9,190 research outputs found
Foggy clouds and cloudy fogs: a real need for coordinated management of fog-to-cloud computing systems
The recent advances in cloud services technology are fueling a plethora of information technology innovation, including networking, storage, and computing. Today, various flavors have evolved of IoT, cloud computing, and so-called fog computing, a concept referring to capabilities of edge devices and users' clients to compute, store, and exchange data among each other and with the cloud. Although the rapid pace of this evolution was not easily foreseeable, today each piece of it facilitates and enables the deployment of what we commonly refer to as a smart scenario, including smart cities, smart transportation, and smart homes. As most current cloud, fog, and network services run simultaneously in each scenario, we observe that we are at the dawn of what may be the next big step in the cloud computing and networking evolution, whereby services might be executed at the network edge, both in parallel and in a coordinated fashion, as well as supported by the unstoppable technology evolution. As edge devices become richer in functionality and smarter, embedding capacities such as storage or processing, as well as new functionalities, such as decision making, data collection, forwarding, and sharing, a real need is emerging for coordinated management of fog-to-cloud (F2C) computing systems. This article introduces a layered F2C architecture, its benefits and strengths, as well as the arising open and research challenges, making the case for the real need for their coordinated management. Our architecture, the illustrative use case presented, and a comparative performance analysis, albeit conceptual, all clearly show the way forward toward a new IoT scenario with a set of existing and unforeseen services provided on highly distributed and dynamic compute, storage, and networking resources, bringing together heterogeneous and commodity edge devices, emerging fogs, as well as conventional clouds.Peer ReviewedPostprint (author's final draft
Reducing Message Collisions in Sensing-based Semi-Persistent Scheduling (SPS) by Using Reselection Lookaheads in Cellular V2X
In the C-V2X sidelink Mode 4 communication, the sensing-based semi-persistent
scheduling (SPS) implements a message collision avoidance algorithm to cope
with the undesirable effects of wireless channel congestion. Still, the current
standard mechanism produces high number of packet collisions, which may hinder
the high-reliability communications required in future C-V2X applications such
as autonomous driving. In this paper, we show that by drastically reducing the
uncertainties in the choice of the resource to use for SPS, we can
significantly reduce the message collisions in the C-V2X sidelink Mode 4.
Specifically, we propose the use of the "lookahead," which contains the next
starting resource location in the time-frequency plane. By exchanging the
lookahead information piggybacked on the periodic safety message, vehicular
user equipments (UEs) can eliminate most message collisions arising from the
ignorance of other UEs' internal decisions. Although the proposed scheme would
require the inclusion of the lookahead in the control part of the packet, the
benefit may outweigh the bandwidth cost, considering the stringent reliability
requirement in future C-V2X applications.Comment: Submitted to MDPI Sensor
Will 5G See its Blind Side? Evolving 5G for Universal Internet Access
Internet has shown itself to be a catalyst for economic growth and social
equity but its potency is thwarted by the fact that the Internet is off limits
for the vast majority of human beings. Mobile phones---the fastest growing
technology in the world that now reaches around 80\% of humanity---can enable
universal Internet access if it can resolve coverage problems that have
historically plagued previous cellular architectures (2G, 3G, and 4G). These
conventional architectures have not been able to sustain universal service
provisioning since these architectures depend on having enough users per cell
for their economic viability and thus are not well suited to rural areas (which
are by definition sparsely populated). The new generation of mobile cellular
technology (5G), currently in a formative phase and expected to be finalized
around 2020, is aimed at orders of magnitude performance enhancement. 5G offers
a clean slate to network designers and can be molded into an architecture also
amenable to universal Internet provisioning. Keeping in mind the great social
benefits of democratizing Internet and connectivity, we believe that the time
is ripe for emphasizing universal Internet provisioning as an important goal on
the 5G research agenda. In this paper, we investigate the opportunities and
challenges in utilizing 5G for global access to the Internet for all (GAIA). We
have also identified the major technical issues involved in a 5G-based GAIA
solution and have set up a future research agenda by defining open research
problems
Etude et réalisation d'un système de communications par lumière visible (VLC/LiFi). Application au domaine automobile.
The scientific problematic of this PhD is centered on the usage of Visible LightCommunications (VLC) in automotive applications. By enabling wireless communication amongvehicles and also with the traffic infrastructure, the safety and efficiency of the transportation canbe substantially increased. Considering the numerous advantages of the VLC technologyencouraged the study of its appropriateness for the envisioned automotive applications, as analternative and/or a complement for the traditional radio frequency based communications.In order to conduct this research, a low-cost VLC system for automotive application wasdeveloped. The proposed system aims to ensure a highly robust communication between a LEDbasedVLC emitter and an on-vehicle VLC receiver. For the study of vehicle to vehicle (V2V)communication, the emitter was developed based on a vehicle backlight whereas for the study ofinfrastructure to vehicle (I2V) communication, the emitter was developed based on a traffic light.Considering the VLC receiver, a central problem in this area is the design of a suitable sensorable to enhance the conditioning of the signal and to avoid disturbances due to the environmentalconditions, issues that are addressed in the thesis. The performances of a cooperative drivingsystem integrating the two components were evaluated as well.The experimental validation of the VLC system was performed in various conditions andscenarios. The results confirmed the performances of the proposed system and demonstrated thatVLC can be a viable technology for the considered applications. Furthermore, the results areencouraging towards the continuations of the work in this domain.La problématique scientifique de cette thèse est centrée sur le développement decommunications par lumière visible (Visible Light Communications - VLC) dans lesapplications automobiles. En permettant la communication sans fil entre les véhicules, ou entreles véhicules et l’infrastructure routière, la sécurité et l'efficacité du transport peuvent êtreconsidérablement améliorées. Compte tenu des nombreux avantages de la technologie VLC,cette solution se présente comme une excellente alternative ou un complément pour lescommunications actuelles plutôt basées sur les technologies radio-fréquences traditionnelles.Pour réaliser ces travaux de recherche, un système VLC à faible coût pour applicationautomobile a été développé. Le système proposé vise à assurer une communication très robusteentre un émetteur VLC à base de LED et un récepteur VLC monté sur un véhicule. Pour l'étudedes communications véhicule à véhicule (V2V), l'émetteur a été développé sur la base d’un pharearrière rouge de voiture, tandis que pour l'étude des communications de l'infrastructure auvéhicule (I2V), l'émetteur a été développé sur la base d'un feu de circulation. Considérant lerécepteur VLC, le problème principal réside autour d’un capteur approprié, en mesured'améliorer le conditionnement du signal et de limiter les perturbations dues des conditionsenvironnementales. Ces différents points sont abordés dans la thèse, d’un point de vue simulationmais également réalisation du prototype.La validation expérimentale du système VLC a été réalisée dans différentes conditions etscénarii. Les résultats démontrent que la VLC peut être une technologie viable pour lesapplications envisagées
Transportation, Terrorism and Crime: Deterrence, Disruption and Resilience
Abstract: Terrorists likely have adopted vehicle ramming as a tactic because it can be carried out by an individual (or “lone wolf terrorist”), and because the skills required are minimal (e.g. the ability to drive a car and determine locations for creating maximum carnage). Studies of terrorist activities against transportation assets have been conducted to help law enforcement agencies prepare their communities, create mitigation measures, conduct effective surveillance and respond quickly to attacks.
This study reviews current research on terrorist tactics against transportation assets, with an emphasis on vehicle ramming attacks. It evaluates some of the current attack strategies, and the possible mitigation or response tactics that may be effective in deterring attacks or saving lives in the event of an attack. It includes case studies that can be used as educational tools for understanding terrorist methodologies, as well as ordinary emergencies that might become a terrorist’s blueprint
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