Can I change the Join Accept RX window or data rate?


#1

Hi,
I’ve got to know that TTN uses the DR 2 for the IN865-867 plan in the RX2 window. Is there any chance to change the join accept packet rx window or data rate?
Best regards!


(Arjan) #2

Indeed, it uses 866.550 SF10BW125.

When using the public network, you cannot change that. However, if all is well, then TTN should use the LoRaWAN defaults for the Join Accept and then, in that Join Accept, include any network settings for anything that is not standard. But I think the TTN frequency plan is just always using the LoRaWAN defaults:

The RX2 receive window uses a fixed frequency and data rate. The default parameters are 866.550 MHz / DR2 (SF10, 125 kHz).

So, why do you think you need changes?

If you’re asking how to enforce RX1: it’s up to the TTN network server to choose either RX1 or RX2, so you cannot really enforce either. But if you use a low SF for the Join Request then chances are better that TTN will use RX1 for the Join Accept, as TTN prefers RX1 as well, at least for EU868. Still, a LoRaWAN compatible device should work with both RX1 and RX2.


#3

I would like to change it because the RN2903 uses a different default DR for RX2 window. Changing the DR in the module will require changes in my device firmware…
If there is no chance to change it from the app console then I’ll code the new DR.

Thanks a lot arjanvanb!


(Arjan) #4

So, that’s a bug in an old RN2903? Or does it not support IN865-867?

I’m quite sure you could change the RX2 settings from code or using a serial connection, as that is also needed for ABP. But maybe that setting does not apply to an OTAA Join Request, so: did you try? See mac set rx2 in the documentation.

(Ah, maybe the above is what you’re referring to with “device firmware”. I thought it was about the RN2903’s firmware.)


#5

Sorry I didn’t make it clear. I was refering to my devices firmware.

Sure, I changed the data rate and it worked.