Q A of satellite live broadcast, what are the functions of satellite live broadcast

The live satellite service enables on-board television programmes to be delivered directly to the home, allowing recipients to receive television or radio programmes from satellites using only small satellite receiving antennas. Since the early 90s, radio and television satellite live broadcast services, satellite mobile communications, and satellite digital audio broadcasting services have first made technological breakthroughs in the United States, and have rapidly entered the track of industrialization and commercialization, forming emerging industries that promote economic growth. At present, these three satellite communication and broadcasting services are rapidly expanding to the world, among which the radio and television satellite live broadcast industry is developing particularly rapidly, and has achieved great success in operation, and has gradually matured.

At present, the application of satellite TV broadcasting has become quite popular. For example, the European company SES has about 10 communication and broadcasting satellites in its two orbital positions, and more than 1,000 sets of television programs are broadcast on the satellites; The United States is the world's largest radio and television satellite live broadcast market, accounting for more than 3 4 digital satellite live broadcast users in the world, and has a number of live broadcast satellites in three live satellite orbits, with more than 600 sets of satellite programs. Another example is Echostar, which has 9 live broadcast satellites, more than 1,000 programs, more than 10 million users, and a revenue of $8 billion in 2004.

Japan Shangxing also has more than 300 sets of TV broadcasting services, with nearly 20 million end customers (including 6 million digital satellite TV users). On the basis of the developed direct broadcast satellite systems that have been established, developed countries such as Europe, the United States, and Japan are constantly expanding their original space culture "camps." In Southeast Asia, Northeast Asia and other countries and regions near China, digital satellite live streaming services have also become a hot spot for development.

In the international market, the satellite live broadcast service has become an important income for satellite operators**. The biggest advantage of live satellite streaming is that hundreds of TV programs can be broadcast live to an unlimited number of home users with only limited satellite resources. China has a vast territory and complex topography, with many islands, mountainous areas and ethnic minority areas. The population is large but unevenly distributed; Economic development is uneven, and cable television networks are not yet developed.

Therefore, the development of radio and television satellite live broadcast business in China has natural advantages and great potential, and it is one of the few countries in the world with such a huge market.

Live Satellite: The signal is digitally compressed, and a single satellite** device is capable of broadcasting several programs, so that a dish antenna pointing to an orbital position can receive up to 200 channels. Programs for various businesses include:

Most major cable businesses, sports, pay-per-use (PPV) movies, audio services, and purpose-built "niche-style" programming aimed at a small audience. While these services are often referred to as direct-to-home (DTH) services, the term live satellite streaming (DBS) services is more commonly used.

The number of channels provided by the satellite live broadcast service is determined by the number of ** devices authorized by the company and the number of channels compressed on each ** device.

The Federal Communications Commission (FCC) authorizes a variety of services to use a certain number of direct-broadcast satellite frequencies corresponding to the number of satellites, all of which appear to be licensed to a different number of satellites at their designated orbital positions.

The number of channels compressed onto a single device is affected by a number of factors, such as the desired image quality (e.g., resolution), the frame rate of the source material, the amount of motion in the source material, the degree to which the digitized product is allowed to be visualized, the complexity of the encoder, the drought of closed error control that forms in the transmitted bitstream, and other factors.

Programs such as basketball games, because some of these frames have a lot of small objects moving fast, so only 3 or 4 channels can be compressed on each **, otherwise there will be obvious digital products. Programs with mostly large still images can be compressed at a larger scale, with 5 or 6 channels compressed on each device. The film is 24 frames per second instead of 30 frames per second, so the raw material content is lower; In addition, motion picture film is not interleaved, and is generally a relatively constant frame transition; Therefore, the compression ratio of the motion picture film can be larger, and the viewing effect can still be achieved when compressing 7 or 8 channels on each **.

As compression technology continues to advance, these estimates are worth being a little conservative.