A survey on vehicular communication for cooperative truck platooning application

Platooning is an application where a group of vehicles move one after each other in close proximity, acting jointly as a single physical system. The scope of platooning is to improve safety, reduce fuel consumption, and increase road use efficiency. Even if conceived several decades ago as a concept, based on the new progress in automation and vehicular networking platooning has attracted particular attention in the latest years and is expected to become of common implementation in the next future, at least for trucks.The platoon system is the result of a combination of multiple disciplines, from transportation, to automation, to electronics, to telecommunications. In this survey, we consider the platooning, and more specifically the platooning of trucks, from the point of view of wireless communications. Wireless communications are indeed a key element, since they allow the information to propagate within the convoy with an almost negligible delay and really making all vehicles acting as one. Scope of this paper is to present a comprehensive survey on connected vehicles for the platooning application, starting with an overview of the projects that are driving the development of this technology, followed by a brief overview of the current and upcoming vehicular networking architecture and standards, by a review of the main open issues related to wireless communications applied to platooning, and a discussion of security threats and privacy concerns. The survey will conclude with a discussion of the main areas that we consider still open and that can drive future research directions.(c) 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Comparison of Radio Frequency and Visible Light Propagation Channels for Vehicular Communications

Recent research has shown that both radio and visible light waves can be used to enable communications in highly dynamic vehicular environments. However, the roles of these two technologies and how they interact with each other in future vehicular communication systems remain unclear. Understanding the propagation characteristics is an essential step in investigating the benefits and shortcomings of each technology. To this end, we discuss salient properties of radio and visible light propagation channels, including radiation pattern, path loss modeling, noise and interference, and channel time variation. Comparison of these properties provides an important insight that the two communication channels can complement each other’s capabilities in terms of coverage and reliability, thus better satisfying the diverse requirements of future cooperative intelligent transportation systems

Exploring Smart Infrastructure Concepts to Improve the Reliability and Functionality of Safety Oriented Connected Vehicle Applications

Cooperative adaptive cruise control (CACC), a form of vehicle platooning, is a well known connected vehicle application. It extends adaptive cruise control (ACC) by incorporating vehicle-to-vehicle communications. A vehicle periodically broadcasts a small message that includes in the least a unique vehicle identifier, its current geo-location, speed, and acceleration. A vehicle might pay attention to the message stream of only the car ahead. While CACC is under intense study by the academic community, the vast majority of the relevant published literature has been limited to theoretical studies that make many simplifying assumptions. The research presented in this dissertation has been motivated by our observation that there is limited understanding of how platoons actually work under a range of realistic operating conditions. Our research includes a performance study of V2V communications based on actual V2V radios supplemented by simulation. These results are in turn applied to the analysis of CACC. In order to understand a platoon at scale, we resort to simulations and analysis using the ns3 simulator. Assessment criteria includes network reliability measures as well as application oriented measures. Network assessment involves latency and first and second order loss dynamics. CACC performance is based on stability, frequency of crashes, and the rate of traffic flow. The primary goal of CACC is to maximize traffic flow subject to a maximum allowed speed. This requires maintaining smaller inter-vehicle distances which can be problematic as a platoon can become unstable as the target headway between cars is reduced. The main contribution of this dissertation is the development and evaluation of two heuristic approaches for dynamically adapting headway both of which attempt to minimize the headway while ensure stability. We present the design and analysis of a centralized and a distributed implementation of the algorithm. Our results suggest that dynamically adapting the headway time can improve the overall platoon traffic flow without the platoon becoming unstable

DSRC Versus LTE-V2X: Empirical Performance Analysis of Direct Vehicular Communication Technologies

Vehicle-to-Vehicle (V2V) communication systems have an eminence potential to improve road safety and optimize traffic flow by broadcasting Basic Safety Messages (BSMs). Dedicated Short-Range Communication (DSRC) and LTE Vehicle-to-Everything (V2X) are two candidate technologies to enable V2V communication. DSRC relies on the IEEE 802.11p standard for its PHY and MAC layer while LTE-V2X is based on 3GPP’s Release 14 and operates in a distributed manner in the absence of cellular infrastructure. There has been considerable debate over the relative advantages and disadvantages of DSRC and LTE-V2X, aiming to answer the fundamental question of which technology is most effective in real-world scenarios for various road safety and traffic efficiency applications. In this paper, we present a comprehensive survey of these two technologies (i.e., DSRC and LTE-V2X) and related works. More specifically, we study the PHY and MAC layer of both technologies in the survey study and compare the PHY layer performance using a variety of field tests. First, we provide a summary of each technology and highlight the limitations of each in supporting V2X applications. Then, we examine their performance based on different metrics

Design and Numerical Implementation of V2X Control Architecture for Autonomous Driving Vehicles

This paper is concerned with designing and numerically implementing a V2X (Vehicle-to-Vehicle and Vehicle-to-Infrastructure) control system architecture for a platoon of autonomous vehicles. The V2X control architecture integrates the well-known Intelligent Driver Model (IDM) for a platoon of Autonomous Driving Vehicles (ADVs) with Vehicle-to-Infrastructure (V2I) Communication. The main aim is to address practical implementation issues of such a system as well as the safety and security concerns for traffic environments. To this end, we first investigated a channel estimation model for V2I communication. We employed the IEEE 802.11p vehicular standard and calculated path loss, Packet Error Rate (PER), Signal-to-Noise Ratio (SNR), and throughput between transmitter and receiver end. Next, we carried out several case studies to evaluate the performance of the proposed control system with respect to its response to: (i) the communication infrastructure; (ii) its sensitivity to an emergency, inter-vehicular gap, and significant perturbation; and (iii) its performance under the loss of communication and changing driving environment. Simulation results show the effectiveness of the proposed control model. The model is collision-free for an infinite length of platoon string on a single lane road-driving environment. It also shows that it can work during a lack of communication, where the platoon vehicles can make their decision with the help of their own sensors. V2X Enabled Intelligent Driver Model (VX-IDM) performance is assessed and compared with the state-of-the-art models considering standard parameter settings and metrics

Robust Low-Cost Multiple Antenna Processing for V2V Communication

Cooperative V2V communication with frequent, periodic broadcast of messages between vehicles is a key enabler of applications that increase traffic safety and traffic efficiency on roads. Such broadcast V2V communication requires an antenna system with omnidirectional coverage, which is difficult to achieve using a single antenna element. For a mounted, omnidirectional antenna on a vehicle is distorted by the vehicle body, and exhibits a nonuniform directional pattern with low gain in certain directions. The thesis addresses this problem by developing schemes that employ multiple antennas (MAs) to achieve an effective radiation pattern with omnidirectional characteristics at both the transmit- and the receive-side. To ensure robust communication, the MA schemes are designed to minimize the burst error probability of several consecutive status messages in a scarce multipath environment with a dominant path between vehicles.First, at the receive-side, we develop a hybrid analog-digital antenna combiner. The analog part of the combiner is composed of low-cost analog combining networks (ACNs) of phase shifters that do not depend on channel stateinformation (CSI), while the digital part uses maximal ratio combining. We show that the optimal phase slopes of the analog part of the combiner (i.e., the phase slopes that minimize the burst error probability) are the same found under the optimization of a single ACN, which was done in earlier work. We then show how directional antennas can be employed in this context to achieve an effective omnidirectional radiation pattern of the antenna system that is robust in all directions of arrival of received signals.Secondly, at the transmit-side, we develop two low-cost analog MA schemes, an analog beamforming network (ABN) of phase shifters, and an antenna switching network (ASN), for the case when receivers employ the ACN or the hybrid combiner. Both schemes are shown to achieve an effective radiation pattern with improved omnidirectional characteristics at the transmit-side without relying on CSI.Thirdly, the schemes above were developed assuming that all vehicles broadcast their messages with the same fixed period. Therefore, we tackle the practical scenario when different vehicles use different and potentially varying broadcast periods. We show that the phase slopes of the MA schemes at the receiver and/or transmitter can be designed to support multiple broadcast periods.\ua0Lastly, the optimal phase slopes of the MA schemes were analytically derived under a worst-case propagation corresponding to a dominant path with an angle of departure, and an angle of arrival that are approximately non-varying over the time it takes to transmit and receive several packets. We relax this assumption and study the system performance under a time-varying dominant component instead. We derive a design rule that yields robust phase slopes that effectively mitigate the losses due to the time-variation of the dominant path

5G-NR radio planning for connected and autonomous vehicles services

Tese para obtenção do grau de Mestre em Engenharia Electrónica e de Telecomunicações com especialização em TelecomunicaçõesThe 5G network development is enabling many emerge technologies as connected and autonomous vehicles (CAV), promising a significant impact in the telecommunications industry in the future. In this thesis, was performed 5G radio planning by coverage and capacity, entirely when CAV applications are provided, requiring minimum and maximum user data rates according to different services categories from 5GMOBIX project. 5G air interface was explored joint to MIMO and modulation orders configurations, intending to analyse the different results in two diverse highways around Lisbon, for urban and rural propagation environments. Vehicles traffic model was simulated using real statistic numbers, aiming to compute more effective KPIs while the radio planning. The final number of sites calculated were compared regarding to each scenario simulated as well as the number of vehicles supported for each service category. The results showed that the cell ranges reached in DL were tens of kilometres, despite of some meters in UL for some network configurations. Also, the radio resources showed being enough when minimum user data rate is required, nevertheless when maximum user data rate is required, new cell and vehicle ranges recalculation were needed, reaching much higher number of sites due to the cell capacity limitation. The number of sites required in urban environment showed being the double when comparing to rural, due to the higher vehicles traffic.O desenvolvimento das redes móveis 5G está permitindo o surgimento de muitas outras tecnologias como veículos autónomos e conectados (CAV), prometendo impacto significativo na indústria das telecomunicações no futuro. Nesta tese, foi realizado planeamento rádio 5G por cobertura e capacidade, para aplicações CAV (e.g. Vehicle platooning, Advanced driving, Extend sensors, Remote driving and Vehicle QoS support), quando estes exigem mínima e máxima taxa de dados do utilizador de acordo com o projeto 5GMOBIX. Considerando que CAVs podem ter seis níveis de automação, de 0 à 5, de acordo com as tarefas que estes desempenhem, foram considerados veículos de nível 3. As comunicações V2X foram criadas para desenvolver mais segurança e eficiência no tráfego e economia no consumo de energia nas ruas e rodovias. Estas foram padronizadas em comunicações baseadas em WLAN e redes celulares. O primeiro apoia-se no mesmo protocolo do Wi-Fi IEEE 802.11p e o segundo (C-V2X) nos protocolos do 3GPP desenvolvidos para redes móveis como LTE, onde foi primeiramente definido e 5G, que é a base desta tese. A arquitetura 5G apresenta é padronizada pelo 3GPP e apresenta-se em duas formas, Standalone (SA) e Non-Standalone (NSA), onde o segundo apoia-se na estrutura core e radio do 4G mas tirando vantagem da interface rádio do 5G. Esta confuguração, permite que o 5G alcance o alto padrão de qualidade de serviço requisitado pelos estudos de caso que são: (i) enhanced mobile broadband (eMBB), (ii) ultra-reliable and low-latency communications (URLLC) and (iii) massive machine-type communications (mMTC). CAV se enquandra no segundo grupo. A interface rádio do 5G, herdou características do 4G e introduziu outras significativas. No 5G, há dois ranges de frequências. FR1 até 7125 MHz e FR2 de 24 à 52 MHz, ambos grupos com diferentes larguras de banda disponíveis. Para esta tese foi utilizado 3.5 GHz de frequência central, e largura de banda de 10 à 100 MHz. Esta banda, é definida pelo 3GPP como sendo TDD, ou seja, é necessário apenas um canal para que transmissor e receptor se comuniquem, e os símbolos OFDM são dispostos no domínio do tempo e configurados como DL, UL ou flexíveis dentro de cada time slot. O método de multiplexação é o mesmo utilizado no 4G, OFDM, que devido à orthogonalidade das subportadoras, permite que estas não interfiram entre si, e assim possam compartilhar o espectro rádio. Uma das principais características do 5G que difere do 4G, é a introdução das numerologias que referem-se ao espaçamento entre subportadoras. Estas, são diferentes, de acordo com o range de frequência a ser utilizado. Nesta tese, numerologias 0, 1 e 2 são aplicadas, ou seja, 15, 30 e 60 KHz de espaçamento. Considerando o formato de onda OFDM, e que um radioframe tem 10 ms e 14 símbolos, desta forma, é possível calcular o tempo de símbolo e número de resource blocks para as diferentes configurações de numerologia, largura de banda, e frequência utilizada, tornando o acesso radio mais flexível e possibilitando a aplicação de diferentes configurações para diferentes serviços. As modulações QPSK, 16QAM, 64QAM e 256QAM foram utilizadas neste trabalho, todas em UL e DL, uma vez que no 5G, são utilizadas diferentes modulações para diferente tipos de mensagens (e.g. dados, controle). MIMO também foi utilizado em matrizes de 2x2, 4x4 e 8x8, alterando o ganho de transmissão de acordo com o aumento do número de layers de antennas. O modelo desenvolvido para simular o planeamento rádio do 5G pra CAVs, foi baseado nas definições do 3GPP. O planeamento foi realizado em cobertura e capacidade, considerando os ambientes rural e urbano, em duas autoestradas do distrito de Lisboa em Portugal. Foram calculados KPIs relevantes e seus limites foram comparados, explorando todas as configurações aplicadas. No planeamento pela cobertura, foi utilizado o modelo do 3GPP para cálculo do PL de acordo com a distancia ao gNB, utilizando a componente aleatória fornecida de acordo com o ambiente de propagação de maneira a atingir valores mais realistas. Estes, resultaram em valores médios de 30 dB de diferença entre LOS e NLOS devido aos valores de desvio padrão definidos, sendo maiores em NLOS devidos às obstruções do sinal. Os valores médios do PL, foram utilizados para calcular a potência do signal recebido RSS, também com sua componente aleatória. Os valores mais baixos encontrados para RSS foram na borda da célula de -95, -113, -94 e -126 dBm em UL, e -71, -89, -70 e -102 dBm em DL, para RMa LOS, RMa NLOS, UMa LOS e UMa NLOS, respectivamente. Posteriormente, os valores de SNR para cada modulação foram definidos, utilizando a simulação de um canal AWGN hipotético que resultou em um gráfico de BER por EB/N0, onde BER foi definido como 1%, e os valores de SNR foram considerados como sendo os de Eb/N0 (i.e. 4, 8, 12 e 16). Estes foram valores de entrada para calcular a sensibilidade dos veículos e do gNB, que apresentaram aumento significativo com a largura de banda e diferença de 1 dB entre as numerologias em ambos ambientes. O PL maximo permitido MAPL, foi calculado considerando 99% de cobertura, onde os maiores valores foram em DL principalmente quando a modulação QPSK e MIMO 8x8 são utilizados. A distância máxima gNB-veículos foi também simulada, apresentando ser menor de acordo com o aumento da largura de banda, atingindo máximo de 23 km em ambiente rural LOS em DL, e mínimo de 72 m em ambiente urbano para NLOS em UL. A distância entre sites foi calculada em todos os cenários, utilizando a máxima distância gNB-veículos resultando em máximo de 40 km e mínima de 12 km para ambiente rural e LOS para DL e UL respectivamente, sendo que 1/3 dessa distância é atingida para largura de banda de 100 MHz. O número final de sites necessários para cobrir a área simulada de 5 km para largura de banda de 100 MHz resultou em 13 à 25 sites em ambiente rural e 20 á 70 sites em ambiente urbano. De acordo com as configurações utilizadas para o planeamento pela cobertura, foi também simulado o número máximo de veículos suportado por célula de acordo com o serviço. O planeamento pela capacidade, baseou-se na modelagem realista do tráfego na hora de ponta em duas autoestradas de Lisboa, a comparação do tráfego de dados exigido dos veículos com a capacidade da rede e destacados os pontos em que a rede é limitada pela cobertura e pela capacidade, calculando também KPIs relevantes para a análise. O resultado da modelagem de tráfego encontrou 23 veículos por km em ambiente urbano e 9 veículos por km em ambiente rural. Sabendo a taxa de dados por serviço do projecto 5GMOBIX, e aplicando percentagem à esses serviços de acordo com uma presumida penetração, atingiu-se taxa de dados total mínima e máxima requerida por km de autoestrada de acordo com o ambiente de propagação, resultando para ambiente urbano mínimo de 108 Mbps e máxima de 2.82 Gbps. E para ambiente rural mínima de 42 Mbps e máxima de 1.1 Gbps. Simulando a capacidade da rede esta mostrou-se ser maior consoante maior a largura de banda principalmente com a utilização da modulação de 256QAM. Posteriormente, a carga de tráfego foi simulada de acordo com a taxa de dados total mínima e máxima requerida por km de autoestrada multiplicada pela máxima distância gNB-veículos calculada durante o planeamento pela cobertura. A carga de tráfego apresentou-se ser maior quanto maior o raio de célula ou distância em UL, porém para ambiente rural LOS DL este apresentou-se ter menor carga de tráfego do que ambiente urbano LOS DL devido ao menor número de veículos. Racio de célula foi aplicado comparando a carga de tráfego com a capacidade da rede, com o intuito de indicar os pontos em que o planeamento é limitado pela cobertura ou pela capacidade e assim recalcular a máxima distância gNB-veículos. Assim, novo número de sites foi simulado após análise das limitações das células, onde resultados mostram que para 100 MHz de largura de banda e mínima taxa de dados exigida, a rede apresenta-se ser apenas limitada pela cobertura e ter condições de prover recursos rádio para todos os veículos, mas quando máxima taxa de dados é exigida quase todos os cenário são limitados pela capacidade devido às longas distâncias, principalmente em DL e para modulações mais baixas. Apenas MIMO 4x4 256QAM e MIMO 8x8 64QAM e 256QAM são limitados pela cobertura.info:eu-repo/semantics/publishedVersio

Modeling and Design of Millimeter-Wave Networks for Highway Vehicular Communication

Connected and autonomous vehicles will play a pivotal role in future Intelligent Transportation Systems (ITSs) and smart cities, in general. High-speed and low-latency wireless communication links will allow municipalities to warn vehicles against safety hazards, as well as support cloud-driving solutions to drastically reduce traffic jams and air pollution. To achieve these goals, vehicles need to be equipped with a wide range of sensors generating and exchanging high rate data streams. Recently, millimeter wave (mmWave) techniques have been introduced as a means of fulfilling such high data rate requirements. In this paper, we model a highway communication network and characterize its fundamental link budget metrics. In particular, we specifically consider a network where vehicles are served by mmWave Base Stations (BSs) deployed alongside the road. To evaluate our highway network, we develop a new theoretical model that accounts for a typical scenario where heavy vehicles (such as buses and lorries) in slow lanes obstruct Line-of-Sight (LOS) paths of vehicles in fast lanes and, hence, act as blockages. Using tools from stochastic geometry, we derive approximations for the Signal-to-Interference-plus-Noise Ratio (SINR) outage probability, as well as the probability that a user achieves a target communication rate (rate coverage probability). Our analysis provides new design insights for mmWave highway communication networks. In considered highway scenarios, we show that reducing the horizontal beamwidth from $90^\circ$ to $30^\circ$ determines a minimal reduction in the SINR outage probability (namely, $4 \cdot 10^{-2}$ at maximum). Also, unlike bi-dimensional mmWave cellular networks, for small BS densities (namely, one BS every $500$ m) it is still possible to achieve an SINR outage probability smaller than $0.2$.Comment: Accepted for publication in IEEE Transactions on Vehicular Technology -- Connected Vehicles Serie

Open Platforms for Connected Vehicles

L'abstract è presente nell'allegato / the abstract is in the attachmen