Looking back at the construction process of the existing communication network, we can see that in the process of developing new services based on the circuit switching network, domestic operators basically adopt the method of carrying a certain type of services with a specific service network. In this way, on the one hand, the network construction cost is basically similar to that of the circuit switching network, and there is no obvious advantage. In addition, because different networks adopt different management systems, when providing comprehensive services for major customers, additional management and coordination and network interconnection costs are often required. Therefore, the industry has always hoped to provide all services on a unified network.
So what benefits does network convergence bring to customers and carriers? Wei leping, Chief Engineer of China Telecom group, believes that for operators, network convergence can achieve a unified network architecture, protocol and interface, simplify network layers, and quickly expand business, it promotes business development in both breadth and depth, reduces construction, O & M, and business marketing service costs, and simplifies customer relationships. For customers, the integrated network allows users to enjoy unified services and products, single access across fixed network, wireless/Internet, single bill, consistent customer experience and services unrelated to the Access Technology quickly provide and simplify customer relationships.
In 1980s, telecom networks moved from analog to digital, providing an opportunity for network convergence. But it is also based on "0" and "1". Different coding systems and network protocols make telecom networks basically miss this opportunity. With the rapid development of the Internet, IP grouping technology provides the second opportunity for network convergence, because IP addresses are not only applied on the transmission network, but also become the basis of the core network. In the core network, IP-based Softswitch technology enables operators to integrate voice, data, and other different networks into a comprehensive solution, that is, telecom operators can build a Unified IP network from the terminal to the access and then to the core network to provide different services. One important point is that mobile communication is also evolving towards the whole IP network, which also lays a solid foundation for IP-based network convergence.
There are four main driving forces behind network convergence. First, business segmentation. The business grouping trend is the biggest driving force behind network evolution and convergence. Second, technological advances. New technologies are emerging, and many new technologies are emerging at all levels of the network. Third, users' needs have changed. Users want to use any terminal to enjoy diversified services anywhere. 4. operational requirements. To support a variety of telecom services, telecom operators operate multiple telecom networks at the same time, which is obviously very unfavorable to telecom operators and will greatly increase the operator's operating costs, this increases the complexity of the commercial operation of telecom operators. The ideal telecom network mode is as simple as possible. It is best to run a telecom basic network. All telecom services are carried and controlled by this network, so as to realize the integration of telecom online services.
In recent years, the industry has carried out in-depth research on how to achieve network convergence. Currently, it is widely believed that the next generation telecommunication network, as a large-scale and complex system, has different manifestations in different layers, it is important to pay attention to the man, access network, smart optical network, wireless access, and the integration of fixed and mobile core networks.
In the metropolitan area network, the fusion mainly refers to the integration of different services and transmission, including the integration of multiple service platforms based on SDH, ATM, IP address, and WDM; integration of circuit switching and group switching; network management, that is, unified network management and circuit Specification; physical convergence, that is, the convergence of different slots in the same rack and the operator's organizational structure.
At the access network level, the convergence mode is to build an IP-based public bearer platform, to achieve wide and narrow band business integration and integrated access, and support wired and wireless convergence, the integration of voice, data and multimedia, network management, unified authentication, billing, and physical convergence.
At the smart optical network layer, the fusion includes the fusion of service layer and transport layer, the fusion of IP router and optical node, the fusion of routing/signaling, the fusion of control plane, the fusion of management plane, and the abstract fusion of management object.
In terms of wireless access technology, the fusion performance is partial convergence of 2g/2.5g/3G networks and terminal convergence, CDMA and WCDMA convergence, GSM/WCDMA and GSM/CDMA Terminal convergence, mobile access and Fixed Wireless integration of access, bluetooth and WLAN can connect a mobile terminal to a wireless broadband network.
In addition, it is worth noting that mobile and fixed integration are embodied in the core transport layer, control layer, and application layer.
The fusion at the core transport layer is represented as a Unified IP/MPLS-based core network that will become a multi-service converged network, it can support all wired and wireless, mobile and fixed as well as voice, data and multimedia services. A dozen different service networks will be integrated into a single unified IP/MPLS service network platform; IP/MPLS-based convergence minimizes the cost of core network construction, operation, and management. Of course, IP/MPLS core networks also face challenges in QoS and manageability.
At the control level, the integration shows that the demand for mobile NGN and fixed NGN is very small, and the same gateway soft switch can be used. The demand for mobile local soft switches and fixed switches is quite different, mobile Softswitch must handle the mobility management and switching functions. On the business control layer, integration can be performed step by step. The first step is to use a soft exchange switch, which is separated from the local soft switch, however, you must be able to directly communicate with each other and provide the same interface to the application layer. The second step is to integrate local soft switches. In some cases, you can do it in one step.
At the application layer, because the business control layer provides standard interfaces, the application layer can adopt the same technology, and the two networks can be fully integrated and shared. In fact, the ultimate goal of the two networks is to achieve converged services. The business types can be simple, complementary, or cost-effective combination services, as well as in-depth integration services, for example, integrated VPN, multi-card, and integrated video services. Establishing a flexible and scalable public service platform is the foundation. In addition, the integration of the same terminal should support wired and wireless access as well as voice, data and multimedia access.
For network convergence, Wei leping's chief engineer once suggested that the value of a unified converged network would be much higher than that of several independent networks. Therefore, the network should focus on connecting businesses, telecom-based converged networks have great economic significance. Integration does not reduce selection and diversification. In the complex integration process, new derivatives are often generated. Similarly, network convergence will also generate a large number of new services and applications in the business and application layers. Speech, data, and video are not simply integrated into a traditional terminal, it is a long process of development for more organic integration to derive a variety of unique and personalized terminals.
