With development of mobile communication, the telephone traffic generated by the users’ mobile phones in large buildings (especially hotels, business and commercial centers) is ever-growing. Therefore, users require not only good mobile communication service of outdoor coverage, but excellent mobile communication service of indoor coverage provided by the network carriers.

      The indoor coverage system can improve the overall communication quality in the building, increase the mobile call completing rate, and develop the high-quality indoor mobile communication area. It can use microcell system to share the outdoor macrocell telephone traffic load, improve network quality, and promote the service level of mobile network as a whole. The good indoor coverage has great significance for improving recognition of network carriers, providing better communication service anytime and anywhere for users, improving competitiveness of enterprises.