1,720,981 research outputs found
On cellular networks supporting healthcare remote monitoring in IoT scenarios
Get PDFIn the next few years, fundamental technological transitions are expected both for wireless communications, soon resulting in the 5G era, and for the kind of pervasiveness that will be achieved thanks to the Internet of Things. The implementation of such new communication paradigms is expected to significantly revolutionize people’s lives, industry, commerce, and many daily activities. Healthcare applications are considered to be one of the most impacted industries. Sadly, in relation to the COVID-19 pandemic currently afflicting our society, health remote monitoring has become a fundamental and urgent application. The overcrowding of hospitals and medical facilities due to COVID-19, has unavoidably created delays and key issues in providing adequate medical assistance. In several cases, asymptomatic or light symptomatic COVID-19 patients have to be continuously monitored to prevent emergencies, and such an activity does not necessarily require hospitalization. Considering this research direction, this paper investigates the potentiality of cloud-based cellular networks to support remote healthcare monitoring applications implemented in accordance with the IoT paradigm, combined with future cellular systems. The idea is to conveniently replace the physical interaction between patients and doctors with a reliable virtual one, so that hospital services can be reserved for emergencies. Specifically, we investigate the feasibility and effectiveness of remote healthcare monitoring by evaluating its impact on the network performance. Furthermore, we discuss the potentiality of medical data compression and how it can be exploited to reduce the traffic load
Investigating VANET dissemination protocols performance under high throughput conditions
No full textThe use of Vehicular Ad-Hoc Networks (VANETs) for the dissemination of data flows to mobile highway vehicles has gained recently attention. For this purpose, vehicle-to-vehicle multi-hop communications are employed. For the effective networking of packets among highway vehicles, it is necessary to implement efficient algorithms that vehicles use to elect themselves as relay nodes to forward packets that they receive from other vehicles. In this work, we investigate the behavior of distributed relay node election protocols. In particular, we consider a class of such protocols whose actions are determined at time instants induced by the expiration of properly calibrated timers. We then investigate the high throughput regime of dissemination protocols. We show that a key factor that limits the achievable throughput rate is the occurrence of spurious forwarding events. These events are shown to lead to message duplications and consequent throughput degradation. We characterize this phenomenon by considering a VANET system that is configured to disseminate a single message flow along a road, as well as a scenario that involves the dissemination of two data flows that are originated by two distinct source nodes. We propose the integration into the protocol of a probabilistic decimation logic, with minimal impact on the protocol complexity. We show that, combined with the use of timers, the probabilistic mechanism serves to alleviate the occurrence of spurious forwarding events and consequently enhances the system's throughput rate and packet delivery ratios. The results of our study provide key guidelines for the design and calibration of such high performance networking protocols for VANET systems
An integrated VANET-based data dissemination and collection protocol for complex urban scenarios
Get PDFData dissemination and data collection to/from vehicles traveling on city roads are key features to fully enable the advent of Intelligent Transport Systems and Autonomous vehicles. Both Road Side Units and On Board Units need to disseminate different kind of data to vehicles or to collect data sensed by the vehicles themselves and transfer them to road monitoring and control centers. In this work we propose a protocol, named DISCOVER, that disseminates and collects the data of interest in a quite large city area efficiently and timely by using a single network structure, i.e., a multi-hop backbone made up only of vehicles nodes. DISCOVER is distributed and adaptive to the different traffic conditions, i.e., to the different levels of vehicular traffic density. Several numerical results show that it attains very good performance in different type of city maps (New York, Paris, Madrid and Rome) when compared with baseline approaches as well as when compared with a theoretical bound
Multi-originator data dissemination in VANETs
No full textIn the framework of the Vehicular Ad-Hoc Networks we propose HBEB (Hybrid Based Election Backbone), a distributed algorithm designed to form multiple backbones of vehicles in charge of propagating data in the VANETs in a fast and efficient way. Differently from other clustering approaches we leverage the ETSI Geonetworking recent standard to form and disseminate data in the backbones. We show that the formation of these backbones is quite easy to be implemented while their use enhances the dissemination performance in an urban scenario
LTE floating car data application off-loading via VANET driven clustering formation
Get PDFFloating Car Data (FCD) applications are based on the collection of geo-localized information updates that are issued by vehicles roaming in a given area. These data are an essential source for traffic information and are widely employed by Intelligent Transportation Systems (ITS). We present and examine a hybrid networking architecture and protocol that are used for the efficient execution of such a collection process. We employ a VANET-based multihop dissemination logic to spread control messages and elect designated nodes. Those nodes are exploited to report vehicular data via LTE communications. The performance behavior of the proposed protocol is evaluated through the consideration of two real urban scenarios. In comparing with performance bounds that characterize the performance behavior attained by state-of-theart hybrid integrated VANET and LTE mechanisms, we show our approach to offer a substantial reduction in the traffic load rates induced over the LTE cellular radio access system
Enhanced VANET broadcast throughput capacity via a dynamic backbone architecture
No full textWe propose a high throughput dissemination scheme for Vehicular Ad Hoc Networks (VANET) based on the dynamic formation of a multi-hop backbone network. We describe and analyze such a networking protocol when used to broadcast message flows generated by a Road Side Unit along a linear road, forming a VANET structure that is identified as a Vehicular Backbone Network (VBN). The VBN is based on elected vehicles that reside at preferred locations to act as backbone relay nodes, jointly optimally configured to operate at designated link data rates and spatial reuse factors. We present both an analytical evaluation of the broadcast throughput capacity that can be achieved by using the VBN mechanism and a simulative analysis based on the IEEE 802.11p CSMA/CA MAC protocol, standardized for VANET. The results demonstrate the significant performance enhancement achieved under VBN in attaining enhanced throughput capacity rate and in providing for a wider dissemination coverage span. Admitted packets are assured low end-to-end packet delays through the employment of a flow control scheme. (C) 2014 Elsevier B.V. All rights reserved
Heterogeneous cellular and DSRC networking for floating car data collection in urban areas
Get PDFVehicular traffic monitoring is a major enabler for a whole range of Intelligent Transportation System services. Real time, high spatial and temporal resolution vehicular traffic monitoring is becoming a reality thanks to the variety of communication platforms that are being deployed. Dedicated Short Range Communications (DSRC) and cellular communications like Long Term Evolution (LTE) are the major technologies. The former is specifically tailored for Vehicular Ad-hoc Network, the second one is pervasive. We propose a fully distributed Floating Car Data (FCD) collection protocol that exploits the heterogeneous network provided by DSRC and LTE. The proposed approach adapts automatically to the penetration degree of DSRC, achieving the maximum possible LTE offloading, given the VANET connectivity achieved via DSRC. Extensive simulations in real urban scenarios are used to evaluate the protocol performance and LTE offloading, as compared to baseline and literature approaches
A Multi-Hop Broadcast Wave Approach for Floating Car Data Collection in Vehicular Networks
Get PDFpeer reviewedInter-Vehicle Communication (IVC) is bringing connected and cooperative mobility closer to reality. Vehicles today are able to produce huge amounts of information, known in the literature as Floating Car Data (FCD), containing status information gathered from sensing the internal condition of the vehicle and the external environment. Adding networking capabilities to vehicles allows them to share this information among themselves and with the infrastructure. Collecting real-time FCD information from vehicles opens up the possibility of having access to an enormous amount of useful information that can boost the development of innovative services and applications in the domain of Intelligent Transportation System (ITS). In this paper we propose several solutions to efficiently collect real-time FCD information in Dedicated Short-Range Communication (DSRC)-enabled Vehicular Ad Hoc Networks (VANETs). The goal is to improve the efficiency of the FCD collection operation while keeping the impact on the DSRC communication channel as low as possible. We do this by exploiting a slightly modified version of a standardized data dissemination protocol to create a backbone of relaying vehicles that, by following local rules, generate a multi-hop broadcast wave of collected FCD messages. The proposed protocols are evaluated via realistic simulations under different vehicular densities and urban scenarios
Comparison of utility functions for routing in cognitive wireless ad-hoc networks
No full textIn Cognitive Radio Ad-Hoc Networks [1] the design of suitable routing solutions is a focal issue to fully unleash the potentials of this networking paradigm. The main challenge is exploiting spectrum holes to build up network paths that remain stable and that achieve specific network performance in terms of delay and percentage of delivered data, even if an opportunistic spectrum access is implemented. In this paper we propose a utility function based on the path connectivity, re-elaborated in a cognitive radio scenario, and we compare it with other utility functions that can be used for routing data in cognitive radio. We show that by using our utility function we select paths for the secondary users transmissions leading to better performance when compared with a utility function that selects paths with the minimum activities of the primary users and an utility function that minimizes the number of hops. These results are derived in great number of topologies and with different primary users activities. © 2011 IEEE
Hidden primary user awareness in cognitive radio routing: the SBBO protocol
No full textWe propose a distributed routing scheme for cognitive radio ad hoc networks which, besides the awareness of the dynamic behavior of the primary users, also considers that some primary users may be hidden to secondary nodes, thus creating asymmetry in the spectrum opportunity availability. We identify this "Hidden Primary User" problem and we introduce in our distributed protocol a mechanism for being aware of it during the routing. To this aim our protocol creates priority lists at the secondary nodes used to have different possibilities to route the data on a path while the primary users activate and deactivate. The tradeoff between packet loss and delay is shown and discussed in the performance analysis. ©2010 IEEE
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