Two-layer wireless access network concept, the previous article we have introduced, the next is the specific analysis of its advantages and characteristics. For the construction of complex community networks, we need to combine existing network structures to achieve a higher standard of performance requirements.
by the macro community and the microcell of the two-tier wireless access wireless network to bring us will be a future, new, perfect wireless access solution, will open up access to a new era. Double-layer wireless access network in the macro-cell and Microcell are based on the IP system, so in the macro community and Microcell do not need any Third-party protocol conversion equipment can be seamless connection, which greatly improve the reliability of the entire system. The entire network uses the topology structure, the modular design, the configuration is flexible, has the good expansibility, its capacity expands and adds the new service to be convenient, fast.
with the development of broadband wireless access technology, the working frequency band of macro-cell (LMDS system) must be upgraded to a higher frequency band, so as to obtain greater bandwidth. High-frequency transmission requires a rigorous visual transmission (LOS), while the Microcell in the scheme works in a lower 2.4GHz, essentially avoiding visual transmission. and work in the 2.4GHZ Low frequency Wireless LAN terminal price is cheaper than LMDS terminal price, do not need microwave antenna to receive signals, so that fully consider the user's economic affordability.
through the use of double layer wireless access network structure can provide operators with more flexible solutions, such as operators can give large and medium-sized enterprises to provide their own Microcell wireless LAN, to ensure the different customers of the wireless local area network between the independence of each other. At the same time for large enterprises with multiple branch offices, a micro-area network can be set up at the branch office location, which enables each Microcell to form a virtual LAN through a double layer wireless access network. Users within the enterprise can automatically roam between all branch offices to complete the receiving and sending of data. These large enterprises can set up their own authentication in their small area network, authorize the server to manage the wireless users within the enterprise.
In addition, the dual-layer wireless access network can also provide operators with a metropolitan roaming function of the broadband wireless network. Operators can be in some network users more intensive, wired laying inconvenient, users have a strong mobility of places (such as airports, stations, stadiums, high-class hotels, etc.) to establish their own microcell, Microcell construction can be based on market demand for gradual expansion. In the macro-Community Network Management Center set up IP access server and background billing server, to form a unified certification and billing platform. The platform solves such problems as user authentication, bandwidth control, management and billing of multiple IP services, dynamic allocation of IP address, and supports a variety of billing strategies and user roaming.
IP Access server is embedded between extranet and intranet (double layer network), authenticate user's identity and collect billing parameters in the second to third layer of network, and manage and control the "user" and "service" in real-time on the fourth layer of the network. The billing server and IP Access server Exchange data in real time, according to the predetermined strategy and rate, and complete the account opening, statistics, operation monitoring and other work.
If a user needs to obtain a network service, it must be authenticated by an access server. All legitimate users have a correct account and password, the account and password can be binding with the MAC address, so even if the legitimate user's account and password is stolen, it will not cause loss. There are two ways that a user can log in one is a simple Web login, the user only need to open any kind of browser, will pop-up login interface, enter account number, password, you can get network services; the other is the client login mode, users need to install a dedicated login software, input account, password can be logged in, The advantage of this approach is that communications are encrypted to prevent the loss of passwords. At the same time can receive real-time SMS system.
IP Access server uses the IP layer fourth technology to realize the limitation of bandwidth (exactly IP traffic). By dividing the total bandwidth into several bandwidth groups within the access server, and then setting the ratio of each user to each bandwidth group, the user is given precise bandwidth limits based on the user's account and password, and charges are charged according to the telecommunication standard fee.
The IP Access server also has the ability to dynamically allocate the end user IP address. The user who is roaming through a subnet in the entire double-decker wireless access network does not need to reassign the new IP address. But if it is roaming across subnets, then he must regain the IP address in a new subnet to continue to enjoy network services, and the LMDS and wireless AP (Access point) are set up in the form of a transparent bridge. The DHCP server in the IP Access server will assign a new IP address directly to the user through the above two. When roaming across subnets, users only need to type the ipconfig/release, ipconfig/renew commands to release the old IP address and get a new IP address. Of course, you can also change the IP address by resetting the computer.
through the use of two-tier broadband wireless access solution, with wireless network card users can be in the two-tier wireless access network coverage of the full enjoyment of the network services, even in the mobile can also maintain a smooth network connection, complete the roaming in the city, this is probably the cable network is far behind. Double-layer Wireless broadband access system, can provide users with high-speed data, internet, voice, video and a variety of multimedia services. The system integrates all the functions of the access network and the station network, and is more flexible and convenient than the traditional access network and the station network, so the scheme will be one of the most reasonable choices in the future access network.