NGN (Next Generation Network, next-generation network, abbreviation is NGN) is a very loose term, which refers generally to a large number of new technologies, with IP technology as the core, while supporting speech, data, and multimedia business integration networks.
The emergence of NGN is a milestone in the history of telecommunications, marking the arrival of a new generation of telecommunications network age. It is a communication network, a combination and extension of a computer network. Represents the development direction of PSTN (public telephone network), 3G and other networks.
Generation of NGN
NGN gradually moved from the traditional PSTN network mainly towards the group exchange, carrying all the services of the original PSTN network, handle a large number of data transmission services to IP network processing, and new IP technology Features increases and enhances many new and old business. In this sense, NGN is a packet-fused product based on TDM (time division multiplexing) PSTN voice network and packet network based on IP / ATM (asynchronous transmission mode). Therefore, NGN is a network of full-service, including telephone and Internet access services, data services, video stream media services, digital TV broadcast services and mobile services.
The next generation is earlier to the next generation of Internet Action Plan (NGI, Next Generation Internet, next-generation Internet) as proposed in October 1997. Its purpose is to study the next-generation advanced networking technology, establish a test field, and develop revolutionary applications. However, in the late 1990s, the telecom market opened competition worldwide, the extensive use of the Internet has grown data business, and users have a strong demand for multimedia services. The demand for mobility is also increasing, and the telecom industry is facing strong Market impact and technology impact. In this situation, NGN has appeared, and it is a topic that is currently the most popular.
In 2002, two more than the world's scope: First, the number of mobile users over the world has exceeded the number of fixed users; the second is that the data traffic transmitted on the world exceeds the voice traffic. These two more than reflecting the trend of advancement with the advancement of the times, the trend of humanity on mobility and information demand, implies a large number of higher value services and applications.
The current network, whether it is a telephone network, or an Internet or mobile network, it is not possible to adapt to this future trend. Therefore, NGN is a new concept in which the network industry is used in order to describe future telecommunications networks. In fact, it seems to have a large umbrella, let's cover the fixed network, Internet, mobile network, core network, metropolitan network, access network, user station, home network, etc.
NGN characteristics
From the technical level, NGN has the following basic features:
◆ Packet transfer. Mainly use IP-based grouping techniques.
◆ Control features are separated from the bearer, call / session, application / service.
◆ The service provides network separation. This feature allows networks and services to evolve independently and does not affect each other.
◆ Use the basic business composition modules to provide a wide range of business and applications (including real-time, streams, non-real-time and multimedia services).
◆ With end-to-end QoS (service quality) and transparent transmission capabilities.
◆ Interact with traditional networks through open interfaces, compatible with traditional networks.
◆ Has universal mobility.
◆ Allow users to freely access different service providers (ISPs).
◆ Support multiple address allocation systems and resolve them to IP addresses for IP networks.
◆ The same business has a unified business characteristics.
◆ Fusion of fixed and mobile services.
◆ Adapt to all management requirements, such as emergency communication, safety and privacy.
From the business level, NGN has the following characteristics:
◆ Openness
NGN can be divided into several modules according to different or different functions of the network, each module can be developed independently, and there is no interference, but also organically combined into a whole; this openness is also manifested in each Operators can choose the market's dominant products according to their needs, but don't have to worry about interconnection between different devices. ◆ Efficiency
The NGN network allows for the separation of business and call control, which provides a good condition for the realization of new business, and the development cycle of new services is effective; with many network interoperability, many emerging services of NGN should also ship Life.
◆ Multi-user
NGN integrates the advantages of fixed telephone network, mobile phone network, and IP networks, making simulation users, digital users, mobile users, ADSL users, ISDN users, IP narrowband network users, IP broadband network users even through satellite accessible users Can become a member in NGN, implement mutual communication.
◆ Multimedia
Voice, video, and other multimedia streams in real-time transmission in NGN is another highlight of NGN.
◆ Resource sharing
The rich information resources of the Internet have always been a piece of fat in front of telecom operators. Because of IP technology, NGN's emergence makes it difficult to get the resources of the Internet during the call.
◆ Low cost
The communication cost of NGN is greatly reduced by a relatively inexpensive IP, and the communication cost of NGN is greatly reduced. This advantage is particularly reflected in domestic long-distance and international long distance calls. This low cost has been reflected in the VoIP (IP phone) currently put into application.
Development status and trend of NGN
The concept of NGN has been continuously promoted worldwide with rapidly developing trends. Its development process and trend can be summarized as the following four stages:
◆ Start stage (1996-1998)
ITU first proposed H.323 VoIP protocol. Although it is not designed for telecommunications grade, some operators seize the market for packet long-distance (ie IP long-distance calls), and the application H.323 system has built a group long-distance telephone network, which has obtained considerable gains. The development of NGN-related protocols and applications launched a certain technical foundation, and the inevitability of speech IP is noted from the other side. At this stage, some domestic operators have also built a long-distance IP telephone network.
◆ Soft exchange test stage (1999-2004)
Since proposing the concept of soft exchange, under the joint promotion of many manufacturers and operators, soft exchange products are gradually mature, the functions are increasing, and the standardization process is steadily advanced, and soft exchange technology begins to gradually go to the market.
During this period, the experiment of softswitch at home and abroad has been continuously carried out. At the beginning, the experimental content of the initial softswitch is limited to the exchange of soft exchange, simple multimedia business, and later with soft exchange technology, the test is gradually turned to be more Large-scale commercial trials, some new operators have begun to build an officially operated NGN commercial network.
◆ Size deployment phase (expected 2005-2009)
It is expected that in the development of these years, the soft exchange system will gradually improve and realize commercialization. More and more operators began to deploy NGN commercial networks, mainly focusing on the construction of NGN infrastructure and existing PSTN network how to Transition to NGN, and the transformation and replacement of the switch using NGN technology. This process can bring profits to the voice business, and some services can also be provided in multimedia.
◆ Stable development stage (after 2010)
Figure NGN's connotation
During this development process, NGN's focus on developing more advanced value-added services. In this process, the integration of the fixed web and mobile networks can also be gradually improved. With the improvement of the network itself, including the perfect carrying network QoS, the network business is gradually stepping to providing multimedia business characteristics. During the development of e-commerce, NGNs can provide more protection for e-commerce, bringing more profits to operators.
Throughout the status, NGN's development in global can be described as "like". In the United States, large operators actively promote relevant trials, whether emerging Leve13, or traditional Sprint, Times Warner is available in soft exchange. Operators such as PT Prime, Egyptian Telecom, and Denmark in Portugal have realized the commercial use of softswitch technology, and Brunei is also built with the help of Huawei to cover the national softswitch commercial network. In Japan, new broadband network operators wish to use softswitch technology as a weapon that competes with traditional operators; NTT DOCOMO tends to use softswitch technology in the 3G system.
In my country, Netcom has started a soft exchange test in 2000, and established the first soft exchange experiment network in Ningbo. Although China Telecom is late in the pace of China Netcom, the scale is very large. In 2002, China has launched the construction of NGN experiment networks in Beijing, Shanghai, Guangzhou and other cities. China Mobile and China Unicom have always paid attention to the development of softswitch technology and products, but its technical strength has a large gap compared to two fixed-network operators.
Overall, NGN has the same development in the world, and my country's NGN market has always been in the forefront of the world. This is a very good historical opportunity for my country's telecommunications industry. Under the joint efforts of the equipment manufacturer, operators, NGN has walked down the altar and embarked on the road of scale commercial.
Four bottlenecks restricting NGN development
The development of NGN is not smooth. Each new technology must face heavy bottlenecks in its development, these barriers come from technical levels or application levels. In the future, the development of NGN must solve the following issues:
(1) Service quality (QoS)
The service level of the business layer is provided in the service quality of the service. The bearer network of the NGN network is based on a packet network (mainly IP network), and its feature provides a business in accordance with its own efforts. Compared to traditional ATM-based PSTN networks, the Quality of the IP network is not satisfactory, has always been a focus on the improvement of the industry.
(2) User management
One of the protruding problems caused by control and carrying separation is that the user is uncontrolled. One of the main factors caused by this problem is that the soft switching device completes the call control function. The media stream interaction between the user is directly connected to the media gateway. It cannot be satisfied. Real-time monitoring of users. How to avoid illegal users' communication resource stealing and avoiding user bypass soft switching devices is a charm facing NGN network business. These issues will bring operators to have certain operational risks.
(3) Terminal access security risks
Traditional ATM-based PSTN networks, user terminal devices are "fool" terminals, and all network intelligent services are implemented by dedicated business networks. The users of each access network have a global unique ID, so it is easier to trace the source of attacks in this network. In the NGN network, all terminals are intelligent terminals, and the end user can access the metropolitan area through a variety of access methods. Typically, the soft switching device uses the parameters such as IP addresses and endpoint markers to authenticate terminal access. Therefore, illegal behavior such as endpoint camouflage and IP address stealing is also a problem that the NGN network is facing.
(4) Business model
In addition to technical factors, the lack of "killer" business is also a factor for restricting the development of NGN networks. The NGN's foothold is how to provide a more abundant telecom application to meet the needs of customers and markets with more favorable prices, more convenient ways, more attractive business portfolios, but so far, NGN has not so-called "Killer" business. The current operator's uniform situation is the lack of value-added business, and the ARPU (average annual earnings per unit) is continuously declining, but operators have sufficient processing capabilities in existing value-added business systems, while operators also do not want to introduce new technologies. Any impact is caused for its main income - "basic voice service".
Twelve business types provided by NGN
NGN retains the basic businesses provided by PSTN, ISDN, intelligent networks, and adds many unique business types, mainly: ◆ Entrance business: mainly for users' terminal environments, providing monitoring, coordination, etc. Function and can provide users with a personalized business environment.
◆ Enhanced multimedia session business: keep multi-party sessions, will not terminate sessions because there is a session to join or leave, and the session is terminated.
◆ Visual Phone: It is possible to establish visual calls between move / fixing, mobile / movement, fixed / fixed calls.
◆ Click to Dial: Enable Click to Dial service in your personal business environment or web session, you can send a call directly to the online user or server.
◆ Web conferencing: multimedia conferences that can be organized through Web Browser.
◆ Enhanced session Waiting: Allows users to process real-time calls.
◆ Speech recognition service: You can automatically identify voice and make standard or user settings.
◆ Text → Voice → Text: Supports two-way conversions of text to voice.
◆ Basic positioning business: Mainly used on mobile phones, providing queries in the actual location.
◆ Personal routing strategy: At different times, the system controls the user's settings, selectively transfer the incoming call to different phones.
◆ VOD: Video on demand service, users can subscribe to different video streams as needed.
◆ Enhanced call function: Because the increasing call type, participate in the increase in call user type, so that the corresponding call / session transfer and other services have also been strengthened. At the same time, the session merge function is also added, that is, two calls or incoming calls can be integrated into a triplet session.
