1, Has a high power frequency or magnetic and signal shielding system environment.For example, mobile devices site near the station,nearby electromagnetic power in refrigerators, air conditioners and other appliances .

2, Physical obstructions:the density, thickness and refractive index of the material in the place and so on.For example, reinforced concrete and glass materials for radio-wave refractive index different penetration is also different.Sheet steel or glass panels and other denser objects strong barrier to signal .

3,Large sound or loud noise.For example,nearby large-scale plant machines roar, large audio equipment some interference with the signal.

4, The other same frequency wireless devices.Two kinds of wireless devices on the same frequency will interfere with each other.

5, Cloudy, thunderstorms.In a thunderstorm or gloomy weather signals decay a lot and sunny days signal transmission distance is farther.