I’m trying to configure a LoRaWAN network. My goal is setting between 300 and 1200 sensors, that will send alarms when specific events happen.
As far as I know, LoRaWAN duty cycles are restricted by ETSI EN300.220 standard as:
- g (863.0 – 868.0 MHz): 1%
- g1 (868.0 – 868.6 MHz): 1%
- g2 (868.7 – 869.2 MHz): 0.1%
- g3 (869.4 – 869.65 MHz): 10%
- g4 (869.7 – 870.0 MHz): 1%
and nodes select the channel frequency for transmission in a pseudo random way. My first doubt is, how can I make sure this duty cycles restrictions are accomplished if I can’t control the frequency selection?
My second question is, these duty cycles are meant for a single device, or for a full network? For example, if duty cycle is 1%, it gives me 864 seconds/day, which means 36 seconds/day. If my Time on Air frame is 30ms (because my alarm payload is just 1 byte), I can send 1200 messages in an hour ((36secs/hour)/(30ms/message)), which means 1 message each 3 seconds ((3600secs/hour)/(1200)). If I have one just single node sending 1 message each 3 seconds, I am respecting duty cycle policy. However, if I am sending this same message each 3 seconds with 300 nodes, I am not respecting it, right??
Thank you in advance for your help. Please correct me if I am doing any wrong suposition.