In a Radio Frequency (RF) Energy Harvesting Network (RF-EHN) the nodes have the capability of converting received electromagnetic RF signals in energy. Traditionally, the RF signals are provided by high power transmitters operating in the neighborhood of the harvesters. Admitting that the transmitters are spatially distributed according to a spatial Poisson process, we start by characterizing the distribution of the RF power received by an energy harvester node. Considering path loss and fading effects, we provide a theoretical approximation for the distribution of the received RF power. Using the distribution of the received RF power, we derive the probability of a node having enough energy to transmit a packet after a given amount of battery charging time. The numerical results obtained with the proposed analysis are close to the ones obtained through simulation, which confirms the accuracy of the proposed analysis.