Download Simulation was carried out with the help of ns 2.29

International Conference On Emerging Trends In Engineering, 14th October 2012
ICETIE/154
Performance Evaluation of Reactive Routing
Protocols for Mobile Ad hoc Network
Harish Rohil1, Seema Nandal2
Assistant Professor, Department of Computer Science and Application
Chaudhary DeviLal University, Sirsa1
Research Scholar Mtech., Department of Computer Science and Application
Chaudhary DeviLal University, Sirsa2
[email protected] ,[email protected]
Abstract- Mobile Ad hoc Network (MANET) is a collection
of mobile nodes that are arbitrarily located so that the
interconnections between nodes are dynamically changing.
In MANET mobile nodes forms a temporary network
without the use of any existing network infrastructure or
centralized administration. A routing protocol is used to
find routes between mobile nodes to facilitate
communication within the network. The main goal of such
an ad hoc network routing protocol is to establish correct
and efficient route between a pair of mobile nodes so that
messages delivered within the active route timeout interval.
Route should be discovered and maintained with a
minimum of overhead and bandwidth consumption.
Routing is a critical issue in MANET. Most of the on
demand routing protocols for Manets namely AODV and
DSR perform well with uniform output under low network
load, mobility, traffic sources. This paper presents
performance evaluation of each of these protocols under
large number of traffic sources, greater mobility with lesser
pause time and varying offered load. Also the metrics taken
into account are: Average throughput, End to end delay,
Packet delivery ratio. On the basis of the obtained results
the performances of the above-mentioned on demand
routing protocols for Manet is compared using network
simulator-2 (NS2).
Index Terms- MANET, DSR, AODV, Throughput, Average
end-to-end delay, Packet delivery ratio
I.
INTRODUCTION
Mobile Ad-hoc networks (MANETs) consist of a set of
mobile
nodes
operating
without
centralized
administration communicating over a wireless interface.
The field of mobile ad-hoc networking grew out of packet
radio networks. In MANETs, the nodes are selforganized; they may move and join or leave the network
without central controlling entities (e.g. access points or
base stations). In MANETs multihop scenario occurs,
where the packets sent by the source host reaches
destination host through several intermediate hosts.
Dynamic discovery is done by individual node so for
direct communication with other node. MANET
applications are now a days used especially in military
and in emergencies, entertainments and outdoor business
environments where centralized administration is difficult
and expensive to install. One of the important research
areas in MANET is establishing and maintaining the ad
hoc network through the use of routing protocols.
Though there are so many routing protocols available,
this paper considers DSR and AODV for performance
comparisons due to varying offered load. The purpose of
simulation is to observe that how these protocols affect
the performance of networks in Random way point
model. Performance evaluation of these protocols is
carried out with respect to parameters – Throughput,
Packet delivery ratio, End to End delayand the effect of
varying number of mobile nodes is also considered in the
evaluation since no such analysis is available in the
literature.
II.
RELATED WORK
Shrestha, F. Tekiner et al [3] used Random mobility and
scalability aspects to analyze the performance of the
AODV, OLSR and TORA routing protocol. OPNET
modeler 14.5 is used for simulation. Throughput analysis
of the selected protocols concluded TORA shows poor
throughput than AODV and OLSR. AODV resulted in
good efficiency over heavy traffic than OLSR and
TORA. Ashish K. Maurya, Dinesh Singh et al [4]
evaluated performance of AODV, DSR and ZRP routing
protocol with respect to pause time. AODV shows best
performance when compared with DSR and ZRP in
terms of packet delivery ratio and throughput. AODV
delivers more than 60 percent of all CBR packets when
network is presented as a function of pause time.
Performance may vary by varying the network and can
ICETIE/154
International Conference On Emerging Trends In Engineering, 14th October 2012
show different results when compared with different
network scenarios.
S. Sathish, K. Thangavel and S. Boopathi et al [6]
presented a performance comparison of DSR, AODV,
FSR and ZRP routing protocols for mobile Ad-hoc
networks as a function of pause time. DSR shows best
performance than AODV, FSR and ZRP in terms of
packet delivery ratio and throughput as a function of
pause time. FSR show lowest end-to-end delay and ZRP
has less average jittering than DSR, AODV and FSR.
DSR and AODV performed the worst in case of average
jitter and ZRP performed the worst in case of throughput.
Samir R. Das and Jiangtao Yan et al [7] evaluate several
routing protocols for manet with respect to fraction of
packets delivered, end-to-end delay, and routing load for
a given traffic and mobility model. The proactive,
shortest path protocols provide excellent performance in
terms of end-to- end delays and packet delivery fraction,
however, at the cost of higher routing load. The ondemand protocols suffer from suboptimal routes as well
as worse packet delivery fraction because of more
dropped data packets. However, they are significantly
more efficient in terms of the routing load.
III.
OVERVIEW OF MANET ROUTING
PROTOCOLS
Proactive (table driven) Routing Protocols
Proactive routing protocols maintain the routing
information of all the participating nodes and update
their routing information frequently irrespective of the
routing requests. Proactive routing protocols transmit
control messages to all the nodes and update their routing
information even if there is no actual routing request.
This makes proactive routing protocols bandwidth
deficient, though the routing itself is simple having this
prior updated routing information. The major drawback
of proactive protocols is the heavy load created from the
need to flood the network with control messages.
Reactive (On demand) Protocols
Reactive protocols establish the route only when it is
required unlike the proactive protocols these protocols do
not update their routing information frequently and will
not maintain the network topology information. Reactive
protocols use the connection establishment process for
communication. Few pitfalls are noticed in these reactive
protocols such as these generally have high latency in
searching the network. In finding the routes if there is
excessive flooding over the network with route request
packets it may result in network clogging.
a. Dynamic Source Routing
Dynamic source routing protocol (DSR) is a
reactive protocol that is known as simple and efficient,
specially designed for the multi-hop mobile ad hoc
network. Often called “On-demand” routing protocol as
it involves determining the routing on demand unlike the
pro- active routing protocols that has periodic network
information. Network nodes use multiple- hops to
communicate, DSR protocol plays a key role in
determining and maintaining all the routing
automatically as the number of hops needed changes at
anytime and the mobile nodes involved may leave or join
the network. DSR protocol involves two major
mechanisms to establish the routing process. These are
route discovery and route maintenance.
Route Discovery
Route discovery is the process of DSR uses to find the
route and to transmit the data from a source to
destination where the source node is unaware of the
destination route.
 Initially source node transmits 'RREQ' (Route
Request) will usually be received by all the
participating nodes in the network.
 This Route request contains information about
the source and the destination along with unique
request identification.
 RREQ even maintains the information about all
the intermediate nodes passed by while reaching
the destination.

‘RREP’ contains a copy of the route
information of the RREQ then the source cache
information to use in further communication
process.
Route Maintenance
DSR protocol implements the route maintenance
mechanism while communicating the packets from
source to destination. But when the communication link
between the source and the destination is broken or else a
change in network topology is noticed. It will lead to
failure of the communication between source node and
destination node. If the route maintenance fails to find an
alternative known route to establish the communication
then it will invoke the route discovery to find the new
route to destination.
b. AODV(Ad-hoc on demand distance vector)
International Conference On Emerging Trends In Engineering, 14th October 2012
ICETIE/154
AODV is an on-demand routing protocol. The AODV
algorithm gives an easy way to get change in the link
situation. For example if a link fails notifications are sent
only to the affected nodes in the network. This
notification cancels all the routes through this affected
node. It builds unicast routes from source to destination
and that’s why the network usage is least. Since the
routes are build on demand so the network traffic is
minimum. AODV does not allow keeping extra routing
which is not in use. If two nodes wish to establish a
connection in an ad hoc network then AODV is
responsible to enable them to build a multihop route.
AODV uses Destination Sequence Numbers (DSN) to
avoid counting to infinity that is why it is loop free. This
is the characteristic of this algorithm. When a node send
request to a destination, it sends its DSNs together with
all routing information. It simply means that the AODV
not blindly forwarded every message. The number of
hops of routing messages in ad hoc network is
determined by Time-To-Live (TTL) in the IP header.
This information will be used to make a reverse path for
RREP message from the destination node. When a link is
failed an RERR message is generated. RERR message
contains information about nodes that are not reachable.
IV.
SIMULATION RESULT AND ANALYSIS
Simulation was carried out with the help of ns 2.29
simulator. Three scenarios were considered to analyze
Average Throughput, End-to-End delay and packet
delivery ratio with varying traffic load and network load.
Each of the mobile nodes select a random destination at
the specified time and moves towards it. The simulation
ends just one second before the total simulation time,
which is taken to be 400 seconds. When the packet size
was further increased to 2048 bytes, there was a lot of
network congestion and both of the protocols failed to
deliver any results.
Following table gives a glance of the simulator
parameters.
Mobility Model
Random way point
Simulation time
400s
Protocols
DSR,AODV
No. of Mobile Nodes
40,80,100
No. of Traffic sources
20,27,30
Type of traffic
TCP
Nodes Speed
(0-20) m/s
Table 1.
a.
Packet Delivery Ratio: Packet delivery ratio is
the fraction of packets sent by the application
that are received by the receivers and is
calculated by dividing the number of packets
received by the destination through the number
of packets originated by the application layer of
the source. For better performance of a routing
protocol, it should be better [16]. Packet
delivery ratio decreases as the packet size
increases. AODV shows better results than DSR
as the packet size increases.
Figure 1
b.
Average Throughput
The throughput is defined as the total amount of data a
receiver receives from the sender divided by the time it
takes for the receiver to get the last packet. The
throughput is measured in bits per second (bit/s or bps)
[15]. One can clearly notice that the average throughput
of generating packets for AODV increases as the packet
size keeps increasing.
International Conference On Emerging Trends In Engineering, 14th October 2012
ICETIE/154
REFERENCES
[1]
[2]
[3]
[4]
Figure 2.
c.
End-to-End delay:
End-to-end delay indicates how long it a packet takes to
travel from the CBR source to the application layer
of the destination. [14]. This graph shows that average
simulation end to end delay of DSR goes on increasing
as the packet size increases.
V.
CONCLUSIONS AND FUTURE SCOPE
On the basis of result, it was concluded that as the packet
size is increased the end-to-end delay of AODV is lesser
than that of DSR for larger number of nodes; average
throughput of generating packets for DSR is larger than
that of AODV for larger number of Nodes and traffic
sources. However the average throughput of generating
packets for AODV is greater when the numbers of nodes
are 40 and 80. Delay is an important metric which
decides the efficiency of the routing protocol. DSR
(Dynamic source routing) protocol is not a winner when
it comes to the large size of the network. The end-to-end
delay is increased when the packet size is increased. The
degraded performance might be because of the
aggressive use of caching. We need to evaluate these
protocols AODV, DSR using different mobility models:
Reference Point Group Mobility, Freeway, Manhattan.
Also none of these protocols have any mechanism for
load balancing, so there is much scope related to this
work.
[5]
[6]
[7]
[8]
[9]
[10]
[11]
C.Sivaram murthy, B.S.Manoj, “Adhoc wireless
networks: Architectures, and protocols”, Pearson
Education, 2004.
D. Johnson, D. Maltz and Yih-Chun Hu. “The
Dynamic Source Routing Protocol for Mobile Ad Hoc
Networks,”http://www.ietf.org/internetdrafts/draftietfmanet- DSR- 09.txt, IETF Internet
draft, Apr. 2003.
F. Tekiner, A. Shrestha, "On Manet Routing
Protocols for Scalability and Mobility", PDCAT ,911 Hiroshima, Japan, December 2009.
Ashish K. Maurya , Dinesh Singh, “Simulation based
Performance Comparison of AODV, FSR and ZRP
Routing Protocols in MANET ”, International Journal
of Computer Applications (0975 – 8887) Volume 12–
No.2, November 2010.
Ayyaswamy Kathirvel, and Rengaramanujam
Srinivasan “Analysis of Propagation Model using
Mobile Ad Hoc Network Routing Protocols”,
International Journal of Research and Reviews in
Computer Science (IJRRCS), Vol. 1, No. 1,2007.
S. Sathish, K. Thangavel and S. Boopathi,
“Performance Analysis of DSR, AODV, FSR and
ZRP Routing Protocols in MANET”, MES Journal of
Technology and Management, 2010.
Samir R. Das, Robert C. and Jiangtao Yan, “
Simulation-based performance evaluation of routing
protocols for mobile ad hoc networks”, Mobile
Networks and Applications 179–189, 2000.
Idris Skloul Ibrahim A. Etorban Dr Peter J.B King,
“Multipath Distance Vector Zone Routing Protocol
for Mobile Ad-Hoc Networks MDVZRP,” PGnet
2008, John Moores University, pages 171-176, July
2008.
T. Camp, J. Boleng, and V. Davies, “A survey of
mobility models for ad hoc network research,”
Wireless Communication and Mobile Computing
(WCMC): Special issue on Mobile Ad Hoc
Networking Research, Trends and Applications, vol.
2, no. 5,pp. 483–502, 2002.
NS -2, The ns Manual, Available at http: //www.
isi.edu/nsnam/ns/doc.
David Oliver Jorg, “Performance Comparison of
MANET Routing Protocols In Different Network
Sizes”, Computer Science Project, Institute of
Computer Science and Applied Mathematics.