There are many types of distributions that are relevant for communication systems. In telecom, for instance, exponential and Erlang distributions modeling talk lengths are typically used to size telecom infrastructure. For wireless communication, one often has to model the interface between transmitter and mobile, even though there can be many obstacles between the two.
RayleighDistribution — multipath fading with no direct line-of-sight
HoytDistribution — multipath fading with no direct line-of-sight (Nakagami-)
RiceDistribution — multipath fading with a strong direct line-of-sight (Nakagami-)
NakagamiDistribution — indoor and ionosphere multipath propagation (Nakagami-)