A new RA-DA hybrid MAC approach for DVB-RCS2

This paper proposes a new MAC scheme for DVB-RCS2 aimed to efficiently address M2M/SCADA traffic. The proposed scheme relies on the idea to complement, in a dynamic way, Random Access (RA) schemes with Dedicated Access (DA) schemes, when traffic spikes feed the network. The rationale is to control the offered load on the RA slots pool to keep the packet loss due to collisions under a pre-defined threshold. New MAC algorithms based on the interaction between NCC and STs add a number of new features and dynamics, such as selective switching on a full DA configuration for greedy STs. A prototype implementation has been developed in the Network Simulator NS-2, in order to verify the effectiveness of the proposed approach in a preliminary study case. Achieved results are promising and they allow highlighting the main MAC scheme dynamics, leading to practical considerations and open issues to be addressed in future activities.