Enhanced mobility state detection based mobility optimization for FEMTO cells in LTE and LTE-Advanced networks

In 3GPP LTE and LTE-Advanced networks, femto cells will be deployed to improve indoor coverage and increase system capacity. Mobility management (MM) for femto cells is challenging due to their huge number, small size and random deployment. This paper investigates the mobility state detection mechanism, which is crucial for the MM. It is observed that the conventional mobility state detection mechanism is not suitable for femto cells due to the lacking of cell type information. And the inaccurate mobility state detection may lead to improper mobility parameter scaling and then cause handover performance degradation. To solve this issue, Enhanced Mobility State Detection (EMSD) mechanism is proposed. In EMSD, cell type information is considered and more accurate mobility state can be detected for feinto cells. Performance evaluation results show that the EMSD can reduce ping-pong handovers without increasing RLF probability significantly.