Usually, normal communication cannot be achieved inside buildings due to the reasons below: The radio wave is greatly attenuated during the transmission by screening, absorbing, and complex structure of the buildings, hence some weak spots or even blind spots inside the buildings appear; The radio frequency jamming often occurs in high-rise space and unstable signals in the service cells frequently cause ‘Ping Pong Effect’, which consequently make it difficult to guarantee the speech quality; In some large buildings, such as shopping malls and conference centers, etc., parts of the network capacity there cannot meet the heavy demands of such large number of MS users and thereby engender the traffic congestion. All these problems mentions above can be effectively solved by the indoor distribution coverage method which can provide MS users with excellent and clear speech environment.

    Reasonable designed indoor distribution system can facilitate the reception of signals from macrocells and microcells. The wanted the signals are then effectively amplified through repeaters and evenly distributed everywhere indoors through antenna distribution system, which helps realize the indoor network optimization and thereby provide an excellent wireless speech environment for the users. For the indoor environment with some weak spots or blind spots, it is advisable to adopt an approach of less antennas and low power, focusing on providing enough signal strength to meet the coverage demand; For the indoor environment with high traffic, it is advisable to adopt an approach of more antennas and normal power, concentrating on absorbing traffic sufficiently and sharing the outdoor BS workload; For the indoor environment with some interference, It is advisable to adopt an approach of more antennas and higher power, focusing on providing master signals so as to eliminate the interference problem.