Which medium is commonly used for long-haul networks?

• A. Copper cables
• B. Fiber optic
• C. Wireless
• D. Coaxial

Answer: (B)

Long-haul networks demand a medium that can carry large amounts of data over great distances without significant signal loss or interference. Fiber optic cables use light to transmit data, which experiences very low attenuation over long distances and is immune to electrical noise. This allows signals to travel thousands of kilometers with repeaters and enables huge bandwidths, especially when technologies like DWDM (multiplexing multiple wavelengths) are used on a single fiber. Copper or coaxial cables lose signal quickly and are more susceptible to interference, and wireless links, while useful in some segments, don’t consistently match fiber for backbone capacity and reliability. That combination of low loss, high capacity, and resilience to interference is why fiber optic is the common choice for long-haul networks.