Breaking duty cycle limitation by resetting RN2483?

jjjexy · January 8, 2019, 9:23am

Hi
I am working on a RN2483 project. On transmitting data, I noticed when I receive no channel available message, if I reset RN2483, I can bypass the duty cycle regulation and send data again.

Does it mean, the duty cycle limitation is implemented in the end-device only or it is rather a self-discipline?

ps. I understand it is stupid and selfish trying to engage or exceed maximum duty cycle. it is just out of curiosity

BoRRoZ · January 8, 2019, 9:45am

it’s implemented on ‘some’ enddevices that contain their own stack.
without they can’t have certification

arjanvanb · January 8, 2019, 10:38am

If your device is even close to the maximum duty cycle all day long, then it’s way over the TTN Fair Access Policy. And while the duty cycle limitations would indeed be enforced by the device, if the Fair Access Policy is ever enforced, then that would be done on the network server, out of your control.

Also, the duty cycle regulations define the maximum during a device’s peak usage, not an all day 24/7 maximum. If all of us would be using a duty cycle of 1% continuously, then even when transmissions magically somehow don’t collide and no downlinks are needed, the capacity would be as low as 100 devices per channel and SF.

So, for production devices stick to the limitations of the Fair Access Policy, or choose a different technology.

hobo · January 8, 2019, 2:00pm

Then it will be useless to breach FAP, but that will not help too much with channel capacity.

Or choose another LoRaWAN network server, right?

arjanvanb · January 8, 2019, 2:09pm

If one is close to the duty cycle maximum all day long, then LoRaWAN should not be your technology of choice, regardless the provider. I’d assume one’s need for that much data also requires (most of) that data to be delivered, which the license-free radio spectrum that LoRaWAN uses simply cannot guarantee. Especially not if many are sending that often. Simple mathematics.

TTN’s Fair Access Policy of 30 seconds of uplinks per 24 hours is based on supporting 1,000 nodes per gateway, which seems really reasonable to me, even for commercial providers.

hobo · January 8, 2019, 2:18pm

If you meant LoRa Alliance certification, it’s clearly stated that “The LoRa Certification testing will not do any duty cycle testing.”

hobo · January 8, 2019, 2:20pm

365 days per year - yes, LoRaWAN doesn’t fit. One day per month - why not?

alexbn71 · January 10, 2019, 10:47am

What is resetted is the “counter” that RN2483 keeps of the previous transmissions done. For this reason is quite normal that a restart of RN2483 clear this “counter” and start again acccumulating the “over the air” time for each channel…

The duty clyle limitations can be configured in the RN2483, through AT commands, see https://ww1.microchip.com/downloads/en/DeviceDoc/40001784B.pdf page 29.

So in this case is in charge of you (or the library you use) set the correct values.

Alex