5G is the fifth generation of cellular mobile communications. It succeeds the 4G (LTE/WiMax), 3G (UMTS) and 2G (GSM) systems. 5G performance targets include high data rate, reduced latency, energy saving, cost reduction, higher system capacity and massive device connectivity. The first phase of 5G specifications in Release-15 will be completed by September 2018, to accommodate early commercial deployment. The second phase in Release-16 will be completed by March 2020, for submission to the ITU as a candidate IMT-2020 technology.