A Mobile Station, an MS (700), for a GERAN system, the MS (700) being arranged (705, 710, 750, 730) to receive bursts from a Base Transceiver Station, a BTS, each of said bursts being modulated with a modulation type chosen from one of a number of modulation types. The MS is arranged (730, 740) to identify bursts from the BTS which may comprise information for the MS by identifying if a Training Sequence Code, a TSC, which is comprised in received bursts corresponds to a TSC which the MS has been assigned, the MS being arranged (705, 710, 750, 730, 740) to be assigned a first and a second TSC to be used for at least one of said modulation types.