1

`

A PERFORMANCE EVALUATION OF PROACTIVE AND REACTIVE

PROTOCOLS USING NS2 SIMULATION

N.Karthikeyan1 Dr.V.Palanisamy2 Dr.K.Duraiswamy3

1 Research Scholar, Department of Computer Application,

SNS College of Technology, Coimbatore-641035, Tamilnadu, India.

Telephone: +91-422-2669118, Mobile: +91-98427 90907

E-Mail: kaartheekeyan@rediffmail.com 2 Principal, Info Institute of Engineering, Sathy Main Road, Coimbatore-641107.

3 Dean, K.S.Rangasamy College of Technology, Tiruchengode – 637215

Abstract

A mobile ad hoc network (MANET) is an infrastructure less, autonomous, and

standalone wireless network. The vision of mobile ad hoc network is to support

robust and efficient operation in mobile wireless networks by incorporating

routing functionality into mobile nodes. A mobile ad hoc network is the collection

of nodes which form the temporary network without the centralized body due to

constant changes in network topology. Each node in a MANET serves as a router

and performs mobility functionalities in an autonomous manner. Guaranteeing

delivery and the capability to handle dynamic connectivity are the most important

issues for routing protocols in mobile ad hoc networks. A number of routing

protocols have been proposed for this purpose like Ad Hoc On Demand Distance

Vector (AODV), Dynamic Source Routing (DSR) and Destination-Sequenced

2

Distance Vector(DSDV). In this paper the Reactive protocols DSR and AODV as

well as a Proactive Protocol DSDV were studied and their characteristics with

respect to different mobility are analyzed based on packet delivery fraction,

routing load, end-to-end delay, number of packets dropped, throughput and jitter

using Network Simulator (NS2) .

Keywords: MANET, Proactive and Reactive Routing Protocols

1. Introduction

In General, the network can be divided into two types based on their operation

namely infrastructure and infrastructure less. The infrastructure network (i.e. a

network with fixed and wired gateways) uses the fixed network topology and it

consists of nodes and base stations. The bridges of the network are known as base

stations. A mobile unit within the network connects the nearest base station for the

communication. In this infrastructure network, communication between nodes by

switching from one base station to another base station.

In infrastructure less network there are no such fixed infrastructures for nodes to

communicate with each other and each node acts as routers and cooperates with

other nodes for communication process. The Internet Engineering Task Force

created a MANET Working Group (WG) to deal with issues related to the

constructing MANET routing protocols. MANET [1] is a kind of wireless

network architecture that can be flexibly deployed in almost any environment

(e.g., conference rooms, forests, battlefields, disaster relief, vehicular services

such as transmission of news, road conditions, location award services,

emergency services, commercial environment, educational applications,

entertainment, sensor networks, home and enterprise networking etc.) without the

need of network infrastructure or centralized administration.

The fundamental difference between fixed networks and MANET is that the

computers in a MANET are mobile. Due to the mobility of these nodes, there are

some characteristics that are only applicable to MANET. Some of the key

3

characteristics are dynamic network topologies, bandwidth constrained links and

energy constrained operation. In real-time applications, such as audio, video, and

real-time data, the ad hoc networks need for Quality of Service (QoS) in terms of

delay, bandwidth, and packet loss is becoming important. Providing QoS in ad-

hoc networks is a challenging task because of dynamic nature of network

topology and imprecise state information. A mobile ad hoc network consists of

mobile nodes such as laptops, personal digital assistants and other devices which

use wireless connections for the purpose of communication. They have no fixed

routers and routes. All nodes are capable of moving and be connected in an

arbitrary manner. These nodes functions as routers, which discover and maintain

routes to other node in the network. The nodes are free to move around randomly,

thus changing the network topology dynamically. So the routing protocols must

be adaptive and be able to maintain routes in spite of changing network

connectivity.

In general routes between nodes in an ad hoc network may include multiple hops

and hence it is appropriate to call such networks as “multi-hop wireless ad-hoc

networks [2]”. Each node will be able to communicate directly with any other

node that resides within the transmission range. For communication with nodes

that reside beyond this range the node needs to use intermediate nodes to relay the

messages hop by hop. Ad hoc networks are useful in wide area of applications

such as military and other rescue application. Commercial applications are also

like where there is a need for ubiquitous communications without the presence of

fixed infrastructure.

2. Related Work

Several researchers have done the qualitative and quantitative analysis of Ad Hoc

Routing Protocols by means of different performance metrics. They have used

different simulators for this purpose.

4

♦ Samir R. Das , Charles E. Perkins et al. [3] evaluated the DSR and AODV on-

demand routing protocols with three performance metrics : Packet delivery

fraction, Average End-to-End Delay and Normalized routing load with varying

pause times. They have used ns-2 simulator. Based on the observations,

recommendations were made as to how the performance of either protocol can be

improved.

♦ J. Broch et al. [4], in their paper have compared the DSDV, TORA, DSR and

AODV Protocols using ns-2 simulator. The simulation was done with 50 nodes

with varying pause times. The results were obtained for the metrics: Packet

delivery ratio, Routing overhead, Number of hops taken by the packet to reach the

destination.

♦ Jyoti Raju and Garcia-Luna-Aceves [5], in their paper have compared WRP-Lite

a revised version of Wireless Routing Protocol with DSR. The performance

parameters used are end-end delay, control overhead, percentage of packets

delivered and hop distribution. The evaluation of the performance metrics was

done with respect to varying pause time. It was observed that WRP-lite has much

better delay and hop performance while having comparable overhead to DSR.

♦ Samir R. Das et al. [6] evaluated the performance of routing protocols with

respect to fraction of packets delivered, end-to-end delay, and routing load by

varying the number of conversation per node. The evaluation was done with 30

and 60 nodes using Maryland Routing Simulator. The protocols used in the

simulation are SPF, DSDV, TORA, DSR, AODV.

♦ Azzedine Boukerche [7] , in his paper has done the performance comparison of

AODV,CBRP and DSR Ad Hoc routing protocols using ns-2 simulator. The key

performance metrics evaluated in his experiments are Throughput, Average End-

to-end delay of data packets and Normalized routing overhead for different data

sources and varying pause times of mobile nodes. As per his observation DSR and

5

CBRP has high throughput than in comparison with AODV.CBRP has high

routing overhead than DSR.

3. Types of MANET Routing Protocols

MANET routing protocols are mainly developed to maintain route inside

MANET, and they do not utilize access points to make connection with other

nodes in the infrastructure network and Internet. Routing protocols can be

classified into different categories depending on their properties. The

classifications are

Centralized versus Distributed

Static versus Adaptive

Reactive versus Proactive

One way to categorize the routing protocols is to divide them into centralized and

distributed algorithms. In centralized algorithms, all route choices are made at a

central node, while in distributed algorithms, the computation of routes is shared

among the network nodes. In static algorithms, the route used by source

destination pairs is fixed regardless of traffic condition. It can only change in

response to a node or link failure. This type of algorithm cannot achieve high

throughput under a broad variety of traffic input patterns. In adaptive routing, the

routes used to route between source-destination pairs may change in response to

congestion. A third classification that is more related to ad-hoc networks is to

classify the routing algorithms as either proactive or reactive.

3.1 Proactive (Table-Driven) Routing Protocols

It maintain one or more routing tables in every node in order to store routing

information about other nodes in the MANET. These routing protocols attempt to

update the routing tables information either periodically or in response to change

in network topology in order to maintain consistent and up-to-date routing

6

information. The advantage of these protocols is that a source node does not need

a route-discovery procedures to find a route to a destination node. The drawback

of these protocols is that maintaining a consistent and up-to-date routing table

requires substantial messaging overhead, which consumes bandwidth and power

uage, and decreases throughput, especially in the case of a large number of high-

mobility mobile nodes. The different types of Table driven protocols are:

Destination Sequeced Distance Vector routing(DSDV), Wireless routing protocol

(WRP), Fish eye State Routing protocol (FSR), Optimised Link State Routing

protocol (OLSR), Cluster Gateway switch routing protocol (CGSR), Topology

Dissemination Based on Reverse path forwarding (TBRPF).

3.2 Reactive (On-Demand) Routing Protocols

It initiate a route discovery mechanism by the source node to discover the route to

the destination node when the source node has data packets to send to the

destination node. After discovering the route, the route maintenance is initiated to

maintain this route until the routes no longer required or the destination is not

reachable.The main advantage of these protocols is that overhead messaging is

less. One of the drawbacks of these protocols is the delay of discovering a new

route. The different types of Reactive routing protocols are : Dynamic Source

Routing (DSR) , Ad hoc On-Demand Distance Vector routing (AODV) and

Temporally Ordered Routing Algorithm(TORA).

3.3 Dynamic Source Routing (DSR)

The Dynamic Source Routing protocol (DSR) [8] is a simple and efficient routing

protocol designed specifically for use in multi-hop wireless ad hoc networks of

mobile nodes. Using DSR, the network is completely self-organizing and self-

configuring, requiring no existing network infrastructure or administration.

Network nodes cooperate to forward packets for each other to allow

communication over multiple "hops" between nodes not directly within wireless

transmission range of one another. The DSR protocol is composed of two main

7

mechanisms that work together to allow the discovery and maintenance of source

routes in the ad hoc network.Route Discovery is the mechanism by which a node

S wishing to send a packet to a destination node D obtains a source route to D.

Route Discovery is used only when S attempts to send a packet to D and does not

already know a route to D. Route Maintenance is the mechanism by which node S

is able to detect, while using a source route to D, if the network topology has

changed such that it can no longer use its route to D because a link along the route

no longer works. When Route Maintenance indicates a source route is broken, S

can attempt to use any other route it happens to know to D, or it can invoke Route

Discovery again to find a new route for subsequent packets to D. When a node

requires a route to a destination, which it doesn’t have in its route cache, it

broadcasts a Route Request (RREQ) message, which is flooded throughout the

network. The first RREQ message is a broadcast query on neighbors without

flooding. Each RREQ packet is uniquely identified by the initiator’s address and

the request id. A node processes a route request packet only if it has not already

seen the packet and its address is not present in the route record of the packet.

This minimizes the number of route requests propagated in the network. RREQ is

replied by the destination node or an intermediate node, which knows the route,

using the Route Reply (RREP) message. The return route for the RREP message

may be one of the routes that exist in the route cache (if it exists) or a list reversal

of the nodes in the RREQ packet if symmetrical routing is supported. In other

cases the node may initiate it owns route discovery mechanism and piggyback the

RREP packet onto it. Thus the route may be considered unidirectional or

bidirectional. DSR doesn’t enforce any use of periodic messages from the mobile

hosts for maintenance of routes. There are two types of packets for route

maintenance: Route Error (RERR) packets and ACKs. Whenever a node

encounters fatal transmission errors so that the route becomes invalid, the source

receives a RERR message. The source node then removes the erroneous hop from

all of its route cache entries, and selects a new route, or if there are no more

8

available routes, it initiates a new route discovery. ACK packets are used to verify

the correct operation of the route links. This also serves as a passive

acknowledgement for the mobile node.

3.4 Ad-hoc On Demand Distance Vector (AODV)

The AODV [9,10] routing protocol is a reactive routing protocol; therefore, routes

are determined only when needed. The following messages are used in AODV

protocol: Hello message, Route Request(RREQ) message, Route Reply(RREP),

and Route Error(RERR) message. Hello messages may be used to detect and

monitor links to neighbors. If Hello messages are used, each active node

periodically broadcasts a Hello message that all its neighbors receive. Because

nodes periodically send Hello messages, if a node fails to receive several Hello

messages from a neighbor, a link break is detected. When a source has data to

transmit to an unknown destination, it broadcasts a Route Request (RREQ) for

that destination. At each intermediate node, when a RREQ is received a route to

the source is created. If the receiving node has not received this RREQ before, is

not the destination and does not have a current route to the destination, it

rebroadcasts the RREQ. If the receiving node is the destination or has a current

route to the destination, it generates a Route Reply (RREP). The RREP is unicast

in a hop-by-hop fashion to the source. As the RREP propagates, each intermediate

node creates a route to the destination. When the source receives the RREP, it

records the route to the destination and can begin sending data. If multiple RREPs

are received by the source, the route with the shortest hop count is chosen. As data

flows from the source to the destination, each node along the route updates the

timers associated with the routes to the source and destination, maintaining the

routes in the routing table. If a route is not used for some period of time, a node

cannot be sure whether the route is still valid; consequently, the node removes the

route from its routing table. If data is flowing and a link break is detected, a Route

Error (RERR) is sent to the source of the data in a hop-by-hop fashion. As the

RERR propagates towards the source, each intermediate node invalidates routes to

9

any unreachable destinations. When the source of the data receives the RERR, it

invalidates the route and reinitiates route discovery if necessary.

3.5 Destination Sequenced Distance Vector(DSDV)

DSDV [11] is a Table driven routing protocol based on the classical Bellman-Ford

routing algorithm. The improvement made to the Bellman-Ford algorithm

includes freedom from loops in routing tables by using sequence numbers. In this

routing protocol, each mobile node in the system maintains a routing table in

which all the possible destinations and the number of hops to them in the network

are recorded. A sequence number is also associated with each route/path to the

destination. The route labeled with the highest sequence number is always used.

This also helps in identifying the stale routes from the new ones, thereby avoiding

the formation of loops. Also, to minimize the traffic generated, there are two types

of packets in the system. One is known as “full dump”, which is a packet that

carries all the information about a change. However, at the time of occasional

movement, another type of packet called “incremental” will be used, which will

carry just the changes, thereby, increasing the overall efficiency of the system.

The data broadcast by each mobile node will contain the new sequence number,

the destination’s address, the number of hops to reach the destination and the

sequence number of the information received regarding that destination. Each

node advertises an increasing even sequence number for itself. When Node A

determines that destination Node D is unreachable, it advertises the next odd

sequence number for the route that has failed with an infinite metric count. Any

node that receives this infinite metric count updates its table for the matching

route and waits until a greater sequence number with non-infinite metric count is

received. Every mobile host also calculates the weighted average of the time taken

to receive a route with the best metric. This time is called as settling time. A

comparison of the characteristics of the above three ad hoc routing protocols

DSDV, DSR, AODV is given in Table 1.

10

Table 1: Ad hoc network protocol comparisons

PROTOCOL PROPERTY DSR DSDV AODV

Loop Free Yes Yes Yes

Multicast Routes Yes No No

Distributed Yes Yes Yes

Unidirectional Link Support Yes No No

Multicast No No Yes

Periodic Broadcast No Yes Yes

QoS Support No No No

Routes Maintained in Route Cache Route TableRoute Table

Reactive Yes No Yes

4 Performance Metrics of Routing Protocols

In order to evaluate the performance of ad hoc network routing protocols, the

following metrics were considered:

End-to-End Delay: The average time interval between the generation of a packet

in a source node and the successfully delivery of the packet at the destination

node. It counts all possible delays that can occur in the source and all intermediate

nodes, including queuing time, packet transmission and propagation, and

retransmissions at the MAC layer. The queuing time can be caused by network

congestion or unavailability of valid routes.

11

Packet Delivery Fraction: The ratio of the number of data packets successfully

delivered to all destination nodes and the number of data packets generated by all

source nodes.

Routing Load: The ratio of the number of routing messages propagated by every

node in the network and the number of data packets successfully delivered to all

destination nodes. In other words, the routing load means the average number of

routing messages generated to each data packet successfully delivered to the

destination.

Number of Packets dropped: The number of data packets that are not

successfully sent to the destination during the transmission.

Jitter: Jitter describes standard deviation of packet delay between all nodes.

Throughput: The throughput metric measures how well the network can

constantly provide data to the sink. Throughput is the number of packet arriving at

the sink per ms.

Power consumption: The total consumed energy divided by the number of

delivered packet.

4.1 Simulation Environment

There are two approaches used to evaluate routing protocols: using simulation or

performing experiments on real time. In both cases, the performance metrics as

well as the network context are equally important. In this work, the characteristics

and behavior of the AODV, DSV and DSDV routing protocols especially in the

initial condition of the communication between nodes for a very short duration.

During the initial condition, the routing protocols will behave varyingly due to the

differences in the mechanism of route discovery. The route discovery process

will be affected by the mobility of each and every nodes of the network. So during

the initial phase of communication, the behavior of the routing protocol and the

12

characteristics of communication will significantly differ from normal conditions.

The scope of the study is to measure such characteristics during the initial

condition of the network.

4.2 Simulation set-up

Comparing with the commercial software OPNET, NS2 has an advantage.

Network Simulator (NS2) is a discrete event simulator targeted at networking

research [12]. NS2 provides substantial support for simulation of TCP, routing,

and multicast protocols over wired and wireless (local and satellite) networks. The

proposed system has been successfully implemented and evaluated using Network

Simulator 2. In order to create the different traffic scenarios files we need to go to

the cmu-scen-gen directory and the path is ns/ns-2.31/inde-utils/cmu-scen-gen.

Here we can find a traffic generator script ns.cbrgen.tcl. By using this script we

can create the different traffic scenario files, by selecting the TCP or CBR

connections between nodes. The mobility models can be generated by using the

directory. /setdest, we can go to that directory by setting the path

ns2/ns-2.31/indep-utils/cmu-scen-gen/setdest.

The following simulation parameters have taken for the simulation.

Number of Nodes 20

Number of Sending Nodes 10

The Pause Time 0, 10, 20, 30&40(sec)

Routing Protocol DSDV/AODV/DSR

The Maximum Node Speed 20m/s

Topography x=500 y=500

Propagation Two Ray Ground

Antenna Type Omni Antenna

The table below shows the performance of the routing protocols DSDV, AODV,

and DSR with respect to different metrics considered above.

13

Destination Sequence Distance Vector:

Table 2: DSDV Performance with different metrics

Pau

se

Tim

e(se

c)

PD

F

Nor

mal

ized

R

outi

ng

Loa

d

En

d t

o E

nd

D

elay

(m

s)

Tot

al

Dro

pp

ed

Pac

ket

s

Th

rou

ghp

ut

Jitt

er

0 74.7 1.69 8.72 1375 76.88 3.98

10 78.9 1.67 9.94 1137 80.73 5.43

20 71.1 1.89 10.56 1613 72.94 5.91

30 70.0 2.28 12.86 1672 72.61 9.85

40 78.4 1.8 10.28 1170 80.11 5.56

Ad hoc On Demand Distance Vector:

Table 3: AODV Performance with different metrics

Pau

se

Tim

e(se

c)

PD

F

Nor

mal

ized

R

outi

ng

Loa

d

En

d t

o E

nd

D

elay

(m

s)

Tot

al

Dro

pp

ed

Pac

ket

s

Th

rou

ghp

ut

Jitt

er

0 99.25 1.88 12.3 42 102.09 7.03

10 99.56 1.8 11.72 24 102.26 6.05

20 99.15 2.16 14.87 52 102.12 9.07

30 99.23 2.1 14.28 48 103.31 7.96

40 99.46 1.87 15.76 27 103.25 12.3

14

Dynamic Source Routing:

Table 4: DSR Performance with different metrics

Pau

se

Tim

e(m

s)

PD

F

Nor

mal

ized

R

outi

ng

Loa

d

En

d t

o E

nd

D

elay

(m

s)

Tot

al

Dro

pp

ed

Pac

ket

s

Th

rou

ghp

ut

Jitt

er

0 99.29 1.5 11.44 84 102.24 7.53

10 100 1.51 12.95 41 103.2 11.54

20 99.69 1.72 23.77 111 102.27 32.14

30 99.22 1.83 15.18 96 101.82 12.53

40 99.93 1.69 13.82 46 102.54 11.49

4.3 Performance results of AODV, DSR and DSDV

The graphs below shows the performance of the routing protocol with respect to

different metric considered above. The X- Axis shows the pause times of the

nodes and the y axis shows the Metric considered for simulation

Figure. 1 Packet Delivery fraction for AODV, DSR and DSDV

15

In terms of PDF with respect to varied pause time, DSR performs well when the

number of nodes is less, which is shown in Fig.1. The performance of AODV is

consistently uniform and DSDV performance is poor than reactive protocols.

Figure. 2 Packet Routing load for AODV, DSR and DSDV

In terms of Routing Load with respect to varied pause time, DSR is found to be

less when compared to AODV and DSDV because of DSR aggressive caching

techniques, which is observed in Fig.2 .

Figure. 3 End-to-End delay for AODV, DSR and DSDV

In terms of end-to-end delay, DSDV is the best performer. As routing information

is constantly updated in the proactive protocols, routes to every destination are

always available and up-to-date, and hence end-to-end delay can be minimized as

shown in Fig.3

16

Figure. 4. Packets dropped for AODV,DSR and DSDV

In terms of packets dropping, DSDV performance is worst when mobility is high.

This is because of the reason that it keeps only one route per destination.

Therefore lack of alternate routes and presence of stale routes in routing table

when nodes are moving at higher rate leads to packet drops, which is shown in

Fig.4

Figure..5. Average throughput for AODV,DSR and DSDV

In Figure.5, with respect to varied pause time, throughput decreases

comparatively in DSDV as it needs to advertise periodic updates and even-driven

updates. If the node mobility is high then occurrence of even driven updates are

more.

17

Figure.6. Jitter performance for AODV,DSR and DSDV

With regard to jitter, DSDV and AODV showed the best average performance

than DSR. Jitter is determined by calculating the standard deviation of the latency

as shown in Fig. 6.

Figure.7. Power efficiency for AODV,DSR and DSDV

In terms of Power efficiency, DSDV is the best performer than reactive protocols.

AODV consumes much power while comparing with the other two, which is

observed in Fig. 7.

18

Figure.8. Throughput Vs Time for AODV,DSR and DSDV

With regard to throughput versus time, DSR consumes considerable power and

gives lower throughput due to network failure, which is shown in Fig. 8. (Since

we started the simulation with very low battery power)

Discussion and Conclusion

In this paper, we have examined simulation studies and also compared the On-

Demand (DSR and AODV) and Table-Driven (DSDV) routing protocols by

varying the pause time and measured the metrics like end-end delay, dropped

packets, routing overhead, power efficiency etc. The results indicate that the

performance of the two on demand protocols namely DSR and AODV is superior

to the DSDV in conformance with the work done by other researchers as

mentioned in section 2. It is also observed that DSR outperforms AODV in less

stressful situations, i.e smaller number of nodes. AODV outperforms DSR in

more stressful situations. The poor delay and packet delivery ratio of DSR is

mainly due to caching and lack of mechanisms to expire stale routes. The routing

overhead is consistently low for DSR and AODV than in comparison with DSDV

especially for large number of nodes. This is due to the fact that in DSDV the

routing table exchanges would increase with larger number of nodes. The results

19

indicate that as the number of nodes in the network increases DSDV would be

better with regard to the packet delivery ratio, but it may have considerable

routing overhead. As far as packet delay and dropped packets ratio are concerned,

DSR/AODV performs better than DSDV with large number of nodes. Hence for

real time traffic AODV is preferred over DSR and DSDV. For less number of

nodes and less mobility, DSDV’s performance is superior. The metric of Power

efficiency concerns, the result indicates that DSDV is best performer. As far as

throughput versus time concern, DSR consumes considerable power and gives

lower consumption due to network failure.

Acknowledgments

The authors would like to thank Dr.S.N.Subbramanian, Director cum Secretary,

Dr.S.Rajalakshmi, Correspondent, Dr.V.P.Arunachalam, Principal, SNS College

of Technology, Coimbatore for their motivation and constant encouragement. The

author would like to thank Supervisor Dr.V.Palanisamy, Principal, Info Institute

of Engineering and Joint Supervisor Dr.K.Duraiswamy, Dean, KSR College of

Technology for their valuable input and fruitful discussions.

References

[1] C.Perkins, Ad Hoc Networking, New York: Addison Wesley, 2000

[2] S.Corson and J.Macker, Mobile Ad hoc Networking: Routing Protocol

Performance issues and Evaluation Considerations, RFC 2501, January 1999.

[3] S.R. Das, C.E. Perkins, and E.E. Royer, “Performance Comparison of Two

On-Demand Routing Protocols for Ad Hoc Networks,” Proc. INFOCOM,

2000, pp.3- 12.

[4] J. Broch, D. A. Maltz, D. B. Johnson, Y-C. Hu, and J.Jetcheva, “A

performance comparison of multi-hop wireless ad hoc network routing

protocols”, Mobicom’ 98, October 1998, pages 85-97.

20

[5] J. Raju and J.Garcia-Luna-Aceves, "A comparison of on-demand and table

driven routing for ad-hoc wireless networks", Proc. of IEEE ICC, June -

2000, pages 1702- 1706.

[6] S.R. Das, R. Castaneda, J. Yan, and R. Sengupta, “Comparative performance

evaluation of routing protocols for mobile ad hoc networks”, 7th Int. Conf.

on Computer Communications and Networks (IC3N), October 1998, pages

153–161.

[7] Boukerche A., “Performance comparison and analysis of ad hoc routing

algorithms”, IEEE International Conference on. Performance, Computing,

and Communications, 2001, Apr 2001, pp 171-178.

[8] D. Johnson, Y. Hu, D. Maltz, “The Dynamic Source Routing Protocol (DSR)

for Mobile Ad Hoc Networks for IPv4” RFC 4728 February 2007

[9] C. E. Perkins, E. M. Belding-Royer, and S. Das. Ad hoc On-Demand

Distance Vector (AODV) Routing. RFC 3561, July 2003.

[10] C. E. Perkins and E. M. Royer. The Ad hoc On-Demand Distance Vector

Protocol. In C. E. Perkins, editor, Ad hoc Networking, pages 173–219.

Addison- Wesley, 2000.

[11] C.E. Perkins and P. Bhagwat, “Highly Dynamic Destination-Sequenced

Distance-Vector Routing (DSDV) for Mobile Computers,” Proc. ACM

SIGCOMM ’94, pp. 234-244, 1994.

[12]Marc Greis. NS2 Tutorial presentation in the website

www.isi.edu/nsnam/ns/tutorial/nsindex.html