A method and arrangement for estimating the current channel quality for a data transfer in a mobile network. In a sending system entity, a channel quality estimate (CQE) associated with a data transfer to a receiving system entity in a mobile communication network is adjusted. One or more probing packets are communicated 400 between the sending system entity and the receiving system entity, each probing packet being formatted according to a predefined combination of transmission parameters. Furthermore, is a Channel State Information (CSI) report received 404 from the receiving system entity, and the CQE is adjusted 406 based on the CSI report and which probing packets have been successfully communicated. By sending a sequence of probing packets, each formatted according to a predefined combination of transmission parameters, and not waiting for each packet to be acknowledged, a fast and accurate estimation of the current channel quality is achieved.