How Cable Works

How Cable Works

Cable Combines Technologies to Bring Programming to Customers

Today´s cable industry is at the center of the revolution in telecommunications. Cable uses a sophisticated network that effectively combines a host of technologies including point-to-point microwave, satellites, and coaxial and fiber optic cable.

The basic structure of a cable system is simple. There are five major parts: the headend, where signals are received and processed; the trunk cable, which carries the signals from one-point to another without directly serving subscribers; the feeder cable, which connects the main trunk line to the smaller drop cable; the drop cable, which feeds into the subscriber´s home; and the terminal equipment, such as a TV or VCR.

Signals from broadcast transmisions, satellites, and local television studios are received and processed at a system´s headend. They then are transmitted to the homes of customers through a wired network of coaxial and/or optical fiber, which is either attached to telephone poles or placed in underground channels.

Generally, a large trunk cable carries the signals from the headend to feeder cables of smaller diameter, which branch off from the trunk into local neighborhoods. Amplifiers are spaced along the cable line to ensure that high quality signals reach the subscriber´s home. When a customer purchases cable service, the cable operator runs a smaller drop cable from the feeder cable directly into the customer´s home where it is attached to the television set.

This system design is known as the "tree and branch" and is the most efficient and economical method to transmit a package of multiple channels of programming from a headend to all customers.