Foresig

System/ Network/ Protocols

Status

Ongoing
Status date

2024-04-26
Activity Code

3B.037

Objectives

The objective of Foresig is to develop a testbed to simulate the performance of a high-throughput SatCom system operating in the Ka-band for the user links and Q/V-band for the feeder links. The SatCom system covers Europe and has by default six gateways located in different parts of Europe. The system includes a Channel Assessment System (CAS) that estimates and predicts tropospheric attenuation, including precipitation, clouds and atmospheric gases. The input data to the CAS are Numerical Weather Product (NWP) data from ECMWF and weather radar data from the Norwegian Meteorological Institute (MET) and OPERA. In addition, user terminal data from THOR 7 and data from several beacon receivers are used to verify the accuracy of the predictions. Based on this information, the link quality can be estimated and predicted for all the links of a SatCom system.

The output from the CAS is used by a Propagation Impairment Mitigation Technique (PIMT) module to optimise the performance of the SatCom system in terms of data throughput, service availability and user terminal energy consumption. The PIMTs included in the testbed are smart gateways (SGWs), ACM and reconfigurable antennas.

In additions, the reduction of energy consumption user terminals can gain by using forecasts is estimated, provided that transmission of data can be delayed up to 12 hours. Analyses of the results from the simulations give an indication of the gain that can be obtained in a real high-throughput SatCom system using PIMTs and channel predictions.

Challenges

Several challenges are related to the data to be processed:

Large data files make data transmission, storage and computation challenging.
Combining heterogeneous data sources different spatial coverage and resolution, and different temporal resolution, to predict attenuation.
Lack of ground truth data for estimated tropospheric attenuation, making optimisation of the models and evaluation of their accuracy challenging.

Other challenges are related to the mitigation techniques, e.g.;

Develop intelligent PIMTs using channel predictions with the temporal resolutions available from the APIs.
Assessing the actual benefit for SatCom operators implementing the system.

Benefits

Several scientific articles from the recent years show the potential benefits of using meteorological forecast data to predict channel fading in high-frequency SatCom systems to increase the data throughput and service availability. The testbed developed in this project shows the practical gain that can be obtained using meteorological forecast data currently available together with user terminal channel quality data and mitigation techniques such as smart gateways. In addition to assess the performance in terms of data throughput and service availability, reduction in energy consumption in a IoT-type of system where user terminals run on battery or energy harvesting is included.

The testbed is flexible in the sense that it can be used to simulate the performance of different systems with their own coverage area, frequencies, satellite orbital position, mitigation algorithms etc. A graphical user interface is used to enter the key parameters required to define the system and scenario to simulate. The only limitation is the availability of meteorological forecast data. The testbed is also designed so that it can easily be extended to include non-GEO SatCom systems, optical communication etc.

Features

The Channel Assessment System (CAS) provides tropospheric attenuation estimates and predictions with a spatial resolution of 2 x 2 km over the entire coverage area. Nowcast estimates are provided each 15 minutes, while predictions are provided with 15 minutes resolution from nowtime to 5 hours ahead, and then each hour to 12 hours ahead. Statistical interpolation is used to obtain higher temporal resolution in the SatCom system simulator.

The mitigation techniques use the data from the CAS to optimise the operation of the SatCom system. A smart gateway system including four active gateways and two standby gateways uses the channel predictions to optimally manage which gateways that are active at any given time. The ACM uses channel predictions to manage margins to the thresholds, while reconfigurable antennas use channel predictions to optimally allocate power between the feeder links.

Several smart gateways, ACM and reconfigurable antenna algorithms are implemented and can be selected in the graphical user interface. The statistical analysis of the simulations enables a comparison of the performance of the different mitigation techniques and an assessment of the gains or benefits obtained compared to baseline scenarios not using channel predictions.

System Architecture

The figure shows the architecture of the testbed.

DS1: The data set DS1 consists of NWP data from ECMWF, weather radar data from MET and OPERA, user terminal channel quality data from THOR 7 provided by Telenor Satellite, and beacon data from several receiver located in Norway.
CAS: The Channel Assessment System uses DS1 to estimate and predict the tropospheric attenuation for a fixed grid covering the service area for all frequencies of the system. The results are saved in a new data set DS2.
DS2: The data set DS2 contains attenuation estimates (nowcast) and predictions for the coverage area. The nowcast data are used in the SatCom system simulator to simulate the communication, and the predictions are used by the Propagation Impairment Mitigation Techniques (PIMTs).
SatCom system: The operation of the SatCom system is simulated, using the input from DS2. The results are end-to-end SNIR values, together with other scenario specific results.
DS3: The results of the SatCom system simulator are stored in data set DS3.
Analysis: DS3 data are used to do statistical analysis of the performance (throughput, availability, energy consumption). The results are stored or visualised.

Plan

The project consists of six outputs:

SOTA and design of the Channel Assessment System
Design of the SatCom system testbed
Implementation of the Channel Assessment System
Implementation of the SatCom system testbed
Execution of the SatCom system testbed and analysis of the performance
Final reporting, roadmap and conclusions

Current status

The final deliveries containing the software package and final reports were delivered to ESA before the summer 2023. The official end date of the project is planned for late 2023.