A method of adapting radio signal transmission times at a mobile station to enable a base station to synchronously receive radio signals from a plurality of mobile stations, said method accounting for a varying propagation delay between the mobile station and the base station, said method comprising the steps of: measuring a frame reception time at the mobile station for an n th data frame; obtaining propagation delay information regarding a propagation delay between the time of transmission of the n th frame and the time of reception of the nth frame; calculating, by the mobile station, a transmission time at the mobile station for the n th data frame using the propagation delay information and the measured frame reception time at the mobile station for the n th data frame; measuring a frame reception time at the mobile station for an m th data frame later than the n th data frame; determining, by the mobile station, that new information on the propagation delay between the times of transmission and reception for the m th data frame has not been received from the base station; and calculating, by the mobile station, the transmission time at the mobile station for the m th data frame by performing the steps of: determining the number of data frames between the nth data frame and an m th data frame later than the n th data frame; measuring a frame reception time at the mobile station for the m th data frame; and calculating, by the mobile station, the transmission time at the mobile station for the m th data frame based on a change in measured frame reception time between the reception time of the n th data frame and the reception time of the m th data frame, the number of data frames between the nth data frame and the m th data frame, and the propagation delay information obtained at the n th data frame. measuring a frame reception time at the mobile station for an n th data frame; obtaining propagation delay information regarding a propagation delay between the time of transmission of the n th frame and the time of reception of the nth frame; calculating, by the mobile station, a transmission time at the mobile station for the n th data frame using the propagation delay information and the measured frame reception time at the mobile station for the n th data frame; measuring a frame reception time at the mobile station for an m th data frame later than the n th data frame; determining, by the mobile station, that new information on the propagation delay between the times of transmission and reception for the m th data frame has not been received from the base station; and calculating, by the mobile station, the transmission time at the mobile station for the m th data frame by performing the steps of: determining the number of data frames between the nth data frame and an m th data frame later than the n th data frame; measuring a frame reception time at the mobile station for the m th data frame; and calculating, by the mobile station, the transmission time at the mobile station for the m th data frame based on a change in measured frame reception time between the reception time of the n th data frame and the reception time of the m th data frame, the number of data frames between the nth data frame and the m th data frame, and the propagation delay information obtained at the n th data frame. determining the number of data frames between the nth data frame and an m th data frame later than the n th data frame; measuring a frame reception time at the mobile station for the m th data frame; and calculating, by the mobile station, the transmission time at the mobile station for the m th data frame based on a change in measured frame reception time between the reception time of the n th data frame and the reception time of the m th data frame, the number of data frames between the nth data frame and the m th data frame, and the propagation delay information obtained at the n th data frame.