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
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.)
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.
You may find some Australian equipment that still has 400mS tx limit.
Larger spreading factors go over the 400mS Tx limit like SF12.
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.