The small wireless network has been running normally, but after a wireless AP, the wireless signal has weakened a lot and the transmission rate has dropped significantly.
The cause of this failure may be a multipath problem, if the wireless signal near the object, is rebounded, at different points in time to reach the receiver, resulting in multiple routes. For example, there is a wireless client in one room and an access point in the house. When the access point is sending the signal, the signal will spread out from all directions and reach the wireless client. However, wireless signals also bounce back from other objects, reaching the wireless client via a path, which means the wireless client receives two or more signals. It is not possible to eliminate multiple signals, but it can reduce this phenomenon. Do not place metal objects near the access point or near the wireless client.