LoRa RANGE ISSUE

Hi,

I am using B-L072Z-LRWAN1and AT-Slave project from I-Cube-LORAWAN SDK. What sequence of AT commands should the host issue to Join the network in OTAA mode and send data. Currently, I am using AT+JOIN and AT+SEND. But with these commands, I am not able to achieve a good range in my range testing. I did try to use AT+TXP=5 but it did not make any difference.

 Are there any AT command to improve the range?

Thank You