AS923 dwell time limitation for Australia

Countries Frequency Plan
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Hello everyone

I am trying to find dwell time related information of AS923 for Australia.

The Dwell time is an optional feature in Lorawan spec for AS923 that can be activated or not and depends on network configuration.

My questions are:

  • For Australia, is the dwell time (both for uplink and downlink) actually activated in the Things Network Community edition (TTN) for AS923?
  • Does this limitations are waived from the Enterprise TTI stack both for uplink and downlink?

Thank you in advance for your help.

Regards

Muntasir Joarder

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Hello @mjoarderbcc,

I am happy I am not the only one who is wondering.
it looks to be mandatory in Japan to turn on limitation with 400ms duration, which have an impact on the payload size, but for Australia it is not clear.
If You check TTN regional parameters on GitHub;

The dwell_time is not mentioned, which mean “per default” or “O” --> Disable perhaps ?

Now, If You compare on GitHub file that has been set for US915, it is clearly set to 1 --> Enable
dwell-time:
uplinks: true
downlinks: false
duration: 400ms

cause as per lora alliance regional parameters for US915 They’ve mentioned:
“FCC regulation imposesa maximum dwell time of 400mson uplinks”

So there is a hope that the DWELL limitation is not compulsory in Australia… is anyone can answer that Question please ? Not only for TTN use case, but regarding the regulation !

Many Thanks

Taoz

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Just like a maximum duty cycle† or Listen Before Talk, a maximum dwell time is a regulation of one’s country, not something TTN has introduced. So, no, TTI cannot waive that. (I don’t know if any of those apply to Australia.)

† See also my update below!

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4

Thank you very much. From my research I didn’t see any restriction on dwell time in Australia. But will confirm when we test our device when available.

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5

Thank you very much for sharing the regional TTN configurations.

6

Australian government regulations in the 900MHz band was derived from the FCC requirements with a 400mS max Tx ON time… However in Australia 2017, the 400mS was removed and there is no limit on how long you can transmit. :grinning: :grinning:

You may find some Australian equipment that still has 400mS tx limit.

Larger spreading factors go over the 400mS Tx limit like SF12.

3 Likes
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Thank you very much.

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Amazing !! Thanks @mjoarderbcc !
Do You know any official document that specify this ? from the ACMA standards files ?
Cheers

Taoz

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Apparently the network may explicitly enable it, or needs to explicitly disable it? The LoRaWAN Regional Parameters 1.0.3 says for AU915:

The default JoinReq Data Rate is DR2 (SF10/125KHz), this setting ensures that end-devices are compatible with the 400ms dwell time limitation until the actual dwell time limit is notified to the end-device by the network server via the MAC command TxParamSetupReq.

AU915-928 end-devices MUST consider UplinkDwellTime = 1 during boot stage until reception of the TxParamSetupReq command.

The TTN Community network is using LoRaWAN 1.0.2, for which the Regional Parameters 1.0.2 Rev B don’t seem to mention this. Also, it’s not clear if TTN does send TxParamSetupReq for AU915. And it seems nothing similar is defined for AS923 in 1.0.3 either. Finally, I don’t know what TTN and your device’s LoRaWAN stack do for AS923.

I think this still applies. But regardless: it seems TTN/TTI would also need to send the proper LoRaWAN MAC commands to configure the device if the maximum dwell time does not apply to one’s region.

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…but apparently the maximum duty cycles may have been limited even more by the LoRaWAN specifications:

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Finally, DWELL “On” or “OFF” -: What Standard regulation says the rule ?
Thanks