I am trying to understand how long range Wi-Fi works. As far as I know, Wi-Fi consists of Tx and Rx. When a laptop is connected to an access point (AP), the laptop is able to receive data from the AP (Rx) and also transmit data back to the AP (Tx).
Let's say I want to build a long range Wi-Fi to cover a large area. I connect a high-gain omni-directional antenna like this to the AP.
Let's say the original AP's Wi-Fi signal radius is 250 m. By using the high-gain antenna, the radius become 1000 m.
At 1000 m away from the AP, by using a normal laptop (without any high gain antenna), I try to connect to the AP.
The Tx signal from the AP is able to reach the laptop. But, the Tx signal from the laptop should not be able to reach the AP. Under this condition, can the laptop connect to the AP?
Best Answer
The antenna changes the shape of the transmission. The electrical signal doesn't get more powerful, but less is wasted in transmission in directions which aren't useful (e.g., up and down).
Similarly with reception, the signals are received from a more narrow field, this strengthens reception and reduces interference.
It's similar to talking through a cone, then listening through the cone for a response. the person at the other end doesn't need any special equipment, but you've increased your range and sensitivity.