LoRaWAN Class C and the 1% duty cycle

[lorawan2016]

Hello,

In the specification of LoRaWAN class A, the duty cycle is 1%.
In class C, the duty cycle in receiving messages does not exist. But how about the uplink messages sent by the end-devices.
1. Is there any duty cycle per channel in class C that affecting the uplink messages?
2. Is there any limitation if there are 1000 end-devices connected to one gateway to send 1 uplink message per hour per end-device?

Thanks for any official answers!

[Peter Ferland]

The duty cycle or “on air time” is the percentage of time that particular radio is allowed to be transmitting on each channel regardless of LoRaWAN mode. So for example during a join request in EU868 there are 3 possible channels that can be used for uplink. The node can send 1 request on each channel before waiting for the first channel to be available again. This restriction also applies to the gateway, so it is important to minimize downlink usage by not requiring ACKs.

So:
1. The rules are exactly the same as in class A, so after one radio transmits on a channel that particular radio must stay off it for a certain period of time.
2. If the gateway is not sending ACKs there is no limitation on the gateway side. However, if the gateway needs to send ACKs it is subject to the same duty cycle limitations on the downlink channels so far fewer nodes can be replied to in a certain time frame.

[Jason Reiss]

Actually the duty-cycle is managed on subsets of frequencies.
The default channels are in h1.4.
If one channel in the subset is used then the device must wait before using any channel in the subset. Another subset may be used.

http://www.erodocdb.dk/docs/doc98/official/pdf/rec7003e.pdf

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