In a Circuit Switched Services over Long Term Evolution via Generic Access Network, CSoLTEvGAN architecture (600), relations between E-UTRAN cells (9201) and Generic Access Network, GAN cells (9101) are configured manually in a generic access node controller, GANC (910). This may become a tremendous burden for the operator. The current invention overcomes this by automatically build the needed relations. This is accomplished by determining at the GANC (910), cell identification information for an E-UTRAN cell (9201) and cell identification information for a GERAN or UTRAN cell (1101) overlaying the E-UTRAN cell (9201). The GAN cell (9101) is determined based on the cell identification information for the GERAN or UTRAN cell (1101). An entry within a translation table (1000) is created so that the cell identification information for the E-UTRAN cell (9201) is mapped to the cell identification information for the GAN cell (9101), or vice versa.