Cable tv or TV cable system, was born to bring image and sound to zones of difficult access for traditional television. Far from television distribution centers, stood a community and via coaxial cable antenna, signal was distributed. Cables transmit radio signals. The possibility of the cable is wide; be accessed through her internet, telephony and radio. The system without antenna, was accepted and began to expand, adding more channels than broadcast television. Cable television had its origin in an initiative of neighborhood network of television in the 1940s.

Cable tv system consists of: header or core team: is the party that governs the entire system. In the case of distribute tv signals, i.e. unidirectional, used television reception by antenna, satellite and microwave equipment. Here RF signals is also overhauling for retransmission. Another function of the header is to apply the rate for subscribers and controlling the service provided.

The outer part: call network, this way a rough trunk or subtroncal. They depart from the header and connected main lines. This network uses amplifiers, coaxial cable trunks, splitters and couplers. User equipment: they are located in the home of the Subscriber, consists of a signal and appropriate TV decoder. In its origins the cable TV did not intend to compete with TV by antenna, simply sought a system that would help it where the antenna signal was poor. Once the open television had no problems reaching every place, it is discouraged to the cable tv industry. In the 1970s was an awakening, when satellite television promoters contacted the cable to add more channels to the offer of open tv. The third part of the development of television by cable came from the hand of the digitization of the network. In this way it was possible to distribute voice, video and data, allowing to the cable companies sell packages differentiated by number of channels and internet services. This turned the relationship with the Subscriber in an almost interactive relationship, since they can choose the language, access to broadband, etc. The sale of cable tv to the wholesale has good prospects, since currently the tv is one service of cable distributors. In our days is distributed by cable, internet and telephony, networks exploiting the laying of cable.