Using a network cable to connect the secondary router and then WIFI expansion is the best way. If it is a direct WIFI relay, then the broadband loss after the relay is very large, depending on the distance between the two machines and whether there are too many obstructions. The general loss may be 30~50%. Moreover, the broadband stability of WIFI relay is difficult to be guaranteed. It is recommended to connect the secondary router with a network cable, and the broadband loss is small enough that you do not feel it.