Swarm of Drones, which hardware will be suitable

Hello everyone,
I am thinking to build a project containing a swarm of drones that does a task collaboratively. I was thinking of a system where each drone will be equipped with pixhawk and raspberry pi (companion computer) and there will be one main server (probably my laptop) that will help to coordinate between multiple drones. So I want a method to communicate between the Ground Control Server to all drones.
What kind of hardware that I can use for communication between the server and raspberry pi lying on the drone? I have seen SwarmLink, but I need more programmatic access to the communication hardware so that I can send data to RPI through the air. (Not thinking to use the internet as transmission medium for now).

Is there any good type of hardware that I can use?

Thanking you in anticipation.