Hi, I am student and I am running some tests using my Archer C6 v2 AC1200 Wireless MU-MIMO Gigabit WiFi Router.
I need to calculate the free space attenuation, log distance attenuation, link budget and so on, but for that I need some specs, such:

Antenna gain in dBi;
Transmission power in dBm;

I plan to use 20 dBm as transmission power (CE EIRP TEST DATA, but it only says less than 20 dBm and not an accurate value).
For the antenna, internet says its common 2 to 5 dBi, but it is a general value.

When I check the ANATEL (Brazil telecommunications certifying body) test results, I can find for the test the following data:



Converting, I have:

• 0,4966 W → 26,96 dBm
• 0,5572 W → 27,46 dBm
• 0,5445 W → 27,36 dBm
• 0,5649 W → 27,52 dBm

I could`t find more accurate data. Still not sure of which value I should consider. Can someone help me?