The project considers different reference GEO and non-GEO satellite systems (MEO and LEO, with and without inter-satellite links) and a set of relevant user applications & services (for broadband access and 5G backhauling), with the following main objectives:
The project focuses on applications that are likely to be prevalent in the 2025 time horizon and that may be especially latency sensitive (e.g., gaming, cloud services or 360º video-on-demand). These applications are being increasingly encrypted, rendering some of the traditional latency mitigation techniques ineffective.
One of the challenges of the project is to handle a relatively high number of evaluation scenarios and test cases adequately and to obtain representative QoE results. Another challenge is to identify properly the potential of technologies that can improve the QoE, by using an emulation test bed and real applications.
The project provides the following benefits:
The project defines a set of system scenarios composed by the combination of satellite access networks (in all the range of orbit heights, covering GEO, MEO, LEO without ISL and LEO with ISLs) and two transport services: broadband Internet access and 5G cell backhauling. These scenarios also include Performance Enhancement Proxies (PEPs).
For each scenario, a set of applications is selected, whose Quality of Experience is quantitatively evaluated through a set of Key Performance Indicators (KPI). For this purpose, the project implements a real-time emulation test bed, which provides a realistic modelling of the different satellite system reference scenarios and, when applicable, the 5G access network. This test bed is used with real applications, using a combination of real and replicated servers.
Measured KPIs are benchmarked against the 5G terrestrial network reference. Then, the project identifies and evaluates technology solutions that can improve KPIs and eventually act as enabler of certain applications.
There is also an assessment of the impact of these solutions on the affected elements in the satellite systems, with recommendations on a roadmap towards implementation.
The project also produces recommendations to standardization entities (mainly 3GPP and ETSI) about including satellite networks as transport networks compliant with 5G requirements.
The following figure depicts the high-level architecture of the emulation testbed that is used for KPI measurements and technology evaluation.
The diagram shows application endpoints and servers, which may be either locally replicated servers or real servers to be accessed through the Internet. Considered applications are:
Application traffic passes through different emulators that model the reference satellite systems (implemented using Indra’s AINE tool) and 5G networks (implemented using NS-3). The satellite system emulator is configured to model the propagation delays of the different GEO and non-GEO satellite systems, delay variations due to HOs and the effects of satellite radio resource management (bandwidth on demand protocols).
The test bed includes also some middleware (PEPs) that implements current latency optimization techniques and that may be updated with new ones.
The project is structured into four main sequential tasks:
The project has completed the first task, about scenario, applications and evaluation methodology definition (PR1 milestone). The test bed is now under development.