Routing Protocols in a Ad-hoc Networks For Message Scattering

Abstract

Ad-Hoc Network

Vehicular ad-hoc networks (VANETs) technology has emerged as an important research area over the last few years. Being ad-hoc in nature, VANET is a type of networks that are created from the concept of establishing a network of cars for a specific need or situation. VANETs have now been established as reliable networks that vehicles use for communication purpose on highways or urban environments. Because of constraint roads and very high speed of vehicles routing is an issue in VANET.

Introduction

Although nowadays wireless networks are a regular and familiar framework for sharing information among devices, the way in which these nets are organized and managed is evolving day by day due to the requirements of the scenarios in which they are deployed.

Many of the wireless networks that we use daily at home, at the office or when we use a cellular are based on those first approaches, in which an Access Point is needed to have connectivity. These setups are called ‘Infrastructure Mode’ and use a fixed and wired backbone to address information from the source Access Point (AP) to the destination AP. on the Other hands, The Network allowing the nodes of a network to routing and forwarding information for other nodes, without relying on a centralized administrator. These types of networks are called wireless ad hoc networks.

Infrastructure and Ad-hoc Network

MANETs Characteristics

Mobile Ad hoc Networks (MANETs), that is, wireless networks with a dynamic shape, a shifting number of nodes, a defined bandwidth and other characteristics, where the nodes can be any kind of devices with communications and networking capability that communicate with each other without a centralized coordinator. In this scenario, each node can play the role of a router, hosting the network topology dynamically, because as it was mentioned above, the shape and the topology of the net can change as well as the nodes on it. The main characteristics of MANETs can be summarized as follows:

Dynamic topologies: network topology can change quickly due to the nodes can move freely in the net.      Bandwidth constraints: compare with wired networks, the capacity of a MANET is relatively small and also it is sensitive to interferences, noise, and signal fading effect.     Energy constraints: although many of the nodes can be plugged to the power line or they can be equipped with big batteries, some of them use small power supplies, so during the network design it is necessary to consider how to save power in order to assure the stability and longevity of the network.    Limited physical security: although the decentralized nature of MANETs provides robustness against the single points of failure, these nets must be protected against eavesdropping, spoofing, and the injection of malicious data attacks. Related Works

One of the major developments towards smart driving experience is Intelligent Transportation Systems (ITS). Intelligent Transportation Systems (ITS) aim to streamline the operation of vehicles, manage vehicle traffic, assist drivers with safety and other information. It adds information and communications technology to vehicles and transportation infrastructures, in an effort to improve their reliability, quality, efficiency, and safety. Some of the existing techniques for traffic monitoring are as follows:

• Magnetic Loops
• Camera-Based System
• Infrared Detectors
• Ultrasonic Detectors

Routing Protocols in Vehicular Ad-hoc network for message Scattering

Movements of vehicles are described in the form of distinct clusters, which is also an observable scene. Therefore, V2V communication within a single group of vehicles depends on the range of wireless coverage being used; commonly deal with physical aspects of the networks. When it comes to the inter-networking, more generic - inter-cluster communication, where source vehicle from a group is unreachable in contact with destination vehicle from other (could be same) group creates the communication discontinuity. To overcome the problem like these terminations, various routing protocols are employed for continuous V2V communication manageability purposes. Hence, the concept of hopping where destinations achieved by mean of relying on other intermediate node is used specifically.

The scope of this work is limited to SIFT (Simple Forwarding over Trajectory), and DREAM (Distance Routing Effect Algorithm for Mobility) routing mechanisms. To make a realistic approach to most of the VANET researchers prefer, a real mobility model already discussed which is used for carrying a comparative simulation study. According to similar author’s viewpoint, routing schemes for actual ad hoc networks (MANET) are not suitable for vehicular ad hoc networks (VANET). Hence the location-based schemes like SIFT and DREAM are more appropriate for such scenarios for enhanced efficiency. Further within these schemes certain issues like low-connectivity zone, spatial-awareness, and others are discussed and studied through simulations. At the end of conclusive remark, SIFT wins the game for efficiently resolving these issues. In addition, the considerations of routing in large scale are further studied. With the help of all these major interrelated sections of mobility and routing explored in this literature review, a formal methodology is derived to consider the overall aspects of mobility and reliability with different VANET routing schemes in a pragmatic simulation environment with the help of NS2.

Performance Evaluation

In the position-based routing protocol, the forwarding dissemination decisions are based on location information. This approach makes sense because in VANETs the movements of the vehicles are usually restricted in just bidirectional movements constrained along roads and streets, and the geographical location information of vehicles is taken from street maps, traffic models or even more prevalent navigational systems onboard the vehicles. This approach makes sense because in VANETs the movements of the vehicles are usually restricted in just bidirectional movements constrained along roads and streets, and the geographical location information of vehicles is taken from street maps, traffic models or even more prevalent navigational systems onboard the vehicles. This protocol is commonly used with multi-hop communications and therefore, nodes usually forward the packet to a node that is geographically closest to the destination.