  Using an approach developed in physics, we propose a new framework for the
study of cellular networks. The key idea of the physical network model we
propose is to replace the discrete base stations (BS) entities by a continuum
of transmitters which are spatially distributed in the network. This allows us
to establish a closed form formula of the other-cell downlink interference
factor f, as a function of the location of the mobile. We define here f as the
ratio of outer cell received power (i.e. the power received from other cells)
to the inner cell received power. This physical model allows calculating the
influence of interference on any mobile in a cell, whatever its position.
Results obtained with that closed-form formula are close to the ones obtained
by simulations using a traditional hexagonal network model. Since the physical
model allows to establish a closed form formula of the interference factor, it
allows to do analytical studies of wireless networks such as outage
probability, quality of service, capacity.
