网络基础知识点（Network basic knowledge point）.docVIP

网络基础知识点（Network basic knowledge point） Basic knowledge of mobile communication network 1, mobile communication refers to both parties or at least one party in the movement of information exchange. 2, the cellular mobile communication system is mainly composed of switching network subsystem (NSS), wireless base station subsystem (BSS) and mobile station (MS) of three parts. The mobile communication network, we set up the 3 most of the area, and the hexagon shape construction of each radio cell. Due to the community arrangement planning is like a honeycomb, so we call the area for cellular or microcellular. The cell size will vary with the volume of traffic, the radius from hundreds of meters to tens of kilometers. 4, multi channel sharing in a wireless cell, several users share a set of wireless channels, users can either idle channels that strictly choose one of the calls, until all the whole channel is occupied busy. 5, according to the National Radio Management Committee of planning division of the wireless channel, 2G mobile communication network, we set up the 900MHz/1800MHz band. 6, the cellular system has three main functions: the basic structure of wireless frequency resource reuse, the automatic switching, channel assignment and cell division 7, GSM system: GSM digital mobile communication technology specification of the structure and the composition of the network provides detail and description. A complete data mobile communication network is mainly composed of the exchange system and base station system, in addition there are a large number of mobile users as user access equipment of mobile communication network. There are lots of interface between each mobile communication network system and the system of the internal functional entity, the GSM specification of the interface and protocol in detail the provisions, so that different manufacturers in accordance with the provisions of production equipment can be within the same network of mutual communicatio