What is GSM indoor distribution system?

With the rapid development of mobile communication, wireless communication devices such as mobile phones have become indispensable modern communication tools, and the business of mobile communication has also expanded from traditional voice to multimedia services such as data, images and videos, especially the upcoming third-generation mobile communication technology, which will make the content of mobile communication more colorful. People are no longer satisfied with outdoor mobile communication services. For example, in large buildings, especially in areas with high population density and large telephone traffic, such as hotels, businesses and business centers, people also want to enjoy high-quality and high-speed indoor mobile communication services, which puts forward higher requirements for the performance of mobile communication systems.

In order to meet the growing demand of users and improve the public reputation of operators, all operators are pursuing seamless coverage of the whole service area while expanding their capacity. Because all mobile communication services are carried by wireless access technology, the quality of wireless link affects the quality of the whole network, as well as the capacity of the system and the development of services. In view of the complex radio wave propagation characteristics of mobile communication, it is the key to solve the radio frequency problems such as multipath fading, noise and interference. The optimization of RF signal is of great significance for seamless network coverage.

Cities have always been the focus of mobile communication services. Due to the high population density and harsh electromagnetic environment, large-scale buildings like mushrooms after rain appear constantly, which brings difficulties to seamless network coverage. The propagation of radio waves is easily influenced by terrain, building structure and other factors, which often leads to the signal in large buildings being difficult to meet the requirements. The penetration ability of existing GSM and CDMA systems is weak, especially PHS and 3G systems, and the signal penetration ability is even weaker. Therefore, the coverage signal of outdoor base station will have the problems of unstable indoor reception and unacceptable underground range. At the same time, a large number of modern buildings cannot be covered by outdoor base station signals because of capacity problems. For example, in the basement of large buildings, underground shopping malls, underground parking lots and other areas, mobile communication signals are weak, and wireless devices such as mobile phones cannot be used normally, forming blind spots and shadow areas for mobile communication; At the middle level, due to the overlapping of signals from different surrounding base stations, the ping-pong effect occurs, and the mobile phone is frequently switched or even dropped, which seriously affects the normal use of the mobile phone; On the roof, due to the limitation of the antenna height of the base station, it can not be covered normally, and it is also a blind spot for mobile communication. In addition, in some buildings, although mobile phones can talk normally, it is difficult for mobile phones to access the Internet because of the high user density and crowded base station channels. Therefore, it is becoming more and more important to solve indoor signal coverage, meet the needs of users and improve the quality of network coverage, and it has also become a key point of network optimization [2]. All the problems listed above can be solved by indoor covering technology.

GSM indoor distribution system introduces the base station signal into the room to solve the indoor blind area coverage; It can effectively solve the problem of signal extension and coverage and improve the indoor communication quality; It scientifically distributes the base station signals to all rooms and channels in the room without interfering with each other. It is the supplement and extension of base stations and microcells, which cannot be replaced by base stations and repeaters, and is an indispensable part of metropolitan mobile communication.