Editing Cell site (section)

=== Signal limiting factor ===
A cell phone may not work at times because it is too far from a mast, or because the phone is in a location where cell phone signals are [[attenuation|attenuated]] by thick building walls, hills, or other structures. The signals do not need a clear [[Line-of-sight propagation|line of sight]] but greater [[radio interference]] will degrade or eliminate reception. When many people try to use the cell mast at the same time, e.g. during a traffic jam or a sports event, then there will be a signal on the phone display but it is blocked from starting a new connection. The other limiting factor for cell phones is the ability to send a signal from its low powered battery to the cell site. Some cell phones perform better than others under low power or low battery, typically due to the ability to send a good signal from the phone to the mast.

The [[base station controller]] (a central computer that specializes in making phone connections) and the intelligence of the cell phone keeps track of and allows the phone to switch from one mast to the next during conversation. As the user moves towards a mast it picks the strongest signal and releases the mast from which the signal has become weaker; that channel on that mast becomes available to another user.
{{Further|Frequency reuse}}