Abstract: A method for performing USSD transfer between a mobile station and a cellular communications network. The USSD transfer has a maximum data rate equal to the data rate of an associated control channel. The method comprises the following steps: 1) evaluating a set of factors in favor of the maximum data rate, for forming a totality of factors, the totality being at least partly independent of the existence of the associated channel prior to said evaluating; 2) comparing the totality of factors to a predetermined margin; and 3) performing the USSD transfer substantially at the maximum data rate in response to a positive result in said comparison, and otherwise at a lower data rate.