Considerable research attention has been dedicated to vehicular sensor networks (VSNs) because of its great potential in traffic monitoring. By taking advantage of sensors embedded in vehicles, a VSN harvests data while vehicles are traveling along the roads and then updates the collected data to the infrastructure to support the intelligent transportation system (ITS) applications. To meet the data collection requirements of different ITS applications, a huge number of update packets are generated, which may exhaust the available wireless communication bandwidth. To improve the efficiency of utilization of wireless bandwidth, in this study, we propose a quality-oriented data collection scheme, which aims to effectively support both the accuracy and real-time requirements stipulated by ITS applications while reducing communication overhead. We formulate a minimized communication overhead (MCO) problem and propose two algorithms, mixed-integer linear programming (MILP) and deviation-detection (DD) , to solve the MCO problem. MILP can obtain the optimal solution by having all the data collected by every vehicle, while DD could achieve an efficient solution without this impractical assumption. We conducted extensive experiments by using SUMO to simulate vehicle traces in freeway and downtown environments. The experimental results have demonstrated the effectiveness of the proposed solutions.

A Quality-Oriented Data Collection Scheme in Vehicular Sensor Networks

Today, vehicular ad-hoc network (VANET) is a hot research topic due to its many applications like collision avoidance, congestion road notification, parking lot availability, road-side business advertisements, etc. All these applications have hard delay constraints i.e. the messages should reach the target location within certain time limits. So, there must be efficient routing in VANET which meets these delay constraints. In this paper, two techniques are proposed to minimize the data traffic and delay in VANET. Firstly, a context based clustering is proposed which takes into consideration various parameters in cluster formation-location of vehicle, direction of vehicle, velocity of vehicle, interest list of vehicle [1] and destination of vehicle. Secondly, a destination based routing protocol is proposed for these context based clusters for efficient inter-cluster communication.

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A Destination Based Routing Protocol for Context Based Clusters in VANET

An adjusted K‐medoids clustering algorithm for effective stability in vehicular ad hoc networks

The fast development of wireless communication technologies allows to enhance intelligent transport systems and utilizes these technologies in communications between vehicles in order to achieve road safety and others benefits to drivers. Recent studies focus on a new aspect of ITS (Intelligent Transport System) that is VANET (Vehicular Ad-hoc Network). This paper gives an overview of vehicular ad-hoc networks (VANETs) and the existing VANET routing protocols. VANETs are a group of moving vehicles with wireless communication. Every vehicle is a node in the network that plays the role of sender, receiver, and router to exchange data such as warnings, traffic conditions with other vehicles. Because of the high mobility of nodes in VANETs, the routing of data is the most challenging task in VANETs which have a dynamic topology. There are various types of routing protocols in VANET which are required by the ITS. Thus, we need to do a detailed research on various routing protocols and their strengths/weakness. The routing protocols basically focus on terms of delay, packet delivery ratio, bandwidth utilization and many other factors. However, there are challenges faced by the choose a proper routing protocol due to a dynamic topology and characteristics of VANETs. VANET is very advantageous as it helps in improving the road safety through reducing the number of accidents by warning drivers about the danger before they actually face it and other facilities to comfort drivers. Researchers have started working to overcome the challenges of data exchange between vehicles to minimize its constraints and maximize its multiple objectives.

A Survey on Routing Protocols in Vehicular Adhoc Networks

Recently, the Intelligent Transport System (ITS) has undergone significant advances aiming at improving safety in the transportation system. One such progress has led to the introduction of Vehicular Ad hoc Network (VANET). This paper analyses the performance of the Nakagami radio propagation model, which is a realistic model to simulate real life scenarios. Furthermore, this paper examines how VANETs effectively reduce traffic congestion. Topologies and scenarios related to the Mauritian road topography have been developed and simulated on NS-2. The results obtained clearly shows that VANETs can successfully diminish the problem of traffic congestion and that the performance of the Nakagami model differs with the level of fading. This contrast in the performance of the Nakagami model is further highlighted when a difference of approximately 12% is observed between the throughputs for the different levels of fading.

Performance evaluation of Nakagami model for Vehicular communication networks in developing countries

Vehicular Ad-hoc Networks (VANET) are a special kind of Mobile Ad-hoc network (MANET), in which vehicles on the road forms the nodes of the networks. Now a days, VANETs find several applications as an Intelligent Transportation System(ITS). Dynamic network architectures and node movement characteristics differentiates VANETs from other kinds of ad hoc networks. The dynamic change in topology shortens the effective time of routing. Hence routing in VANETs is complicated. Ad-hoc On-Demand Distance Vector (AODV) routing protocol is the most commonly used topology based routing protocol for VANET. During the route discovery process AODV broadcasts route request message (RREQ). It creates many unused routes between a source and a destination node. This paper aims at improving the performance of AODV by enhancing the existing protocol by creating stable clusters and performing routing by Cluster Heads and Gateway nodes.

http://www.airccse.org/journal/ijgca/papers/3312ijgca04.pdf

A Cluster Based Enhancement to AODV for Inter-Vehicular Communication in VANET

Radio frequency identification (RFID) is an integral part of the IoT system. RFID along with other sensor systems provide a huge development in the field of agriculture, tracking system, transportation etc. The RFID is a system which transmits a unique identity signal and is mainly used in automatic identification technology. This paper gives a brief introduction regarding current developments in this RFID technology, different types of RFID systems, Application, Advantages,Limitations etc.

M C Aswathy

Papers

A Cluster Based Enhancement to AODV for Inter-Vehicular Communication in VANET

An Overview of Radio Frequency Identification systems