A method in a mobile communication system, comprising a mobile station and a base transceiver station, which are both arranged to use radio link protocol (RLP) and link protocol (L2R) in non-transparent data transmission. At least a first and a second frame of fixed lengths are defined for the radio link protocol for data transmission, the frames being of different lengths. The link protocol is arranged to transmit status information defining data transmission. In non-transparent data transmission between the mobile station and the base transceiver station, remapping during the data transmission between said frames is arranged to be initiated. The initiation of the remapping is arranged to be indicated to the link protocol layer (L2R). Current status information on the link protocol (L2R) is arranged to be transmitted in the radio link protocol (RLP) frame transmitted first after said remapping.