摘要 |
<p>A communications system including an initially installed coaxial cable may be readily upgraded by installing a fiber optic cable therein. The coaxial cable has an empty longitudinal channel extending continuously along substantially the entire length thereof. A propellable fiber optic cable is later installed in the channel by a fluid flow which create a sufficient drag to advance the fiber optic cable into the channel. The fiber optic cable is installed to meet increasing communications demands or when otherwise desired. The coaxial cable may include an empty electrically conductive tube serving as the center conductor for later receipt therein of the fiber optic cable. In other embodiments, the coaxial cable may have a channel provided in a dielectric material between the center and outer conductors, or a channel formed in the outer protective jacket.</p> |