Information Technology Reference
In-Depth Information
introduce problems with ground currents and ground loops. Particular attention must
be paid to the information and practices contained in EIA/TIA-607,
Commercial
Building Grounding and Bonding Requirements for Telecommunications
.
Screened cables are also available with individually screened pairs. In the current
implementations of Category 7 cables, for example, individually screened pairs are
further screened with an overall foil or braid shield. This type of construction provides
the optimum in electromagnetic isolation between pairs, as well as providing electro-
magnetic interference (EMI) immunity and very low EMI emission characteristics.
These cables may be characterized up to 1000 MHz (1 GHz), and are well
suited for leading-edge developments in copper cable transmission.
Fiber-optic cable has a construction surprisingly similar to some multi-conductor
wire. One or more buffer-coated optical fibers are enclosed in a protective outer
jacket with a fibrous strength member in between.
Outer jacket
Buffer
Optical fiber strand
Strengthening
fibrous material
125 mm
900 mm
FIGURE 5.4
Fiber-optic cable, cross section.
