Specific Data on RF communications for Herelink1.1

Hey guys,
I bought a Herelink1.1 controller and I was wondering if I can get some specific data on the direction and omnidirectional antennas. The purpose is so that I can create a mission simulation based on hardware specs. I am quite new to the RF world. I have some questions below:

  1. What is the purpose of both omnidirectional and directional antennas?

  2. I see gains listed on the website, are these transmitter or receiver gains?

  3. Am I able to get specific data such as antenna diameter, efficiency, power?

Any help would be great! Thank you