Bluetooth signals can suffer from path loss, which reduces signal strength, meaning Bluetooth devices such as SmartConnect may not transmit.
Path loss is the reduction in signal strength that occurs as a radio wave propagates through the air. Path loss, or path attenuation, occurs naturally over distance and is impacted by the environment in which the signal is being transmitted. Obstacles between the transmitter and the receiver can deteriorate the signal.
Attenuators can be anything from humidity and precipitation, to walls, windows, and other obstacles made of glass, wood, metal, or concrete, including metal towers or panels that reflect and scatter radio waves. While radio waves can pass through objects, the amount of attenuation and effective path loss varies with the type and density of the obstruction. Think about when you are trying to hear someone in the next room and the difference between the volume and clarity of what you can hear if the wall that separates you is made of wood compared to concrete.
For more information, see Bluetooth's explanation on Bluetooth range.