1. A data communications method for a time-division multiplexed communications protocol in which data intended for plural user terminals can be simultaneously transmitted in one time slot, the method comprising: receiving data in a first user terminal during a time slot assigned for simultaneous transmission of data to a first set of at least one user terminal and to a second set of at least one user terminal; estimating an applied power ratio between the transmission power of a first sub-channel to the first set and the transmission power of a second sub-channel to the second set, wherein available power ratios are divided into at least one known region and each applied power ratio belongs to one region; estimating a bit error probability for each burst of the received data; and applying an adaptation process in order to make the estimated bit error probabilities fall into one bit error probability interval of a predefined mapping table with a predetermined probability, wherein the bit error probability interval in which the estimated bit error probabilities fall determines the bit error probability that is to be reported to a network, and the adaptation process to be applied depends on which region the applied power ratio belongs to.