Enhanced inter-system handover in a telecommunications system

The application provides a solution for managing a failed handover situation in a cellular telecommunications system when a call is to be handed over from a first radio access system, such as UMTS, to a second radio access system, such as GSM. Before the handover of the call from a UMTS cell to a GSM cell, the BSIC code of the GSM cell has to be verified (2-5) by the mobile station. According to the present solution, at least one criterion, relating to the handover of the call to the GSM cell, is predetermined in the system. In case that the BSIC verification fails, the system updates (2-7) one or more counters (i.e. the RNC collects information of the UTRAN cells that have been connected to a mobile station when the BSIC verification has failed). The following counters are verified: number of BSIC verification failures, number of consecutive verification failures, etc. The value of the counters is compared (2-8) to the criteria, and if at least one of the threshold criteria is fulfilled, the system discontinues (2-9) the inter-system measurement process of said mobile station to said GSM cell.