12,396 research outputs found
Insights in the cost of continuous broadband Internet on trains for multi-service deployments by multiple actors with resource sharing
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
A QoS-Aware Scheduling Algorithm for High-Speed Railway Communication System
With the rapid development of high-speed railway (HSR), how to provide the
passengers with multimedia services has attracted increasing attention. A key
issue is to develop an effective scheduling algorithm for multiple services
with different quality of service (QoS) requirements. In this paper, we
investigate the downlink service scheduling problem in HSR network taking
account of end-to-end deadline constraints and successfully packet delivery
ratio requirements. Firstly, by exploiting the deterministic high-speed train
trajectory, we present a time-distance mapping in order to obtain the highly
dynamic link capacity effectively. Next, a novel service model is developed for
deadline constrained services with delivery ratio requirements, which enables
us to turn the delivery ratio requirement into a single queue stability
problem. Based on the Lyapunov drift, the optimal scheduling problem is
formulated and the corresponding scheduling service algorithm is proposed by
stochastic network optimization approach. Simulation results show that the
proposed algorithm outperforms the conventional schemes in terms of QoS
requirements.Comment: 6 pages, 3 figures, accepted by IEEE ICC 2014 conferenc
High Speed Railway Wireless Communications: Efficiency v.s. Fairness
High speed railways (HSRs) have been deployed widely all over the world in
recent years. Different from traditional cellular communication, its high
mobility makes it essential to implement power allocation along the time. In
the HSR case, the transmission rate depends greatly on the distance between the
base station (BS) and the train. As a result, the train receives a time varying
data rate service when passing by a BS. It is clear that the most efficient
power allocation will spend all the power when the train is nearest from the
BS, which will cause great unfairness along the time. On the other hand, the
channel inversion allocation achieves the best fairness in terms of constant
rate transmission. However, its power efficiency is much lower. Therefore, the
power efficiency and the fairness along time are two incompatible objects. For
the HSR cellular system considered in this paper, a trade-off between the two
is achieved by proposing a temporal proportional fair power allocation scheme.
Besides, near optimal closed form solution and one algorithm finding the
-optimal allocation are presented.Comment: 16 pages, 6 figure
A Survey of Wireless Communication Technologies & Their Performance for High Speed Railways
High Speed Railway (HSR) provides its customers not only safety, security, comfort and on-time commuting, but also a fast transportation alternative to air travel or regular passenger rail services. Providing these benefits would not be possible without the tremendous growth and prevalence of wireless communication technologies. Due to advances in wireless communication systems, both trains and passengers are connected through high speed wireless networks to the Internet, data centers and railroad control centers. Railroad communities, academia, related industries and standards bodies, even the European Space Agency, are involved in advancing developments of HSR for highly connected train communication systems. The goal of these efforts is to provide the capabilities for uninterrupted high-speed fault-tolerant communication networks for all possible geographic, structural and weather conditions. This survey provides an overview of the current state-of-the-art and future trends for wireless technologies aiming to realize the concept of HSR communication services. Our goal is to highlight the challenges for these technologies, including GSM-R, Wi-Fi, WIMAX, LTE-R, RoF, LCX & Cognitive Radio, the offered solutions, their performance, and other related issues. Currently, providing HSR services is the goal of many countries across the globe. Europe, Japan & Taiwan, China, as well as North & South America have increased their efforts to advance HSR technologies to monitor and control not only the operations but also to deliver extensive broadband solutions to passengers. This survey determined a trend of the industry to transition control plane operations towards narrowband frequencies, i.e. LTE400/700, and to utilize concurrently other technologies for broadband access for passengers such that services of both user and train control systems are supported. With traditional technologies, a tradeoff was required and often favored train control services over passenger amenities. However, with the advances in communication systems, such as LTE-R and cognitive radios, it is becoming possible for system designers to offer rich services to passengers while also providing support for enhanced train control operations such as Positive Train Control
A Survey of Wireless Communication Technologies & Their Performance for High Speed Railways
High Speed Railway (HSR) provides its customers not only safety, security, comfort and on-time commuting, but also a fast transportation alternative to air travel or regular passenger rail services. Providing these benefits would not be possible without the tremendous growth and prevalence of wireless communication technologies. Due to advances in wireless communication systems, both trains and passengers are connected through high speed wireless networks to the Internet, data centers and railroad control centers. Railroad communities, academia, related industries and standards bodies, even the European Space Agency, are involved in advancing developments of HSR for highly connected train communication systems. The goal of these efforts is to provide the capabilities for uninterrupted high-speed fault-tolerant communication networks for all possible geographic, structural and weather conditions. This survey provides an overview of the current state-of-the-art and future trends for wireless technologies aiming to realize the concept of HSR communication services. Our goal is to highlight the challenges for these technologies, including GSM-R, Wi-Fi, WIMAX, LTE-R, RoF, LCX & Cognitive Radio, the offered solutions, their performance, and other related issues. Currently, providing HSR services is the goal of many countries across the globe. Europe, Japan & Taiwan, China, as well as North & South America have increased their efforts to advance HSR technologies to monitor and control not only the operations but also to deliver extensive broadband solutions to passengers. This survey determined a trend of the industry to transition control plane operations towards narrowband frequencies, i.e. LTE400/700, and to utilize concurrently other technologies for broadband access for passengers such that services of both user and train control systems are supported. With traditional technologies, a tradeoff was required and often favored train control services over passenger amenities. However, with the advances in communication systems, such as LTE-R and cognitive radios, it is becoming possible for system designers to offer rich services to passengers while also providing support for enhanced train control operations such as Positive Train Control
A Comprehensive Survey on Moving Networks
The unprecedented increase in the demand for mobile data, fuelled by new
emerging applications such as HD video streaming and heightened online
activities has caused massive strain on the existing cellular networks. As a
solution, the 5G technology has been introduced to improve network performance
through various innovative features such as mmWave spectrum and HetNets. In
essence, HetNets include several small cells underlaid within macro-cell to
serve densely populated regions. Recently, a mobile layer of HetNet has been
under consideration by the researchers and is often referred to as moving
networks. Moving networks comprise of mobile cells that are primarily
introduced to improve QoS for commuting users inside public transport because
the QoS is deteriorated due to vehicular penetration losses. Furthermore, the
users inside fast moving public transport also exert excessive load on the core
network due to large group handovers. To this end, mobile cells will play a
crucial role in reducing overall handover count and will help in alleviating
these problems by decoupling in-vehicle users from the core network.
To date, remarkable research results have been achieved by the research
community in addressing challenges linked to moving networks. However, to the
best of our knowledge, a discussion on moving networks in a holistic way is
missing in the current literature. To fill the gap, in this paper, we
comprehensively survey moving networks. We cover the technological aspects and
their applications in the futuristic applications. We also discuss the
use-cases and value additions that moving networks may bring to future cellular
architecture and identify the challenges associated with them. Based on the
identified challenges we discuss the future research directions.Comment: This survey has been submitted to IEEE Communications Surveys &
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