Abstract: In the 2010 Report on the Work of the Government, delivered by Wen Jiabao, tri-network convergence is interpreted as“the integration of telecommunications networks, cable television networks, and the Internet”[1]. Enabling these three networks to interconnect with each other and share resources will provide users with diverse voice, data, radio, and TV services. Pilot projects have already been launched in China with the aims of integrating radio, TV services, and telecommunication services; quickening overall planning and reconstruction of the networks, and reinforcing monitoring of information and cultural security. The ultimate goal is to promote the development of related sectors.

Some developed countries have already achieved tri-network convergence, and others are promoting it. Tri-network convergence will bring about new management modes and new challenges, and China has its own characteristics in implementing it. First, only a small number of broadcast and TV networks are digital and connected to telecom networks. These are prerequisite for broadcast and TV networks to deliver telecom services. According to the State Administration of Radio, Film and TV, Next Generation Broadcasting (NGB) networks will be constructed to connect radio and TV networks. NGB networks adopt IP technologies to support telecom services. However, adopting packet technologies in broadcast video transmission is untried, and its cost-effectiveness is yet to be assessed.

Second, the Chinese government pays special attention to security. Transforming a TV set into an Internet terminal opens the possibility that it may be attacked by hackers or viruses. Undesirable or even illegal content, which cannot be completely eliminated in the open Internet, may appear on the television screen at home. However, the existing security platform, technical infrastructure, and guaranteed mechanism of broadcast and TV networks are not capable of processing a sharp increase in video flow that would arise as a result of network convergence. The existing broadcasting control mechanism also needs to be improved to meet the demands of operating multiple services. In short, both information security and network security issues have to be addressed.

Third, a new management mode is required for tri-network convergence. For content security, Chinese authorities have issued regulations stipulating that for a telecom operator to transmit broadcast and TV services, its video services must be managed by the integrated broadcasting control platform of the Broadcast and TV Authority. However, some issues are not clearly defined and need further clarification; for example, to what extent is content controlled and what interfaces and functions should the platform provide? The benefits of IPTV lie in the Internet-based value-added services that come with it. But these services may not be video services and need not be managed and operated by the platform. The problem arises of how to coordinate value-added services with IPTV. According to the requirements of the pilot projects, the integrated broadcasting control platform should manage not only content, but also users and billing. This means a user may be managed by both the telecom operator and the broadcast and TV operator when accessing a service. This is a great challenge to the network management system and client management mechanism. Therefore, it is necessary to coordinate management and services of the broadcast and TV operator with those of the telecom operator. In short, an integrated broadcasting control platform brings new challenges to the management mode. Meeting these challenges requires cooperation and innovation. It requires reform of management mechanisms of administrative bodies and reform of the technical and service modes of operators.

Fourth, the pilot projects have clear requirements in terms of access rate: In 2012, the downlink and broadband access rates for broadcast and TV services will exceed 2 Gbit/s and 100 Mbit/s respectively; while the downlink and household access rates for telecom services will reach 1 Gbit/s and 100 Mbit/s respectively. As Chinese urban areas are densely populated, the costs of Fiber to the Building (FTTB) and Fiber to the Zone (FTTZ) will be much lower than those in developed countries. FTTB and FTTZ have become the main access methods in tri-network convergence programs in China. A telecom operator may adopt FTTB or FTTZ plus Digital Subscriber Line (DSL) or Local Area Network (LAN), while a broadcast and TV operator may use FTTB or FTTZ plus Ethernet over Coax (EoC). For FTTB/FTTZ, Ethernet Passive Optical Network (EPON) or Gigabit Passive Optical Network (GPON) or a combination of these is suitable for densely populated areas in China. Because tri-network convergence involves a huge number of users, developing low-cost access systems such as PON is key for success. The household access rate of 100 Mbit/s is not difficult to achieve in an optical access system, but it is a great challenge for core networks, especially Metropolitan Area Networks (MANs). The rate requirement of 100 Mbit/s is higher than that in some developed countries, and high bandwidth requires high value and high return on investment. Therefore, we should explore advanced technologies that are suitable for China’s situation and develop new broadband services and business models that bring value to users and provide sustainable return to operators. According to a statistics report of the China Internet Network Information Center (CNNIC), Chinese netizens spend around 4% of their disposable income on the Internet. If mobile communications are included, the ratio of communications expenses to income is higher than in some developed countries. Despite this, telecom operators are suffering from a lack of profit-making modes. Therefore, the development of new services and business models is key to the success of tri-network convergence.

Fifth, the multicasting problem needs to be solved. Other countries also encounter this problem when deploying IPTV services. But because of the huge number of users in China, existing telecom networks have to be reconstructed as manageable IP networks that can support large-scale multicasting. The network layer multicasting solution based on routers is complicated to implement. And while application layer multicasting based on terminals is easy to deploy and does not involve changing infrastructure, it does not perform as well as network layer multicasting in terms of stability and efficiency. Multicasting suffers problems such as multicast video source fraud and registration packet fraud by illegal users. In sum, it is necessary to develop a large-capacity and manageable IPTV multicast solution.

Sixth, Chinese telecom operators and broadcast and TV operators differ from their counterparts in other countries in monitoring mechanisms and scale. These differences impact network technologies, services and maintenance management mechanisms to be adopted.

In China, tri-network convergence is regarded as an important program for deepening reform in the telecom industry, fostering the emergence of strategic industries, and bringing benefit to the public. It is expected to drive the development of the telecom industry, and broadcast and TV industry. Achieving tri-network convergence demands the efforts of all parties in the telecom, and broadcast and TV industries. Chinese tri-network convergence has a long way to go and 2011 will be a critical year.

Key words: Tri-Network Convergence