On the Impact of Satellite Communications Over Mobile Networks: An Experimental Analysis

Future telecommunication systems are expected to co-exist with different backhauling nodes such as terrestrial or satellite systems. Satellite connectivity can add flexibility to backhauling networks and provide an alternative route for transmission. This paper presents experimental comparisons of satellite and terrestrial based backhaul networks and evaluates their performances in terms of different Key Performance Indicators (KPIs) including Channel Quality Index (CQI), Modulation Coding Scheme (MCS) index, Downlink (DL) throughput, Frame Usage (FU) ratio and number of Resource Block (RB) utilization. Our experimental satellite network system uses a real satellite-based backhaul deployment and works in Ka band. As a benchmark, we compare our system with terrestrial network with regular cellular backhaul connection. Our experiments reveal three main observations: The first observation is that problems with FU ratio and number of RB utilization exist in satellite eNodeB even though a single test user equipment (UE) with high CQI and MCS index values is connected. The second observation is that in satellite link relatively low numbers of Protocol Data Units (PDUs) are generated at Radio Link Controller (RLC) layer compared to the Packet Data Convergence Control (PDCP) layer. Finally, our third observation concludes that the excessive existence of PDCP PDUs can be due to utilization of General Packet Radio Service (GPRS) Tunneling Protocol-User Plane (GTP-U) accelerator where an optimal balance between the caching size and the number of UEs using satellite eNodeB is needed. Hence, the existence of a trade-off between the supported number of UEs using satellite link and the GTP-U acceleration rate is also revealed with our experimental results.