1, has a high power frequency or magnetic, and signal shielding system environment. For example: mobile device near the place of electromagnetic power in refrigerators, air conditioners and other appliances nearby.

2, physical obstructions: places the density, thickness and refractive index of the material, and so on. For example, reinforced concrete and glass materials for different refraction of radio waves so penetration is different; the entire plate or glass panels, such as denser objects to signal strong barrier.

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

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

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