Cell breathing, sectorization and densification in cellular networks

In this paper, we establish a closed form formula of the other-cell interference factor f for omni-directional and sectored cellular networks. That formula is based on a fluid model that approximates the discrete base stations (BS) entities by a continuum of transmitters which are spatially distributed in the network. Simulations show that the obtained closed-form formula is a very good approximation, even for the traditional hexagonal network. From f, we are able to derive the outage probability on the downlink as a function of the mobile density and the coverage range. From a maximum acceptable outage probability, we can deduce the link between cell coverage and mobile density and thus highlight with a new, easy and fast method the notion of cell breathing. At last, we show how an operator can use this approach in order to evaluate the impact of sectorization or BS densification on the cell coverage.