Buffer management algorithms need to decrease queue delay as well as to improve throughput. Because of unique issues in wireless channels, providing delay guarantee in wireless networks is much more complex than that of wired networks. We propose a random early expiration detection based buffer management algorithm for real-time traffic over wireless networks. The main idea is to predict whether new arrival packet can reach the receiver under the limit of maximal delay bound, and random discard the packet based on estimate result, so as to prevent invalid transmission, and at meanwhile to decrease queue delay and to reduce expiration probability of following packets. Considering the characters of wireless link such as variable channel condition and having transmission errors, the algorithm is divided into three stages. We also consider the influence on TCP performance in the design.