Six-Year BDS-2 Broadcast Navigation Message Analysis from 2013 to 2018: Availability, Anomaly, and SIS UREs Assessment

The second-generation of the Beidou Navigation Satellite System (BDS-2) has been officially providing positioning, navigation, and timing (PNT) services within the Asia–Pacific region for six years, starting from 2013. A comprehensive analysis of BDS-2 satellite broadcast navigation message performance during the past six years is highly demanded, not only for the regional service but also for the global service announced in December 2018. Therefore, this study focuses on the performance assessment of six-year BDS-2 broadcast navigation messages from 2013 to 2018 in three aspects: Message availability, anomaly detection, and signal-in-space user range errors (SIS UREs). Firstly, our results, based on International GNSS service (IGS) Multi-GNSS Experiment (MGEX) navigation files, indicate that the BDS-2 Geosynchronous Earth Orbit (GEO) and Inclined Geosynchronous Satellite Orbit (IGSO) satellites have >98.51% broadcast navigation message availability, and the Medium Earth Orbit (MEO) satellites has a ~90.03% availability. Secondly, the comparison between broadcast navigation messages and IGS precise products reveals that the User Range Accuracy Index (URAI) contained in the broadcast message could not reflect satellite performance correctly. Another satellite status indicator, space vehicle (SV) health, can only partially detect a satellite anomaly. The anomaly detection result using IGS precise products for reference shows 20241 anomalies out of 651038 broadcast navigation messages within six years. Finally, compared with the IGSO and MEO satellites, the orbit qualities of GEO satellites are significantly worse due to their large along-track orbit error. The clock performance of all satellites are at the comparable level. The satellite orbit type (GEO/IGSO/MEO) does not impact the orbit-only URE, global-average URE, and worst-case URE

Satellite Systems in the Era of 5G Internet of Things

In recent years, IoT applications have drawn a great deal of attention, both in academia and industry. A crucial requirement of any infrastructure serving the IoT market will be to guarantee ubiquitous connectivity to the low-cost, low-powered devices distributed all over the globe. It is widely accepted that this requirement will not be met by the terrestrial network alone. There will be, in fact, vast areas of the globe where the terrestrial infrastructure deployment will be unfeasible or not economically viable, thus leaving those areas un- or under-served. For this reason, several studies and projects are addressing the use of a Non-Terrestrial Network component to seamlessly complement and extend the terrestrial network coverage in future systems. The design of these extremely complex systems requires manifold analyses at different levels of abstraction, from satellite constellation and ground segment architecture aspects, to the evaluation of the air interface behaviour, in order to evaluate the system performance. The aim of this work is to perform a detailed analysis of the SatCom system aspects, trying to be as accurate as possible but without getting lost in unnecessary details, in order to provide a comprehensive set of tools, organised in a simulation platform, to support the design and performance evaluation of the system. Notably, simulation softwares play an important role in this framework; however, a full-featured simulation tool does not yet exist for the evaluation of the described emerging technologies. ESA M2M Simulator (ESiM2M) is a System-Level Simulator, developed in collaboration with the European Space Agency, which is intended for closing this gap, as a tool for the design and analysis, from a system-level point of view, of Satellite-IoT systems. This work is primarily focused on the description of the ESiM2M simulation tool and the results derived with the latter from analyses on Satellite-IoT systems

Memorias del Congreso Argentino en Ciencias de la Computación - CACIC 2021

Trabajos presentados en el XXVII Congreso Argentino de Ciencias de la Computación (CACIC), celebrado en la ciudad de Salta los días 4 al 8 de octubre de 2021, organizado por la Red de Universidades con Carreras en Informática (RedUNCI) y la Universidad Nacional de Salta (UNSA).Red de Universidades con Carreras en Informátic