Will a 14Dbi, 2.4 Ghz antenna (for wireless internet) transmit a distance of 5000' (no obstructions between)

Question

Is there a standard way to calculate the distance an antenna will transmit providing you know the rating of the antenna (assuming no obstructions between the antenna and the power source)?
Thanks,
Don

Answer 1

Hi Don,
This should work but it will depend on the transmit output power, which will probably be 100mW max. It would also depend on the receive sensitivity of the radio on the other end. What data rates are you looking for? Because higher data rates have more complex signalling and need better receive sensitivity. It also depends on how the antenna is connected, if you have a longer cable with more loss then this can change things dramatically. The difference between a 5 and 20 and 100 foot antenna cable makes a big difference, the shorter the better.

You also mention there are no obstructions, but be aware of the "fresnel zone"... that is, a clear visual line of site does not necessarily mean a clear RF line of site. The first fresnel zone (shaped like a football between both endpoints) should be at least 60% unobstructed. This won't be hard in your case, for a 1-mile link at 2.4GHz the middle of the fresnel zone is less than 20 feet.

Check out the link below to a free wireless bridge link calculator. It is a bridge link, right? If so, this should all work, especially if you use the 14dBi on both ends of the link. If not, and you have a client that is 5000 feet away with a wireless NIC, it will not work, the client will not have the power to transmit back to the high gain antenna.