Method for computing a signal-to-interference-plus-noise ratio in a territorial portion of a geographic area covered by a cellular network, wherein the cellular network comprises a plurality of network cells provided by respective beamforming active antennas each one configured to radiate traffic beams in a plurality of radiating directions depending on number and arrangement of array elements of the beamforming active antenna, the method comprising: subdividing each network cell into a plurality of cell sectors each one corresponding to a respective radiating direction among the plurality of radiating directions in which the corresponding beamforming active antenna is configured to radiate; characterized by comprising; determining, for each cell sector of each network cell, a respective radiation probability, β H, V ppg k, indicative of the probability that the respective beamforming active antenna radiates traffic beams in that cell sector, each radiation probability depending on a user propensity indicative of a propensity of users of the cellular network to be physically located and/or to generate service requests in that cell sector of that network cell; determining, among the plurality of network cells, a best server network cell and at least one interfering network cell associated with the territorial portion, and computing the signal-to-interference-plus-noise ratio in the territorial portion based on a useful signal strength associated with the best server network cell, and at least one interfering signal strength associated with the at least one interfering network cell, wherein each interfering signal strength is weighted by a respective radiation probability, β H, V ppg k, associated with the cell sector of the respective interfering network cell at least partially covering the territorial portion. subdividing each network cell into a plurality of cell sectors each one corresponding to a respective radiating direction among the plurality of radiating directions in which the corresponding beamforming active antenna is configured to radiate; characterized by comprising; determining, for each cell sector of each network cell, a respective radiation probability, β H, V ppg k, indicative of the probability that the respective beamforming active antenna radiates traffic beams in that cell sector, each radiation probability depending on a user propensity indicative of a propensity of users of the cellular network to be physically located and/or to generate service requests in that cell sector of that network cell; determining, among the plurality of network cells, a best server network cell and at least one interfering network cell associated with the territorial portion, and computing the signal-to-interference-plus-noise ratio in the territorial portion based on a useful signal strength associated with the best server network cell, and at least one interfering signal strength associated with the at least one interfering network cell, wherein each interfering signal strength is weighted by a respective radiation probability, β H, V ppg k, associated with the cell sector of the respective interfering network cell at least partially covering the territorial portion.