130 research outputs found
LTE and Millimeter Waves for V2I Communications: an End-to-End Performance Comparison
The Long Term Evolution (LTE) standard enables, besides cellular
connectivity, basic automotive services to promote road safety through
vehicle-to-infrastructure (V2I) communications. Nevertheless, stakeholders and
research institutions, driven by the ambitious technological advances expected
from fully autonomous and intelligent transportation systems, have recently
investigated new radio technologies as a means to support vehicular
applications. In particular, the millimeter wave (mmWave) spectrum holds great
promise because of the large available bandwidth that may provide the required
link capacity. Communications at high frequencies, however, suffer from severe
propagation and absorption loss, which may cause communication disconnections
especially considering high mobility scenarios. It is therefore important to
validate, through simulations, the actual feasibility of establishing V2I
communications in the above-6 GHz bands. Following this rationale, in this
paper we provide the first comparative end-to-end evaluation of the performance
of the LTE and mmWave technologies in a vehicular scenario. The simulation
framework includes detailed measurement-based channel models as well as the
full details of MAC, RLC and transport protocols. Our results show that,
although LTE still represents a promising access solution to guarantee robust
and fair connections, mmWaves satisfy the foreseen extreme throughput demands
of most emerging automotive applications.Comment: 7 pages, 5 figures, 2 tables. Accepted to VTC-Spring 2019, workshop
on High Mobility Wireless Communications (HMWC
A City-Scale ITS-G5 Network for Next-Generation Intelligent Transportation Systems: Design Insights and Challenges
As we move towards autonomous vehicles, a reliable Vehicle-to-Everything
(V2X) communication framework becomes of paramount importance. In this paper we
present the development and the performance evaluation of a real-world
vehicular networking testbed. Our testbed, deployed in the heart of the City of
Bristol, UK, is able to exchange sensor data in a V2X manner. We will describe
the testbed architecture and its operational modes. Then, we will provide some
insight pertaining the firmware operating on the network devices. The system
performance has been evaluated under a series of large-scale field trials,
which have proven how our solution represents a low-cost high-quality framework
for V2X communications. Our system managed to achieve high packet delivery
ratios under different scenarios (urban, rural, highway) and for different
locations around the city. We have also identified the instability of the
packet transmission rate while using single-core devices, and we present some
future directions that will address that.Comment: Accepted for publication to AdHoc-Now 201
Interface Selection in 5G vehicular networks
ITA
Negli ultimi anni, la quantità di dati condivisa nel mondo è aumentata esponenzialmente grazie alle applicazioni innovative che riguardano la sicurezza (e.g. domotica, smart cities, controllo del traffico stradale, veicoli autonomi) e i servizi di intrattenimento (e.g. audio e video streaming, ricerche web, videogiochi online di massa). Per supportare questo trend, le principali compagnie nell’industria delle telecomunicazioni stanno sviluppando nuovi standard che saranno disponibili agli utenti finali nei prossimi anni e che saranno presentati come la Quinta Generazione di Reti Cellulari (5G). Questi standard prevedono miglioramenti ai precedenti standard 4G (e.g. LTE, WiMax, DSRC) e tecnologie completamente nuove (e.g. onde millimetriche, comunicazione con luce visibile) per permettere la diffusione di nuovi servizi che richiedono un throughput estremamente alto e una latency bassa. Nella maggior parte dei casi, queste tecnologie dovranno cooperare per assicurare una rete affidabile e accessibile in ogni situazione.
Una delle applicazioni più promettenti di questa nuova generazione di tecnologie sono le reti veicolari, un insieme di servizi che includono la comunicazione con le infrastrutture, come il download di un film da Internet o la ricezione di informazioni riguardanti l’ambiente circostante (e.g. un semaforo manda un messaggio a un veicolo in avvicinamento per farlo fermare), o la comunicazione direttamente tra veicoli, in questo caso il datarate è tipicamente più basso dato che l’uso più tipico sarà , per esempio, mandare informazioni riguardanti le macchine più vicine per fare in modo di diminuore il numero di incidenti stradali o gestire il traffico.
Questa tesi è focalizzata sulle applicazioni per reti veicolari, l’obiettivo è di analizzare le prestazioni del protocollo IEEE 802.11p a diversi datarate in un tipico
scenario V2V, e di confrontare LTE e mmWaves usando una comunicazione V2I in diverse circostanze, per mostrare come ogni tecnologia offra vantaggi per determinate applicazioni mentre non è adatta per altre.
ENG
In the last years, the amount of data shared among the world is increased exponentially thanks to the novel applications for security (e.g. home automation,
smart cities, traffic control, autonomous vehicles) and infotainment (e.g. audio and video streaming, web browsing, massive online videogames). To support this
trend, the major companies in the telecommunication industry are developing new standards that will be available to the final users in the next years and that will
be presented as the Fifth Generation of Cellular Networks (5G). These standards provide improvements to the 4G standards (e.g. LTE, WiMax, DSRC) and brand
new technologies (e.g. mmWaves, Visible Light Communication) to enable new services that demand extremely high throughput and low latency. In most cases
these technologies will cooperate to ensure a reliable and accessible network in every situation.
One of the most promising applications of these new generation technologies is vehicular networks, a set of services that includes the communication with infrastructures, such as the download of a film from the Internet or the reception of information about the surrounding environment (e.g. a traffic light sends a
message to an incoming vehicle to make it stop), or the communication between vehicles, in this case the datarate is tipically lower since the typical use will be, for example, to send information about the closest cars in order to decrease the number of accidents or to manage the traffic.
This thesis is focalized on the vehicular networks applications, it aims to analyze the performance of IEEE 802.11p protocol at different datarates in a typical V2V scenario, and to compare LTE and mmWaves using a V2I communication in different circumstances to show how each technology offers advantages for some
applications while is not suitable for others
Coverage and Connectivity Analysis of Millimeter Wave Vehicular Networks
The next generations of vehicles will require data transmission rates in the
order of terabytes per driving hour, to support advanced automotive services.
This unprecedented amount of data to be exchanged goes beyond the capabilities
of existing communication technologies for vehicular communication and calls
for new solutions. A possible answer to this growing demand for ultra-high
transmission speeds can be found in the millimeter-wave (mmWave) bands which,
however, are subject to high signal attenuation and challenging propagation
characteristics. In particular, mmWave links are typically directional, to
benefit from the resulting beamforming gain, and require precise alignment of
the transmitter and the receiver beams, an operation which may increase the
latency of the communication and lead to deafness due to beam misalignment. In
this paper, we propose a stochastic model for characterizing the beam coverage
and connectivity probability in mmWave automotive networks. The purpose is to
exemplify some of the complex and interesting tradeoffs that have to be
considered when designing solutions for vehicular scenarios based on mmWave
links. The results show that the performance of the automotive nodes in highly
mobile mmWave systems strictly depends on the specific environment in which the
vehicles are deployed, and must account for several automotive-specific
features such as the nodes speed, the beam alignment periodicity, the base
stations density and the antenna geometry.Comment: In press of Elsevier Ad Hoc Network
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