I am using testing the CubeCell in Australia using OTAA on AU915. I have gateways in close proximity and and am seeing good reception. I want to specify the DR to be used to enable me to send payloads greater than 51 bytes. I am using the LoRaWAN.ino demo application modified to send payloads from 1 to 128 bytes.
Depending on the successful join OTAA join request, I am limited to either 51 bytes or 128 bytes maximum payload size depending on the data rate.
How can I specify I only want to use a specific DR to be able to supports more that 51 bytes payloads?