2,365 research outputs found

    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

    Network planning for the future railway communications

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    Los Sistemas Inteligentes de Transporte están cambiando la forma en que concebimos el futuro de la movilidad. En particular, los ferrocarriles están experimentando un proceso de transformación para modernizar el transporte público y las operaciones ferroviarias. Tecnologías como el 5G, la fibra óptica y la nube han surgido como catalizadores para digitalizar el ferrocarril proporcionando comunicaciones de alta velocidad y baja latencia. Este TFG se centra en la exploración de redes que permitan el control del tren y la transmisión de datos a bordo. El objetivo es planificar la infraestructura de red (dimensionamiento y asignación de recursos) necesaria para las futuras comunicaciones del sistema ferroviario de larga distancia de la Deutsche Bahn en Alemania. En este trabajo, proponemos una arquitectura de red que puede satisfacer los requisitos de rendimiento de las aplicaciones para trenes y pasajeros. Presentamos un método para la colocación de estaciones base 5G a lo largo de las vías del tren para garantizar el rendimiento necesario en el borde de la celda. Por último, presentamos el problema de colocación y asignación de centros de datos. El objetivo es encontrar el número necesario de centros de datos y su ubicación en la red, y asignarlos a cada estación de tren. Realizamos simulaciones en cuatro escenarios diferentes, en los que modificamos parámetros de entrada como la latencia máxima tolerada y el número máximo de centros de datos. Los resultados obtenidos muestran el compromiso entre la latencia alcanzada y el coste de la infraestructura.Els Sistemes Intel·ligents de Transport estan canviant la manera en què concebem el futur de la mobilitat. En particular, els ferrocarrils estan experimentant un procés de transformació per modernitzar el transport públic i les operacions ferroviàries. Tecnologies com el 5G, la fibra òptica i el núvol han sorgit com a catalitzadors per digitalitzar el ferrocarril proporcionant comunicacions d'alta velocitat i baixa latència. Aquest TFG se centra en l'exploració de xarxes que permetin el control dels trens i la transmissió de dades a bord. L'objectiu és planificar la infraestructura de xarxa (dimensionament i assignació de recursos) necessària per a les futures comunicacions del sistema ferroviari de llarga distància de la Deutsche Bahn a Alemanya. En aquest treball, proposem una arquitectura de xarxa que pot satisfer els requisits de rendiment de les aplicacions per a trens i passatgers. Presentem un mètode per a la col·locació d'estacions base 5G al llarg de les vies del tren per garantir el rendiment necessari a la vora de la cel·la. Per últim, presentem el problema de col·locació i assignació de centres de dades. L'objectiu és trobar el nombre necessari de centres de dades i la seva ubicació a la xarxa, i assignar-los a cada estació de tren. Realitzem simulacions en quatre escenaris diferents, on modifiquem paràmetres d'entrada com la latència màxima tolerada i el nombre màxim de centres de dades. Els resultats obtinguts mostren el compromís entre la latència assolida i el cost de la infraestructura.Smart Transportation Systems are changing the way we conceive the future of mobility. In particular, railways are undergoing a transformation process to modernize public transportation and rail operation. Technologies like 5G, optical fiber and the cloud have emerged as catalysts to digitalize the railway by providing high-speed and low-latency communications. This bachelor's thesis focuses on the exploration of networks enabling train control and on-board data communications. The goal is to plan the network infrastructure (dimensioning and resource allocation) needed for the future communications in the train mobility scenario for Deutsche Bahn's long-distance railway system in Germany. In this work, we propose a network architecture that can meet the performance requirements of train and passenger applications. We present an approach for 5G base station placement along the rail tracks to guarantee the necessary throughput at the cell edge. Finally, we introduce the data center placement and assignment problem. The objective is to find the required number of data centers and their location in the network, and to assign them to each train station. We perform simulations in four different scenarios, in which we modify input parameters such as the maximum tolerated latency and the maximum number of data centers. The obtained results show the trade-off between the achieved latency and the infrastructure cost

    Design and Test of a High QoS Radio Network for CBTC Systems in Subway Tunnels

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    Communications Based Train Control Systems require high quality radio data communications for train signaling and control. Actually most of these systems use 2.4GHz band with proprietary radio transceivers and leaky feeder as distribution system. All them demand a high QoS radio network to improve the efficiency of railway networks. We present narrow band, broad band and data correlated measurements taken in Madrid underground with a transmission system at 2.4 GHz in a test network of 2 km length in subway tunnels. The architecture proposed has a strong overlap in between cells to improve reliability and QoS. The radio planning of the network is carefully described and modeled with narrow band and broadband measurements and statistics. The result is a network with 99.7% of packets transmitted correctly and average propagation delay of 20ms. These results fulfill the specifications QoS of CBTC systems

    Business models for deployment and operation of femtocell networks; - Are new cooperation strategies needed for mobile operators?

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    In this paper we discuss different business models for deployment and operation of femtocell networks intended for provisioning of public mobile broad band access services. In these types of business cases the operators use femtocells in order to reduce investments in "more costly" macro networks since the traffic can be "offloaded" to "less costly" femtocell networks. This is in contrast to the many business cases presented in Femtoforum where femtocells mainly are discussed as a solution to improve indoor coverage for voice services in homes and small offices, usually for closed user groups The main question discussed in this paper is if "operators need to consider new forms of cooperation strategies in order to enable large scale deployment of femtocells for public access?" By looking into existing solutions for indoor wireless access services we claim that the answer is both "Yes" and "No". No, since many types of cooperation are already in place for indoor deployment. Yes, because mobile operators need to re-think the femtocell specific business models, from approaches based on singe operator networks to different forms of cooperation involving multi-operator solutions, e.g. roaming and network sharing. --

    Propagation and Wireless Channel Modeling Development on Wide-Sense Vehicle-to-X Communications

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    The need for improving the safety and the efficiency of transportation systems has become of extreme importance. In this regard, the concept of vehicle-to-X (V2X) communication has been introduced with the purpose of providing wireless communication technology in vehicular networks. Not like the traditional views, the wide-sense V2X (WSV2X) communications in this paper are defined by including not only vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications but also train-to-X (T2X) communications constituted of train-to-train (T2T) and train-to-infrastructure (T2I) communications. All the information related to the wide-sense V2X channels, such as the standardization, scenarios, characters, and modeling philosophies, is organized and summarized to form the comprehensive understanding of the development of the WSV2X channels
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