A method and an arrangement are disclosed for a mobile station (111) of a cellular radio system to exchange capability information with the fixed parts (101) of the cellular radio system. The mobile station receives (513, 513') capability information (103) from discussed parts (101) if the cellular radio system and compares (515, 516, 517, 517' 518, 518', 519, 520) the received capability information (103) to a piece of capability information (112) describing the capability of the mobile station (111). The mobile station transmits (522, 522') to the fixed parts (101) of the cellular radio system a comparison result (113) that indicates whether matches occurred between the received capability information (103) and said piece of capability information (112) describing the capability of the mobile station (111).