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Cable network

Basic information

Chinese name: cable television network

English name: cable television network;CATV network

Definition: Use optical cable or the same A shaft cable is used to transmit broadcast TV signals or locally broadcast TV signals on a network.

Subject: Communication technology (first-level discipline); communication network (second-level discipline)

The distinction between the first-level catalog and the second-level catalog

Business type

The future development of cable networks is closely related to the enrichment of their business content. Generally, we divide the services of cable TV networks into three categories, basic services, extended services, and value-added services.

Basic business

The basic business is the traditional business of the cable TV network, including the signal transmission of public broadcast television channel programs, the installation services for new users, and the landing fees of satellite programs. Its income includes initial installation fees, program viewing fees, program transmission maintenance fees, advertising fees, and additional transmission channel fees. Basic business income (mainly the viewing fee of TV programs) is the main part of the income of my country's cable TV network.

Expanded business

Expanded business is a business brought about by the further development of cable network in TV program services, including professional channels, data broadcasting, video on demand (VOD), etc. Although these services still revolve around television, they serve specific audiences. The audience has changed from simply receiving programs passively to a certain degree of selectivity. The charging standards for such services are much higher than those for basic services.L.Professional Channel Professional Channel is a TV channel that subdivides the viewing needs of TV users and provides a certain type of program for the needs of user segmentation. The cable TV network has a home bandwidth of 750M, and can transmit more than 60 sets of analog TV programs or 300 sets of digital TV programs at the same time, which makes it possible for the cable TV network to provide a large number of professional channel programs. In developed countries such as the United States and Britain, in addition to providing a small number of comprehensive TV programs for the society, cable companies also provide a large number of other types of programs such as sports, finance, education, and entertainment. For example, the basic service of American cable television provides more than 20 channels, and the monthly fee is about 19 US dollars. There are hundreds of other professional channels. Users can set a number of professional channels according to their own needs. The average monthly consumption per household is more than 30 US dollars. The total amount of channel charges is twice the basic service charges. 2. Video-on-demand (VOD) At present, the programs we watch on the cable TV network are all broadcast by the TV station. What the TV station broadcasts is what we have to watch. In addition to the slight freedom in choosing the channel, the audience has a little freedom in the choice of programs. There is no freedom. However, the opening of the video-on-demand service will completely change this situation. Viewers can upload their own selected programs to the broadcast control center through the video-on-demand system, and the broadcast control center will then broadcast the programs selected by the user. This brand new The video service can flexibly meet the individual needs of users, and there is great room for future development. 3. High-speed data broadcasting High-speed data broadcasting uses the existing cable TV network to transmit various information (electronic newspapers, teaching information, stock market quotations, Internet information, etc.) through one-way data broadcasting at a transmission rate of up to 2Mbps. System providers can lease dedicated satellite channels to cover the whole country and realize economies of scale. To carry out this service, the cable TV network does not need to be modified, and the existing network resources can be fully utilized. The user-side access cost is only about 700 yuan, and the information cost is low, which can be fully affordable by ordinary users. This service is now widely used in cable TV stations everywhere. Unfold.

Value-added services

Value-added services are multi-function services developed on wired networks, including Internet access, IP telephony, video conferencing, bandwidth rental, TV business, etc. These new services will expand the service content of the cable network from television to voice and data communications, finance, education and other fields, greatly expanding the business development space of the cable network. At present, the value-added services of the cable network are still in the stage of development and experimentation in various regions, and the income is still very small, but its future potential is incalculable.L.Internet Broadband AccessWith the rapid development of the Internet and enterprise wide area networks, people's dependence on the network is increasing, and the requirements for network bandwidth and access service speed are also increasing. After the two-way transformation of the cable TV network, the Cable Modem can provide low-cost Internet access services or high-speed Ethernet access services with an uplink rate of 10M, a downlink rate of 36M, and 24-hour online. At present, the use of Cable Modem to access through the cable TV network is the access method with the highest share of the broadband market, accounting for more than 45% of the global broadband access market (the other main broadband access technology is XDSL technology).2. IP phone After the cable TV network is upgraded and reconstructed, VOIP technology can be used to provide very low-priced IP phone services, reducing the phone charges to one-tenth of the current ordinary phone charges. Traditionally, people are worried about the quality of voice services provided by Cable. However, the development of DOCSIS technology has greatly improved the support of cable networks for delay-sensitive services and improved the Qos (Quality of Service) of services. At present, many new cable networks in the United States Television operators can already provide telecom-level voice services. In the future, this service will have a greater impact on telecommunications' circuit-switched telephone service, but it is expected to become an important source of income for wired networks.

3. TV businessAs one of the most important information media today, once it is connected to financial institutions and enterprises, it will have the preliminary conditions for conducting business. Compared with e-commerce, TV commerce is more realistic and feasible, and has more room for development. Many consulting agencies predict that within ten years, TV commerce will become a trillion-level industry. China has the world's largest cable TV network and the largest number of cable TV users. It is uniquely equipped to develop TV business. The revenue from this business is expected to reach more than 100 billion within ten years.4. Video conferenceUsing the cable TV network, through special channels and recording and playback equipment, it can provide video conferences with very smooth sound and images, realizing effective real-time communication between multiple points, and achieving communication effects that cannot be achieved under traditional technology. In addition to the above business, the value-added services of the cable TV network also include distance education, telemedicine, remote securities trading, electronic automatic meter reading and home security monitoring, TV games, etc. These businesses also have huge room for development in the future.

Development status

From the perspective of the development of my country’s CATV network in recent years, more than 1,500 cable TV stations have been built across the country, and the total length of cable TV optical cables and cables exceeds 2 million kilometers. The number of users has reached More than 80 million, with a national coverage of 50%, and it is still growing at a rate of 30% every year. The TV has become one of the information tools with the highest rate of household entry in our country, and the CATV network has also become the multimedia channel closest to the family, but it still relies on coaxial cables to transmit TV programs to users, which is still at an analog level. Broadband two-way on-demand television (VOD) and access to the Internet through the CATV network for TV on-demand and CATV calls are the development direction of the CATV network. The ultimate goal is to make the CATV network a broadband two-way multimedia communication network.

According to the goal and requirements of the SARFT to basically achieve "one province, one network" by the end of 2010, 19 provinces across the country have completed or most of the cable TV network integration work. The integration work started late in Guangdong, Liaoning, Heilongjiang, and Chongqing. Four provinces and cities have increased their efforts in network integration and achieved important results. The remaining eight provinces and cities are also studying and formulating network integration plans and work plans. The development pattern of "one network" cable TV network in each province is taking shape. /p>

According to the State Administration of Radio, Film and Television, 8 provinces including Beijing, Tianjin, Shaanxi, Guangxi, Hainan, Jilin, Jiangsu and Guizhou have all completed the integration of provincial, municipal and county networks. Hebei, Anhui, Jiangxi, Hunan, Yunnan, Xinjiang In 11 provinces, including Inner Mongolia, Qinghai, Ningxia, Henan, and Zhejiang, on the basis of completing the network integration of most cities and counties or major cities in the early stage, they are further improving the policies and measures for the development of wired networks, accelerating the progress of network integration, and achieving In order to achieve good social and economic benefits, the development pattern of "one network" cable television network in various provinces is taking shape.

Technical competition

Public television channel transmission, Pay TV, VOD, data communication, IP telephony and other services have a variety of technical implementation means, such as wireless TV, satellite TV, telecommunication network, etc., cable networks will face their competition in these fields in the future. 1, wireless TV, wireless TV Competing with cable TV networks is mainly in the field of basic services. In this field, cable networks have obvious advantages. The main reason is that the quantity and quality of programs provided by wireless TV are not as good as cable TV. At the same time, they cannot provide interactive services and are difficult to meet. The audience’s viewing needs. Due to the limitation of the radio frequency spectrum, wireless TV can only arrange a few TV channels in a city. Beijing, which has the most radio video channels in the country, currently only arranges 8 radio video channels. With various communication services With the development of the city, the radio wave interference in the city is becoming more and more serious, which has led to the continuous decline of the quality of wireless TV programs. At the same time, wireless TV cannot provide uplink channels, so it cannot provide interactive services. The bandwidth of China's cable TV HFC network is mostly above 450M, 750M and 1G. The network is developing rapidly. This type of network can transmit dozens of analog programs or hundreds of digital TV programs, and can provide viewers with a wide range of viewing options. Because cable TV is a closed system, TV signals are transmitted in optical cables and cables, which avoids At the same time, the signal strength is relatively consistent, and the viewing quality is very good. After the two-way transformation of the wired network, a variety of integrated services can be carried out. Compared with wireless TV, the operation, management, and maintenance costs of cable TV are also lower, and Carrying out fee-based services, the replacement of wireless TV by cable TV will continue in the future.

2. Satellite Direct TV (DTH) Satellite Direct TV means that the TV signal is sent to the satellite after analog, digital conversion and compression, and then forwarded by the satellite, the user receives it through the antenna, and the decoder restores the digital signal to an analog signal input The viewing technology of television receivers has been widely used in many countries such as the United States and Japan. The competition between direct satellite TV and cable TV is mainly in the fields of pay TV and data broadcasting. Compared with cable TV, direct satellite TV has the characteristics of large coverage, simple maintenance, low price of receiving device, and convenient installation. Before 1990, satellite live TV was struggling because of the small amount of program transmission and the expensive ground receiving equipment. Since the 1990s, digital compression technology has made significant progress. The capacity of satellite live TV programs can reach more than 100 sets, and the price of receiving equipment has been greatly reduced. Therefore, it has had a strong impact on the pay TV business of the cable TV network. Two digital live satellite companies, Direct TV and KISH Network in the United States, have taken millions of users from the cable TV network in a short period of time and developed more than 1,000. Million users. The main way for cable TV networks to contend with satellite TV is to give play to the relative advantages of cable networks in terms of interaction, and to transform the disadvantages of cable TV coverage into characteristic advantages through the localization of program content. At present, the threat of satellite TV to the pay TV service of cable TV networks is not great in China. On the one hand, my country still has strict controls on the reception of non-overseas satellite TV programs, and the possibility of liberalization in the short term is very small; at the same time, domestic Satellite live TV is still in the early stage of development, the content is not very attractive, the terminal price is as high as 5,000 yuan, and it is impossible to achieve multiple satellites in one device, and the cost performance is very low.

3. Telecommunication network Due to policy restrictions on the participation of cable TV networks in voice services, the competition between cable networks and telecommunications in the next few years will mainly focus on data communications, especially in the field of broadband access. At present, the main broadband access technologies are: ADSL (Asymmetric Digital Subscriber Loop), VDSL (Ultra High Speed ​​Digital Subscriber Loop), HFC (Coaxial Fiber Hybrid Cable), FTTC (Fiber to the Roadside), in addition, broadband Wireless access and FTTH (Fiber to the Home) are also currently developing, but it is still very difficult to be widely accepted in recent years. Old telecom operators currently mainly use ADSL technology to develop Internet broadband access services. Some new telecom operators use FTTC (China’s commonly referred to as high-speed Ethernet) technology to provide broadband access, while cable television networks mainly use Cable Modem technology (also Ethernet technology can be used to achieve broadband access. Each of these technologies has its own merits. The Cable Modem technology is characterized by its low cost, which can provide Qos-guaranteed video, voice and other services on a digital platform. At present, Cable Modem access accounts for more than 50% of the global broadband access market. North America generally believes that the prospect of using Cable Modem technology to provide high-speed Internet access is relatively optimistic. In China, telecommunications are relatively strong, and FTTC is also a broadband access method that is more suitable for national conditions. It is expected that cable TV networks will be in the broadband access market. The share is not as high as it is in North America.

Development trend

Digitalization and networking are the main development trends of radio and television. Network integration has effectively promoted the realization of network scale benefits. Network integration has not only broken through the space constraints of local decentralized development of wired networks, but also concentrated on advantages to create a backbone enterprise that leads the development of wired networks, in order to accelerate wired networks from a higher starting point. Digital and two-way development provide the foundation and conditions for promoting network industrialization and intensive operation.

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