Assuming you’re using the TTN community network that only supports Class A devices: if the above implies that your “Siren” device is sending uplinks just to poll for a downlink command to control it, then I very much doubt that this is a suitable use case for LoRaWAN. Even less so on the TTN community network, which defines a fair access policy (with limitations that, I feel, should apply to any other low-density LoRaWAN network as well).
Also beware that there’s just no guarantee that your device’s uplinks are received; it’s radio in a shared spectrum after all.