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Along with advances in technologies and equipment of vehicles with communication devices, vehicular networks were developed. Various applications are proposed and defined for these networks, and as the number of deaths caused by accidents are increasing, safety applications became the most important one. Dynamicity of the nodes in addition to wireless transmission problem cause challenges for disseminating...
Motivated by studies of wireless ad hoc networks in obstructed environments, in this work we focus on the problem of establishing connectivity at an intersection of two roads, or streets, surrounded by obstacles. An instance of the problem is defined by four street segments meeting at an intersection point, a street width, a node density at each street segment and a transmission range of the communication...
In this paper, we investigate the performance of advertisement delivery scenarios of Vehicular DTN (VDTN) under highly stressed environment. The simulations for two scenarios are conducted considering obstacles (buildings), where Road Side Units (RSUs) are present or not present. We consider 802.11p standard and send bundle messages in a realistic scenario of east side of Tokyo station area in Japan...
Service discovery in vehicular networks has been extensively investigated in literature. Collecting and disseminating data in high mobility networks in a reliable and efficient way without exhausting network bandwidth is still challenging, due to unreliable channel access in broadcast scenarios and thus results in loss of time through resending packets. Sending delta information to reduce network...
This paper reports an experimental validation of the feasibility of cooperative approach for extending the coverage of vehicular-to-infrastructure (V2I) communication using our software platform named Airplug. Although the access time between a vehicle and a roadside unit (RSU) providing Internet access is limited in the real-world condition, our field trials demonstrate that it is extended by just...
Cooperative wireless communication has attracted intense interest as an alternative way to multiple-antenna systems to obtain spatial diversity. In this paper, we investigate the performance of a vehicle-to-vehicle cooperative scheme where another vehicle in the vicinity of the source vehicle acts as a relay. The underlying source-to-relay, relay-to-destination, and source-to-destination links are...
This paper proposes a novel cognitive cellular automata (CA) approach that can adapt to immediate requirements, spread to use in cross-area car societies, enhance system performance, and decrease traffic-congestion problems. We propose a mechanism that operates in a cognitive radio mode for increasing the channel-reuse rate and decreasing the consumption of redundant channels. The advantage is a heterogeneous-communication...
Reliability and timely information delivery are highly concerned factors in Vehicular ad-hoc network. A better handover mechanism plays an important role in the handover process between the vehicle nodes during the vehicles on the road. Vertical handover is very much essential to ensure service continuity in Vehicular Ad-hoc network. When we compared with conventional handover decision taken by single...
This paper introduces the MARCO POLO Algorithm (MPA) that uses wireless discovery and control signals from a Master Control Node (MCN) with a cognitive engine to learn the relative location and orientation of a randomly distributed set of array elements. The elements are then synchronized and instructed to apply appropriate magnitude and phase offsets to collectively radiate as an array with beamforming...
The development of wireless communication systems has resulted in the availability of several access technologies in any geographical area, such as 3G networks, wireless local area networks (WLANs), and wireless broadband networks. The development of these technologies is provided for users who have experienced mobile network environments which are slow or fast with changes in distance between the...
Vehicular Ad-hoc Network, VANET, offers new opportunities for better road traffic management. Using vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communications, several research works were published on road traffic improvement in general and at road intersection in particular. One of the challenging problems is to minimize vehicles' waiting time at the intersection as well optimize...
This paper investigates the information dissemination process in wireless communication networks formed by vehicles. As vehicles are moving constantly, a vehicular ad-hoc network exhibits a highly-dynamic network topology and a fast-changing radio environment. These distinguishing characteristics result in random and unreliable wireless connections between vehicles. Consequently, vehicles need to...
We are interested in delay-constrained data aggregation in delay tolerant vehicular networks, in which contact opportunities are usually scarce and thus become critical resources. Data aggregation has been recognized as an effective technique for reducing communication cost while obtaining useful aggregated information. The unique characteristics of the network present great challenges to the delay-constrained...
Time-sensitive mobile service with vehicular networks depend on continuous coverage on the road system. It is a challenge to meet a tight budget while maintaining coverage quality. In order to resolve the problem, we model the road system as an undirected graph and reduce it to a Knapsack Constrained Steiner Tree model. Since the reduced model is an NP-hard problem, we resolve it by using Lagrangian...
This paper deals with a clustering approach for VANETs operating in highway scenarios, where a certain degree of correlation among vehicles emerges such that a group mobility pattern is expected. The proposed protocol is inherently mobility driven as the reference metric to select a Cluster Head (CH) takes into account the node connectivity within an estimated coherence time interval. Our clustering...
In this paper, we investigate a maximum allowable time that ensure a given outage probability target in vehicle-to vehicle cooperative communication (VVCC) with a decode-and-forward (DF) relay, which is referred to quality-supporting duration (QSD). QSD depends on the velocity of relaying vehicle and the initial positions of communicating vehicles. Numerical investigation shows how QSD greater than...
Broadcasting plays vital role in vehicle-to-vehicle communication. However, it must face to challenges such as lack of acknowledgment, no retransmission, hidden terminals and low link quality that leads to unreliable communication because of message loss caused by collisions and poor link conditions. It is especially critical for safety messages in vehicular networks. To make broadcast more reliable,...
Advances in low-power wireless communications and micro-electronics make a great impact on a transportation system and pervasive deployment of road-side units (RSU) is promising to provide drive-thru Internet to vehicular users anytime and anywhere. Downloading data packets from the RSU, however, is not always reliable because of high mobility of vehicles and high contention among vehicular users...
Vehicular ad hoc networks (VANETs) leverage communication equipment and infrastructure to improve road safety. These networks, by the rapid change of their topology and their broadcasting dissemination nature, can experience mainly two major problems; (1) the broadcasting storm and (2) network disconnection. In this paper, we focus on safety-related messages and propose a new approach to avoid the...
In this paper, we design and implement a new Intrusion Detection Framework for Vehicular Networks (IDFV). These networks are vulnerable to various security attacks due to the lack of centralized infrastructure. The aim of our framework is then to secure them against the most dangerous routing attacks that have a high severity damage such as selective forwarding, black hole, wormhole, packets duplication...
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