.3 G-inn (the Femto) Technology Principle And The Application

With rapid development of wireless communication, the indoor traffic also expands. In wireless communication systems, the cell size becomes smaller and smaller and the frequency gets higher and higher, and the penetration capability of the building is bad, so the signal of base stations outdoor are not able to penetrate into the indoor environment. Therefore it is urgent to develop a technique that is able to improve the indoor coverage range and service quality. Femtocell is such an emerging technology which is used to strengthen the indoor coverage. It also promotes the fixed-mobile convergence. Compared with other similar techniques, femtocell has many advantages, such as low cost, high quality of service. Moreover, no change of core network is needed for the operation of femtocell. Thus, femtocell is more adapted to the indoor coverage scenario, and can provide better quality of service guarantee. Besides, with the development of femtocell, it has received close attention from the standardization organizations and the industrial field.This paper first introduces the import and concept of femtocell, expatiates the developments and applications of femtocell at home and abroad. Then, the technical principle, key elements, system components and network structures of femtocell are analyzed in detail. The related services and products of femtocell are also introduced briefly. And then, the practical structure of femtocell and its effect on the structure of existing networks are analyzed. The development prospects are also discussed. Finally, the technique advantages and shortcomings of femtocell compared to other indoor coverage strategies are analyzed. And the commercial realization situation and the problems to be solved are proposed.