A cable television company now typically receives signals relayed from a communications satellite and sends those signals to its subscribers over coaxial or fiber-optic cable. Some television viewers use small satellite dishes to receive signals directly from satellites.
Most satellite-delivered signals are scrambled and require a special decoder to receive them clearly. The Columbia Electronic Encyclopedia, 6th ed. All rights reserved. See more Encyclopedia articles on: Electrical Engineering.
Cable TV is the system where in TV signal is delivered to the users using coaxial cable rather than radio waves. A cable TV company collects all the TV signals and multiplexes them. Later multiplexed signal is delivered to the subscribers. Cable channels are allowed bandwidth of 6 Megahertz, or MHz, per channel.
Given that coaxial cable is capable of many times this, it can carry many channels into the home on a single RG-6 coaxial feed. Some cable providers use a thicker, stiffer cable, called RG, to get high-definition, or HD, cable service and broadband Internet into your home.
This cable is capable of carrying delicate digital data for miles without loss. It may be surprising to learn that most cable companies get their signals from, ironically, satellite providers.
Using large dishes, these companies receive the channel data from their providers, package the channel and broadband Internet bundles as desired, and resell them to their subscribers. TV Network companies beam their TV shows via satellites. Cable operators or multi-system operators MSO install head-ends control centres for cable network for aggregation of TV channels received from different satellites.
They can mix this with content received from other sources such as broadband connections, local channels, etc. To access the cable television services, one needs to subscribe to a cable company which will then connect a simple coaxial cable from the wall outlet to the television sets.
In case one does not have a cable ready television then one needs to install a device called a converter box. In CATV, the signals are sent through cables and not through the air, thus doing away with "line of sight" requirement and enabling much better quality of reception.
The television signals that come via cable are not disturbed by trees, buildings, or other hindrances. Cable television signals use only a portion of the bandwidth available over coaxial lines. This leaves plenty of space available for other digital services such as cable, internet and cable telephony. Broadband cable internet is made possible by having a cable modem at the customer's end and a cable termination system at the cable operator's end.
Cable internet works very well when the distance between the cable modem and the cable termination system is not more than km. In Urban India, 88 per cent of all households have a TV and over 70 per cent of all households have access to satellite, cable or DTH services.
India now has over TV channels covering all the main languages spoken in the nation. An ordinance has been passed by the Government of India making digitization of cable services compulsory.
As part of the first phase, October 31, is the sunset date for the four metro cities in India to adopt set-top boxes. The Ministry of Information and Broadcasting has clarified that there would be no further extensions on the sunset date.
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