First Experimentation Results with the Full Galileo CS Demonstrator

D. Calle, S. Cancela, E. Carbonell, I. Rodríguez, G. Tobías, I. Fernández-Hernández

Abstract: The Commercial Service (CS) is one of the services of Galileo, the European GNSS. According to the Galileo Mission, its objective is to provide 'added value' services to the final users through the Galileo E6 signal and the support of the open signals. Since 2012, and in parallel to the system deployment, the Galileo Program has been working with the European industry, the public institutions and Member States to trace the lines and demonstrate the future Galileo CS. First, a definition step was carried out in order to evaluate the most suitable and promising services for its future provision. The proposed services were authentication and high-accuracy, the former being divided in Open Service (OS) Navigation Message Authentication, to be offered on an open basis in the E1 signal, and CS authentication. In January 2014 the AALECS project (“Authentic and Accurate Location Experimentation with the Commercial Service”) was launched with the objective of developing a CS demonstrator and evaluate the capabilities and performance of the future CS. The project also comprises the execution of end-to-end tests in real and simulated environments to assess the service capabilities and performance. The first outcome of the activity arrived in 2014, a simplified CS demonstrator platform, the EPOC (Early Proof-of-Concept), was developed aiming to perform preliminary demonstration of the service. For the first time it allowed the global transmission of Precise Point Positioning (PPP) corrections and authentication information by a GNSS, through the E6 signal of the available Galileo satellites at the time. After two years of work, the Galileo Commercial Service Demonstrator was finalized and accepted at the end of 2015. It is composed of several elements distributed across Europe, and it is already ready for the execution of the experimentation activities. The experimentation tests have been split into three stages to align the Galileo CS demonstrator project with the status and schedule of the GNSS Service Center (GSC) and the Galileo Ground Mission Segment (GMS). The first stage comprises the demonstration and analysis of the proposed authentication and high accuracy services in simulated conditions. The second stage foresaw to perform tests with real transmission of real-time data through the Galileo SignalIn-Space. As this option is currently not available, an intermediate stage has been introduced using a novel working mode called Advance Replay Mode (ARM). The ARM seeks to evaluate the achievable performance of a future Galileo CS user without actually transmitting CS data through the Galileo Signal in Space. The representativeness of this working mode relies on the fact that it allows extracting real sequences of bit errors observed by a receiver (both in the E1 and E6 navigation signals), and introducing them in the CS data generated by the CS Demonstrator in order to evaluate the impact on the performances of the different Authentication and High Accuracy (HA) services at user level. This will allow performing tests in which the data demodulation errors, multipath effects and signal degradation will be fully representative of what a future CS user will face. This phase has been specifically defined to allow start the experimentation with CS Signal-in-Space (SIS) in advance of the GNSS Service Center put-into-operation. Once the first and second stages of the experimentation campaign are completed and the Galileo core infrastructure (i.e. the GNSS Service Center (GSC) and Ground Mission Segment (GMS)) is ready to be integrated with the CS demonstration platform and the proposed approach accredited, the CS Demonstrator will be integrated with the Galileo system elements. The objective for this third stage is twofold: on the first hand, the results obtained in the simulated environment shall be reassessed and consolidated using real SIS; on the other hand, a set of new challenges derived from the interaction with the real Galileo infrastructure will be addressed, such as the real-time communication with GSC, real-time CSData packets uplink and real SIS reception allowing the final closure of the Commercial Service loop. The conclusions obtained from the three test phases will represent a major outcome for the project and the future Galileo CS. This paper describes the first High Accuracy experimentation tests performed with the Advanced Replay Mode corresponding to the second stage of the experimentation campaign. The paper also provides some elements on the next steps for the CS Demonstrator and plans for future CS operational provision. In addition, the conclusions and relevant lessons learned obtained during the experimentation activities will be presented.
Published in: Proceedings of the 29th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2016)
September 12 - 16, 2016
Oregon Convention Center
Portland, Oregon
Pages: 2870 - 2877
Cite this article: Calle, D., Cancela, S., Carbonell, E., Rodríguez, I., Tobías, G., Fernández-Hernández, I., "First Experimentation Results with the Full Galileo CS Demonstrator," Proceedings of the 29th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2016), Portland, Oregon, September 2016, pp. 2870-2877.
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