The present invention relates to a method for adapting the GBR/MBR (Guaranteed Bit Rate/Minimum Bit Rate) for data communication in a radio network (3), where the adaptation is used to comply to the highest capacity available at the radio network (3). The method comprises the steps: providing a predefined GBR to a component (5) in the radio network (3); and calculating an MBR using the GBR as input data, where a predefined algorithm is used for the calculation. The present invention also relates to a radio network comprising a piece of user equipment (2, 10), a radio control device (4, 11) and an SGSN (Switching GPRS Support Node) (5). The radio network (3) is arranged for adapting the GBR/MBR for data communication in the radio network (3) in order to comply to the highest capacity available. The invention also relates to a node which is arranged for calculating an MBR starting with a given GBR.