  In this article we develop a three dimensional (3D) analytical model of
wireless networks. We establish an analytical expression of the SINR (Signal to
Interference plus Noise Ratio) of user equipments (UE), by using a 3D fluid
model approach of the network. This model enables to evaluate in a simple way
the cumulative distribution function of the SINR, and therefore the
performance, the quality of service and the coverage of wireless networks, with
a high accuracy. The use of this 3D wireless network model, instead of a
standard two-dimensional one, in order to analyze wireless networks, is
particularly interesting. Indeed, this 3D model enables to establish more
accurate performance and quality of services results than a 2D one.
