What is Satellite TV?

Digital satellite television is a form of broadcast television that uses geostationary satellites to transmit digitally encoded and compressed television signals to users. There are two main ways. One is to transmit the digital TV signal to the front end of the cable TV, and then the cable TV station converts the analog TV to the user's home. American Direct TV is the first satellite TV operator to apply this technology. Another method is to directly transmit the digital TV signal to the user's home, that is, the Direct to Home (DTH) method. Compared with the first method, the DTH satellite has a larger transmitting power and can be received by a smaller antenna, which can be used by ordinary households. At the same time, it can directly provide user authorization and encryption management, and carry out advanced TV services such as digital TV, pay-per-view TV (PPV), and high-definition TV, without being restricted by intermediate links. In addition, the DTH method can also be downloaded on the Internet at high speed, interactive TV, etc.

Cable TV

(Broadcast television format)

1. In its coverage area, there can be many lines that directly contact each ground and transmit information.

2. Its communication links with local stations are not limited by distance, and its technical performance and operating costs are not affected by distance.

3 The connection between the satellite and the ground station can provide lines according to actual needs, because the satellite itself has many lines to connect any two ground stations.

There are two international standards for DTH, the European standard

The transmission process of satellite TV is generally: long-distance transmission of microwave signals transmitted by ground base stations through satellites.

A typical DTH system consists of six parts: Front-end system, transmission and uplink system (

First set

The satellite TV program signal is input to

At 20:15 on June 9, 2008, the "Zhongxing Nine" radio and television live satellite was successfully launched in Xichang. Satellites will begin transmitting digital television signals before the Beijing Olympics, when tens of millions of families will be able to watch the Olympic Games directly.

China already has three digital program transmission methods: cable digital television, terrestrial digital television and IPTV. For the first time, "Zhongxing Nine" will adopt the non-encrypted method to carry out the live broadcast of TV programs to the home. The successful launch means that China will enter the era of live TV satellite broadcasting.

As the initiator of China's satellite live broadcast era, what are the highlights of "Zhongxing Nine"? Is it the first live satellite launched by China? Is it a free lunch? Is cable TV in an awkward position? How is it developing? Chen Lei, a professor at the College of Engineering.

Three highlights of satellite TV

The "Zhongxing Nine" live satellite is a new generation of live broadcast satellites introduced by China Satellite Communications in April 2005 from Thales Alenia Aerospace (TAS) of France, with a value of 100 million Euros. It uses the French SB4000 series mature commercial satellite platform with a design life of 15 years, a launch weight of 4.5 tons, and is equipped with 22 Ku-band high-power repeaters with a total power of about 11,000 watts. As the initiator of China's satellite era, what are its highlights?

Highlight 1: Signals can be delivered directly to the home

"Zhongxing Nine" is a direct broadcast satellite, and the signal can be delivered directly to the home, without having to be retransmitted by the TV station. Only one and a half meters of "small pot" can be received on the ground.

Highlight two: Large coverage area

Compared with terrestrial and cable digital TV, the advantage of satellite live digital TV is the large coverage area, and the price of a satellite TV receiving station is only a few hundred yuan. Specifically, after the satellite is put into use, it not only greatly increases the transmission capacity, improves the quality of program viewing, but also increases China's radio and television coverage to more than 98%. The use of "Zhongxing Nine" will effectively solve the embarrassment of China's vast remote villages being unable to watch live satellite programs.

Three questions about satellite TV

Question 1: Is " Zhongxing Nine" China's first live satellite?

In fact, "Zhongxing Nine" is not the first live broadcast satellite launched by China. In October 2006, "Xinnuo 2", which was also loaded with 22-channel Ku transponders and designed for 15 years, was launched. According to the design, one-third of its resources are used to send 47 non-profit TV and radio programs nationwide, and the remaining two-thirds are used to launch commercial programs. At that time, "Zhongxing Nine" only appeared in the plan as its backup satellite. However, in December of the same year, the China National Space Administration confirmed that the "Xinnuo 2" failed to complete the secondary deployment of the solar sail and the deployment of the communication antenna due to a technical failure during the positioning process, and was unable to provide communication broadcast transmission services. Space junk.

The failure of "Xinnuo 2" made "Zhongxing Nine" take on the heavy task of starting the era of live broadcasting satellites in China. The Xinnuo 4, which is scheduled to be launched at the end of 2008, will work with them to jointly build the first generation of China s first-generation radio and television satellite live space segment system using advanced dual-satellite common rail technology, so that the majority of TV users have the opportunity to directly receive 150 200 sets of standard and high definition satellite radio and television programs.

Question 2: Is "Zhongxing Nine" a free lunch?

Among the related reports of "Zhongxing Nine", the most noticeable is its unencrypted program transmission method. The business model of "Zhongxing Nine" is to collect satellite bandwidth rental and sales fees from satellite TV stations around the country, and it is free for TV viewers. Compared with the cable digital TV with "a few hundred yuan initial installation fee + dozens of yuan monthly rental fee", viewers can spend a few hundred yuan to install satellite ground receiving facilities to watch digital TV programs for free. Does this mean that viewers are watching cable digital Have a new choice outside of TV?

In fact, as early as the "China Village Broadcasting Satellite System Technology System White Paper" released by the State Administration of Radio, Film and Television in mid-May, "Zhongxing Nine" was positioned as the "Village Village" satellite. A person in the Department of Science and Technology of the State Administration of Radio, Film and Television said that "Zhongxing 9" is mainly targeted at remote rural areas where no television or radio can be heard, and it is difficult to say whether it is free in the city. Some people think that in the early days of the Live Satellite Program, countries will not allow urban areas to receive satellite TV because cable television networks and digitization have already invested huge upfront funds and resources. Therefore, cable television will continue to monopolize in urban areas.

According to the "Regulations on the Administration of Ground-Receiving Facilities for Satellite Television Broadcasting" promulgated by the State Council, individuals are not allowed to install and use satellite ground-receiving facilities. Units setting up satellite ground-receiving facilities must be examined and approved by the radio and television administrative department of the provincial people's government. This means, at least, that city dwellers are not eligible for free satellite live digital TV.

Question three: " Zhongxing Nine" challenges cable TV?

Although satellite live TV is positioned as a supplement and extension to cable digital TV, relevant persons from the State Administration of Radio, Film and Television have also stated that the original policies will have some adjustments after the launch of live satellite. With the adjustment of policies and the development of satellite value-added services, will the competition between live satellite broadcasting and television services and cable TV increase?

"When a certain scale of live satellite TV is formed , it will inevitably have an impact on the cable digital TV business." Chen Lei said, "If paid live satellite TV becomes a reality, larger-scale and higher-rated satellite TV stations will become the biggest beneficiaries."

The "China Live Satellite Industry Report" released in 2006 predicts that once the individual's policy of receiving satellite programs is liberalized, by 2010, China's live satellite users will exceed 15 million, and the overall scale of the terminal equipment market and viewing fees will be in the tens of billions. Around Yuan.

From the perspective of the development of live satellite TV in the United States, from 1993, when digital live satellite technology was adopted, live satellite TV robbed 21 %% of users from cable TV, and its average annual growth rate exceeded that of cable TV. Subscriber growth rate.

"At present, while cable TV networks in various places charge television users, they also charge certain fees to satellite TV stations in various places." Chen Lei introduced, "It is not uncommon to affect the broadcast of programs due to cost disputes, and even some local cable TV In order to protect the ratings of local programs, the network is unwilling to cooperate with satellite TV stations with better ratings. However, under the operating mode of satellite live TV, program providers can directly charge viewers without having to go through the local cable network, which is very conducive to scale The development of large, high-rated satellite TV stations. "