Abstract
In this paper it is presented the process of designing equi-interference lines in the CDMA mobile telephony systems. It is proved that shape of these lines in one base station cell is determined by emission characteristics of that base station and the base stations, which form the first ring around the considered cell. The influence of base stations from the other rings after the first one is dominantly noticed as the interference increase in each point of equi-interference line. The value of interference increase depends on the value of environmental propagation coefficient. For its small values it is necessary to consider the influence of base stations from more than twenty rings around the analyzed cell, while for great values it is enough to consider only two rings.