The simulation system according to the invention memorizes data representative of results of GPRS transfer quality measurements (11) made on test platform or similar for a variable number of time slots available for GPRS, of at least one quality of service indicator (52), of at least one cell configuration (20) and of traffic volumes for the GSM circuit and GPRS data transfers (51). Said system uses this data to simulate (21) arrivals of GSM circuit calls and GPRS data transfers, and subsequently to calculate a level of GPRS performance achieved for a selected cell configuration (20).With the method of the invention it is possible, by dichotomy, to scale the radio interface of a given cell for a given traffic.