Cross layer design for equal and unequal loss protection frameworks in cognitive radio networks

This study addresses the reliability of secondary multimedia transmissions under delay constraints and lossy conditions. In particular, a cognitive radio (CR) infrastructure collocated with a licensed network is considered. The primary traffic evolves following a Poisson distribution. During the sensing operations, the best spectrum opportunities are identified using a new subchannel quality metric. To mitigate the effects of packet loss, the use of a multiple description coding (MDC) framework of the unequal loss protection (ULP) class is explored. The performance of the proposed scheme is evaluated by comparing the results with those of the traditional equal loss protection (ELP) technique. Finally, a general cross layer model is proposed to ensure end-to-end message delivery in realistic cognitive radio contexts, which are characterized by difficult primary signal detection and random primary interruptions, in addition to subchannel impairments. Numerical simulations are conducted to investigate the peak signal-to-noise ratio (PSNR) benefits of the proposed system using both ULP and ELP schemes.