This article describes the connotation of IPTV, and through its technical analysis, it explains that IPTV plays an important role in the development of broadband networks.
Keywords: IPTV, triple play, next generation network NGN
1 Introduction
In recent years, China's broadband Internet network has developed rapidly, and various Internet applications based on IP have emerged one after another. Among them, the new broadband interactive media, namely IPTV (Interactive Internet TV), is the most eye-catching. It uses the infrastructure of a broadband network, uses computers or TVs plus network set-top boxes, mobile phones, etc. as the main terminal equipment, integrates a variety of technologies such as the Internet, multimedia, and communication next-generation networks, and provides home users through the Internet Protocol (IP) A variety of interactive digital media services including digital TV. Since the beginning of the 21st century, with the development and application of broadband network technology, streaming media technology, codec technology, information encryption technology, chip technology, and storage interaction technology, it has become a reality to provide TV services through high-speed Internet. Users only need a computer. Can enjoy IPTV service.
2. The connotation of IPTV and the development trend of broadband networks
Based on the Internet, IPTV is a personalized, interactive service media form that can provide services such as on-demand, broadcast, video communications, short messages, MMS, information services, and games. People are optimistic about the huge market potential and broad development prospects of IPTV. Operators and numerous terminal equipment manufacturers also regard it as a development focus of future broadband applications. As one of the important services of the Next Generation Network (NGN), it belongs to the category of voice, data, and video triple play services. Its basic definition should be a broad broadband network service, which is based on IP technology and depends on the TCP/IP protocol. Broadcast or on-demand interactive TV services running on the Internet. This application combines the three fields of TV, communication and PC. It can not only provide users with broadband services such as digital broadcast television, VOD on-demand, and video recording, but also can browse the Internet, send and receive emails, and consult a variety of online information. , Entertainment, and education functions are combined to achieve real interaction. From the perspective of IP defining TV, IPTV belongs to the transmission, application and development of digital TV, and is an advanced form of digital TV. It is the product of the integration of the Internet and TV networks today. It covers all the meanings of digital TV and contains more media formats, from traditional audio and video, text, and picture multimedia formats to Flash graphics, from interactive media to streaming media formats , Including services that can provide all media formats that the Internet can provide at the same time. It is precisely because IPTV uses the Internet as the main transmission network, its development is bound to be closely related to the progress of the broadband network, and has become the biggest entry point for the so-called "three networks".
3. IPTV technical analysis
The IPTV program broadcasting service system realizes the broadcasting and transmission of IPTV program streaming media data, mainly including streaming media broadcasting, multicasting, unicasting, etc. that support the IP protocol, and it needs the support of streaming media server and streaming media playback software. The streaming media server broadcasts the encrypted IPTV program streaming media data to the transmission network under the control of the user management system. At the same time, the IP program broadcasting service system needs to authenticate the user or user terminal device, and send it from the DRM authorization key server to the authenticated The user or user terminal device of the user transmits the ORM authorization key, so that the user can decrypt and play the received encrypted IPTV program streaming media data.
3.1IPTV management system
The IP transmission network, program source, and user group are the foundation for the survival and development of IPTV. The front-end IPTV management system includes program source content management system, user management system, program broadcast and transmission control management system, network security supervision system, etc.
3.2 IPTV bearer and transmission network
In order to ensure that the real-time viewing quality of the transmitted IPTV programs is equivalent to the viewing quality of broadcast and television analog TV programs, the performance of the IPTV bearer and transmission network must meet the following requirements:
(1) Bandwidth: When using MPEG-4 or H.264 compression encoding, each IPTV user's access bandwidth is required to reach 1.5M-2M.
(2) Channel switching delay: The channel switching of radio and television analog TV is very fast, and IPTV should also minimize switching delay.
(3) Network QoS: IP broadband transmission network should reduce packet loss and jitter as much as possible to ensure the quality of IPTV viewing (listening). Such as MPLS, P2P technology.
(4) IPTV should adopt multicast/broadcast mode to provide IPTV program streaming media data broadcasting services.
(5) In order to improve the response and real-time transmission of IPTV on-demand/interactive services (such as VOD), the IP broadband transmission network is required to effectively push IPTV program streaming media data to the content distribution network (CDN/VDN) to alleviate the impact In response to the pressure on the front-end caused by the volatility of on-demand/interactive service requests, the IP backbone network/metropolitan area network of the IPTV system adopts the distributed deployment of central servers and edge servers to build a CDN/VDN content distribution network to transfer IPTV program streaming data content from The central server distributes to the edge servers. The IPTV bearer and transmission network adopts an IP broadband transmission network that supports the Internet IP protocol, including backbone networks/metropolitan area networks, broadband access networks, and content distribution networks (CDN/VDN). The backbone network/metropolitan area network mainly completes the transmission of IPTV program streaming media data within and between cities. At present, the metropolitan area network mainly adopts Gigabit/10 Gigabit Ethernet, and the long-distance backbone network can adopt methods such as IPoverSDH, IPoverATM or IPoverDWDMoptical. The broadband access network mainly completes the connection of users to the metropolitan area network. IPTV supports FTTH access, FTTB+LAN access, ADSL access, HFC/CableModem access, WLAN wireless access and other access methods. The CDN/VDN content distribution network is an application system superimposed on the backbone network/metropolitan area network. It distributes and stores the front-end video program stream content to the edge server of the network to improve the quality of users' access to services and reduce program stream pairs. The bandwidth pressure of backbone network/metropolitan area network. The front end of the IPTV system is connected to the backbone network/metropolitan area network, and the program stream is copied to the edge server of the network through the content distribution network, and then transmitted to the service receiving end through the broadband access network. Therefore, the program flow in the IPTV service is completed by each edge server distributed at the edge of the network together with the front end.
3.3 IPTV user terminal receiving system
The IPTV user terminal receiving system is responsible for receiving, storing and playing or forwarding IPTV program streaming media data, electronic program guides, and so on. Its receiving terminals include computers, mobile phones, TV sets and other smart terminal devices. Advanced user terminal devices also have built-in hard disks, which can provide IPTVDVR functions, support IEEE802.11 wireless networking functions, and can stream DRM-protected IP audio and video The media program is sent and transmitted to other devices.
In addition, IPTV involves digital video coding and decoding technology, media asset management technology, streaming media technology, content distribution network (CDN/VDN) technology, IP multicast (multicast) technology, digital rights management (DRM) and user authorization authentication and management And charging system technology, IPTV set-top box and middleware technology, IP broadband access network technology such as LAN/ADSLCableModem, and various application business related software technologies. At the same time, a variety of streaming media formats, digital compression standards such as MPEG-2, MPEG-4, H.264/AVC, AVS, etc., and multiple protocols such as RTP, KTCP, RTSP, etc. are used to realize the broadcast of the transmission video stream on the network , On-demand, multicast and other interactive control functions. It can be seen that the development of IPTV technology and applications is closely related to the development of broadband networks.
4. IPTV catalyzes the integration of resources and services of the three networks
At present, networks are all communication networks that complete the transmission of various business information, such as three major networks, such as a telecom network with voice services, a computer network with data services, and a television network with image services. However, these communication networks still have many problems, such as limited capacity resources, low transfer efficiency, and too much individualization in technology, which are not suitable for the needs of the development of a modern information society. In fact, the three major networks are now more or less infiltrating and cooperating with each other. The characteristics of IPTV and its advantages in the video field make it the biggest entry point for the "three networks". Its emergence and development are constantly leading New areas of broadband network applications.
IPTV can include three major industries. For the telecommunications industry, IPTV is a typical business in the future and has broad industry development prospects. The IPTV value-added approach of video services has become a choice for major telecom operators to seek sustainable development. Only relying on Internet services, due to their lack of content and poor profitability, they make full use of telecom’s own broadband network advantages to cut in and make development The IPTV business has become the original driving force for industry changes. Software providers, including Microsoft, are optimistic about the development of IPTV and the assistance of powerful equipment providers have also strengthened the confidence and determination of telecom operators to get involved in IPTV. New wired and wireless broadband transmission technologies and high-efficiency digital video compression technologies such as H.264/AVC have gradually matured, and have also laid a practical foundation for the operation of IPTV. Telecom companies use ADSL technology to broadcast TV programs and Internet access services through IP, that is, provide IPTV services through broadband networks.
In the Internet industry, how to enable more users to obtain multimedia information through the Internet and actively explore profitable business operation models are important issues facing informatization. IPTV services based on Internet platforms have natural advantages in terms of interactivity.
The radio and television industry is based on a two-way high-speed wired broadband network, which can also provide IPTV services. In the development of digital TV services, a bundled operation service of telephone and Internet access is added to promote and merge in the direction of the telecommunications industry. Compared with telecom operators, the huge obstacle to realizing value-added video comes from the lack of innovative content, which is the real advantage of radio and television.
It can be seen that the characteristics and potential strategic role of IPTV have changed the traditional divisional lines. The development of telecommunications, Internet, and radio and television industries encounters content, business, and technical bottlenecks. Therefore, they can cooperate with each other to complement each other. IPTV obtains the actual benefits of win-win cooperation. Therefore, IPTV catalyzes the integration of resources and services of the three networks. Triple play is also an inevitable trend.
5. IPTV leads the network to new areas
IPTV has opened the door to network transformation, and its emergence and development play an important role in the evolution of the network. Although IPTV can use its advantages in the Internet to provide services, it must also have radio and television systems to provide programs and other collaborations. Similarly, radio and television also need the cooperation of telecommunications departments. In the future development, digital television must rely on interactive on-demand like IPTV. Telecom broadband network access. The innate advantage of radio and television lies in the production of program content, while the advantage of telecommunications and the Internet lies in the wide network coverage, which facilitates communication with the development of next-generation networks, and has rich experience in large-scale network design, operation and management. In addition to broadband two-way network infrastructure, the development of IPTV also requires a wealth of audio and video programs. This has also promoted the spontaneous complementary and win-win cooperation between the radio, television and telecommunications parties.
Under the market demand situation represented by broadband data and multimedia services, a single-service telephone communication network, computer network, and radio and television network obviously cannot meet people’s needs. People hope to have a comprehensive service network that provides them with multiple services. Personalized service. However, the current representative N-ISDN, B-ISDN, ATM, and Internet all have great limitations. Under the existing network and technical conditions, they are unable to provide users with acceptable and satisfactory new In the face of multi-level and all-round network interconnection requirements, they are unable to achieve satisfactory expected results in terms of multi-service integration.
The IPTV business closely links the three-network industry chain, so that the future next-generation network will be based on IPv6, based on user needs, based on multi-network business integration, and with flexible user access and a unified digital processing mode of information. , Gradually transition the current PSTN network based on circuit switching to an IP network based on packet switching, and integrate the current TDM-based PSTN voice network and IP/ATM-based packet network to make telecommunications, TV and data services flexible Built on a unified IP open platform, it comprehensively provides telephone and Internet access services, data services, video streaming services, and digital TV broadcasts carried by heterogeneous networks such as PSTN, IP, ATM, and mobile networks. Services such as business and mobile services can satisfy people anytime, anywhere and by what means to achieve communication or personal customized personalized communication services and services, and provide end-to-end QoS quality assurance on the unified forwarding platform of IP, a full-service network, Enable the network to fully realize data packet-based transmission, and at the same time realize end-to-end transparent broadband capabilities, can work with previous networks, support wide mobility, and provide users with unlimited access to multiple service providers and extreme Wide choice of degrees of freedom. Therefore, IPTV based on IP technology comprehensively accelerates the mutual penetration of traditional telecommunication networks, computer networks and cable television network services, and the natural extension and evolution of mutual integration, leading the next generation of networks to new areas.
6. Concluding remarks
It is the requirement of IPTV for real-time broadband interactivity that allows users to be free from time constraints, easy to operate and personalized interactive multimedia services, which has spawned and promoted the integration of resources and services of the three networks, and promoted the development of the network towards the "triple play" On the other hand, the potential of IPTV has been further tapped. At present, the three major networks are mutually infiltrating and promoting each other, and will eventually move towards the "triple network integration." The current structure of the telecommunications network and the cable television network are respectively combined with the computer network, and actively promote the existing network to be broadband and high-speed broadband with integrated service functions. The evolution of next-generation networks will be a development trend. On the whole, the integration of the three networks has become an inevitable trend. The integration of technology will inevitably bring about the integration of services. The integration of services leads to the merger and reorganization of different industries. The role of IPTV in it is becoming more and more noticeable. According to statistics from professional organizations, in 2008, revenue from media and entertainment services will account for 11% of the total revenue from mobile communications services. The revenue from media and entertainment services carried on fixed broadband networks exceeds that of mobile communications. Potential IPTV users in China in 2008 It may reach 10 million or so in 2010, and it may reach 20 million in 2010. This is a very attractive market. It can be predicted that during the 2008 Beijing Olympics, about half of the audience will benefit from this.
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