Specifying Transmission Power

I am in a strange situation where the lora gateway and the sensors are not able to communicate with each other, probably because of range issues. They communicate well when they are in a distance of about 30 meters, but farther than that, they are not able to communicate. Even join requests are not seen by the loraserver.

So I am thinking if adding a better external antenna will help. Before I make a purchase of an external antenna, I want to make sure that I have exhausted all possibilities of increasing range in the loraserver side. Is it possible to increase the transmission power of the gateway from loraserver? Could anything be tweaked from the loraserver/lora app server to make these devices communicate?

I am a total novice in antenna design etc. It would be great if someone can tell me if an external antenna is a good idea.

Thanks!

PS: I have setup everything at default in the lora app server interface. If a field was optional, I did not change it at all.

Increasing power transmit power on a gateway will not help the gateway receive uplink messages from the sensors. Setting up an external antenna is definitely a good idea.