This paper presents measurements of train motion with a low-cost inertial measurement unit (IMU) based on micro electro mechanical systems (MEMS). The were recorded on-board during normal passenger transport service network dense urban railway environment as well rural, regional environment. Sensor from several runs therefore analyzed and the data is presented discussion typical characteristics, noise dynamics. As dependent track, local track characteristics are inferred measurements....

ABSTRACT Quantum key distribution (QKD) allows the generation of cryptographic keys beyond computational hardness paradigm and is befitting for secure data transmission requiring long‐term security. The communication distance fiber‐based QKD, however, limited to a few hundred kilometers due exponential scaling signal attenuation. Satellite QKD (SatQKD) can instead leverage free‐space optical links establish long‐range connections enable global‐scale QKD. In this work, we review manifold...

Future safety-related vehicular applications require reliable information exchange provided by cooperative Vehicular Ad-hoc NETworks (VANETs). Although the WLAN standard IEEE 802.11p has been adapted to challenging environment, it not stringent communication requirements imposed applications. In particular, broadcast transmissions are mostly periodic and initiated at common TX powers. This makes potential interferences recurring instead of spurious lowers performance medium access for this...

ETSI ITS-G5 is the current vehicle-to-vehicle communication technology in Europe, which will be standardized by TC ITS. It based on IEEE 802.11p and therefore uses a CSMA/CA scheme for Media Access Control (MAC). In this paper we analyze performance of Cooperative Awareness Message (CAM) safety applications using MAC challenging scenario with respect to issues: A suitable freeway segment 6 lanes each direction. The thoroughly modeled implemented well known ns-3 simulation environment. Based...

The avoidance of train collisions is vital for human safety in railway transportation. Technical approaches are general control or collision systems as well semi-automated fully autonomous trains. These rely on robust and exact localization an accurate map the track network.We present Simultaneous Localization Mapping relying exclusively train-side sensors. RailSLAM, implemented a probabilistic filter, uses measurements from multiple sensors computes map. We heavily that not affected by...

Cooperative safety applications require dedicated short-range communications (DSRC) to provide position-awareness of neighboring vehicles at a specific level reliability, i.e., awareness-quality, up given distance, awareness-range. However, heavy communication loads negatively impact such awareness requirements due impairments, ranging from strict capacity limitations DSRC channels correlated packet collisions periodic patterns. Transmission control strategies may adapt power or rate...

This paper presents a channel model for direct train- to-train communication appropriate the 400 MHz band. Extrapolation of theoretical and experimental results obtained planning other railway systems like GSM-R is not obvious due to difference in frequencies, antenna height absence base stations. In this paper, analysis covers different radio phenomena including path loss, Doppler, fading, delay spread. Concretely we consider three scenarios (train stations, shunting yards regional...

Forward collision warning systems, lane change assistants or cooperative adaptive cruise control are examples of safety relevant applications that rely on accurate relative positioning between vehicles. Current solutions estimate the position surrounding vehicles by measuring distance with a RADAR sensor camera system. The perception range these sensors can be extended exchange GNSS information using an inter-vehicle communication link. In this paper we analyze two competing strategies...

Within the next decades railway systems will change to fully autonomous high speed trains (HSTs). An increase in efficiency and safety a reduction of costs would go hand hand. Today's centralized management system established regulations can not cope with driving within absolute braking distance as it be necessary for electronic coupling or platooning maneuvers. Hence, ensure reliability, new applications changes train control are necessary. Such demand reliable communication links between...

This paper addresses the problem of efficient data dissemination in Vehicular Ad Hoc Networks (VANETs), which particularly suffer from changing densities network topology due to congested and sparse traffic on roads. We present a new layer protocol family geographic protocols, makes use distance time information following strategy efficiently distribute messages adapting varying VANETs. have evaluated different road density scenarios its performance has been proved comparison two other...

The paper presents an overview of the state art in collision avoidance related with transportation systems like automatic identification system (AIS) for maritime transportation, traffic alert and system/automatic dependent surveillance-broadcast (TCAS/ADS-B) aircraft, car-2-car communication (C2C) road transportation. examined rely on position detection direct among vehicles. Alike a railway "RCAS" is introduced. Focussing aspects, possible applicability to RCAS studied. analysis are...

Current driver assistance systems merely use a minimum set of information. By using additional information the environment hazardous situations can be detected earlier, more reliably and with higher precision. This situational has significant impact not only on hazard detection, but also other modules such as human-machine-interface or knowledge distribution between vehicles over suitable networks. For number reasons is inherently subject to uncertainty. may handled by dynamic Bayesian...

The localization of trains in a railway network is necessary for train control or applications such as autonomous driving collision avoidance systems. Train safety critical and therefore the approach requires robust, precise track selective localization. Satellite navigation systems (GNSS) might be candidate this task, but measurement errors lack availability parts environment do not fulfill demands system. Therefore, additional onboard sensors, an inertial unit (IMU), odometer feature...