基站基础学习（Base station learning）.docVIP

基站基础学习（Base station learning） In cities, base stations can be installed in office buildings; in rural areas, installed in containers. A base station is a device for serving a wireless community, usually an omnidirectional or three fan-shaped wireless community. In the early 90s, the China Mobile communications market was dominated by American Motorola, Ericsson of Sweden and NEC of japan. The three party has a certain experience in producing TACS system. The TACS base station includes a wireless transceiver device and its interface or control system. There are two kinds of control methods usually base station, a mobile switching center is composed of direct control, base station equipped with a transceiver, only the interface necessary, Ericsson and NEC two companies that adopt this way; and the other is the base station has a control system (BSC), which has some intelligence Motorola, that is in this way. There are two kinds of equipment in Motorola company. Figure 1 is a combination of a series of 5 typical HC frame base station fixed, from right to left, the first one is the power supply frame, second, third is from frame, fourth is the frame, fifth is the base station control system (BSC) and audio frame. A transceiver consists of 8 voice channels and one control channel. At present, the two transmitting frames are based on each other, the standby state, automatic switching, that is called the redundant type. Fig. 2 is a composite diagram of a typical LD series of 3 rack base stations, from the right to the left, the first is the power rack, and the second, third is the transceiver (including the base station control system). A transceiver has 8 voice channels and two control channels. Each power supply frame can only provide two receiving and transmitting frames, and when the receiving and sending frame is added according to the expansion requirement, the power supply frame must be correspondingly increased. Each additional frame can add 10 voice channels, acco