoRaWAN frequencies between the gateway and the antenna.
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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 …
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