8 research outputs found

    Design and prototype of a train-to-wayside communication architecture

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    Telecommunication has become very important in modern society and seems to be almost omnipresent, making daily life easier, more pleasant and connecting people everywhere. It does not only connect people, but also machines, enhancing the efficiency of automated tasks and monitoring automated processes. In this context the IBBT (Interdisciplinary Institute for BroadBand Technology) project TRACK (TRain Applications over an advanced Communication networK), sets the definition and prototyping of an end-to-end train-to-wayside communication architecture as one of the main research goals. The architecture provides networking capabilities for train monitoring, personnel applications and passenger Internet services. In the context of the project a prototype framework was developed to give a complete functioning demonstrator. Every aspect: tunneling and mobility, performance enhancements, and priority and quality of service were taken into consideration. In contrast to other research in this area, which has given mostly high-level overviews, TRACK resulted in a detailed architecture with all different elements present

    Insights in the cost of continuous broadband Internet on trains for multi-service deployments by multiple actors with resource sharing

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    The economic viability of broadband Internet services on trains has always been proved difficult, mainly due to a high investment cost and low willingness to pay by train passengers, but also due to unused opportunities such as non-passenger services (e.g. train performance monitoring, crew services) and optimization of the resources consumed to offer Internet services. Evaluating opportunities to improve the return on investment is therefore essential towards profitability of the business case. By efficiently sharing resources amongst services, costs can be pooled over several services in order to reduce the investment cost per service. Current techno-economic evaluation models are hard to apply to cost allocation in a multi-service deployment with multiple actors and resource sharing. We therefore propose a new evaluation model and apply it to a deployment of Internet services on trains. We start with a detailed analysis of the technical architecture required to provide Internet access on trains. For each component, we investigate the impact by the different services on resource consumption. The proposed techno-economic evaluation model is then applied in order to calculate the total cost and allocate the used and unused resources to the appropriate services. In a final step, we calculate the business case for each stakeholder involved in the offering of these services. This paper details the proposed model and reports on our findings for a multi-service deployment by multiple actors. Results show important benefits for the case that considers the application of resource sharing in a multi-service, multi-actor scenario and the proposed model produces insights in the contributors to the cost per service and the unused amount of a resource. In addition, ex-ante insights in the cost flows per involved actor are obtained and the model can easily be extended to include revenue flows to evaluate the profitability per actor. As a consequence, the proposed model should be considered to support and stimulate upcoming multi-actor investment decisions for Internet-based multi-service offerings on-board trains with resource sharing

    DragonNet: a robust mobile internet services system for long distance trains

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    Wide range wireless networks often suffer from annoying service deterioration due to ever-changing wireless environments. This is especially the case with passengers on long-distance trains (LDT, such as intercity, interprovincial, and international commuter trains) connecting to the Internet. To improve the service quality of wide-area wireless networks, we present the DragonNet system and protocol with practical implementations. The DragonNet system is a chained gateway that consists of a group of interlinked DragonNet routers running the DragonNet protocol for node failure amortization across the long stretching router chain. The protocol makes use of the spatial diversity of wireless signals when not all spots on a surface see the same level of radio frequency radiation. In the case of an LDT of around 500 meters, it is highly possible that some of the DragonNet routers in the gateway chain still see sound signal quality when the LDT is partially blocked from the wireless Internet. The DragonNet protocol fully utilizes this feature to amortize single-point router failure over the whole router chain by intelligently rerouting traffic on failed ones to sound ones. We have implemented the DragonNet system and tested it in real railways over a period of three months. Our results have pinpointed two fundamental contributions of the DragonNet protocol. First, DragonNet significantly reduces the average temporary communication blackout (i.e., no Internet connection) to 1.5 seconds compared with 6 seconds without the DragonNet protocol. Second, DragonNet nearly doubles the aggregate system throughput compared with gateway without running the DragonNet protocol

    A novel network architecture for train-to-wayside communication with quality of service over heterogeneous wireless networks

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    In the railway industry, there are nowadays different actors who would like to send or receive data from the wayside to an onboard device or vice versa. These actors are e.g., the Train Operation Company, the Train Constructing Company, a Content Provider, etc. This requires a communication module on each train and at the wayside. These modules interact with each other over heterogeneous wireless links. This system is referred to as the Train-to-Wayside Communication System (TWCS). While there are already a lot of deployments using a TWCS, the implementation of quality of service, performance enhancing proxies (PEP) and the network mobility functions have not yet been fully integrated in TWCS systems. Therefore, we propose a novel and modular IPv6-enabled TWCS architecture in this article. It jointly tackles these functions and considers their mutual dependencies and relationships. DiffServ is used to differentiate between service classes and priorities. Virtual local area networks are used to differentiate between different service level agreements. In the PEP, we propose to use a distributed TCP accelerator to optimize bandwidth usage. Concerning network mobility, we propose to use the SCTP protocol (with Dynamic Address Reconfiguration and PR-SCTP extensions) to create a tunnel per wireless link, in order to support the reliable transmission of data between the accelerators. We have analyzed different design choices, pinpointed the main implementation challenges and identified candidate solutions for the different modules in the TWCS system. As such, we present an elaborated framework that can be used for prototyping a fully featured TWCS

    Mobile internet access for high-speed trains via heterogeneous networks

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    This paper describes how a heterogeneous network that comprises of satellite and WLAN systems could be implemented in a high-speed train environment to provide Internet access. The focus of the paper is on the design of the network architecture and mobility management procedures. In particular, the implementation of WLAN to complement satellite coverage in various operating environments is investigated. For mobility management, issues related to location and handover management are described. In addition, the paper also elaborates on the use of location detection procedures and antenna diversity in trains to aid the process of handover
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