VANET

Afrah Salman
12/24/2015
Vehicle Ad-Hoc Network
(VANET)

1. Introduction
There are various types of networks have been developed due to recent
advances in hardware, software, and communication technologies. One such
network that has received a lot of interest in the last couple of years is the
Vehicular Ad-Hoc Network (VANET) that has become an active area of
research, standardization, and development because it has tremendous
potential to improve vehicle and road safety, traffic efficiency, and
convenience as well as comfort to both drivers and passengers.
Figure a: VANET System
2. Intelligent Transportation Systems (ITSs)
In intelligent transportation system, each vehicle takes on the role of
sender, receiver, and router to broadcast information to the vehicular network
or transportation agency, which then uses the information to ensure safe,
free-flow of traffic. For communication to occur between vehicles and Road

Side Units (RSUs), vehicles must be equipped with some sort of radio
interface or On Board Unit (OBU) that enables short-range wireless ad hoc
networks to be formed. Vehicles must also be fitted with hardware that
permits detailed position information such as Global Positioning System
(GPS) or a Differential Global Positioning System (DGPS) receiver.
Figure b: ITS in Vehicle
Though it is safe to assume that infrastructure exists to some extent and
vehicles have access to it intermittently, it is unrealistic to require that
vehicles always have wireless access to roadside units. Figures 1, 2 and 3
depict the possible communication configurations in intelligent
transportation systems. These include inter-vehicle, vehicle-to-roadside, and
routing-based communications. Inter-vehicle, vehicle-to-roadside, and
routing-based communications rely on very accurate and up-to-date
information about the surrounding environment, which, in turn, requires the
use of accurate positioning systems and smart communication protocols for
exchanging information.
Forward radar
Computing platform
Event data recorder (EDR)
Positioning system
Rear radar
Communication
facility
Display
(GPS)
Human-Machine Interface

2.1. Inter-Vehicle Communication (IVC)
The IVC, also called Vehicle-to-Vehicle Communication (V2V), uses
multi-hop multicast/broadcast to transmit traffic related information over
multiple hops to a group of receivers.
2.2. Vehicle-to-Roadside Communication (V2R)
The V2R communication configuration, also called Vehicle-to-
Infrastructure (V2I) communication, (Figure 2) represents a single hop
broadcast where the roadside unit sends a broadcast message to all equipped
vehicles in the vicinity.

2.3. Routing-Based Communication
The routing-based communication configuration (Figure 3) is a multi-hop
unicast where a message is propagated in a multi-hop fashion until the
vehicle carrying the desired data is reached.
3. Routing
Routing in VANET has been studied and investigated widely in the past
few years. Since VANETs are a specific class of ad hoc networks, the
commonly used ad hoc routing protocols initially implemented for MANETs
have been tested and evaluated for use in a VANET environment. Use of
these address-based and topology-based routing protocols requires that each
of the participating nodes be assigned a unique address. This implies that we
need a mechanism that can be used to assign unique addresses to vehicles
but these protocols do not guarantee the avoidance of allocation of duplicate
addresses in the network. Thus, existing distributed addressing algorithms
used in mobile ad-hoc networks are much less suitable in a VANET
environment. VANET uses the following protocols:

1) Proactive Routing Protocols
 These are based on shortest path algorithms.
 The information in this routing is in the form of tables.
 Proactive algorithms: a. Link-state routing (e.g. OLSR)
b. Distance-vector routing (e.g. DSDV)
2) Reactive Routing Protocols
 It is developed to overcome the overhead that was created by
the proactive routing protocols.
 Route discovery can be done by sending RREQ (Route
Request).
 Reactive routing can be classified either as source routing or
hop-by-hop routing.
3) Position-Based Routing
 Uses positions of nodes to provide successful communication.
 It assumes that each node have knowledge about its physical/
geographic position by using determining services.
 It provides hop-by-hop communication to vehicular networks.

VANET

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (14)

Similar to VANET

Similar to VANET (20)

More from University of Technology - Iraq

More from University of Technology - Iraq (19)

Recently uploaded

Recently uploaded (20)

VANET