Novel MF-TDMA/SCPC Switching Algorithm for DVB-RCS/RCS2 Return Link in Railway Scenario

This work focuses on the return channel resource allocation in the DVB-RCS/RCS2 system for mobile terminals. A continuous carrier (CC) operation mode based on DVB-S2/S2X is considered and investigated. The paper focuses on the possibility of transmitting simultaneously in multifrequency-time division multiple access (MF-TDMA) or single channel per carrier (SCPC) medium access techniques, as suggested by a previous DVB-RCS+M standard. The introduction of this capability has also been analyzed for a new DVB-RCS2 standard that gives the possibility of using both return link (RL) modalities. Moreover, we propose a detailed study of the RL channel in a satellite platform in order to understand the operative range of SCPC and MF-TDMA techniques. The contribution seeks to provide some threshold indications to network operators for dynamically managing satellite resources. We considered the railway market, which is characterized by an N-LOS condition due to blockage caused by tunnels, vegetation, and buildings, as the reference scenario. Furthermore, we introduced a transparent gap filler (GF) solution to overcome this issue. Simulation campaigns are shown, in order to give satellite operators some guidelines, when they want to make use of this hybrid channel modality.