[tobyportugal]

Hi,

As with any RF transmission the range depends on several factors, such as the number of concrete walls the signal need to pass through, antennas used, etc.
Under normal conditions, an indoor receiver can easily receive data from an outdoor transmitter placed 200 to 300 meters away. With external antennas and line of sight between receiver and transmitter range can go to 2 to 3 Km or even more.


Image bellow is from a test I did a year ago: On the test I used two TX units placed indoor, and a receiver installed on a car. No special directional antennas are used, just regular 868Mhz omni directional antennas, easily found on eBay and other online stores.