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Due to their ability to provide a worldwide absolute outdoor positioning, Global Navigation Satellite Systems (GNSS) have become a reference technology in terms of navigation technologies. Transportation-related sectors make use of this technology in order to obtain a position, velocity, and time solution for different outdoor tasks and applications. However, the performance of GNSS-based navigation is degraded when employed in urban areas in which satellite visibility is not good enough or nonexistent, as the ranging signals become obstructed or reflected by any of the numerous surrounding objects. For these situations, Ultra-Wideband (UWB) technology is a perfect candidate to complement GNSS as a navigation solution, as its anchor trilateration-based radiofrequency positioning resembles GNSS’s principle. Nevertheless, this fusion is vulnerable to interferences affecting both systems, since multiple signal-degrading error sources can be found in urban environments. Moreover, an inadequate location of the augmenting UWB transmitters can introduce additional errors to the system due to its vulnerability to the multipath effect. Therefore, the misbehavior of an augmentation system could lead to unexpected and critical faults instead of improving the performance of the standalone GNSS. Accordingly, this research work presents the performance improvement caused by the application of Fault Detection and Exclusion methods when applied to a UWB-augmented low-cost GNSS system in urban environments.

Independently on the business case addressed, one of the main drawbacks of the railway use cases that need continuous Global Navigation Satellite Systems data is the lack of availability for the 100% of the time of the journey. Additionally, the integrity assessment of the position estimation given is also mandatory for safety critical applications. Thus, tunnels and multipath effects are one of the most challenging situations for the continuous positioning systems. In this context, an autonomous on-board Complementary Positioning System has been proposed to overcome the limitation of Global Navigation Satellite System based positioning systems. This paper proposes a positioning enhancement solution by means of fusing data from the satellite navigation system and inertial measurement units. That hybrid solution provides higher availability and accuracy to the positioning specially on known blocked scenarios, such as tunnels, or urban canyons, by means of a novel environment aware map aided software technique named Known Blocked Scenarios algorithm… This paper describes the Complementary Positioning System and the field test carried out in a challenging environment to validate the enhancement proposed by the authors, which demonstrate the benefits that this system has in known harsh environments for railways.

The European Union (EU) is bolstering the railway sector with the aim of making it a direct competitor of the aviation sector. For that to occur, railway efficiency has to be improved by means of increasing capacity and reducing operational expenditure. Tracks are currently used below their maximum capacity. Given this fact and the EU’s goals for the railway sector, research on solutions for on-board positioning system based on global navigation satellite systems (GNSS) have arisen in recent years. By taking advantage of GNSS, safety critical positioning systems will be able to use the infrastructure more efficiently. However, GNSS based positioning systems still cannot fulfill current normative validation processes, mainly, due to the fact that GNSS based positioning performance evaluation is not compatible with the key performance indicators (KPIs) used to assess railway systems performance: reliability, availability, maintainability, and safety. This paper proposes a methodology and unified key performance indicators (KPIs). Additionally, it shows real examples to address this issue. It aims to fill the gap between the current railway standardization process and any on-board positioning system.

Global Navigation Satellite System (GNSS) has become the main technology in terms of navigation technologies, as it ensures a worldwide absolute outdoor positioning. The transportation sector employs this technology to obtain a position, velocity and time solution for the corresponding outdoor application. When talking about indoor positioning, nevertheless, GNSS becomes an unreliable navigation technology, as the below-noise signals get obstructed. In these cases, the Ultra-Wideband (UWB) technology can be used as a navigation solution, as its anchor trilateration based radiofrequency positioning resembles GNSS’s principle and, depending on the anchor location, it can be used for indoor positioning. However, just like other radiofrequency based technologies, UWB is vulnerable to interferences and the multipath effect. With the aim of overcoming these drawbacks, this article discusses how to apply Fault Detection and Exclusion (FDE) techniques to avoid using faulty anchors when employing UWB in indoor/urban environments such as tunnels or train stations.

The current low modal share of intra-EU rail freight transport is partly due to limitations of operational and technical nature, which impact the overall capacity and performance of the sector. In order to overcome these issues, Shift2Rail set a specific Innovation Programme 5 (IP5) focused on Technologies for Sustainable & Attractive European Rail Freight. In this context, the FR8RAIL project, is working on the “Development of Functional Requirements for Sustainable and Attractive European Rail”. To overcome these limitations, among other technical areas, the communications of the freight train is involved. This paper deals with the analysis of the and mainly with the evaluation of the technologies currently available. This will lead to the definition of the future freight train communication as an outcome of FR8RAIL project that will positively contribute to and support the Shift2Rail goals to strengthen the role of the freight rail transport.

This paper shows the strategy and results of the simulation of the Train integrity determination system into the on-board ETCS. It first shows the Smart Train Positioning System (STPS), a GNSS based on-board system that determines the the train integrity. Then, scenarios are derived for two different routes. After that, the test setup based on the ETCS on-board unit virtual laboratory is explained. Finally, the results show that the on-board ETCS equipment is able to detect correctly the integrity loss and operates accordingly. Then, the capability of STPS of providing integrity information is proven and that leads to the conclusion that train's integrity can be determined on-board by using STPS.

An on-board Complementary Positioning System (CPS) has been proposed to overcome the limitation of GNSS positioning systems. This paper deals with the test phase of CPS to guarantee the localization functions in areas in which GNSS signals are not available. In order to analyze the suitability of CPS its performance in a railway operational line has been evaluated. The CPS is based mainly on GNSS, Inertial Measurement Units (IMU) and Wireless Communications Technologies (WCT) as input sources for localization. The field tests have been carried out in an operational regional line and availability has been increased as it was the purpose.

In order to assess the performance of the wireless communication systems, a railway line is characterised through the identification of electromagnetic interferences (EMI). The aim of this paper is to show the strategy to identify EMI on field as well as the results obtained. First, the need of the analysis and the objectives of the measurement campaign in a non-electrified Italian Regional Railway line between Caligari and San Gavino are shown. After that, the measurement setup developed for the tests is described. Then, the description of the measurement campaign carried out is exposed. Finally, the measurement results are presented. The results show that the frequency bands of GSM, UMTS and Italian 4G are in the frequency ranges where the highest powered signal (around 800 MHz–900 MHz, 1.8 GHz and 1.9 GHz), on the other hand GPS L1 and Galileo E1frequency band is not impacted by any kind of interference signal.

Wireless communications interfaces are vulnerable to interferers and noise. The effect of interferers and noise in the system will depend on the robustness of the communication system and the criticality of the system. ETCS European Train Control System is a safety-critical system responsible for the train control and command. There are two ETCS constituents installed on the track with a wireless communication to the train, namely Eurobalises and Euroloops that communicate with Balise Transmission Module BTM and Loop Transmission Module LTM. This paper includes an analysis of the state of the art of noise and interferers and proposes the worst case scenarios to be used in the laboratory to measure the robustness of the systems against noise and interferers.

Communication technologies are in continuous evolution and as well, the different applications making use of them. In order to succeed with the roll-out of the communication-based applications, it is required that the communications technologies are intensively tested and validated before deployment. Current strategies for testing and validation cover field tests and laboratory tests. Railways is also taking advantage of the communication technologies evolution, and therefore, there is a need for having testing and validation strategies adapted to the railway environment, especially for safety-critical applications. Field tests and laboratory tests also apply in Railways. In the frame of laboratory tests, this paper includes an overview of different network emulators existing currently in the market. Furthermore, an analysis of the gaps of the network emulators with regards to the needs of the railways environment is also included. The goal of this paper is to show that network emulators are a flexible cost-effective solution for communication technologies testing purposes. Additionally, this paper also shows that there is a need to adapt current emulators to the railway environment in order to test and validate the future railway applications based on communication technologies.

The European initiative Shift2Rail (S2R) joins efforts for smart and sustainable growth in the railway sector by fostering research and innovation. Specifically, the project FR8RAIL within the Innovation Programme 5 (IP5)'rail freight' of S2R aims to remove limiting factors of rail freight transportation. The work presented here is part of FR8RAIL and addresses the use and implementation of positioning strategies for rail freight transportation. Freight localization services based on on-board positioning, for example, can facilitate logistic optimization schemes that rely on continuous position and speed information. No extra trackside infrastructure is required, which reduces implementation and maintenance costs. The paper describes the challenges and requirements of on-board positioning strategies for the use in rail freight transportation and presents solution concepts (positioning requirements, hardware architecture, algorithms) for a more competitive rail freight.