In the case of only shadow fading or slow fading, this random variable may have Gaussian distribution with  standard deviation in decibels, resulting in a log-normal distribution of the received power in watts.
The scenario describes a situation where the received power is affected by shadow fading or slow fading. The random variable representing this effect can be modeled using a Gaussian distribution with a standard deviation expressed in decibels, leading to a log-normal distribution of the received power measured in watts.