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

Abstract

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.Index Terms-ARQ, DVB, forward error correction, ReedSolomon code, wireless home networks.

Predictable Reliability and Packet Loss Domain Separation for IP Media Delivery

“…We assume that the best choice for each individual segment will depend on the respective PLR and delay behavior of the segment and the scenario, i.e. the target requirements, the number of sources and the interdependency of segments and links to the sources [6], [7].…”

“…In our earlier and recent work [6], [7] we have optimized a general hybrid error correction (HEC) architecture in a way that -under a given delay constraint and an allowed residual error-the Shannonbound is approached dynamically, as opposed to similar work [8]. We could prove that due to the fast changing channel capacity especially in wireless networks the efficiency of this adaptive error coding is far higher than that of purely FEC or retransmission based systems.…”

Beacon-driven Leader Based Protocol over a GE Channel for MAC Layer Multicast Error Control

“…For the application layer multicast error control, many authors [5,8] studied the ARQ based schemes and concluded that when combined with feedback suppression and other accessorial techniques, ARQ is effective to repair multicast packet losses for small groups with low error rates. However, the application layer ARQ always take a long time and they are not efficient at high error rates and with large numbers of receivers due to feedback implosion and the limitation to scale.…”

“…Hence the multicast error is controlled in the application layer. The existing application layer multicast error control schemes include automatic repeat request (ARQ), forward error correction (FEC) and hybrid error correction (HEC) [5][6][7][8][9][10]. Unfortunately the total multicast delays of the application layer schemes are always high and sometimes do not satisfy the strict application delay constraints, or these schemes are not efficient when the delay constraints are short.…”

“…To guarantee a very low PLR under strict delay constraints for video multicast over a GE channel, we analyze BLBP and compare it with LBP and two application layer multicast error control schemes via simulation experiments. One is an ARQ based scheme from [8], called HEC-PR, which combines a NACK based ARQ scheme with a packet repetition (PR) technique. The other one is a nearly optimal application layer multicast error control scheme called Hybrid ARQ (HARQ) Type I [9,10], which combines FEC and NACK based ARQ scheme together.…”