An Uplink Based Mobility Management Scheme for 5G Wireless Network

In the previous generations of mobile communication system, mobility management is based on downlink measurement. In other words, reference signals in downlink are measured at the user equipment (UE) and the reference signal receiving quality (RSRQ) is reported back to the base station (BS). The power consumption and signaling overhead at the UE are significant, especially in the 5G mobile network systems where smaller and denser cells are deployed. To solve this problem, a novel mobility management scheme based on uplink reference signal is proposed in this paper. Unlike legacy mobility schemes, the proposed scheme allows the UE to transmit an uplink reference signal and BSs at surrounding cells to perform measurement in uplink. By taking advantage of the uplink measurement, the measurement report is eliminated and the handover delay is also shortened. Moreover, the power consumed for downlink measurement is also saved. Thus, the signaling overhead, paging miss rate and UE power consumption for uplink based mobility are lower than those for traditional downlink based scheme in LTE systems. Simulation results shows that compared with downlink based mobility, the paging miss rate and UE power consumption can be reduced by up to 38% and 63%, respectively.