Optimization of an RTP Level Hybrid Error Correction Scheme for DVB Services Over Wireless Home Networks Under Strict Delay Constraints

摘要

In order to meet very low packet loss rate (PLR) requirements under strict delay constraints for IP based DVB services over wireless home networks (WHN), an optimized real-time transport protocol (RTP) level hybrid error correction (HEC) scheme is proposed in this paper. The scheme is compared with the Adaptive Forward Error Correction (AFEC) scheme using Reed-Solomon code. By the HEC scheme, the needed redundancy information (RI) for repairing missing packets can be minimized, especially in DVB systems with a single user. The result of quantitative analysis shows that the needed RI of the proposed scheme can even achieve the Shannon limit with only three retransmission rounds. On the other hand, our studies show that the performance of the HEC scheme is better than that of the AFEC scheme if both the average link PLR and group size are small. However, if both the average link PLR and group size are large enough, the AFEC scheme performs better than the HEC scheme. At last, the simulation results for one typical scenario are also provided in the paper to validate the result of quantitative analysis for the HEC scheme. As a result, because of the simplicity and efficiency of the proposed HEC scheme, it is a very good choice for guaranteeing the Quality of Service for DVB systems in WHN with the small group size and small average link PLR. However, for scenarios with the large average link PLR and large group size, the AFEC scheme should be taken into account