Simple Formulas for Area Coverage Probability of Cellular Wireless Networks

Reudink´s formula which describes the relationship between cell edge coverage probability and cell area coverage probability is routinely used in link budgets for cellular wireless network dimensioning and designs. A major drawback of this formula is that the effect of handoffs in the cellular network is not taken into account. The formulas derived in this paper overcome this drawback. The new formulas take into account the correlation between two fading handoff links, and allow the shadow fading standard deviations and the RF propagation loss exponents to be different for the two fading handoff paths. In addition, the formulas also allow the correlation between the handoff links to vary as a function of the distance between the mobile and the base stations. These new formulas are easily implemented in a spreadsheet since they are all represented as an integral of an explicit smooth function on the interval [0,1]. The importance and the necessity of the new formulas are demonstrated by applying them to some typical RF design scenarios and show that the widely used link margins in today´s RF designs are too optimistic by more than one dB.