I am trying to relate electromagnetic superposition to apply to radio waves (specifically cell phone signals). I understand the phenomena but I don't understand its effects.

Is this statement accurate?
Electromagnetic superpositon causes interference in waves of the same frequency. Because of this waves of identical frequencies cannot be transmitted in the same area, (the need for seperate transmission cells in a cellular network).

If this is incorrect what effects would superposition have on radio signals?

Thanks alot,