In the early days, C-band satellite television systems used one Low Noise Amplifier, which was conne

As we know, television programs transmitted by communications satellite and used a satellite dish and set-top box to receive is called satellite television. cheap hotels in virginia beach Although we have already had terrestrial television programs and cable television programs, but satellite television cheap hotels in virginia beach still offers a large amount of channels and services covered many areas of the world, mainly focus on the areas that cannot receive terrestrial or cable television signal.
In 1962, the first satellite television signal was transmitted cheap hotels in virginia beach from Europe to the Telstar satellite over North America. In 1963, the first geosynchronous communication satellite Syncom cheap hotels in virginia beach 2 was launched. On April 6, 1965, the first commercial communication satellite Intelsat, also known as Early Bird, was launched cheap hotels in virginia beach into synchronous orbit. In 1967, Soviet Union created the first national network of satellite cheap hotels in virginia beach television Orbita, which relayed and delivered television signal to ground stations by using highly elliptical satellite Molniya based on the same working principle. In 1972, geostationary Anik 1 of Canada was launched as the first domestic North American satellite used to transfer television signal. In 1974, the first experimental educational and Direct Broadcast Satellite ATS-6 was launched. In 1976, geostationary satellite Ekran was launched by Soviet Union to transmit Direct-To-Home television program. 2. Technology of Satellite Television
There are two orbits for satellites transmitting television signals. One is naturally highly elliptical orbit, also called Molniya orbit, with inclination of ?63.4 degrees and orbital period of about 12 hours. The other is geostationary orbit of 37,000 km above the earth's equator.
Satellite television is much similar cheap hotels in virginia beach with other applications provided by satellite, transmitting antenna is the start point and built inside an uplink facility. The size of uplink satellite dishes is very big, almost 9 to 12 meters in diameter. The larger the diameter is, the more accurate pointing and stronger signal at the satellite. cheap hotels in virginia beach Then the uplink dish is looking toward a specific satellite cheap hotels in virginia beach and using a specific frequency range to transmit the uplink signals. Then one of the transponders which has the same frequency range in that specific satellite receives the uplink signals. After that, the signals are retransmitted back to Earth station by the transponder and use a different frequency band for retransmitting. This process is called translation, which use different frequency band to prevent interference with the uplink signals. Nowadays, we mainly use C-band (4GHz-8GHz) or Ku-band (12GHz-18GHz) or both. In addition, the direction from the satellite to the Earth station is called the downlink.
A classical satellite has a maximum value of 32 transponders for Ku-band and a C-band only satellite has a maximum value of 24 transponders. There are more transponders for hybrid satellites. Each transponder has a frequency band between 27MHz and 50MHz. C-band only satellite has to be separated from each other for 2 degrees because of the interference. Ku-band satellite has to be separated from each other for 1 degree. In other words, we can maximum launch 180 geostationary C-band cheap hotels in virginia beach satellites (360 degree/2 degree = 180) and 360 geostationary Ku-band satellites (360 degree/1 cheap hotels in virginia beach degree = 360). Transmission provided by C-band satellite is sensitive to the interference with terrestrial transmission. On the other side, transmission provided by Ku-band satellite is sensitive to rain, since water can absorb microwaves at this frequency.
After transmitting quite long distance, the weak downlink signals are gathered by a receiving cheap hotels in virginia beach dish and reflected to the focal point. Feedhorn is a device built on brackets at the focal point. This device works as a section of flared front end waveguide, cheap hotels in virginia beach which collects signals at or close to the focal point and feed them to a probe, which connects to a low noise block downconverter or LNB. The LNB can implement several cheap hotels in virginia beach functions, like amplifying the weak downlink signals, filtering the frequency band of satellite television signals, transforming the frequency band to a lower frequency range (low frequency band) and etc. The improvement of LNB is one significant cheap hotels in virginia beach research direction these days.
In the early days, C-band satellite television systems used one Low Noise Amplifier, which was connected to the feedhorn cheap hotels in virginia beach at the focal point. Then the increased signal was driven into an indoor receiver by using gas filled hardline coaxial cable, which cost so much and has 50 ohm impedance. Or sometimes, due to other design principles, the increased signal was driven into a downconverter for transforming to an intermediate frequency. Besides, microstrip based converters designed for Amateur Radio frequencies have to changed to the 4 GHz C-band.
Replacing Low Noise Amplifier with an LNB has many advantages. For example, the indoor receiver is connected with the satellite television dish and LNB by using cheaper cable and it is much cheaper for using technology to process low band signal and UHF (UltraHigh Frequency) signal rather than using technology to process C-band signal. Replacing the 50 Ohm impedance cable and N-Connectors with the 75 Ohm impedance cable and F-Connectors makes the original satellite television receivers available to use. However, in fact, modified UHF television tuners downconvert the satellite television channel to a lower intermediate frequency surrounded cheap hotels in virginia beach by 70 MHz (demodulation cheap hotels in virginia beach frequency). According to this shift, cheap hotels in virginia beach evolution of satellite television industry decreases the cost of complete system and increases the production efficiency.
At the end, television signals were demodulated and converted to the appropriate form (video, audio and data) by the satellite receiver. In some design, the satellite receiver is able to decrypt or unscramble, which is known as Integrated Receiver/Decoder (IRD). Besides, we need specific type of cable to connect the satellite receiver to the LNB, like low loss type RG-6, quad shield RG-6 or RG-11 and so on. (NB. RG-59 is not allowed.) 3. Direct Broadcast Satellite cheap hotels in virginia beach (DBS)
Direct Broadcast Satellite (DBS) is mainly focus on the satellite television broadcasting for home reception. In most cases, DBS television program is available as same as the program available to cable television subscribers. The different thing is DBS subscribers can receive the television programs directly from the telecommunications satellites, which are powerful and launched in the geosynchronous orbit (22,000 miles above the Earth), rather than receiving programs from terrestrial cable systems. In the other hand, DBS suppliers put multiple kinds of services or channels cheap hotels in virginia beach together and sell them to potential DBS subscribers for monthly payment.
There are three main differences between DBS and Television Receive Only (TVRO), technology, programming and cost. Almost four million families in the United States use TVRO and they have to pay approximately $1,800 for a satellite dish (including installation fee), of which the diameter is between 7 to 10 feet. TVRO users can receive 75 unscrambled programs but also have to pay monthly for a collection cheap hotels in virginia beach of scrambled programs. TVRO programs are transmitted cheap hotels in virginia beach by using C-band (3GHz-6GHz) and a maximum cheap hotels in virginia beach power of 10 watts.
However, the diameter of DBS dish is less or equal to 18 inches and cost about $700. Although DBS and TVRO provide similar program collections, but DBS subscribers cannot receive the completely same unscrambled programs that TVRO can receive. DBS programs are transmitted by using Ku-band (11GHz-15GHz) and a minimum power of 120 watts. In other words, Ku-band can provide much stronger satellite television signal because of the high power. Therefore, compared with the size of receiver dish for C-band reception, a much smaller receiver dish is required.
In 1975, it was the first time that Home Box Office (HBO) used one satellite to transmit program to local cable television systems. cheap hotels in virginia beach It was also the beginning of DBS. A large number of people from rural areas who cannot receive cable television programs, installed TVRO dishes outside their houses and received all the programs radiated from satellites. After that, TVRO suppliers stopped providing free service for their subscribers. Therefore, in 1985, HBO and other similar organizations started to encrypt the television signals, and then TVRO subscribers had to pay extra fee for receiving such type of television programs.
In 1980, it was the first time that Satellite Television Corporation (STV) raised an idea of true DBS service to the Federal Communications Commission (FCC) in the United States. After that, STV's idea was accepted by FCC and other companies cheap hotels in virginia beach started to focus on DBS services as well. At the end, 13 companies sent their ideas to the FCC and eight of them were accepted. Unfortunately, when time went to the early 1990s, it was estimated that more than a billion dollars were required to build up a DBS service. That was the main reason why a lot of DBS projects were delayed or canceled at the same time. In addition, DBS companies doubted whether program suppliers can apply their services into DBS, because in the past time they always provided services to cable systems. cheap hotels in virginia beach However, the Cable Television Consumer Protection and Competition Act of 1992 handled this problem by enforcing cable program suppliers to sell their services to DBS operators.
FCC allows DBS companies to provide their services cheap hotels in virginia beach by distribution of satellite transmitter and DBS orbital slot. Satellites are allowed to launch DBS services by using 8 orbital slots, which are 175, 166, 157, 148, 119, 110, 101 and 61.5 degrees west longitude.
In July 1991, the first generation of DBS service, known as Primestar, was launch by collaboration of cable television system owners. In 1995, Primestar can provide 67 program channels to almost 70,000 families by using 45 watt transmitters, which was built on the Satcom K1 satellite of America. As a result, DBS subscribers had