Knowledge Base

Asymmetric link

Our LoRa-link is a basestation and a sensor, equipped with 30dBm modules. It is not LoraWAN.
Both are equipped with a l/4 whip. The problem is, that the whole link is far better in one direction, about 10dBm (based on the readings of the LoRa modules). We checked the power adjustments of both sides, they work. The 30dBm PA is also ok. Software routines in base and sensor are equal. We changed antennas, the effect did not go away. The link from the base station to the sensor is much weaker than the other way.
As I remember, radio links should be equal in both directions when using the same output power. A very bad effect is that we have to adjust SF and Power to the "bad" direction to keep the link up and running. The other direction could work with much lower settings.
We tried with 2 different basestations and sensors, same behaviour.
Any ideas?