QoS Support in SGD-based High Throughput Satellite Networks

This paper proposes a Quality of Service (QoS) management framework for High Throughput Satellite (HTS) systems using EHF frequency bands, which can achieve high capacity provided that feeder link outage events caused by severe weather conditions can be properly counteracted. To this regard, Smart Gateway Diversity (SGD) architectures implementing advanced gateway handover procedures are certainly attractive, although they can only partly mitigate the negative effects of adverse weather conditions in terms of packet losses, delays, and jitters, which significantly degrade the performance of delay-sensitive and -insensitive traffic flows. To cope with these technical challenges, we propose an incremental rerouting scheme to control congestion events because of capacity reduction during the transient phase, consisting in offloading high-priority QoS traffic flows from the affected gateway towards gateways operating in more favorable conditions. Moreover, we apply interflow network coding at the gateways to protect delay-insensitive flows from packet losses occurring during feeder link outage. Finally, extra capacity is reserved at the gateways to handle the additional traffic resulting from gateway handover. The theoretical analysis (validated by simulation campaigns) allowed characterizing network coding performance and confirming the potentialities of our QoS management framework for HTS systems.