I am using a rak811 node with an 3.6 dbi gain antenna, thus with tx_power = 0 I should get 16+3.6=19.6 dBi as output ( ideally, without any losses ).
Trying to comply with EU868 regulations, I set my node at tx_power = 2 , in order to have 12+3.6 = 15.6 dBi as output. However, when ADR is enabled , chirpstack network server always commands my node to have tx_power = 0 ( in addition to the respective Datarate ).
I tried to find an appropriate option in chirpstack-network-server.toml but I couldn’t find the suitable parameter ( the closest I found was “uplink_max_eirp” but didn’t have any effect )
Is there a way to limit node’s Tx Power from Chirpstack Network server during ADR ?
You might need to write your own ADR backend (which is possible)
I thought the devices themselves need to comply, even under ADR. Dont know if your radio library supports setting a maximum output regardless of txPower, or translating that into something that complies.
Thank you for the insight. The device can’t know the gain of the selected external antenna beforehand (I could had selected an antena with 0 dBi total gain , or anything), that’s why I try to limit the output. Right now I am checking before every uplink if the TxPower is above the desired level (however I am worrying that “forced” change is messing indirectly with the ADR calculation).
I was wondering if I could put that ckeck/limit in the network server, instead of every node . If that isn’t possible, maybe ADR plugin is the way
But you are the one programming the nodes right? A device es software+hardware certified, if you change any of those you need to go thru the certification again. That’s why the devices themselves need to comply with the law, regardless of wrong input by the network-server.
Wouldn’t it be better to “compensate” for the antenna gain inside the device firmware instead of using the txPower for this? That way txPower=0 can still be used.
