Cross-layer enhancement of error control techniques for adaptation layers of DVB satellites

This paper assesses the way error control is managed jointly by Forward Error Codes (FEC) and Cyclic Redundancy Checks (CRC) in the lower layers of today's Digital Video Broadcasting (DVB) satellites. Mathematical and simulation results clearly show that the outer block codes of the coding schemes used in DVB-S and DVB-S2 (Reed-Solomon and Bose-Chaudhuri-Hocquenghem, respectively) can provide very accurate error-detection information to the receiver in addition to their basic correction task at virtually no cost, making an uncorrected error after decoding an extremely improbable event. For this reason, the workload of CRCs can be ensured safely by the FEC subsystem if a dedicated function allowing the physical layer to share its decoding information with the adaptation layer is set. This particular cross-layer mechanism would allow freeing up the bandwidth currently used by CRCs-which adds up to 10% for more than 35% of the total number of IP packets-and pave the way for an enhanced transport of IP over DVB-S2. Copyright (c) 2006 John Wiley & Sons, Ltd.