Novel Handoff Decision Algorithm in Hierarchical Macro/Femto-Cell Networks

Hierarchical macro/femto-cell networks are considered as a promising technology for the improvement of indoor coverage and network capacity. In these emerging networks, handoff procedures for a mobile station moving from a macrocell to a femtocell should be provided to maximize the advantages of femtocells with respect to user satisfaction and system performance. Therefore, we propose an efficient handoff decision algorithm that can be utilized in the situation where a user enters the coverage area of the femtocell. The main idea of the proposed algorithm is to combine the values of received signal strength from a serving macro BS and a target femto BS in the consideration of large asymmetry in their transmit powers. Numerical results show that there is a significant gain in view of the probability that the user will be assigned to the femtocell while keeping the same level of the number of handoffs.