Unequal error protection for H.263 video over indoor DECT channel

Several techniques have been proposed to limit the effect of error propagation in video sequences coded at a very low bit rate. The best performance is achieved by combined FEC and ARQ coding strategies. However, retransmission of corrupted data frames introduces additional delay which may be critical either for real-time bidirectional communications, or when the round-trip delay of data frames is high. In such cases, only a FEC strategy is feasible. Full reliable protection of the H.263 stream would produce a significant increase of the overall transmission bit rate. In this paper, an unequal error protection (UEP) FEC coding strategy is proposed. The proposed technique operates by protecting only the most important bits of an H.263 coded video with periodically INTRA refreshed GOB's. ARQ techniques are not considered to avoid delays and simplify the receiver structure. Experimental tests are carried out by simulating a video transmission over a DECT channel in an indoor environment. The results, in terms of PSNR and overall bit rate, prove the effectiveness of the proposed UEP FEC coding.