In a backbone distribution system, which media types can be used?

• A. Copper only
• B. Fiber only
• C. Wireless only
• D. Can include any combination of copper, fiber, and wireless

Answer: (D)

The backbone distribution system is designed to carry high-capacity traffic between major network nodes, and the physical medium isn’t limited to one type. You can mix copper, fiber, and wireless as needed. Copper is typically cheaper and works well for shorter hops or legacy links, though it has distance and bandwidth limits. Fiber offers very high bandwidth and long reach, with excellent immunity to interference, making it ideal for backbone runs between buildings or across campuses. Wireless backhaul provides flexible, rapid deployment where laying cables isn’t practical or as a temporary/redundant path. In a cross-connect facility, you’ll often see equipment and interconnects that accommodate multiple media, enabling flexible routing and redundancy. So, any combination of copper, fiber, and wireless can be used in a backbone distribution system.