A User´s State and SINR -Based Handoff Algorithm in Hierarchical Cell Networks

Femtocell systems are providing cost-effective high-bandwidth service in wireless cellular systems under very low transmission power compared to macro-cell. Normally, conventional handoff algorithms can´t well satisfy the mobility in hierarchy networks because of femtocell´s characteristic. Therefore a user´s state and SINR-based handoff (SINR-US) algorithm from macrocell to femtocell under the consideration of both large discrepancy in the transmit power of the cells and users´ state is proposed, which combines SINR used instead of RSS and users´ velocity, QoS requirement of users as decision criterion. Numerical results show that the proposed algorithm obviously increases the number of the handoff compared to conventional algorithm, as well as improving the utilization of Femtocells. Additionally it cuts down the unnecessary handoff that doesn´t satisfy users´ state requirement.