Although fiber-optic telephone cable is more expensive to manufacture than copper telephone cable, a telephone network using fiber-optic cable is less expensive overall than a telephone network using copper cable
This is because copper cable requires frequent amplification of complex electrical signals to carry them for long distances, whereas the pulses of light that are transmitted along fiber-optic cable can travel much farther before amplification is needed
The cost associated with frequent amplification of signals traveling through copper cable exceeds the extra manufacturing cost of fiber-optic cable.