Spreading factor

Hey every one
Im using Ra_02 ,SX1278 chip in 433MHz .
I want to know how can i separate channels by spreading factor.
I want to know how this is done with the functions in the library available in Arduino.
Because the communication half duplex ,How can a node block the gateway and exchange communication?

Which Arduino library are you using ?

LoRa.h

That is a point to point LoRa library, so is out of scope for discussion on this TTN forum.

Please do not double post on this forum - it’s not a good use of the volunteers time figuring out which to answer, even if your post is unanswerable.