Hello,
I was reading in on LoRaWAN and how the gateways work. I understand that a gateway is used to receive LoRa messages from end nodes and can transmit downlinks to nodes when requested by the network.
A proper gateway listens on multiple channels and can demodulate multiple datarates at the same time. But what happens when there are multiple gateways on one network and they are in proximity to eachother? The other gateway would use the same channels and datarates for downlinks on which the other gateway is listening. So in theory the gateway would receive and demodulate the other gateway’s downlink.
What would prevent this from happening, I couldn’t find any information about this subject. I was wondering where the downlinks of other gateways would be filtered out. Is this done on the gateway itself or is this the job of the LoRaWAN network server?
I thought this filtering would be done by the packet forwarder running on the gateway to save the trouble of the network server having to deal with these messages, but can’t seem to find any evidence of this in the source code.
To test this I forwarded the received packets to my PC resulted in only receiving uplinks from end-nodes and not in receiving downlinks from other gateways. This would confirm that the gateway itself is doing the filtering. But as mentioned I cannot find any evidence of this in the packet forwarder source. Is there any other place the downlinks would be filtered out? Is this an option and can a gateway be used to receive downlinks send by another gateway?