Jaizki Mendizabal - Academia.edu (original) (raw)

Papers by Jaizki Mendizabal

Lecture Notes in Computer Science, 2017

In order to assess the performance of the wireless communication systems, a railway line is chara... more 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.

2017 15th International Conference on ITS Telecommunications (ITST), 2017

This paper shows the strategy and results of the simulation of the Train integrity determination ... more 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.

Networking Simulation for Intelligent Transportation Systems, 2017

Global System for Mobile Communications – Railway (GSM-R) is one of the most used radio technolog... more Global System for Mobile Communications – Railway (GSM-R) is one of the most used radio technologies in railway network for transmitting control information. However, nowadays IP-based technology is quite up-to-date and mature. Since there are many approaches for providing support to IP mobility and adaptable communications, it is important first to measure and understand the performance of IP networks in current railway routes. This paper provides the details of a framework entitled Channel Characterization Tool (CCT), a distributed network performance evaluation framework for the feasibility study of public IP networks in railway network. This paper describes the architecture of CCT, and some results obtained in field testing, as the first step in the validation of the framework. Finally, future research lines and conclusions are drawn.

The European initiative Shift2Rail (S2R) joins efforts for smart and sustainable growth in the ra... more 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.

The modal share of intra-EU rail freight transport is less than 20% of the freight transport sect... more The modal share of intra-EU rail freight transport is less than 20% of the freight transport sector. The current rail freight situation is not only due to the existence of legal barriers restricting competition (including the track access regime, taxation, etc.), but also 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, a holistic approach involving several technical areas, that form the backbone of the project approach. The outcomes of FR8RAIL will positively contribute to and support the ...

Security is gradually taking center stage. Since traditional transport systems were based solely ... more Security is gradually taking center stage. Since traditional transport systems were based solely on mechanical or electromechanical devices and closed networks, today with an increasing number of information technologies and communications devices, systems are being migrated towards new communication technologies and open protocols. Although this has increased the efficiency and reduced costs to companies, the systems have become more vulnerable to external attacks. And railway is not and exception, its infrastructure is mainly based on computers that are interconnected via wired or wireless networks and it is highly distributed, therefore railway's infrastructure is difficult to protect and it is vulnerable to cyber-attacks. This work shows an analysis about the standards used in security. A comparison with safety norms and the main reasons why security is currently not considered when developing safety critical devices are also described. Finally, an example of safety and secu...

Lecture Notes in Computer Science, 2021

Applied Sciences, 2021

Railway applications are in continuous evolution with the aim of offering a more efficient, susta... more Railway applications are in continuous evolution with the aim of offering a more efficient, sustainable, and safer transportation system for the users. Generally, these applications are constantly exchanging information between the systems onboard the train and the trackside through a wireless communication. Nowadays, Global System for Mobile communications-Railway (GSM-R) is the technology used by European Train Control System (ETCS), but it is becoming obsolete. Therefore, alternatives for this technology have to be found for the different railway applications. Its natural evolution is to move forward with the latest technology deployed: Long-Term Evolution (LTE), which the Public Land Mobile Networks (PLMN) have already deployed. Therefore, testing the performance of this communication technology in the railway environment could be useful to assess its suitability and reduce the cost of railway network dedicated deployment. In order to do that, a methodology to characterize the c...

Lecture Notes in Computer Science, 2020

Lecture Notes in Computer Science, 2018

The current low modal share of intra-EU rail freight transport is partly due to limitations of op... more 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.

As long as YouTube is one of the most used services of the World Wide Web, it consumes an enormou... more As long as YouTube is one of the most used services of the World Wide Web, it consumes an enormous quantity of bandwidth along the network. In order to maintain a high efficiency in this bandwidth management requirement, YouTube needs to adopt (and renew) highly efficient video streaming techniques. These changes produce a deprecated literature about YouTube service traffic characterization. This work reports an analysis of the recent DASH adaptive video streaming technique adopted by YouTube. In addition, this article includes the state of art about the literature with regard to the YouTube traffic characterization and analyses the DASH implementation of YouTube, reporting the relationship between download bandwidth consumption and video quality obtained and its performance.

The Communication Technologies for Vehicles Workshop series provides an international forum on th... more The Communication Technologies for Vehicles Workshop series provides an international forum on the latest technologies and research in the field of intra- and intervehicles communications and is organized annually to present original research results in all areas related to physical layer, communication protocols and standards, mobility and traffic models, experimental and field operational testing, and performance Analysis among others.

2017 15th International Conference on ITS Telecommunications (ITST), 2017

An on-board Complementary Positioning System (CPS) has been proposed to overcome the limitation o... more 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.

As safety critical systems introduce new safety functionalities that need to be tested, fault inj... more As safety critical systems introduce new safety functionalities that need to be tested, fault injection techniques must be provided. This work focuses on the design and implementation of a network saboteur which injects faults at network communication level between devices working into a virtual laboratory. The combination of a virtual laboratory and the network saboteurs offers a portable and scalable testing environment reducing the money and time costs. The inclusion of the described saboteur into the EATS (ETCS Advanced Testing and Smart train positioning system) project laboratory is also detailed as a case study of the exposed work.

IEEE Transactions on Industrial Electronics, 2022

A scalable system for wireless wear monitoring in a distributed harsh industrial environment, in ... more A scalable system for wireless wear monitoring in a distributed harsh industrial environment, in which installation of the electronic equipment near the distributed wearing measuring locations is unfeasible, has been successfully designed, developed and deployed. The system is composed of a novel LC-type passive wireless wear sensor system, a sensor readout coil, an electronic equipment, a readout unit for a scalable multisensor system and a control and monitoring system. The capacitor structure, employed as a sensing device in the LC sensor manufactured on low cost PCB, provides a linear response to the wear level. This allowed us to define a measuring and calibration method to suppress the cable effects from each distributed readout coil to the electronic equipment readout unit. It was possible to achieve a multiple simultaneous measurements in different sensors distributed along an industrial process without significant cabling influence. Concerning the sensor data analysis, a double Holt-Winters method with trend was used to reduce noise effects and an “experience based learning” tool was implemented in order to solve any misbehavior or time lag. Laboratory measurements and on-site operation results in an article mill indicate 1 mm precision and about 0, 5 MHz/mm sensitivity of the LC-type passive wireless wear sensor system.

IEEE Vehicular Technology Magazine, 2018

This article has been accepted for inclusion in a future issue of this journal. Content is final ... more This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. 2 ||| 1556-6072/18©2018ieee ieee vehicular technology magazine | march 2018 M ost critical applications today depend on computers, so a computer failure can cause financial disaster, serious injury, or even death. In this context, railways are considered a critical application, so they must meet the highest standards of availability and safety. Availability ensures continuous operation of the system, while a safe system must behave correctly in all operating and environmental conditions. But what happens if an external attack compromises the availability and/or safety of the system? In railways today, cybersecurity is not considered to be as important as safety-but a cybersecurity threat can lead to safety problems. Moreover, current railway standards dealing with the development of security modules are just general or only recommendations, unlike railway safety standards for developing electronic devices, which are both general and particular. This article shows the current cyberthreats that affect the railway transport network, presents a general analysis about the standards used in security compared with those used in safety, and describes some recommendations to improve cybersecurity. Overwhelming Focus on Safety According to the definition provided in [1], safety is defined as "the degree to which accidental harm is prevented, detected, and reacted to." The same source also defines security as "the degree to which malicious harm is prevented, detected, and reacted to." One useful example to understand the difference is a public office building: the smoke detectors are safety devices to prevent accidental harm, and the turnstile and control access are security devices to prevent malicious harm. One of the most popular components of security is cybersecurity, which focuses on protecting networks, computers, and data from unauthorized access. Railways and other transportation systems are considered safety-critical applications, i.e., systems, the failure of which may result in human disaster of one sort or another. A failure occurs when an application or system is not able to guarantee its required function. While safety-critical applications are not necessarily controlled by computers, as application complexity matures, computers become much more reliable than humans for performing safety tasks. So it is not surprising that computers are increasingly replacing humans for such tasks. Therefore, since most

Transportation Research Procedia, 2016

The suitability of EGNSS (including EGNOS and Galileo early services) for safety railway applicat... more The suitability of EGNSS (including EGNOS and Galileo early services) for safety railway applications has been analysed by several European projects such as Grail, Grail-2, Satloc, 3InSat, and it is currently being analysed by ERSAT EAV. ERSAT EAV in particular is addressing the following three challenges beyond the state-of-the-art: a) reuse of ETCS odometry by adding the virtual balise concept to eliminate the fixed balise along the line; b) adoption of the public EGNOS Augmentation network "upgraded" with Local augmentation networks to fulfil the railways' requirements; c) verification and validation of alternative GNSS solutions to guarantee localization functions in areas where the GNSS signal is not available and/or subject to interference. This paper focuses on the third of these challenges, addressing the design and the implementation of a complementary positioning system (CPS) for GNSS-denied areas. This system is based mainly on the Public Land Mobile Network (PLMN) information but also incorporates additional source information (such as predefined GNSS blocked zone information and GNSS positioning information for calibration purposes, when available) in order to enhance positioning performance. This paper deals with the different steps taken to create the CPS: 1. Analysis of the alternatives for complementary positioning systems when GNSS is not available 2. Simulation and development of algorithms for the CPS in the lab 3. Creation of a prototype for the CPS based on COTS components More specifically, after analysing the state-of-the-art technologies, the algorithms for the selected solution will be implemented in the laboratory. In order to analyse the theoretical performance of the algorithms, the environment and observables for the algorithms will also be modelled in the simulation platform. The performance of the CPS will be analysed in terms of accuracy, reliability, continuity and integrity in a way similar to the GNSS systems. Finally, the algorithms will be implemented in a prototype based

Theory and Applications, 2009

Lecture Notes in Computer Science, 2017

2017 15th International Conference on ITS Telecommunications (ITST), 2017

Networking Simulation for Intelligent Transportation Systems, 2017

Lecture Notes in Computer Science, 2021

Applied Sciences, 2021

Lecture Notes in Computer Science, 2020

Lecture Notes in Computer Science, 2018

2017 15th International Conference on ITS Telecommunications (ITST), 2017

IEEE Transactions on Industrial Electronics, 2022

IEEE Vehicular Technology Magazine, 2018

Transportation Research Procedia, 2016

Theory and Applications, 2009