Disclosed herewith is a wireless system capable of reducing packet sending delay occurrence and packet sending delay jittering at the time of hand-over processing executed therein. In the wireless system, upon estimating occurrence of a hand-over event, a subject mobile station and its base station extend the packet buffering period respectively and furthermore, the base station changes the current burst scheduling method for another. The base station and the mobile station then exchanges messages required to execute the hand-over procedure in a period between when sending of a burst ends and when sending of the next burst begins.