Novel system architecture for railway wireless communications (original) (raw)
Related papers
Seamless Wireless Connectivity for Multimedia Services in High Speed Trains
IEEE Journal on Selected Areas in Communications, 2012
The recent advent of high speed trains introduces new mobility patterns in wireless environments. The LTE-A (Long Term Evolution of 3GPP - Advanced) networks have largely tackled the Doppler effect problem in the physical layer and are able to keep wireless service with 100Mpbs throughput within a cell in speeds up to 350 km/h. Yet the much more frequent handovers across cells greatly increases the possibility of service interruptions, and the problem is prominent for multimedia communications that demand both high-throughput and continuous connections. In this paper, we present a novel LTE-based solution to support high throughput and continuous multimedia services for high speed train passengers. Our solution is based on a Cell Array that smartly organizes the cells along a railway, together with a femto cell service that aggregates traffic demands within individual train cabins. Given that the movement direction and speed of a high-speed train are generally known, our Cell Array effectively predicts the upcoming LTE cells in service, and enables a seamless handover that will not interrupt multimedia streams. To accommodate the extreme channel variations, we further propose a scheduling and resource allocation mechanism to maximize the service rate based on periodical signal quality changes. Our simulation under diverse network and railway/train configurations demonstrates that the proposed solution achieves much lower handover latency and higher data throughput, as compared to existing solutions. It also well resists to network and traffic dynamics, thus enabling uninterrupted quality multimedia services for passengers in high speed trains.
Performance simulation study of a wimax based telecom architecture for train control systems
2008
A great amount of the research being carried out in the transportation industry, and motivated by public administrations, is focused on safety and sustainability issues. European Union has encouraged the interoperability between the different European railway signalling systems with the design and standardization of the ERTMS (European Rail Traffic Management System). The communication technology that supports ERTMS is GSM-R, designed to support high mobility scenarios (up to 500km/h). Nevertheless, this technology presents the same data communication characteristics as 2nd generation mobile GSM. In heavy load situations, such as complex yards or busy junctions, communication flows have presented bottlenecks for new high priority connections. At the same time, off railway environment, there are many standardization groups, IEEE and IETF, focused on mobilizing Internet by standardizing new access technologies and protocols. Some of the research working groups are related to technologies such as 802.11p, 802.16e [1] or 802.20. In this paper we present the performance results obtained when deploying an ETCS application on a 802.16e-WiMAX based telecom architecture. The same QoS KPI [2] demanded to GSM-R in EIRENE specification have been evaluated.
IRJET-A Novel Scheme for Wireless Connectivity for Multimedia Services in High Speed Trains
The beginning of high speed trains launch new mobility patterns in wireless environments. The LTE-A(Long Term Evolution-Advanced)networks have mainly tackled the Doppler Effect problem and maintain wireless service with 100Mpbs throughput within a group in speeds up to 350 km/h. However much more repeated handovers across group significantly increases the possibility of service disruption, and the problem is major for multimedia communications that require both high-throughput and continuous connections. In this, paper a novel LTE-based solution is proposed to support high throughput and continuous multimedia services for high speed train traveler. The proposed solution is based on a Group Array that smartly organizes the groups along a railway, together with a Pico group service that collective traffic demands within individual train cabins. Given that the movement direction and speed of a high-speed train are known, Group Array effectively predicts the upcoming LTE groups in service, and enables a seamless handover that will not disrupt multimedia streams. To hold the extreme channel variations, Scheduling and Resource Allocation Mechanism (SRAM) is further proposed to maximize the throughput based on periodical signal quality changes. The results demonstrates that the proposed solution achieves much lower handover latency ,low handover failure rate ,low delay and higher data throughput, as compared to existing solutions. It also well defends against to network and traffic dynamics, thus enabling continuous quality multimedia services for travelers in high speed trains.
Top challenges of LTE to become the next generation railway communication system
Computers in Railways XIII, 2012
Railway environments cannot be away from the current evolution of public communication systems. The Long Term Evolution (LTE) mobile communication system is considered to be the natural evolution for current Global System for Mobile Communications Railways (GSM-R). LTE all IP networking technology plays a key role for the integration and convergence of heterogeneous networks and services, both the specific for the railway operative and the commercial broadband ones for passengers. The adoption of a new generation standard for railway communication must be based on an exhaustive feasibility study of the new system to become the railway mobile communication system. In this paper, LTE's top challenges to address the specific requirements and features of railway communication services are evaluated. Under this scope, LTE features to implement the required railway functionalities, LTE technical challenges, spectrum harmonization, network deployment considerations and LTE capabilities to meet the railway service Reliability, Availability, Maintainability and Safety (RAMS) requirements, are assessed.
System-Level Evaluation of Next-Generation Radio Communication System for Train Operation Services
2018
GSM-R, the radio communication system based on GSM and enhanced to support services required for train operation has been adopted in most of the European countries on main lines. In order to fulfill railway operators' requirements evolving toward a larger use of the radio communication system with new applications, like closed-circuit television, and to overcome the upcoming GSM obsolescence, the design of the next radio communication system for train-to-ground communications has started in Europe. In this context, the X2Rail-1 project evaluates the system throughput of the 3GPP Long Term Evolution (LTE) mobile cellular system in a railway environment for both train-to-ground and ground-to-train links. Realistic system-level evaluation results taking into account typical railway deployment scenarios, including train density and speed, wayside base station deployment, propagation model, inter-cell interference and its mitigation are presented in this paper.
2009
In the last few years, in the European context, railway communication architectures have migrated from a juxtaposition of different, and mostly proprietary, technological solutions-each of them addressing the particular requirements of a specific railway IT service-to a single unique and integrated telecom open architecture based on GSM-R (Global System for Mobile Communications - Railways). Next envisaged movement is to integrate the current different railway IT services and emerging railway needs in a global open and standard 4th generation mobile communication architecture. However, in-depth studies are necessary to validate these packet switched technologies and architectures as usable for the highly demanding railway operational communications such as the automatic train control service. The standardized version of this service in the European context, is known as ETCS service (European train control system). These packet switched technologies, since they are based on a different philosophy, they need adequate engineering rules. This paper is focused on building a simulation framework able to carry out these in-depth performance evaluation studies.
IP Impairment Models for Performance Evaluation of Wireless Systems in Railway Environments
IEEE Access
Validation measurements for the Future Railway Communication System in railway environments is a very challenging task and should be reduced to a minimum for cost and time efficiency. ''Zero-on-site testing'' consists of using simulation/emulation tools and testing procedures to allow validation and verification activities in the laboratory to avoid complex and expensive trials with trains on real-world sites. A solution to test a communication network in a laboratory under realistic conditions consists of injecting perturbations at the IP level (such as additional delay, packet losses, or jitters). It is essential to correlate the IP impairments with the radio environment, their effects on end-to-end transmission, and how the network and its elements react. To do so, IP impairments (or the conditions that lead to them) should be generated in such a way that allows assessing their impact on the performance of transmissions. This paper presents the results of an experimental research based on an original emulation platform (Emulradio4Rail platform), able to emulate and test wireless systems taking into account both physical layer as well as IP traffic in realistic railway environments. Different types of IP traffics are injected at the application layer and go through the platform. The work aimed at extracting various statistical distributions of classical IP metrics (delay, packet loss, jitter, throughput) versus time, as a function of radio channel conditions for Wi-Fi and LTE transmissions in typical railway environments. Then, the modeled IP impairments statistical distributions can be considered at the IP level to test very easily wireless system modems. The results and methodology can be considered for the evaluation of the Future Railway Mobile Communication System modems. INDEX TERMS IP metrics, railway communications, tapped-delay-line models, channel emulator, open air interface, LTE. The associate editor coordinating the review of this manuscript and approving it for publication was Jesus Felez .
Wireless Technologies in the Railway: Train-to-Earth Wireless Communications}
Among the technologies of communication "train-to-earth", one of the most important advances of the last decade has been the GSM-R (Global System for Mobile Communications -Railway) (International Union of Railways, 2011). This system is based on the GSM telephony, but has been adapted to the field of railways. GSM-R is designed to exchange information between trains and control centres, and has as key advantages its low cost, and worldwide support.
Enhancing Service Availability during Handover in Wireless Communication-Based Train Control Systems
The paper introduces handover system by use of two radio connections onboard the train operating on different channels as well as use of the train's location and directional information to aid in reducing ping pong during handover. The paper formulates the Global Systems for Mobiles railway (GSM-R)algorithmto help make decisions on when to handover with the objective of minimizing the handoff latency. These measures allow seamless connection to the network while moving along the railway boundaries which improves communication. This reduces outage duration. Simulation of the system is done using MATLAB. The algorithm used is disruption free and quite effective in high speed train travel, and the handoff decision very efficient and more exact.Therefore, this will significantly improve service availability and reduce latency in data communication.
EURASIP Journal on Wireless Communications and Networking, 2012
The cross layer RMPA handover: a reliable mobility pattern aware handover strategy for broadband wireless communication in a high-speed railway domain Abstract Enhancing the handover process in broadband wireless communication deployment has traditionally motivated many research initiatives. In a high-speed railway domain, the challenge is even greater. Owing to the long distances covered, the mobile node gets involved in a compulsory sequence of handover processes. Consequently, poor performance during the execution of these handover processes significantly degrades the global end-to-end performance. This article proposes a new handover strategy for the railway domain: the RMPA handover, a Reliable Mobility Pattern Aware IEEE 802.16 handover strategy "customized" for a high-speed mobility scenario. The stringent high mobility feature is balanced with three other positive features in a high-speed context: mobility pattern awareness, different sources for location discovery techniques, and a previously known traffic data profile. To the best of the authors' knowledge, there is no IEEE 802.16 handover scheme that simultaneously covers the optimization of the handover process itself and the efficient timing of the handover process. Our strategy covers both areas of research while providing a cost-effective and standards-based solution. To schedule the handover process efficiently, the RMPA strategy makes use of a context aware handover policy; that is, a handover policy based on the mobile node mobility pattern, the time required to perform the handover, the neighboring network conditions, the data traffic profile, the received power signal, and current location and speed information of the train. Our proposal merges all these variables in a cross layer interaction in the handover policy engine. It also enhances the handover process itself by establishing the values for the set of handover configuration parameters and mechanisms of the handover process. RMPA is a cost-effective strategy because compatibility with standards-based equipment is guaranteed. The major contributions of the RMPA handover are in areas that have been left open to the handover designer's discretion. Our simulation analysis validates the RMPA handover decision rules and design choices. Our results supporting a high-demand video application in the uplink stream show a significant improvement in the end-to-end quality of service parameters, including end-to-end delay (22%) and jitter (80%), when compared with a policy based on signal-to-noise-ratio information.