Very often we hear people calling about cable TV. What's the difference with TV nonkabel?
Broadcast Television (TV) cable is already a part of most societies the United States. While in Indonesia, it is still so consumption is quite expensive. With a condition: the number of small operators, there are only in major cities (such as Jakarta, Medan, Bandung, and Surabaya), and a limited number of customers in the upper classes. Actually, what the hell it is cable TV?
As the name implies, is a media liaison between the cable TV operators and customers. The first cable TV system (made in 1948) uses the type twin lead cable. This cable is shaped like a ribbon that is placed on black and white TV. The next system (made in 1950) have used coaxial cable. Coaxial cable consists of conductors in the insulator and conductor-covered outside, as installed between the antenna and TV sets today. Subsequent developments, the network also used the microwave, satellite, and fiber optic cables.
Travel Cable TV
Actually, the first cable TV was built to cope with difficulties receiving television broadcasts suffered by areas with poor signal reception. Usually an antenna mounted on the tower located on top of a mountain or other high places in the area. Then, the cables used to connect the antenna to the TV in some houses around it.
In 1948, Ed Parson who lives in Astoria, Oregon, a community antenna television system (CATV) with twin-lead cable media and installed from one roof to another roof. Meanwhile, in 1950, Bob Tarlton to build the system in Lansford, Pennsylvania, using coaxial cable installed on pole. He gained a monopoly in town and three channels broadcast to subscribers.
It turned out that television broadcast reception difficulties not only in remote areas, but also in cities full of tall buildings. Therefore, cable TV is also growing in urban areas. In addition, the longer it is not just a line extension of local TV broadcasts, but was able to provide services that can compete with other TV broadcasts.
Looking at these developments, the Federal Communications Commission (FCC) to make restriction for cable TV to receive broadcast television remote. In early 1970, the FCC policy was strengthened by making laws that restrict the ability of cable TV operators in the broadcast: the movie, a glimpse of the events, and others.
However, in 1972 issued a gradual deregulation policy for cable TV. As a result, the more relaxed rules. It generates the cable television industry completeness makers at local and federal level. Thus, there was growth of broadcasting services and additional customers. The use of microwave technology, satellite communications, and fiber optic cable as an additional media also enhance the growth of the service. In addition, also obtained by increasing channel digital video data compression.
In Indonesia alone cable TV emerged in the early 1990s. Currently there are at least three operators are still rooted to serve certain circles in several major cities. Connection fees and subscriptions are high make not many people interested in becoming customers. Not to mention the number of television stations that appear to still be able to meet the needs of the majority of our society. Especially with the emergence of local TV's.
Headend is the source of the emitted signal to cable systems. Headend not only receive local broadcast signals to be transmitted, but also can receive signals: broadcast from a distant city, broadcasts from satellites, and from wave microwave. Therefore, the headend is equipped with supporting devices, such as towers and various types of antennas, including satellite dish, to receive broadcasts from satellites.
In addition, the headend may have broadcast their own programs and thus require an adequate studio to produce a broadcast program. For this application, the headend can set their own time and channel is required. As for time and channel for community access is usually entrusted to the local franchise. In general, cable TV systems can not do the editing control over the quality or content of community access programs.
Cable system consists of two parts, the trunk system and distribution system. Trunk system works to send signals to groups of customers. The devices in the system and the trunk is a trunk cable trunk amplifier. Trunk amplifiers serve to strengthen the signal is weakened due to the length of cable. He was installed at each distance. Total amplifier mounted on the cable is limited by the noise and distortion on the amplifier in question. Good quality cable will reduce the number of amplifiers to the same cable length.
Functioning distribution system to distribute signals to each home in one group of customers. Between the trunk and distribution system installed interface called Bridger amplifier. Support device distribution system is distribution cable, line extender amplifiers, and taps. The function of line extender amplifiers in the distribution system similar to the function of trunk amplifiers in the trunk system. TAP serves as a point of decision or branching signal to the drop cables associated with the device on the customer. Unlike the rigid structure of distribution cable, drop cable has a flexible structure / flex.
At the customer's home, the output drop cable connected to a TV or VCR (video cassete recorder). However, if TV or VCR customers can not find all the existing channels (because VCRs are not compatible with cable systems), required converter that serves as an interface / translator between the TV and cable systems. Typically, the converter has been provided by cable TV operators. If the broadcast signal sent by the headend through the process of randomization (scrambling), the converter must be installed descrambler.
Frequency band and channel
Signal frequency band is relatively wide cable TV operations, ranging from 50 MHz to 450 MHz, even up to 1 GHz. Wide frequency band is divided into many channels. The width of each channel is adjusted with a standard video bandwidth of 4.2 MHz. More and more channels are used, the frequency band width is also required. These channels are sent simultaneously via a cable.
The problem, though the cable TV system has a wide frequency band, a TV set used is not like that. Therefore, this system provides multiple channels (usually channels 2,3,4,5) as the channel of reference for the TV or VCR. In the TV channels that serve as monitors and election broadcasts done by adjusting the tuner / tuner in the converter.
The development system
The emergence of new technologies and the increasing need for diversification benefits of cable TV system causing the system is developed from time to time. Development occurs on the hardware and software. Among them is the use of microwave wave, if the tower broadcast receivers remotely located away from the headend. If the trunk or distribution cabling is difficult or expensive, then the wave of the microwave can be used as a substitute.
The emergence of optical fiber cables, which can be worn on the trunk and distribution system, produce a better broadcast signal resistant to interference because of weather or interference from other radio waves. The use of fiber optic cables also reduce the number of amplifiers that are used for fiber optic cables have low values of cable loss.
Digital system implemented on devices as well as the TV broadcast also caused a lot of changes. Digital video compression techniques make the system capacity becomes higher, so multiply the number of channels. The techniques of Forward Error Correction (FEC) that can correct data errors due to noise is also used to obtain a higher transmission rate.
A quite new is the use of cable systems to the Internet. This application can occur if the headend add to its function as an Internet gateway. Headend also be a server for web services, e-mail, and e-news. For that, cable systems must provide two-way channel for sending and receiving data with the system LAN (Local Area Network).
Other developments certainly should continue to be done, given the many competitors who are always trying to be a "one stop server / service" that can meet all your communication needs as well as entertainment for its customers. Competition could come from a TV cell phone system that is more mobile or fixed telephone lines that can be developed into a video broadcast signal carrier. With excess-excess, these systems must be a strong competitor for cable TV.
Broadcast Television (TV) cable is already a part of most societies the United States. While in Indonesia, it is still so consumption is quite expensive. With a condition: the number of small operators, there are only in major cities (such as Jakarta, Medan, Bandung, and Surabaya), and a limited number of customers in the upper classes. Actually, what the hell it is cable TV?
As the name implies, is a media liaison between the cable TV operators and customers. The first cable TV system (made in 1948) uses the type twin lead cable. This cable is shaped like a ribbon that is placed on black and white TV. The next system (made in 1950) have used coaxial cable. Coaxial cable consists of conductors in the insulator and conductor-covered outside, as installed between the antenna and TV sets today. Subsequent developments, the network also used the microwave, satellite, and fiber optic cables.
Travel Cable TV
Actually, the first cable TV was built to cope with difficulties receiving television broadcasts suffered by areas with poor signal reception. Usually an antenna mounted on the tower located on top of a mountain or other high places in the area. Then, the cables used to connect the antenna to the TV in some houses around it.
In 1948, Ed Parson who lives in Astoria, Oregon, a community antenna television system (CATV) with twin-lead cable media and installed from one roof to another roof. Meanwhile, in 1950, Bob Tarlton to build the system in Lansford, Pennsylvania, using coaxial cable installed on pole. He gained a monopoly in town and three channels broadcast to subscribers.
It turned out that television broadcast reception difficulties not only in remote areas, but also in cities full of tall buildings. Therefore, cable TV is also growing in urban areas. In addition, the longer it is not just a line extension of local TV broadcasts, but was able to provide services that can compete with other TV broadcasts.
Looking at these developments, the Federal Communications Commission (FCC) to make restriction for cable TV to receive broadcast television remote. In early 1970, the FCC policy was strengthened by making laws that restrict the ability of cable TV operators in the broadcast: the movie, a glimpse of the events, and others.
However, in 1972 issued a gradual deregulation policy for cable TV. As a result, the more relaxed rules. It generates the cable television industry completeness makers at local and federal level. Thus, there was growth of broadcasting services and additional customers. The use of microwave technology, satellite communications, and fiber optic cable as an additional media also enhance the growth of the service. In addition, also obtained by increasing channel digital video data compression.
In Indonesia alone cable TV emerged in the early 1990s. Currently there are at least three operators are still rooted to serve certain circles in several major cities. Connection fees and subscriptions are high make not many people interested in becoming customers. Not to mention the number of television stations that appear to still be able to meet the needs of the majority of our society. Especially with the emergence of local TV's.
Headend is the source of the emitted signal to cable systems. Headend not only receive local broadcast signals to be transmitted, but also can receive signals: broadcast from a distant city, broadcasts from satellites, and from wave microwave. Therefore, the headend is equipped with supporting devices, such as towers and various types of antennas, including satellite dish, to receive broadcasts from satellites.
In addition, the headend may have broadcast their own programs and thus require an adequate studio to produce a broadcast program. For this application, the headend can set their own time and channel is required. As for time and channel for community access is usually entrusted to the local franchise. In general, cable TV systems can not do the editing control over the quality or content of community access programs.
Cable system consists of two parts, the trunk system and distribution system. Trunk system works to send signals to groups of customers. The devices in the system and the trunk is a trunk cable trunk amplifier. Trunk amplifiers serve to strengthen the signal is weakened due to the length of cable. He was installed at each distance. Total amplifier mounted on the cable is limited by the noise and distortion on the amplifier in question. Good quality cable will reduce the number of amplifiers to the same cable length.
Functioning distribution system to distribute signals to each home in one group of customers. Between the trunk and distribution system installed interface called Bridger amplifier. Support device distribution system is distribution cable, line extender amplifiers, and taps. The function of line extender amplifiers in the distribution system similar to the function of trunk amplifiers in the trunk system. TAP serves as a point of decision or branching signal to the drop cables associated with the device on the customer. Unlike the rigid structure of distribution cable, drop cable has a flexible structure / flex.
At the customer's home, the output drop cable connected to a TV or VCR (video cassete recorder). However, if TV or VCR customers can not find all the existing channels (because VCRs are not compatible with cable systems), required converter that serves as an interface / translator between the TV and cable systems. Typically, the converter has been provided by cable TV operators. If the broadcast signal sent by the headend through the process of randomization (scrambling), the converter must be installed descrambler.
Frequency band and channel
Signal frequency band is relatively wide cable TV operations, ranging from 50 MHz to 450 MHz, even up to 1 GHz. Wide frequency band is divided into many channels. The width of each channel is adjusted with a standard video bandwidth of 4.2 MHz. More and more channels are used, the frequency band width is also required. These channels are sent simultaneously via a cable.
The problem, though the cable TV system has a wide frequency band, a TV set used is not like that. Therefore, this system provides multiple channels (usually channels 2,3,4,5) as the channel of reference for the TV or VCR. In the TV channels that serve as monitors and election broadcasts done by adjusting the tuner / tuner in the converter.
The development system
The emergence of new technologies and the increasing need for diversification benefits of cable TV system causing the system is developed from time to time. Development occurs on the hardware and software. Among them is the use of microwave wave, if the tower broadcast receivers remotely located away from the headend. If the trunk or distribution cabling is difficult or expensive, then the wave of the microwave can be used as a substitute.
The emergence of optical fiber cables, which can be worn on the trunk and distribution system, produce a better broadcast signal resistant to interference because of weather or interference from other radio waves. The use of fiber optic cables also reduce the number of amplifiers that are used for fiber optic cables have low values of cable loss.
Digital system implemented on devices as well as the TV broadcast also caused a lot of changes. Digital video compression techniques make the system capacity becomes higher, so multiply the number of channels. The techniques of Forward Error Correction (FEC) that can correct data errors due to noise is also used to obtain a higher transmission rate.
A quite new is the use of cable systems to the Internet. This application can occur if the headend add to its function as an Internet gateway. Headend also be a server for web services, e-mail, and e-news. For that, cable systems must provide two-way channel for sending and receiving data with the system LAN (Local Area Network).
Other developments certainly should continue to be done, given the many competitors who are always trying to be a "one stop server / service" that can meet all your communication needs as well as entertainment for its customers. Competition could come from a TV cell phone system that is more mobile or fixed telephone lines that can be developed into a video broadcast signal carrier. With excess-excess, these systems must be a strong competitor for cable TV.
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