Geographical Forwarding Methods in Vehicular Ad hoc Networks

Vehicular ad hoc networks are new and emerging technology and special class of mobile ad hoc networks that provide wireless communication between vehicles without any fixed infrastructure. Geographical routing has appeared as one of the most scalable and competent routing schemes for vehicular networks. A number of strategies have been proposed for forwarding the packets in geographical direction of the destination, where information of direct neighbors is gained through navigational services. Due to dynamically changing topologies and high mobility neighbor information become outdated. To address these common issues in network different types of forwarding strategies have been proposed. In this review paper, we concentrate on beaconless forwarding methods and their forwarding methods in detail

Performance improvement in geographic routing for vehicular Ad Hoc networks

Geographic routing is one of the most investigated themes by researchers for reliable and efficient dissemination of information in Vehicular Ad Hoc Networks (VANETs). Recently, different Geographic Distance Routing (GEDIR) protocols have been suggested in the literature. These protocols focus on reducing the forwarding region towards destination to select the Next Hop Vehicles (NHV). Most of these protocols suffer from the problem of elevated one-hop link disconnection, high end-to-end delay and low throughput even at normal vehicle speed in high vehicle density environment. This paper proposes a Geographic Distance Routing protocol based on Segment vehicle, Link quality and Degree of connectivity (SLD-GEDIR). The protocol selects a reliable NHV using the criteria segment vehicles, one-hop link quality and degree of connectivity. The proposed protocol has been simulated in NS-2 and its performance has been compared with the state-of-the-art protocols: P-GEDIR, J-GEDIR and V-GEDIR. The empirical results clearly reveal that SLD-GEDIR has lower link disconnection and end-to-end delay, and higher throughput as compared to the state-of-the-art protocols. It should be noted that the performance of the proposed protocol is preserved irrespective of vehicle density and spee

PDPD: Packet Delivery Prediction-based Data Forwarding to Moving Targets in Vehicular Networks

Department of Electrical EngineeringVehicular Ad hoc Network (VANET) is one of technologies to realize various ITS services that provide safe driving and efficient traffic condition. VANET consists of moving nodes, and hence its topology frequently changes. In VANETs, multi-hop data delivery is complicated by the fact that vehicular networks are highly mobile and frequently disconnected. In this thesis, we develop a novel forwarding scheme that accounts for the vehicle density, and delivers packets in a reliable and timely manner. We pay attention to the encounter event between two vehicles and the probability of successful transmission at the encounter place to guide forwarding decision. The proposed forwarding scheme uses traffic statistics to predict vehicle encounters, and optimize forwarding decision by taking into consideration the quality of wireless communications. We verify the results through simulations and show that our proposed scheme achieves reliable data transmission in VANET.ope

Inter Vehicle Distance based connectivity aware routing in vehicular adhoc networks

Connectivity in vehicular traffic environment has witnessed significant attention due to the direct impact on the performance of most of the traffic safety applications of intelligent transport system. Various parameters such as density, speed, direction, link quality and inter vehicle distance (IVD) have been utilized for measuring connectivity. IVD has greater impact on connectivity and controls the impact of other parameters. Usage of real time IVD for measuring connectivity has not received sufficient attention in VANETs. This paper proposes IVD based connectivity aware routing (Ivd-CAR) for enhancing connectivity aware data dissemination. IVD calculation is robust and can effectively handle instantaneous GPS failure. Two localization techniques; namely, cooperative localization and Geometry based Localization are developed. Standard deviation of real time IVDs of a forwarding path is derived. Distribution of IVDs of a forwarding path is employed for estimating connectivity. Segment vehicle based next hop vehicle selection is utilized for incorporating network load, link quality and direction into consideration while selecting forwarding path. Simulations are carried out in ns2 to evaluate the performance of Ivd-CAR in realistic traffic environment. Comparative analysis of simulation results attests the superiority of Ivd-CAR to the state-of-the-art techniques: CSR and A-CAR

TDMP-Reliable Target Driven and Mobility Prediction based Routing Protocol in Complex VANET

Vehicle-to-everything (V2X) communication in the vehicular ad hoc network (VANET), an infrastructure-free mechanism, has emerged as a crucial component in the advanced Intelligent Transport System (ITS) for special information transmission and inter-vehicular communications. One of the main research challenges in VANET is the design and implementation of network routing protocols which manage to trigger V2X communication with the reliable end-to-end connectivity and efficient packet transmission. The organically changing nature of road transport vehicles poses a significant threat to VANET with respect to the accuracy and reliability of packet delivery. Therefore, a position-based routing protocol tends to be the predominant method in VANET as they overcome rapid changes in vehicle movements effectively. However, existing routing protocols have some limitations such as (i) inaccurate in high dynamic network topology, (ii) defective link-state estimation (iii) poor movement prediction in heterogeneous road layouts. In this paper, a target-driven and mobility prediction (TDMP) based routing protocol is therefore developed for high-speed mobility and dynamic topology of vehicles, fluctuant traffic flow and diverse road layouts in VANET. The primary idea in TDMP is that the destination target of a driver is included in the mobility prediction to assist the implementation of the routing protocol. Compared to existing geographic routing protocols which mainly greedily forward the packet to the next-hop based on its current position and partial road layout, TDMP is developed to enhance the packet transmission with the consideration of the estimation of inter-vehicles link status, and the prediction of vehicle positions dynamically in fluctuant mobility and global road layout.Comment: 35 pages,16 Figure

An Efficient Routing Mechanism for Vehicular Ad Hoc Networks

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

An Ant Colony Optimization based Routing Techniques for VANET

With number of moving vehicles, vehicular Ad Hoc Network (VANET) is formed. These are provided with the wireless connections. Among various challenges in the VANET such as security and privacy of the messages, data forwarding is also considered as a major challenge. The effective communication is mainly depends on the how safely and fast the data is being forwarded among the vehicles. Data forwarding using Greedy mechanism suitable for routing in the VANETs, it depends only on the position of nodes and also data forwarding is done with minimum number of hops. In this paper, Position based GPCR and topology based DYMO routing protocol are adapted to make the use of Ant Colony Optimization (ACO) procedures. The resulting bio-inspired protocols, ACO_GPCR and ACO_DYMO had its performance evaluated and compared against existing GPCR and DYMO routing protocols. The obtained results suggest that making the use of ACO algorithm make these protocols more efficient in terms of Delay, Jitter, Packet Delivery Ratio and energy consumption