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Unable to receive downlink in class A mode of LoRaWAN

Associate II

Hey ST Community!

I've been using an LoRaWAN AT Slave example provided by STM32Cube_FW_WL_V1.3.0 on a new Nucleo STM32WL55JC1 board and managed to successfully join the network. Sending data using the AT+SEND=<Port>:<confirm/unconfirm>:<data> command has been smooth sailing, with successful transmissions to the server. However, I encountered a hurdle when attempting to implement downlink communication in Class A mode.

Here's the situation: According to TTN guidelines, in Class A mode, after an uplink transmission, the device switches to the receiver window, which consists of two consecutive slots, RX_1 and RX_2, each open for a specific period of time. Now, I want to send a message to the device on a specific port during this receiver window, but I'm facing a challenge.

When the device sends data to the server, it switches to the receiver window to await any potential downlink messages. However, since the event +EVT:SEND_CONFIRM is received via downlink, the receiver window closes before the message intended for the device can be transmitted. This leaves me puzzled as to how to effectively achieve downlink communication in this scenario.

I'm reaching out to the community for advice or guidance on how to tackle this issue. Has anyone successfully implemented downlink transmission in Class A mode? Are there any strategies or workarounds that could help overcome this challenge?

Your insights and experiences would be greatly appreciated as I work towards a solution. Let's collaborate and unravel the mysteries of LoRaWAN downlink in Class A mode together!

Looking forward to your responses.


Best Regards,

Taksh Patel.

ST Employee

Hello @Taksh 

For a more detailed and specific implementation, you should typically refer to the LoRaWAN specification and the documentation of the LoRaWAN stack being used for such implementations.

Best Regards.


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