Method and arrangement for managing a service in a mobile communications system

摘要

The invention pertains to a method and arrangement for managing a service in a mobile communications system, mobile station and an intelligent module in a mobile station. An idea of the invention is that the data needed in the mobile station for a mobile communications service are transferred in encrypted form to several mobile stations at a time. The encryption is based on a key which is transferred individually to mobile stations. Applied to mobile station location this means that the location of a mobile station is determined in the mobile station by means of the timing difference of the signals received from at least two (preferably at least three) base stations and on the basis of the location data of said base stations. The location data are transferred to the mobile station in encrypted form so that they can be utilized only by mobile stations to which the operator has delivered a decryption key needed to decrypt the location data. The decryption key is transferred preferably individually to each mobile station. Decryption may occur in an intelligent module of a mobile station, in which case no location data appear in a non-encrypted form outside the intelligent module, resulting in data confidentiality. If chargeability is the only requirement, decryption and location calculation may also take place elsewhere in the mobile station. The decryption key can be changed, in which case the new decryption key is transferred to the mobile station advantageously periodically in conjunction with the location update procedure.