At each service area, an optical node is installed. The node is an electronic device that converts light from the fibre back into RF signals, so they can be distributed on coaxial cables. The fifth component, the subscriber drop, provides the connection between the feeder cable and the subscriber premises. Homes passed are all of the homes in the community that are passed by the cable network and could conceivably connect to it. We also define our HFC network architectures in terms of the number of homes passed per node.
Cable systems are broadband networks.
This is because of their incredible bandwidth, or ability to carry a large number of RF signals simultaneously. The very first cable systems could carry only one to three TV channels, but as technology evolved that channel capacity increased. Today s cable systems can carry more than 130 regular analogue TV channels, and many times more than that if the TV channels are converted to compressed digital signals. For comparison, the AM radio broadcast band in many countries is a little more than 1 MHz wide, and the FM radio broadcast band is 20 MHz-wide. Ron Hranac is a consulting systems engineer for Cisco Systems.