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Platooning of vehicles allows to saving energy and increasing safety provided that there are reliable wireless communication protocols. In this paper, the optimization of the medium access control (MAC) protocol based on IEEE 802.11e for the platoon joining is investigated. The exchange of prosperous dynamic information among vehicules through certain bounded and closed-fitting timeout windows is...
In the light of more traffic status variables are considered under low traffic flow in traffic intensity-based two-stage fuzzy control for urban traffic signals, thus leading to the inefficiency of traffic states weakening at isolated intersections. This paper introduces a two-stage combination fuzzy optimal controller for traffic signals at urban isolated intersections: the proposed controller adopts...
This paper presents a navigation system for an Autonomous Underwater Vehicle (AUV) which merges standard dead reckoning navigation data with absolute position fixes from an Ultra-Short Base Line (USBL) system. Traditionally, the USBL transceiver is located on the surface, which makes necessary to feed the position fixes back to the AUV by means of an acoustic modem. An Information filter, which maintains...
In this paper, the suitability of the existing MANET routing protocols for VANETs has been evaluated. Even though a VANET is a subset of MANET, it has unique characteristics and message delivery requirements. VANETs are characterized by a very dynamic topology with partial infrastructure support, patterned mobility, mobile nodes with sufficient resources, intermittent connectivity and varied channel...
Vehicular ad hoc network (VANET) can be considered as a basic and an important interconnected system for road transmissions which is considered as one of the most important types of next generation networks. It helps vehicle drivers to access to the information anywhere and at any time. Their essential advantages are the road safety improvement, air pollution reducing and data transmission optimization...
Data dissemination over long distances in urban scenarios is the foundation of many VANET applications, but rapid shifting in network topology, unstable quality of wireless communication and channel capacity constraints of VANETs pose many challenges to data dissemination. In response, we propose a connectivity-aware data delivery mechanism on the basis of an improved greedy broadcasting. Moreover,...
Considering vehicles as sensors for traffic and pollution information is a new paradigm to monitor the environment and to open the way to an efficient smart navigation. In this work we focus on the uplink acquisition of traffic information from vehicles toward a remote control center. With the increase in the number of vehicles equipped with on board units (OBUs) enabling cellular transmissions, this...
This paper presents the URBAN XOR1 protocol, an XOR-based flat routing mechanism developed for vehicular ad hoc networks (VANETs) formed in urban scenarios. The paper firstly describes the URBAN_XOR routing principle, which requires reduced knowledge about the set of nodes present in the VANET in order to provide traffic forwarding. Basically, the URBAN XOR protocol introduces the concept of local...
To improve the operation efficiency and service levels of Bus Rapid Transit (BRT) systems, we propose a novel realtime BRT signal priority approach through two-stage green extension. For social justices, we control traffic signal lights under the people first principle after constructing BRT Internet of Things. This requests us to collect enough traffic information related to BRT vehicles, social...
Intra-vehicular wireless sensor networks is a promising new research area that can provide part cost, assembly, maintenance savings and fuel efficiency through the elimination of the wires, and enable new sensor technologies to be integrated into vehicles, which would otherwise be impossible using wired means, such as Intelligent Tire. The most suitable technology that can meet high reliability, strict...
This paper analyses the performance of a new routing protocol for vehicular delay-tolerant networks, called GeoSpray. This geographic routing protocol performs a store-carry-and-forward, combining replication and forwarding/ routing decisions based on location information, with explicit delivery acknowledgments to improve network resources utilization. The performance of the proposed routing protocol...
Vehicular Ad hoc Networks (VANETs) provide vehicle-to-vehicle and vehicle-to-infrastructure communication using Dedicated Short-Range Communications (DSRC). The core objective of VANETs is to provide safety message communication among vehicles. In dense urban traffic, safety message communication encounters severe packet collisions due to excessive number of nodes contending to access the control...
Nowadays transportation systems suffer from many adversities. One of the most notorious issues is the traffic congestion. The transportation of persons and goods experiment notable delays with the consequent waste of precious resources and the rise of pollution. Actual Intelligent Transportation systems (ITS) are intended to relief the broad spectrum of challenges that affect our modern traffic infrastructures...
In this paper, we address the beacon congestion issue in Vehicular Ad Hoc Networks (VANETs) due to its devastating impact on the performance of ITS applications. The periodic beacon broadcast may consume a large part of the available bandwidth leading to an increasing number of collisions among MAC frames, especially in case of high vehicular density. This will severely affect the performance of the...
Pulsed-RF (aka. Ultrawideband, or UWB) signaling strategies inherently produce separation of multipath reflections from the earliest Line-of-Sight (LOS) signal. Direct waveform scanning in each UWB transceiver allows coarse estimation of distance through relative signal strength measure of the earliest, most direct path pulse. Even with multipath separation this technique suffers from errors due to...
This paper presents a study of the Dedicated Short Range Communication (DSRC) Physical Layer in order to determine its reliability for Vehicle-2-Vehicle (V2V) communication under varying Signal-to-Noise Ratio (SNR), vehicle speed, delay spread, and packet lengths. In particular, we focus on computing the expected delay when packets with errors are retransmitted until received correctly. IEEE 802.11a...
A separate turn phase is often used at intersection with heavy left turns. This wastes capacity on the approach because some of its lanes cannot discharge during its green phases. The problem can be eliminated by reorganizing traffic on all the lanes upstream of an intersection using a mid-block pre-signal. To evaluate the effectiveness of the pre-signal control system, this study has also conducted...
Battery systems for electric vehicles (EVs) or uninterruptible micro-gridsâ"prototypical cyber-physical systems (CPSs)â"are usually built with several hundreds/thousands of battery cells. How to deal with the inevitable failure of cells quickly and cost-effectively for vehicle warranty or uninterruptible service, for instance, is key to the development of large-scale battery systems. Use...
Based on the Instantaneous Stopped Delay (ISD), this paper proposed a novel closed-loop feedback signal control strategy, which takes the total amount of ISD (ISD Total) as input detector data for measurement frame-by-frame in traffic flow video, and realizes real-time switches of the signal status when the amount reaches the threshold, and adaptively distributes the green interval to the most needed...
Deploying roadside access points (APs) or an infrastructure can improve data delivery. Our empirical results from real trace driven simulations show that deploying APs produces up to 5× performance gain in delivery ratio and reduces delivery delay by as much as 35% with simple routing. However, we also find that buffer resources at the APs become a critical factor and poor buffer allocation leads...
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