Research conclusions:From the analyses, comparisons and field tests of several optional schemes, it is concluded the 3G system signals should be connected atend ofPOI. In the system ofcombiningmultiple networks into one network, in order to prevent the disturbances of signals each other, the insulation of the every network must be increased tomeeting the requirement. The 3G system can use the antenna subsystem of 2G system to reduce the construction cost and construction difficlty.