Factors That Affect Range

Communication distance is determined by four factors:

Output power, recieve sensitivity, Antenna systems and the environment.

Visit this application note for Maximizing Range.

(Also please see Distance and Obstacles document with Fresnel Zone: https://www.digi.com/resources/documentation/Digidocs/90001942-13/#concepts/c_distance_and_obstacles.htm)

Actual performance varies in each environment. Digi strongly recommends that no radio decision be made without evaluating all radio modem candidates in the actual environment of the application.