Multicast: how make it work?

Hi everyone,

I want to send downlink messages from TTS to STM32WL end-nodes (class C enabled) by using multicast. However, I am not sure I have understood all the multicast process, especially on the server side (I work with TTS).

If I have already created an end-node device on my application and it already joined (with the OTAA) and sent uplink to my application, is it possible to add my end-node to a multicast group? If so, I am wondering about the device address. Indeed, when you want to create a multicast group with TTS, it works like an ABP profile. Device address, AppSKey and NwkSKey are asked. But which address and keys should I choose here?

Eager to learn, I am a beginner with multicast protocol! So, any advice is welcome!

Really appreciate your attention, thank you!

Hi again,
I forgot to mention that my gateway does not support GPS synchronisation. Is it a prerequisite to multicast?