scholarly journals Collision Avoidance Method Using Vector-Based Mobility Model in TDMA-Based Vehicular Ad Hoc Networks

2020 ◽  
Vol 10 (12) ◽  
pp. 4181 ◽  
Author(s):  
Jung-Hyun Bang ◽  
Jung-Ryun Lee

The rapid development of wireless technology has accelerated the development of Vehicular Ad Hoc Networks (VANETs) to support accident prevention and the safety of a vehicle driver. VANET is a form of Mobile Ad Hoc Network (MANET), and it differs from MANET in that the network topology of a VANET changes dynamically in response to the high mobility of a vehicle and the unstable link quality due to various types of road patterns. Since most access and merging conflicts occur due to vehicle movement patterns and traffic conditions, the collision rate can be reduced if each vehicle can predict the location, movement direction, and resource occupancy information of other vehicles. In this paper, we propose a collision avoidance method based on the vehicle mobility prediction model in TDMA-based VANET. The proposed algorithm allocates time-slots of TDMA to avoid access and merging collisions by predicting the mobility of nearby vehicles using control time-slot occupancy information, vehicle ID, hop information, vehicle movement direction, and longitude and latitude of a vehicle. Simulation results show that the proposed algorithm can reduce access and merging collision rates compared with other legacy algorithms, and the performance gain of the proposed algorithm is enhanced in road environments when traffic density is high and where vehicles have high mobility and change their travel directions frequently.

2017 ◽  
Vol 63 (3) ◽  
pp. 309-313 ◽  
Author(s):  
C. Suganthi Evangeline ◽  
S. Appu

Abstract A special type of Mobile Ad-hoc Networks (MANETs) which has frequent changes of topology and higher mobility is known as Vehicular Ad-hoc Networks (VANETs). In order to divide the network into groups of mobile vehicles and improve routing, data gathering, clustering is applied in VANETs. A stable clustering scheme based on adaptive multiple metric combining both the features of static and dynamic clustering methods is proposed in this work. Based on a new multiple metric method, a cluster head is selected among the cluster members which is taken from the mobility metrics such as position and time to leave the road segment, relative speed and Quality of Service metrics which includes neighborhood degree, link quality of the RSU and bandwidth. A higher QoS and cluster stability are achieved through the adaptive multiple metric. The results are simulated using NS2 and shows that this technique provides more stable cluster structured with the other methods.


2020 ◽  
Vol 5 (1) ◽  
pp. 56-63
Author(s):  
Chi-Fu Huang ◽  
Jyun-Hao Jhang

Due to advances in wireless communication technologies, wireless transmissions gradually replace traditional wired data transmissions. In recent years, vehicles on the move can also enjoy the convenience of wireless communication technologies by assisting each other in message exchange and form an interconnecting network, namely Vehicular Ad Hoc Networks (VANETs). In a VANET, each vehicle is capable of communicating with nearby vehicles and accessing information provided by the network. There are two basic communication models in VANETs, V2V and V2I. Vehicles equipped with wireless transceiver can communicate with other vehicles (V2V) or roadside units (RSUs) (V2I). RSUs acting as gateways are entry points to the Internet for vehicles. Naturally, vehicles tend to choose nearby RSUs as serving gateways. However, due to uneven density distribution and high mobility nature of vehicles, load imbalance of RSUs can happen. In this paper, we study the RSU load-balancing problem and propose two solutions. In the first solution, the whole network is divided into sub-regions based on RSUs’ locations. A RSU provides Internet access for vehicles in its sub-region and the boundaries between sub-regions change dynamically to adopt to load migration. In the second solution, vehicles choose their serving RSUs distributedly by taking their future trajectories and RSUs’ loading information into considerations. From simulation results, the proposed methods can improve packet delivery ratio, packet delay, and load balance among RSUs.


Author(s):  
Anant Ram

Background: VANETs (Vehicular Ad-Hoc Networks) are the subclass of MANETs, which has recently emerged. Due to its swift changing topology and high mobility nature, it is challenging to design an efficient routing protocol for routing data amongst both moving vehicles and stationary units in VANETs. In addition, the performance of existing routing protocols is not effective due to high mobility characteristics of VANETs. Methods: In this paper, we proposed link reliable routing strategy that makes use of restricted greedy forwarding by considering neighborhood vehicles density and the least, average velocity with its own neighboring vehicles for the selection of next forwarder. Result: The proposed approach take the assumption that at every junction the police patrolling car (i.e. PCR junction node), which forwards the packet to vehicle onto correct road segment only. The link reliability is ensured by the mechanism for the selection of the next forwarder. Conclusion: The objective of this paper is to increase route reliability to provide increase throughput without greatly affecting end-to-end delay. The simulation results reveal that the proposed approach Reliable GPSR(R-GPSR) outperforms existing GPSR and E-GyTAR approach.


2013 ◽  
Vol 11 (1) ◽  
pp. 89-103 ◽  
Author(s):  
R. Oliveira ◽  
M. Luísa,b ◽  
A. Furtadoa ◽  
L. Bernardoa ◽  
R. Dinisa,b ◽  
...  

Author(s):  
Kashif Naseer Qureshi ◽  
Abdul Hanan Abdullah ◽  
Anwar Mirza ◽  
Raja Waseem Anwar

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.


Sign in / Sign up

Export Citation Format

Share Document