Study of a key factor for performance evaluation of wireless cellular networks: The f-factor

The f-factor, which is roughly the interference to signal power ratio, plays a crucial role in the performance evaluation of wireless cellular networks. The objective of the present paper is to study the properties of the f-factor and establish approximations for it which we compare to previously proposed approximations. We consider the hexagonal network model, where the base stations are placed on a regular hexagonal grid which may be infinite. The propagation loss is assumed to be a power of the distance between the transmitter and the receiver. In this context, we build a reference method to calculate the f-factor to which previously proposed approximations as well as a new one are compared. It is shown that the previous approximations are not always close to the reference. One should choose the approximation carefully since the performance of cellular networks depend strongly on the f-factor. The results in our paper help to make the appropriate choice. This is particularly important for operational needs as for example dimensioning a real network.