A cross-layer video multicasting routing protocol for cognitive radio networks

摘要

In this work we investigate the problem of video streaming in cognitive radio networks from a cognitive radio video source to a set of cognitive radio destinations using multicasting. Our objective is to improve the overall quality of the received video by all destinations. To achieve this, we propose a cross layer approach to multicast the video packets. The video source implements the proposed approach to multicast a video packet to all destinations at the same time by selecting the best unified channel of all available channels for all destinations to send the video packet on. To select the best unified channel, the source jointly considers the required transmission time of the packet and the average spectrum availability time of the available channels. Moreover, by using the proposed approach, the video source guarantees that the required transmission time of the packet over the selected channel is less than its average spectrum availability time. We conduct simulation experiments to evaluate the performance of our proposed protocol under various network parameters. We compare our protocol with three multicast protocols. The first one selects the unified channel based on the minimum transmission time. The second one selects the unified channel based on the average spectrum availability time. The last one selects the unified channel randomly. We use packet delay, the ratio of bad frames, and control overhead as performance metrics. Simulation results demonstrate that the proposed multicasting routing protocol achieves significantly better performance compared to the other studied routing protocols in terms of all studied performance metrics. Specifically, it reduces the packet delay by at least 25%, the control overhead by at least 5%, and the ratio of bad frames 44%.