Framing Efficiency Optimization for DVB-S2 Systems with QoS Guarantees

Kurzfassung

This paper deals with the design, evaluation and performance comparison of smart framing strategies that complement the packet scheduler in DVB-S2 systems with Adaptive Coding and Modulation, when QoS guarantees are to be provided. User data packets are transmitted grouped in frames according to a scheduling algorithm. Each of these frames uses a selected modulation and coding setting (ModCod), the most efficient pair that provides sufficient robustness given the channel state experienced by the satellite terminals that will receive the data. This is promising for the achievement of highly efficient resource utilization; however, the inherent spectral efficiency of the selected ModCod can be cancelled by a poor framing efficiency, i.e. transmitting frames with large padding component. In this paper, an extension of the Group-efficient Scheduler [3] is proposed to support QoS guarantees. In addition, smart framing strategies are proposed, which optimize the total transmission efficiency by different flavors of trade-off between spectral efficiency and framing efficiency. Finally, the performances of the QoS extension of the Group-efficient Scheduler complemented by the aforementioned smart framing strategies are compared in terms of different QoS metrics.