Adaptive RED for Cross-layer DVB-S2 systems

Systems with an adaptive physical layer make use of the channel conditions information in order to adapt their transmission to the channel with adaptive coding and modulation (ACM) techniques. These systems present a challenge in providing quality-of-service since the capacity is not constant. Previous work has covered capacity allocation solutions that provide service guarantees and fairness in terms of bandwidth allocation. In this paper, we present active queue management techniques that provide delay guarantees. We analyse the adaptive RED algorithm and present the required changes for implementing RED over an adaptive physical layer system. We show through simulations that there is an optimal operating point in the trade-off between packet marking and maximum queuing delay.