China's vast territory, information development imbalance, about 1/5 of the administrative region has not yet called the telephone. Therefore, various wireless access modes have become an irreplaceable important means in the construction of information network in China.
The internet has been developing in our country only a few years, but our internet infrastructure is not popular, especially as the "last kilometer" access network resources are still relatively short. Copper wire still occupies the main position of access network, many local optical fiber is not popular, therefore, the vast number of users do not enjoy the benefits of broadband services, broadband wireless access can be a good solution to this problem, so, such as the Chinese telecommunications service providers are beginning to provide broadband wireless access services. Wireless access technology transmits information through the carrier from the air, including ground fixed wireless access (LMDS) and satellite remote access.
Lmds
Compared with the broadband of Wired access network, LMDS has obvious advantages:
High frequency multiplexing, large system capacity. In the 3.5GHz band of single 3.5MHz bandwidth, the use of high efficiency modulation technology, can provide users with 10 megabytes to 20 trillion transmission rate. And the use of multi-sector, multi-cell space segmentation technology, but also the capacity of the system reached thousands of trillion orders of magnitude.
Start-up funds are small and do not require extensive infrastructure construction.
Provide fast service, wireless system installation and debugging easy, construction cycle greatly shortened, can quickly provide services to users.
have great flexibility in development. The wireless system has the good expansibility, may according to the user demand carries on the system design or the dynamic allocation system resources, therefore does not cause the fund or the equipment waste.
Bi-directional Satellite international Internet access Service
Provide high quality and low price of a variety of business. At the same time to provide users with voice, data, video and other integrated services, but also to provide various types of bearer services (such as wireless base Station and controller connection), without the use of optical fiber and optical port equipment.
Low cost of operation and maintenance. Because of the wireless characteristics of the system, it can save a lot of line maintenance personnel and reduce the operation maintenance cost.
Satellite access
The main features of satellite communication are wide coverage, natural broadcasting (multicast), fast construction, flexible configuration and deployment. The use of satellite technology for Internet access, mainly used in the following areas:
Provides remote internet connectivity for large ISPs;
Extend the Internet to remote areas and provide links between ISPs;
Provides point-to-point connectivity for areas with insufficient communication capabilities, providing high-speed connectivity between the large ISP and its subordinate small ISP.
Experts expect the VSAT newsletter to develop considerably. Based on the experience of the development of VSAT communications abroad, VSAT is still an important means of communication, even when terrestrial communications reach the basic communication requirements. In the future, China's large chain stores networking, automotive, electrical industry, the national sales network, financial security Network of the world backup, large enterprises across the region networking, and so on, VSAT communication will be one of the best candidates. As for the telephone network in the vast rural areas of China, it is also a huge potential market for the advantages of VSAT communication. However, industry experts also pointed out that satellite network access equipment costs and services must be reduced to enable new users to accept the broadband satellite business. Therefore, it is necessary to optimize the performance of end-user access equipment, reduce the cost of equipment, and provide users with customized application services.
The satellite access service provided by most of our service providers is the use of existing space resources to carry out satellite broadband services, that is, the development of satellite broadband services for the technology, technology products (System equipment), using it to build satellite broadband network. Giton, Netcom, etc. have satellite access services. The transport layer of the network is a combination of fiber lines, satellite links and local microwave loops, all controlled by Beijing's network control center, and partially backed up in Shanghai's Backup network control center. The transponder capacity includes the Pan-American satellite 27M and Xinnuo satellite 13M and has 198 satellite earth stations.