Class C device downlink gateway choose strategy


#1

We install each gateway on two nearby buildings, and in each building, there are many class c devices.

And for some devices in some specific places, both of the gateways can receive the devices’ uplink data, but the devices can only receive downlink data from one gateway. (Because gateway’s antenna is usually better than device’s.)

At first, one of the devices in the specific places communicates with gateway A, we call it device A, everything goes well.

But when the gateway A is sending downlink data, and at the same time, device A is sending uplink data. Because gateway A is half-duplex, so gateway A cannot receive the uplink data from device A while sending data, but gateway B can.

After that, the downlink data to device A will go through gateway B, but as we mentioned, gateway B can only receive uplink from device A, the device A cannot receive downlink data from gateway B.

So device A cannot be reached by the lora network server until it sends uplink data and received by gateway A again.

Since device A will only send uplink data in an several hours interval, so during that interval, there is no way to control device A.

Do anyone have any ideas about this problem?

Thank you, best regards!


#2

My understanding is that the Network Server will pick the best gateway to send the downlink packet. In this scenario, Gateway B is the only gateway that received an uplink from Device A; therefore, Gateway B is the only gateway that can send the downlink. I’m not sure why Device A could not receive the downlink from Gateway B.

  1. Can you confirm that Gateway B cannot send a downlink to Device A if Gateway B received the uplink from Device A.
  2. You could try to change the firmware on Device A to retry to send an uplink a few times if it does not receive a downlink.