ISSUES OF ROUTING IN VANET

Presented by:

Dr. SK.Mastan Vali

ABSTRACT

This seminar deals with the different

routing concept that measures the performance of the

VANET. Vehicular Ad Hoc Network (VANET) is a sub class of

mobile ad hoc networks.

INTRODUCTION

VANET :- “provides wireless communication among vehicles and

vehicle to road side equipments.” The networks with the absence

of any centralized or pre-established infrastructure are called Ad

hoc networks

It is a sub-class of mobile ad hoc networks (MANET).

Used for safety , comfort and entertainment as well.

Figure 1: Vehicular Ad Hoc Network overview

AIMS AND OBJECTIVES

Aim is to identify which ad hoc routing method has

better performance in VANET.

To achieve this aim we have set the following objectives:

1. Finding problems with traditional MANET routing protocols

used in VANET.

2. Finding problems with various proposed routing techniques

for VANET.

3. Comparing performance results of both routing protocols.

TRADITIONAL AD HOC ROUTING

This ad hoc routing uses the theoretical analysis of

routing protocols for VANET.

1. Mobile ad hoc networks routing

2. Topology based routing

a. Proactive routing

b. Reactive routing

c. Hybrid routing

1. Mobile ad hoc networks Routing:

There is no fixed network topology

Adopt any runtime topology due to dynamic behaviour

Route discovery, Route maintenance, and sudden change in

the topology are major barriers in MANET.

2. Topology Based Routing:

It was developed to meet the dynamic nature of the ad hoc

networks

It uses link’s information within the network to send the data

packets

Proactive routing:

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)

Reactive Routing:

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.

Ad Hoc On Demand Distance Vector Routing (AODV) and

Dynamic Source Routing (DSR) are different types of Reactive

Routing protocols.

VANET ROUTING PROTOCOLS

Vehicular Ad hoc Network Routing:

High mobility, frequent changes in topology and limited life

time

Other factors such as road layout and different

environments

VANET uses position information of the participating nodes

within the network to take routing decisions.

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.

As compared to topology based routing, it uses the additional

information.

It provides hop-by-hop communication to vehicular networks.

It’s protocol consists of many major components. Those are:

a. Beaconing

b. Location Service and Servers

c. Recovery and Forwarding Strategies

i. restricted directional flooding

ii. hierarchal forwarding

iii. greedy forwarding

Greedy Perimeter Stateless Routing-GPSR:

- It is the best example of position based routing.

- Uses the nearest router ‘s information of destination to forward

packets.

- Helps the path with less interference of topology information.

- GPSR protocols divided into two groups:

1. Greedy Forwarding

2. Perimeter Forwarding

Geographic Source Routing (GSR):

- It fails in the presence of radio obstacles.

- It deals with high mobility of nodes and uses road layout to

discover routes.

- Uses Reactive Location Services(RLS) which combines both

geographic routing and road topology knowledge .

- Multiple hops, Routing Loops and Incorrect Route Selection.

Anchor-based Street and Traffic Aware Routing(A-STAR):

- It is also a Position based routing protocol.

- The drawback like effect of high mobility is overcome by A-

STAR.

- In this the address of the header is given to the all other nodes

that packet travels.

- This is called Anchor based Routing.

- It also deals with “Spatial Aware Routing”.

- It computes number of junctions using traffic information and

street awareness to find the path.

- A-STAR has two features that make it different from all other

protocols.

- A-STAR uses Statistically and Dynamically rated maps to find

number of junctions.

- Statistically Rated maps uses schedule of buses for high

connectivity.

- Dynamically Rated maps collect the latest information of traffic

in finding path.

CONCLUSION

The main goal is to identify different routing protocols

and to evaluate these routing protocols against each other in

VANET. Here, we suggest that Position based protocols are

more promising than Traditional ad hoc routing protocols for

VANET.

FUTURE WORK

In Wireless network community VANET received

attention of many researchers due to its unique nature. Here, we

only focused on the traditional and position based routing

protocols. But there some areas that need more attention. New

algorithms should be proposed to provide reliable QoS for safety

and comfort applications in VANET.