For connectivity between two buildings that are over 750 meters apart, which type of fiber cabling is recommended?

Single mode fiber is the recommended type of cabling for connectivity between two buildings that are over 750 meters apart due to its ability to transmit data over long distances with minimal signal loss. This type of fiber has a smaller core diameter, allowing it to carry light directly down the fiber without much reflection, which reduces attenuation and increases distance capabilities. Single mode fiber is designed for long-distance telecommunications and is typically utilized in scenarios where distances exceed 500 meters, making it suitable for the situation described in the question.

In comparison, multi-mode fiber, while capable of handling shorter distances effectively, does not perform as well over longer distances due to modal dispersion, which can lead to signal degradation. Coaxial and twisted pair cables are generally more suited for shorter runs and specific applications, such as video or local area networking, and are not ideal for connecting two buildings separated by over 750 meters. Hence, single mode fiber is the most appropriate choice for ensuring reliable connectivity across such distances.