Wireless Access

Refers to the user terminals from switching nodes between, some or all adopted wireless means.

The typical wireless access system mainly consists of controller, operation and maintenance center, base-station, fixed users unit and mobile terminal and so on several parts. Each branch finish

Function as follows

1 controller

Through its offer and controller switches, base station and operation maintenance center interface and these functions entity connections. Controller's main function is to handle user calls (including call setting up, take out stitches, etc.), to base stations management, through base stations wireless channels, base station monitoring and control of fixed and mobile terminal user unit monitoring and management.

2 operation maintenance center

Operation maintenance center is responsible for the entire wireless access system operation and maintenance, its main function is to the whole system configuration management, to each network unit of software and various configuration data operation: in system during the running of parts of the system for monitoring and data collection, For system operation process appears fault record and alarm. In addition, still can on the system's performance testing.

3 stations

Base station through wireless transceiver letter machines provide with the fixed end connect devices and mobile terminal between radio channel, and through a radio channel complete voice calls and data transfer. Controller for wireless channels through base station carries on the management. Base station and fixed end connect devices and mobile terminal between interface can use different wireless technology, and decide the characteristics of the whole system, including the use of the radio frequency and certain scope.

4 fixed end meet equipment

Fixed end meet equipment for users provide telephone, fax, data modem etc user terminals of standard interface - Z interface. It with base station through wireless interface inferiorly. And to end users transparent transmitting switches can provide the business and function. Fixed end meet equipment can use directional antenna or no directional antenna, using directional antenna leads directly to the base station direction can improve wireless interface signals in the transmission quality, increase of the base coverage. According to the user can be connected terminals; quantity? Fixed end meet equipment can be divided into the single user unit and multiple user unit. Single user unit (SSU) connect only a user terminal, Suitable for user density low, distance between users; Multi-user unit may support multiple user terminals, generally more familiar with support for four, eight, 16 and 32 user multi-user unit, multi-user unit in the distance between users close (such as an upstairs and user) more economic.

5 the mobile terminal

The mobile terminal from the function can be regarded as a fixed end will pick up equipment and user terminals of a physical entity constitutes a merger. Because it has certain mobility, therefore support mobile terminal wireless access system besides should have fixed wireless access system with the functions, but also have certain mobility management cellular mobile communication system with functions. If a breakthrough on price, mobile terminal is more users and operator's welcome.