Reception
The cable TV headend will normally have several large C-Band FSS-type television receive-only satellite television dishes for reception of cable/satellite TV networks. A dedicated, non-movable dish is required for each satellite that the cable TV utility wishes to receive cable channels from for distribution over its system. For reception of signals from several adjacent satellites, a larger non-parabolic multi-satellite dish (such as the Simulsat) that can see up to 3 or more satellites is often used. Many digital cable systems use services like HITS ("Headend in the Sky"), a unit of Comcast, which carry hundreds of channels on just a few satellites; this is commonly used by small systems to expand service without adding expensive new dishes or other equipment.
Most cable TV systems also carry local over-the-air television stations for distribution. Since each terrestrial channel represents a defined frequency, a dedicated commercial-grade receiving antenna is needed for each channel that the cable company wishes to receive and distribute. Smaller systems may use a broadband antenna to share several channels. These antenna are often built into a single tower structure called a master antenna television structure. Commercial TV pre-amplifiers strengthen the weakened terrestrial TV signals for distribution.
Some cable TV systems receive the local television stations' programming by dedicated coaxial, microwave link or fiber-optic line, installed between the local station and the headend. A device called a modulator at the local station's facilities feed their programming over this line to the cable TV headend, which in turn receives it with another device called a demodulator. It is then distributed through the cable TV headend to subscribers. This is usually more reliable than receiving the local stations' broadcasts over the air with an antenna. However, off-air reception is used as a backup by the headend in case of failure. In some cases systems receive local channels by satellite.
Other sources of programming include those delivered via fiber optics, telephone wires, the Internet, microwave towers and local Public-access television channels that are sent to the cable headend on an upstream frequency over the cable system itself (known in the industry as "T"-channels), or via a dedicated line set up by the cable company, as mentioned earlier for reception of local television stations' programming by the headend.
Read more about this topic: Cable Television Headend
Famous quotes containing the word reception:
“I gave a speech in Omaha. After the speech I went to a reception elsewhere in town. A sweet old lady came up to me, put her gloved hand in mine, and said, “I hear you spoke here tonight.” “Oh, it was nothing,” I replied modestly. “Yes,” the little old lady nodded, “that’s what I heard.””
—Gerald R. Ford (b. 1913)
“He’s leaving Germany by special request of the Nazi government. First he sends a dispatch about Danzig and how 10,000 German tourists are pouring into the city every day with butterfly nets in their hands and submachine guns in their knapsacks. They warn him right then. What does he do next? Goes to a reception at von Ribbentropf’s and keeps yelling for gefilte fish!”
—Billy Wilder (b. 1906)
“But in the reception of metaphysical formula, all depends, as regards their actual and ulterior result, on the pre-existent qualities of that soil of human nature into which they fall—the company they find already present there, on their admission into the house of thought.”
—Walter Pater (1839–1894)