892 research outputs found

    Study on QoS support in 802.11e-based multi-hop vehicular wireless ad hoc networks

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    Multimedia communications over vehicular ad hoc networks (VANET) will play an important role in the future intelligent transport system (ITS). QoS support for VANET therefore becomes an essential problem. In this paper, we first study the QoS performance in multi-hop VANET by using the standard IEEE 802.11e EDCA MAC and our proposed triple-constraint QoS routing protocol, Delay-Reliability-Hop (DeReHQ). In particular, we evaluate the DeReHQ protocol together with EDCA in highway and urban areas. Simulation results show that end-to-end delay performance can sometimes be achieved when both 802.11e EDCA and DeReHQ extended AODV are used. However, further studies on cross-layer optimization for QoS support in multi-hop environment are required

    Detecting Traffic Conditions Model Based On Clustering Nodes Situations In VANET

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    In the last decade, cooperative vehicular network has been one of the most studied areas for developing the intelligent transportation systems (ITS). It is considered as an important approach to share the periodic traffic situations over vehicular ad hoc networks (VANETs) to improve efficiency and safety over the road. However, there are a number of issues in exchanging traffic data over high mobility of VANET, such as broadcast storms, hidden nodes and network instability. This paper proposes a new model to detect the traffic conditions using clustering traffic situations that are gathered from the nodes (vehicles) in VANET. The model designs new principles of multi-level clustering to detect the traffic condition for road users. Our model (a) divides the situations of vehicles into clusters, (b) designs a set of metrics to get the correlations among vehicles and (c) detects the traffic condition in certain areas. These metrics are simulated using the network simulator environment (NS-3) to study the effectiveness of the model

    SURVEY STUDY FOR VEHICULAR AD HOC NETWORKS PERFORMANCE IN CITY AND URBAN RESIDENTIAL AREAS

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    This thesis it survey study for VANET (Vehicular Ad-Hoc Networks) and it performance in city and urban residential areas, when the the number of vehicles on roads is increasing annually, due to the higher amount of traffic, there are more accidents associated with road traffic complexity. VANET can be used to detect dangerous situations which are forwarded to the driver assistant system by monitoring the traffic status.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

    Video streaming in urban vehicular environments: Junction-aware multipath approach

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    © 2019 by the authors. Licensee MDPI, Basel, Switzerland. In multipath video streaming transmission, the selection of the best vehicle for video packet forwarding considering the junction area is a challenging task due to the several diversions in the junction area. The vehicles in the junction area change direction based on the different diversions, which lead to video packet drop. In the existing works, the explicit consideration of different positions in the junction areas has not been considered for forwarding vehicle selection. To address the aforementioned challenges, a Junction-Aware vehicle selection for Multipath Video Streaming (JA-MVS) scheme has been proposed. The JA-MVS scheme considers three different cases in the junction area including the vehicle after the junction, before the junction and inside the junction area, with an evaluation of the vehicle signal strength based on the signal to interference plus noise ratio (SINR), which is based on the multipath data forwarding concept using greedy-based geographic routing. The performance of the proposed scheme is evaluated based on the Packet Loss Ratio (PLR), Structural Similarity Index (SSIM) and End-to-End Delay (E2ED) metrics. The JA-MVS is compared against two baseline schemes, Junction-Based Multipath Source Routing (JMSR) and the Adaptive Multipath geographic routing for Video Transmission (AMVT), in urban Vehicular Ad-Hoc Networks (VANETs)

    An Efficient Routing Mechanism for Vehicular Ad Hoc Networks

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    Vehicular Ad-hoc Network is a new technology which have become dominant of all the wireless communication with time. It is a group of mobile nodes (vehicles) which forms a infrastructure less temporary network. To route a packet to destination, a node uses intermediate nodes. In VANET, because of frequent topology changes and disconnection of path, it is difficult to provide an efficient protocol. This research work states that, geographical approach routing will have low end to end delay and maximum packet delivery ratio. In this paper we analyze the performance of Greedy Perimeter Stateless Routing Protocol (GPSR) [4] which is a location based protocol and compared it with Ad hoc On Demand Distance Vector Routing protocol (AODV) [3]. To measure and evaluate the parameters NS-2.33 is used as network simulator and Simulation of Urban Mobility (SUMO) as traffic simulator

    Unicast Ad-Hoc Routing in Vehicular City Scenarios

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    Within Vehicular Ad-Hoc Networking (VANET), i.e., networking between radio-equipped vehicles, unicast packet forwarding can be separated into the one-dimensional highway case and the two-dimensional city case. In this report, we survey the routing methods developed in the FleetNet and Network-on-Wheels projects plus a novel combination of two wellknown methods called PBR-DV or Position-Based Routing with Distance-Vector recovery. On the quest for a city-capable candidate routing algorithm as a possible standard, we discuss the usability and performance of the protocols in city scenarios. Finally, we conclude proposing PBR-DV as a candidate protocol for small-hop-count unicast VANET scenarios

    Comparison among Different Routing Protocols of Vehicular Ad Hoc Networks

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    To improve highway transport security VANET Vehicular Ad Hoc Network is used which is a developing technology incorporating ad hoc network cellular technology and wireless LAN VANETs are different from other type ad hoc networks by their cross network constructions node association features and new application setups The approach of an effective routing protocol for VANETs is vital as VANETs show various distinctive networking research challenges In this paper we discuss the research challenges of routing in VANETs and compare recent routing protocols of VANET
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