In 2019, it will be based on NSA, pilot SA, and evolve to SA in 2020, initially using the international mainstream 3.5G band. Among them, NSA is a non-independent network, which refers to the use of existing 4G networks to deploy 5G network capabilities. SA is an independent network, which refers to an independent 5G network. Among the 5G mobile phones currently on the market, some mobile phones support both NSA and SA, and some mobile phones only support NSA. For some time to come, the NSA and SA networks will coexist, and there is no situation in which NSA phones will be unavailable anytime soon. Phones that also support SA support NSA. For details about the supported mode of the mobile phone model, see the terminal section. For details about the time for advancing SA, see the following official information.