Network Coded Multicast over Multibeam Satellite Systems

Abstract

We propose a multicast scheme for multibeam satellite systems exploiting both the multiuser and spatial diversity inherent in this type of systems while taking into account realistic physical distributions of User Terminals (UTs) over the coverage. Our proposed scheme makes use of the well-known Adaptive Coding and Modulation (ACM) feature in Digital Video Broadcasting over Satellite, 2nd Generation (DVB-S2) and Extension (DVB-S2X) standards but also incorporates a set of innovative features. First, multilink reception, that is, receivers that can syntonize different frequencies and/or polarizations, together with Network Coding (NC) is used to enable decoding of signals from adjacent beams (spatial diversity). Second, efficient and fair allocation of resources is achieved through Proportionally Fair Multicast (PFM) scheduling. Our results, obtained over realistic nonuniform UTs distributions, show average system multicast throughput gains up to 88% with regard to state-of-the-art multicast schemes. Furthermore, a complete cross-layer architecture is proposed, fully compliant with the standard providing Quality of Service (QoS) guarantees.

Network coding for system‐level throughput improvement in satellite systems

“…The results with theoretical UTs distributions in Alegre‐Godoy and Vázquez‐Castro show that the proposed design achieves higher gains when UTs are predominantly located in the beam overlapping areas or close to the edge. This is also the case for the realistic distributions in Figures , and where the throughput improvement with respect to WCM is 32%, 65%, and 30%, respectively.…”

“…The main figure of merit we analyze is the average multicast throughput defined as the average bit‐rate sum offered to the UTs. The work in Alegre‐Godoy and Vázquez‐Castro provides results for several theoretical nonuniform UTs distributions showing significant throughput advantage compared to worst case multicast (WCM). When UTs are located in the beam overlapping area or close to the edge of the beam concentrated in small areas, the throughput gain is 64% to 88%.…”

“…Hence, a switching scheme between sending packets conventionally or network coded would be desirable. The work in Alegre‐Godoy and Vázquez‐Castro covers the above‐mentioned aspects to propose a full multicasting scheme including: Combined proportionally fair multicast (C‐PFM) scheduling policy, including method to decide when to use the multilink reception with NC feature, based on proportionally fair multicast (PFM) and a minimum service level agreement (SLA). C‐PFM selects the multicast throughput‐optimal MODCOD, taking fairness into account, for the multicast service based on the adaptive physical layers of DVB‐S2 and DVB‐S2×. End‐to‐end system functional diagram including all the necessary new functions in the GW and UT side to implement the proposed multicast scheme based on NC and UT multilink reception. Associated cross‐layer packet scheduling architecture with respect to the Internet engineering task force diffserv (IETF diffserv) model. …”

“…Previous work conducted by the authors covers separately the preliminary concepts and the designs ( designs 1 and 2 ). Those are presented in this paper in a common framework of NC applications for satellite systems.…”

Energy Efficient Communications for Reliable IoT Multicast 5G/Satellite Services

“…The benefits of adoption of NC for content delivery in DVB-SH systems for handheld terminals without return link and for DVB-S2/RCS systems with fixed and mobile terminals, are highlighted in [24]. NC multicast is also analyzed in [25] for multibeam satellite system, where receivers can tune different frequencies or polarizations to simultaneously decode orthogonal transmissions from adjacent beams and NC is used to enable decoding of signals from adjacent beams (spatial diversity).…”