DSL Advances

9.1. The Loop Plant Environment

POTS is provisioned to customers by routing twisted wire-pairs between the telephone network equipment at a central office (CO) or remote terminal (RT) and the customer premises (CP) location. The twisted wire pair that connects the CO to the CP is the subscriber loop, which may consist of sections of copper twisted wire pairs of one or more different gauges.

Twisted wire pairs are contained in cables that have large cross sections near the central office. Within each cable, the twisted wire pairs are grouped into binders of 10, 25, or up to 50 wire pairs, and there could be up to 50 binder groups per cable.

Figure 9.1 shows the basic architecture of the loop plant, in which subscriber loops are provisioned. Each ...