Vraag

Max uplinks per hour

  • 21 februari 2017
  • 6 reacties
  • 746 keer bekeken

Reputatie 3
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Are there any limits for receiving uplinks per hour.
I know the fair use policy of airtime on the 868 band but it is not clear to me if this percentage is per day or per hour.

If i have a bundle of say 30 messages per day. Can i use them in one hour? Or even in 10 minutes?

Has the developer portal limitations in up/downlinks per hour?

6 reacties

Reputatie 7
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Hi Bas,

The fair use policy of airtime on the 868 band is defined per hour. My understanding is, as long as you are have less than 1% duty-cycle, you're able to sent messages. Although if it's only a fair use policy, there are no technical limitations. I've asked an egineer to verify this :)

From the FAQ:
What is the maximum number of message I can sent?
Your device should always obey duty cycle. KPN offers serveral different bundles where the number of uplink and downlink message are given per device. Currently, the largest bundle offers 300 messages per day. Sending more is possible, but you will be charged additional cost per extra message.

Example: A device just transmitted a 0.5 s long frame on one default channel. This channel is in a sub-band allowing 1% duty-cycle. Therefore this whole sub-band (868 – 868.6) will be unavailable for 49.5 s."
Reputatie 1
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Example: A device just transmitted a 0.5 s long frame on one default channel. This channel is in a sub-band allowing 1% duty-cycle. Therefore this whole sub-band (868 – 868.6) will be unavailable for 49.5 s."


Please note that this is just an example. If you sent 72 frames with 0.5 s time-on-air each and then keep silence for 3384 seconds (considering that RX2 delay is 2 seconds), you still meet the duty cycle reqs.
Reputatie 1
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[quote=hobo]
3384 seconds


Oops, 3386 🙂
Hello,

I have a few questions about the frequency I can send packages.

1. I have read that the maximum size of data I can send is 51 bytes. Is this correct? (so I can send a sentence with 51 ASCII characters)
2. How many bytes will be added to the data of 51 bytes? (parity check, keys, encryption ect.)
3. If I have to use SF12 with the max size message plus added information. What will the Time on Air be?
4. Does the note send every message 3 times for insurence that it will be received? If so, will this be added to the time on Air?
5. Can i still send a max size message every 5 minutes? (300 message a day subscribtion)

I want to measure something and use to maximum data per message and as often as possible.
Reputatie 1
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2. How many bytes will be added to the data of 51 bytes? (parity check, keys, encryption ect.)


12 or 13 (12 bytes of LoRaWAN header + FPort, if used)


3. If I have to use SF12 with the max size message plus added information. What will the Time on Air be?


It depends on CR used. Roughly, 2.8 sec. to 4 sec.
Reputatie 7
Badge +11
Thanks @hobo for your explanation!

KPN uses LoRa license-free ISM band, however, some conditions are attached.
The duty-cycle is defined as the ratio, expressed as a percentage, between the maximum transmission time on one or more frequencies with respect to a period of 1 hour.

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