Adaptive retransmission to improve MPEG-4 video streaming quality in WiMAX

Abstract

In this paper we provide better quality of MPEG-4 video streaming under the superior IEEE 802.16 wireless network. There are three types of frames used in video compression: I-frame, P-frame and B-frame. Different types of frames have different significances on video quality. In this paper we propose an adaptive retransmission mechanism to improve MPEG-4 video streaming quality based on both deadline and decoding importance of each frame. We first construct a GOP (Group Of Pictures) tree from a GOP structure. Then we assign different weights to I/P/B-frames to form a GOP weight tree. Next, we classify those frames into \"backbone frames\" and \"non-backbone frames\". The backbone frames are allowed to have more retransmissions than those of non-backbone frames. As a further enhancement, we apply Lagrange multiplier method to non-backbone frames to maximize the number of decoding frames. Simulation results show that the proposed method outperforms IEEE 802.16 Standard and Priority Queue in average throughput, average lost & invalid frame and PSNR.