Micro mobility management for heterogeneous networks in LTE-A

Heterogeneous network, which consists of macro-cells and small cells, is actively researched in Long Term Evolution (LTE) area. The present handover procedure is not considered for the heterogeneous network environment. As the coverage of a small cell is limited, more frequent handovers occur. Therefore, workloads of a Mobility Management Entity (MME) and a Serving Gateway (SGW) increase. We propose the micro mobility management to reduce the workloads of the MME and the SGW. The proposed scheme introduces the mobility anchor, which handles handover between small cells without the participation of the MME and the SGW. The mobility anchor hides the change of the data path of a User Equipment (UE) from the SGW. Also, the MME can receive the notification of the change of the control path for maintenance of the Non Access Stratum (NAS) channel between the MME and the UE. The MME no longer relays the data path control signal to the SGW. The simulation result shows the reduction of the handover latency due to the simplified handover procedure.