IMRDWS is an aerial wire designed for use in extending communications
service (voice, data, and/or video) to a subscriber premises from the
distribution point. This product has additional capabilities over the
standard IMRDW product because it contains a shielding screen. The
conductors are wrapped within a metallic aluminum shield to insulate
them from interference and thus provide high-quality digital transmission.
In addition, a drain wire runs longitudinally the length of the wire to drain
off Electromagnetic Interference (EMI) and Radio Frequency Interference
(RFI). Without shielding and a drain wire, noise can be introduced into
circuits from high voltage AC power lines, machinery with motors, x-ray
systems, TV sets and AM radio stations. Shielding also lessens the
chance that DSL or other high frequency transmission protocols will
interfere with other signals on adjacent cables.