Sending response to end device in RX Window1 or RX window2

Hi all,

How Network Server or gateway would take decision that it needs to send response to end device in RxWindow1 or RxWindow2?

If some how device has not been able to get data sent for RxWindow1 time frame is there any way network server/ gateway would be able to send that frame for RxWindow2 time frame?

Lalit Shah

Hello @lalitshah,

LNS always uses RX1 window, on the end-device, to forward the downlink. If the RX1 window is not enough to forward an uplink, LNS uses RX2 window to forward downlink. And it is always recommended to use confirmed downlink to receive an acknowledgment from the enddevice after downlink reception.

Can you please let us know the type of end device and its class (A/B/C) to provide further information?

RX1 and RX2 window information are available here An In-depth look at LoRaWAN® Class A Devices | DEVELOPER PORTAL, I hope it helps you.

Best regards,
Chay Tholeti.

Hello Chay,

Thanks for response.
We are currently using this in IN865 region and we have multiple devices sending join request and some of them not able to get join response.

We have seen that it always provides join request for RX1 window only, as issue is during join it does not have any dependency on class.

Is there any way we can increase the RX1 window timing just to evaluate that we can get join response from gateway, just to check there is no timing issue?

Lalit Shah

In the NS configuration, you can increase the rx1_delay value.

With regards to RX1 vs RX2, by default ChirpStack tries to schedule the downlink using RX1 parameters, if the gateway is unable to transmit using RX1 parameters, the NS tries sending using RX2 parameters.