Seamless Handover Algorithms for Non-Standalone 5G mmW Networks

Millimeter wave (mmW) communication systems have attracted significant interest in meeting the capacity requirements of the present 5G network and future 6G networks. This technology delivers peak and cell-edge data rates in the order of 10 Gbps and 100 Mbps. The mmW systems have frequency ranges between 30 GHz and 300GHz. However, poor propagation characteristics, shadowing and blockages may result in sudden outages and necessitate frequent handovers. In this paper, we consider non-standalone (NSA) architecture by integrating 4G LTE with a macro base-station (BS) and mmW system with a micro base-station (BS) to address these issues. As the frequency range of mmW is significantly high, so the coverage area apparently becomes small, hence the small cell requirement in the integrated network needs to be increased to fulfill the bandwidth requirement. Therefore increase in number of small cells causes significantly increase in handovers, resulting in severe drop in system performance. In this paper, we consider RSS based handoff algorithms. Handoff initiation will be triggered based on UE reported measurements and network will decide whether to initiate handoffs or not. Decision metrics such as hysteresis margin is considered for handoff decision.