Introduction

This section describes the terms, methods, and issues related to the physical movement (transmission) of information over various media and identifies the impact of telecommunications cabling installation methods.

Transmission, as discussed in this section, is the movement of information as electrical or optical signals from one point to another via a medium. The medium can be air, water, copper, optical fiber, or whatever else might be used to carry the signal.

This section deals with the use of copper conductors and glass strands for the passing of signal in either analog or digital form.

The choice of a specific medium is influenced by economics and technical considerations, such as the:

• Physical diameter of the cable.

• Type of services to be provided (e.g., voice, data, and video).

• Topology and size of the network.

• Transmission path distance.

For copper systems, where there is concern that electromagnetic interference (EMI) conditions exist that cannot be solved readily by means of an increased physical separation, optical fiber may be used. With the exception of electromagnetic pulse (EMP), EMI or other electrical interference does not affect optical fiber cable.

All media have certain characteristics that will limit performance. Media selection should be based on the specific network requirements. Once the proper selection has been made, common degradation factors are improper system design or cabling installation techniques.

To ensure compliance with industry cabling standards, manufacturers of copper and fiber cable institute design changes in the manufacture of their products as the...