scholarly journals DSRC versus 4G-LTE for Connected Vehicle Applications: A Study on Field Experiments of Vehicular Communication Performance

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Zhigang Xu ◽  
Xiaochi Li ◽  
Xiangmo Zhao ◽  
Michael H. Zhang ◽  
Zhongren Wang
Keyword(s):  
Collision Avoidance ◽  
High Speed ◽  
Field Experiments ◽  
Traffic Information ◽  
Connected Vehicle ◽  
Vehicular Communication ◽  
Test Bed ◽  
Traffic Sign ◽  
Communication Performance ◽  
4G Lte

Dedicated short-range communication (DSRC) and 4G-LTE are two widely used candidate schemes for Connected Vehicle (CV) applications. It is thus of great necessity to compare these two most viable communication standards and clarify which one can meet the requirements of most V2X scenarios with respect to road safety, traffic efficiency, and infotainment. To the best of our knowledge, almost all the existing studies on comparing the feasibility of DRSC or LTE in V2X applications use software-based simulations, which may not represent realistic constraints. In this paper, a Connected Vehicle test-bed is established, which integrates the DSRC roadside units, 4G-LTE cellular communication stations, and vehicular on-board terminals. Three Connected Vehicle application scenarios are set as Collision Avoidance, Traffic Text Message Broadcast, and Multimedia File Download, respectively. A software tool is developed to record GPS positions/velocities of the test vehicles and record certain wireless communication performance indicators. The experiments have been carried out under different conditions. According to our results, 4G-LTE is more preferred for the nonsafety applications, such as traffic information transmission, file download, or Internet accessing, which does not necessarily require the high-speed real-time communication, while for the safety applications, such as Collision Avoidance or electronic traffic sign, DSRC outperforms the 4G-LTE.

In situ study of volcanic ash resuspension using a portable wind tunnel.

2020 ◽  
Author(s):  
Jacopo Taddeucci ◽  
Elisabetta del Bello ◽  
Jonathan P Merrison ◽  
Keld R Rasmussen ◽  
Jens J Iversen ◽  
...  
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
High Speed ◽  
Volcanic Ash ◽  
Field Experiments ◽  
Critical Parameters ◽  
Test Bed ◽  
High Definition ◽  
Sustained Activity

<p>The resuspension of volcanic ash deposits by wind is a well-known source of hazard following explosive eruptions. Besides the mail control exerted by the local wind field, ash resuspension is also influenced by: 1) atmospheric humidity; 2) features of the deposit (grain size distribution, sedimentary structures, etc.), and 3) features of the substrate (i.e. moisture, roughness). Ash resuspension is modeled using numerical simulations, which however require physical characterization and identification of the critical parameters controlling ash resuspension. Wind tunnel studies on volcanic particles are very limited and restricted to laboratory parameterizations, with in-situ effects not been parameterized. We tested field experiments of volcanic ash resuspension developing a portable wind tunnel and deploying on proximal (3 km) ash deposits from the semi-sustained activity of Sakurajima volcano (Japan) and from distal (250 km ca.) ash deposits from the 2011 Cordon Caulle eruption (Chile). The wind tunnel is calibrated with both LDA and pitot tubes measurements. The device allows generating a controlled wind profile within a 110x12x12 cm test section, which is placed directly on an untouched test bed of naturally deposited ash. Two types of experiments were performed: 1) ramp up speed experiments, where the wind speed is increased until reaching the threshold friction speed on four different substrates; 2) constant speed experiments, where three wind speed values where kept for 20 minutes using the same substrate. The threshold friction speed is measured with a hot wire anemometer, and the movement of resuspended ash is detected by means of multiple high speed and high definition digital camcorders. In-situ measured threshold friction speeds are compared to 1) in situ observed episodes of resuspension driven by local winds and 2) laboratory determination of threshold friction speed in controlled environmental conditions, and using the same ash deposited homogeneously.</p><p> </p>

Interlinking Vissim and ns-3 for Connected Vehicle Simulation: Case Study of Intelligent Dilemma Zone Avoidance

2017 ◽  
Vol 2619 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Praprut Songchitruksa ◽  
Srinivasa Sunkari ◽  
Ines Ugalde ◽  
Justinian Rosca ◽  
Juan Aparicio Ojea
Keyword(s):  
Wireless Communication ◽  
High Speed ◽  
Fixed Time ◽  
Communication Model ◽  
Connected Vehicle ◽  
Test Bed ◽  
Application Performance ◽  
Dilemma Zone ◽  
Vehicle Simulation ◽  
Analysis System

The effects of realistic wireless communication are important for the modeling and evaluation of emerging connected and automated vehicle applications. This paper discusses the development of a novel closed-loop connected vehicle analysis system (CONVAS) interlinking Vissim microscopic traffic simulation and ns-3 wireless communication simulation. In CONVAS, ns-3 uses Vissim’s vehicle positions for wireless modeling and in turn Vissim uses the packet reception from ns-3 to modify vehicle behaviors. The authors propose an application for intelligent avoidance of the dilemma zone to demonstrate the use of the platform for modeling connected and automated vehicles and to illustrate the effects of communications on the application performance. A simulation experiment was conducted with a test bed for an isolated high-speed, fixed-time signalized intersection with different communication model configurations. The evaluation results showed that the effectiveness of the application as measured by successful clearing of vehicles from the dilemma zone depended greatly on performance of wireless communication.

Novel Cooperative Collision Avoidance Model for Connected Vehicles

2017 ◽  
Vol 2645 (1) ◽  
pp. 144-156 ◽  
Author(s):  
Pangwei Wang ◽  
WenXiang Wu ◽  
Xiaohui Deng ◽  
Lin Xiao ◽  
Li Wang ◽  
...  
Keyword(s):  
Collision Avoidance ◽  
Traffic Safety ◽  
Traffic Information ◽  
Connected Vehicles ◽  
Time Interval ◽  
Connected Vehicle ◽  
Emergency Braking ◽  
Acceleration Rate ◽  
Vehicle Platoon ◽  
Connected Vehicle Technology

Connected vehicle technology exchanges real-time vehicle and traffic information through vehicle-to-vehicle and vehicle-to-infrastructure communication. The technology has the potential to improve traffic safety applications such as collision avoidance. In this paper, a novel cooperative collision avoidance (CCA) model that could improve the effectiveness of the collision avoidance system of connected vehicles was developed. Unlike traditional collision avoidance models, which relied mainly on emergency braking, the proposed CCA approach avoided collision through a combination of following vehicle deceleration and leading vehicle acceleration. Through spacing policy theory and nonlinear optimization, the model calculated the desired deceleration rate for the following vehicle and the acceleration rate for the leading vehicle, respectively, at each time interval. The CCA approach was then tested on a scaled platform with hardware-in-the-loop simulation embedded with MATLAB/Simulink and a car simulator package, CarSim. Results show that the proposed model can effectively avoid rear-end collisions in a three-vehicle platoon.

Selective MIMO in Vehicular Communication for Reliable Safety Services and High Speed Non-Safety Services

2021 ◽  
Author(s):  
Utpal Kumar Dey ◽  
Robert Akl ◽  
Robin Chataut ◽  
Mohammadreza Robaei
Keyword(s):  
High Speed ◽  
Vehicular Communication

scholarly journals Decentralized 3D Collision Avoidance for Multiple UAVs in Outdoor Environments

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4101 ◽  
Author(s):  
Eduardo Ferrera ◽  
Alfonso Alcántara ◽  
Jesús Capitán ◽  
Angel Castaño ◽  
Pedro Marrón ◽  
...  
Keyword(s):  
Collision Avoidance ◽  
System Integration ◽  
Field Experiments ◽  
Positioning Systems ◽  
Wind Gusts ◽  
Aerial Vehicles ◽  
Multiple Uavs ◽  
Outdoor Environments ◽  
External Conditions ◽  
Field Experimentation

The use of multiple aerial vehicles for autonomous missions is turning into commonplace. In many of these applications, the Unmanned Aerial Vehicles (UAVs) have to cooperate and navigate in a shared airspace, becoming 3D collision avoidance a relevant issue. Outdoor scenarios impose additional challenges: (i) accurate positioning systems are costly; (ii) communication can be unreliable or delayed; and (iii) external conditions like wind gusts affect UAVs’ maneuverability. In this paper, we present 3D-SWAP, a decentralized algorithm for 3D collision avoidance with multiple UAVs. 3D-SWAP operates reactively without high computational requirements and allows UAVs to integrate measurements from their local sensors with positions of other teammates within communication range. We tested 3D-SWAP with our team of custom-designed UAVs. First, we used a Software-In-The-Loop simulator for system integration and evaluation. Second, we run field experiments with up to three UAVs in an outdoor scenario with uncontrolled conditions (i.e., noisy positioning systems, wind gusts, etc). We report our results and our procedures for this field experimentation.

scholarly journals High speed internet development in Africa using 4G-LTE technology-a review

2019 ◽  
Vol 8 (2) ◽  
pp. 577-585
Author(s):  
Mohamed Njikam ◽  
Nanna S. ◽  
Shahrin S. ◽  
Mohd Fairuz Iskandar Othman
Keyword(s):  
High Speed ◽  
Telecommunication Networks ◽  
African Continent ◽  
African Countries ◽  
Lte Networks ◽  
Telecommunication Infrastructure ◽  
Long Time ◽  
Populated Region ◽  
4G Lte ◽  
Internet Development

The African continent is ranked second most populated region and has a huge amount of natural resources to be locally transformed or outsourced overseas. The traditional telecommunications system has helped connect people and enabled them to manage their businesses and trading in Africa for a long-time; many African countries have embarked early in changing their network and technology systems during the first years of the information age. Over a few decades ago, the introduction of new telecommunication methods and techniques have influenced much of African countries’ growth via different perspectives. The situation has triggered an enormous interest in people. They analyzed the factors supporting such changes, which in the case of this paper is all about the advent and adoption of LTE/4G-LTE technologies including its service commercialization in Africa. This review article attempts to provide an overview of 4G-LTE networks technologies and the internet; it includes the current evolution of telecommunication networks within and even beyond the African continent, assisted by the 4G-LTE expansion. An extended view is provided throughout this article’s development with respect to what could be expected (or is missing) for the sake of this continent’s telecommunication infrastructure enhancement and a better QoS to Africa’s dwellers.

scholarly journals Microscopic Estimation of Freeway Vehicle Positions from the Behavior of Connected Vehicles

2020 ◽  
Author(s):  
Noah J. Goodall ◽  
Brian L. Smith ◽  
Byungkyu Brian Park
Keyword(s):  
Traffic Signals ◽  
The United States ◽  
Traffic Information ◽  
Connected Vehicles ◽  
Connected Vehicle ◽  
Travel Time Prediction ◽  
High Penetration ◽  
Initial Penetration ◽  
Car Following Model ◽  
Status Data

Given the current connected vehicles program in the United States, as well as other similar initiatives in vehicular networking, it is highly likely that vehicles will soon wirelessly transmit status data, such as speed and position, to nearby vehicles and infrastructure. This will drastically impact the way traffic is managed, allowing for more responsive traffic signals, better traffic information, and more accurate travel time prediction. Research suggests that to begin experiencing these benefits, at least 20% of vehicles must communicate, with benefits increasing with higher penetration rates. Because of bandwidth limitations and a possible slow deployment of the technology, only a portion of vehicles on the roadway will participate initially. Fortunately, the behavior of these communicating vehicles may be used to estimate the locations of nearby noncommunicating vehicles, thereby artificially augmenting the penetration rate and producing greater benefits. We propose an algorithm to predict the locations of individual noncommunicating vehicles based on the behaviors of nearby communicating vehicles by comparing a communicating vehicle's acceleration with its expected acceleration as predicted by a car-following model. Based on analysis from field data, the algorithm is able to predict the locations of 30% of vehicles with 9-m accuracy in the same lane, with only 10% of vehicles communicating. Similar improvements were found at other initial penetration rates of less than 80%. Because the algorithm relies on vehicle interactions, estimates were accurate only during or downstream of congestion. The proposed algorithm was merged with an existing ramp metering algorithm and was able to significantly improve its performance at low connected vehicle penetration rates and maintain performance at high penetration rates.

A study about trajectory planning sensitivity in high-speed cooperative collision avoidance

2015 ◽  
Author(s):  
Juan-Bautista Tomas-Gabarron ◽  
Felipe Garcia-Sanchez ◽  
Antonio-Javier Garcia-Sanchez ◽  
Joan Garcia-Haro
Keyword(s):  
Collision Avoidance ◽  
Trajectory Planning ◽  
High Speed
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