In microwave telecommunications systems, the transmission media primarily used is:

Microwave telecommunications systems primarily utilize air as the transmission medium due to their reliance on line-of-sight propagation. This method allows for the transmission of high-frequency microwave signals, which can travel through the atmosphere without the need for physical cables. Microwave radio signals are effective over long distances and can traverse large geographic areas when properly aligned. This characteristic makes air the optimal medium for such communication systems.

Fiber optic cables, coaxial cables, and landlines are physical media that are typically employed in other forms of telecommunications, but they do not align with the specific operational principles of microwave technology. Fiber optics, for example, utilize light transmission through glass or plastic and are not suitable for microwave signal propagation. Similarly, coaxial cables, which transmit electrical signals, are more associated with traditional cable systems rather than microwave transmission. Landlines, being physical wired connections, also do not facilitate the kind of high-frequency, short-wave transmission that microwave systems rely on.