Access control mechanisms for femtocells

Femtocells are a solution that helps to reduce the capital and operational expenditure of a mobile network while enhancing system coverage and capacity. However, the avoidance of interference is still an issue that needs to be addressed to successfully deploy a femtocell tier over existing macrocell networks. Moreover, interference is strongly dependent on the type of access control, which decides if a given user can or cannot connect to the femtocell. In this article the existing access methods for femtocells together with their benefits and drawbacks are explained. A description of the business model and technical impact of access methods in femto/macro networks is also provided. Finally, the need for hybrid access methods and several models are presented.