Comparative Performance Analysis of MANET Routing ...533411/FULLTEXT01.pdfCourse code: Degree...

Degree project

Comparative Performance

Analysis of MANET Routing

Protocols in Internet Based

Mobile Ad-hoc Networks

Author: Roja Rani Mannam, Mahe

Zabin

Date: 2012-06-13

Subject: Computer Science

Level: Master

Course code: 4DV01E

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Abstract

In crucial times, such as natural disasters like Earthquakes, Floods,

military attack, rescue and emergency operations, etc., it is not

possible to maintain an infrastructure. In these situations, wireless

Mobile Ad-Hoc networks can be an alternative to wired networks. In our

thesis, due to the importance of MANET (Mobile Ad-hoc Network)

applications, we do research on MANET and its subtype IMANET

(Internet based Mobile Ad-hoc Network). In MANETs, finding an

optimum path among nodes is not a simple issue due to the random

mobility of nodes and topology changes frequently. Simple routing

algorithms like Shortest Path, Dijksta‟s and Link State fail to find route

in such dynamic scenarios. A number of ad-hoc protocols (Proactive,

Reactive, Hybrid and Position based) have been developed for

MANETs.

In this thesis, we have designed an IMANET in OPNET 14.5 and

tested the performance of three different routing protocols namely

OLSR (Optimum Link State Routing), TORA (Temporarily Ordered

Routing Algorithm) and AODV (Ad-hoc On-demand Distance Vector)

in different scenarios by varying the number of nodes and the size of

the area. The experimental results demonstrate that among the three

protocols, none of the routing protocol can ensure good quality HTTP

and voice communication in all our considered scenarios.

Key words: Mobile Ad hoc Network (MANET), OLSR, TORA, AODV, HTTP and

voice.

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ACKNOWLEDGMENT

We are grateful to Almighty for showering his blessings on us.

We are sincerely thankful to honorable supervisor Professor Ola Flygt, for his constant

directions to enhance the quality of the thesis.

We convey deep respect to our thesis coordinator Professor Mathias Hedenborg, who

supported us for the completion of the work. We extend our gratitude to our program

coordinator Professor Jonas Lundberg, Ph.D for his cooperation and inspiration to

complete our master degree at Linnaeus University, Sweden.

Roja Rani & Mahe Zabin

I am blessed to have my husband Mr. Praveen, your cherish and support in all aspects is

esteemed. Thank you and I love you forever. Heartfelt thanks to my parents and my

brother. Roja Rani

In this very moment, I passionately remember my beloved father Mr. M.M. Zakaria, a

true benefactor of learning throughout his life who tried by all his means to provide the

best possible education for me and my dearest mother Mrs. Rawshan Ara Begam who

gives unconditional love and affection for the happiness of me.

Finally, I would like to express my sincere gratefulness to my love, Jia, for his

unconditional support, devotion and care and to my father in law Golam Quader and

mother in law Ayesha Khatun whose encouragement helped me to reach at this stage.

This thesis is dedicated to my twins, Jasra and Jahra.

Mahe Zabin

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Contents 1. Introduction .................................................................................................................1

1.1 Problem Statement ...................................................................................................1

1.2 Research Challenges ................................................................................................1

1.3 Thesis Goal and Research Methodology .................................................................2

1.4 Thesis Outline ..........................................................................................................2

2. Background ..................................................................................................................3

2.1 Statistical data of Earthquakes .................................................................................3

2.2 Densities of Earthquakes ..........................................................................................4

2.3 Comparison of real densities and experimental densities ........................................4

3. Classification of Wireless Networks ...........................................................................5

3.1 Infrastructure Wireless Networks and Ad-hoc Networks ........................................5

3.2 Types of Ad-hoc Networks ......................................................................................6

4. Routing and Routing Protocols ..................................................................................7

4.1 Overview of Routing ................................................................................................7

4.2 Routing Protocols .....................................................................................................7

4.2.1 Routing Protocols for Wired Networks.............................................................8

4.2.2 Routing Protocols for Ad-hoc Networks...........................................................8

5. Overview of MANET ................................................................................................10

5.1 Properties of MANET ............................................................................................10

5.2 Limitations of MANET ..........................................................................................10

5.3 MANET Applications ............................................................................................11

5.4 Types of MANET ..................................................................................................11

5.5 The System Design of IMANET ...........................................................................12

5.5.1 An Aggregate Chaching Mechanism ..............................................................12

5.6 Devices supporting in MANET networks ..............................................................13

6. MANET Routing Protocols.......................................................................................16

6.1 OLSR (Optimized Link State Routing) .................................................................16

6.2 TORA (Temporary Ordered Routing Algorithm) ..................................................17

6.3 AODV (Ad Hoc On-demand Distance Vector) .....................................................18

6.4 GRP (Geographic Routing Protocol) .....................................................................19

6.4.1 GRP Quadrant .................................................................................................19

6.4.2 GRP Flooding .................................................................................................19

6.4.3 GRP Routing Table .........................................................................................20

6.4.4 HELLO Protocol in GRP ................................................................................20

6.4.5 GRP Routing Lookup ......................................................................................20

6.4.6 GRP Routing Backtrack ..................................................................................20

7. Experimental Environment Setup ...........................................................................21

7.1 Network Simulation tools ......................................................................................21

7.2 Detailed View of OPNET Simulator .....................................................................21

7.2.1 OPNET Simulator for MANET ......................................................................21

7.2.2 Workflow of OPNET ......................................................................................22

7.3 Description of Experimental Parameters ...............................................................22

7.4 Design the IMANET scenario in OPNET .............................................................24

7.5 Data Entities. ..........................................................................................................25

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7.5.1 Application Configuration ..............................................................................25

7.5.2 Profile Configuration. .....................................................................................26

7.5.3 Mobility Configuration ...................................................................................26

7.5.4 Server ..............................................................................................................26

7.5.5 Nodes ..............................................................................................................27

8. Experimental Results and Analysis .........................................................................28

8.1 Impact of the number of nodes on the QoS parameters of HTTP traffic for

different protocols ........................................................................................................28

8.1.1 Scenario 1(a), QoS of HTTP traffic for 10, 25 and 100 nodes in an area of

1km*1km .................................................................................................................28

8.1.2 Scenario 1(b), QoS of HTTP traffic for 10, 25 and 100 nodes in an area of

3km*3km .................................................................................................................29

8.1.3 Scenario 1(c), QoS of HTTP traffic for 10, 25 and 100 nodes in an area of

10km*10km .............................................................................................................30

8.2 Impact of the number of nodes on the QoS parameters of Voice traffic for

different protocols ........................................................................................................31

8.2.1 Scenario 2(a), QoS of Voice traffic for 10, 25 and 100 nodes in an area of

1km*1km .................................................................................................................31

8.2.2 Scenario 2(b), QoS of Voice traffic for 10, 25 and 100 nodes in an area of

3km*3km .................................................................................................................32

8.2.3 Scenario 2(c), QoS of Voice traffic for 10, 25 and 100 nodes in an area of

10km*10km .............................................................................................................33

8.3 Impact of network area on the QoS parameters of HTTP traffic for different

protocols .......................................................................................................................35

8.4 Impact of network area on the QoS parameters of Voice traffic for different

protocols .......................................................................................................................35

8.5 Theoritical Explanation of Simulation Results ......................................................35

9. Conclusion and Future Works .................................................................................37

9.1 Conclusion .............................................................................................................37

9.2 Proposed Solutions to the Research Questions ......................................................37

9.3 Future Works .........................................................................................................38

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Appendix

A. HTTP Server Configuration ...................................................................................... 41

B. Backbone Network Configuration ............................................................................. 42

C. Application Configuration ......................................................................................... 43

D. Profile Configuration ................................................................................................. 43

E. MANET Gateway Configuration ............................................................................... 44

F. Mobility Configuration .............................................................................................. 44

G. Scenario of HTTP for 10 nodes in different areas 1km*1km, 3km*3km, 10km*10km

........................................................................................................................................ 44

H. Scenario of HTTP for 25 nodes in different areas 1km*1km, 3km*3km, 10km*10km

........................................................................................................................................ 45

I. Scenario of HTTP for 100 nodes in different areas 1km*1km, 3km*3km, 10km*10km

........................................................................................................................................ 46

J. Scenario of Voice traffic for 10 nodes in different areas 1km*1km, 3km*3km,

10km*10km .................................................................................................................... 46

K. Scenario of Voice traffic for 25 nodes in different areas 1km*1km, 3km*3km,

10km*10km .................................................................................................................... 47

L. Scenario of Voice traffic for 100 nodes in different areas 1km*1km, 3km*3km,

10km*10km .................................................................................................................... 48

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List of Figures

Figure 3.1 A Wireless Network in Infrastructure Mode ................................................... 5

Figure 3.2 A Wireless Network in Ad hoc ModeMode ................................................... 5

Figure 5.1Indirect connection between the devices........................................................ 10

Figure 5.2 System design of IMANET ........................................................................... 12

Figure 5.3 MANET configuration .................................................................................. 14

Figure 6.1 Overview of MANET routing protocols ....................................................... 16

Figure 6.2 HELLO message in MANET using OLSR ................................................... 16

Figure 6.3 Route discovery procedure in TORA (Query Message) ............................... 17

Figure 6.4 Height of each node updated as a result of UDP message ............................ 18

Figure 6.5 RREQ and RREP messages in AODV ......................................................... 19

Figure 6.6 Concept of Quadrants in GRP ....................................................................... 20

Figure 7.1 Workflow of OPNET .................................................................................... 22

Figure 7.2 A Backbone Network of an IMANET .......................................................... 26

Figure 7.3 A Scenario of IMANET with MANET gateways ......................................... 27

Figure 8.1 Analysis of QoS parameters of different protocols in HTTP traffic (10, 25,

100 nodes in 1km*1km area).......................................................................................... 28




100 nodes in 10km*10km area) ..................................................................................... 30

Figure 8.4 Analysis of QoS parameters of different protocols in voice traffic (10, 25,





100 nodes in 10km*10km area) ..................................................................................... 34

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List of Tables

Table 2.1 Stactstics of Earthquakes .................................................................................. 3

Table 2.2 Densities of people using communication devices .......................................... 4

Table 2.3 Statistics of the densities of our designed network scenarios........................... 4

Table 7.3 List of Experimental Parameters .................................................................... 23

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Acronyms

ABR Associativity Based Routing

AODV Ad hoc On-demand Destance Vector

AP Access Point

ASL Ad hoc Support Library

BSN Body Sensor Network

DAG Directed Acyclic Graph

DSDV Distance Sequence Distance Vector

DSR Dynamic Source Routing

DV Distance Vector

FTP File Transfer Protocol

GloMoSim Global Mobile Information system Simulator

GPS Global Positioning System

GRP Geographical Routing Protocol

GSM Global System for Mobile communication

GSR Global State Routing

GUI Graphical User Interface

HTTP Hypertext Transfer Protocol

IETF Internet Engineering Task Force

INVANET Intelligent Vehicular Ad hoc Network

IMANET Internet based Mobile Ad hoc Network

MAD Media Access Delay

MANET Mobile Ad hoc Network

MFR Most Forwarding Progress within Routing

MN Mobile Node

MOS Mean Opinion Score

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MPR Multi Point Rely

NS Network Simulator

OLSR Optimized Link State Routing

OPNET Optimized Network Engineering

OSPF Open Shortest Path First

PDA Personal Digital Assistance

PNR Position and Neighborhood based Routing

QoS Quality of Service

RERR Route Error

RIP Routing Information protocol

RREP Route Reply Packet

RREQ Route Request

SPF Shortest Path First

TBRPF Topology Broadcast based on Reverse Path Forwarding

TC Topology Control

TCP Transmission Control Protocol

TORA Temporarily Ordered Routing Algorithm

VANET Vehicular Ad hoc Network

WAP Wireless Access Point

WLAN Wireless Local Area Network

WMN Wireless Mesh Network

WRP Wireless Routing Protocol

WSN Wireless Sensor Network

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1. Introduction

An Ad-hoc network is a wireless network without infrastructure like fixed routers in

wired network and access point in wireless network. Instead of infrastructure, here

every node participates in routing by forwarding the data to other nodes.

A Mobile Ad-hoc Network (MANET) is a wireless system, where nodes are moving

randomly. There are different subtypes of MANETs such as, IMANET (Internet-based

Mobile Ad hoc Network), VANET (Vehicle Ad-hoc Network), WSN (Wireless Sensor

Networks), and BSN (Body Sensor Network). At present, researchers are continuing to

explore and develop MANETs. Routing is a key concern in the design of all such

communication networks.

1.1 Problem Statement

The performance of IMANETs may be influenced by mobility, scalability and traffic

load. These factors may affect the QoS parameters of different traffics by either

increasing or decreasing the overall efficiency of network. In this thesis, we will

design network scenarios of IMANET and measure the different QoS (Quality of

Service) parameters to evaluate the performance of different routing protocols by

varying the two important network parameters- network area and number of nodes. So far, research studies on performance analysis of MANET routing protocols

have shown distinctive results based on the different network conditions by

using different network simulators such as, Packet Tracer, NS-2/NS-3 [5, 28], GloSim,

QualNet, OPNET[2, 3].

1.2 Research Challenges

In this section, we address the following research questions as research challenges.

1. Is MANET a viable solution to the communication demands that exist in a

disaster area without a fixed infrastructure?

2. Why routing is a key issue in MANETs? By theoretical study in

background chapter we try to focus on it.

3. Among different types of routing protocols, such as table driven, on

demand and position based; which type of routing protocols can perform

better performance in IMANETs?

4. Which networks factors influence on the performance of MANET routing

protocol in IMANET? To observe it in our experimental setup, we designed

different network scenarios of IMANET changing the network area, no. of

nodes, node speed, etc.

5. How to design IMANET scenarios in OPNET to collect proper simulation

results?

6. Which protocol shows better performance in different network traffics,

such as HTTP and voice in IMANETs?

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1.3 Thesis Goals and Research Methodology

Our goal is to gain the theoretical knowledge on MANET [1] routing protocols and

gather the knowledge on the development of MANET routing protocols. In our thesis,

we will study details on a proactive protocol OLSR (Optimized Link State Routing) [2,

3], reactive protocol TORA (Temporary Ordered Routing Protocol) [4] and AODV (Ad

hoc On-demand Distance Vector) and a position based protocol GRP (Geographic

Routing Protocol) [2, 3].

In the simulation part, we will carry out the experimental work using a network

simulation tool- OPNET 14.5 as it has attractive GUI interface rather than other existing

simulators such as Qualnet, GloMoSim, NS-2/ NS-3(Network Simulator version 2/3).

We will design different IMANET scenarios in OPNET by varying the network area,

node density for different traffics such as HTTP and voice. We will also test the

performance of different routing protocols- OLSR, TORA and AODV by collecting

simulation results of different network metrics - throughput, network load, media access

delay, MOS, and download page response. At the end of the report, we will summarize

the findings based on theoretical and empirical study of our research.

Finally we will conclude our works by analyzing the protocols and lining up the better

protocol in performance among the three routing protocols for different IMANET

scenarios. As we know the geographical based protocols need to update the positions of

neighbor nodes as well as the source node itself, differentiating GRP to other protocols

in such dynamic scenarios is also a key issue in our research.

1.4 Thesis Outline

This thesis report is divided into nine chapters. First chapter gives an introduction of

MANETs. Second chapter presents the background of the research work. In chapter

three we classify wireless networks and the ad hoc networks. Forth chapter gives a brief

overview of routing and Ad-hoc routing protocols. Fifth chapter contains the theoretical

discussion on MANETs and IMANETs. The overview of different MANET routing

protocols such as, OLSR, TORA, AODV and GRP is presented in chapter six. Seventh

chapter mainly discuss about the OPNET simulator and design procedure of network

scenarios of IMANET. The simulation results and analysis are presented in chapter

eight followed by conclusion in final chapter nine.

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2. Background

In this chapter, we present the background studies of our research work.

Mobile Ad-hoc networks play a key-role in today‟s wireless communication due to its

infrastructure less feature. The MANET is designed for electronic communication

devices such as mobile phones, smart phones, PDAs, laptops, etc. As the nodes in

MANET are randomly mobile, it can be helpful in different real scenarios such as,

disaster areas, emergency and rescue situations, military applications, etc. The people in

the disaster situations may move randomly, and then the electronic devices with

MANET setup can be useful to communicate with each other. In disaster situations [6],

any kind of infrastructure in that disaster prone area may have been destroyed and then

there is a demand for the communication systems that are independent of infrastructure

in that “disaster area scenario”. Therefore, MANETs satisfy the requirements of being

independent of any kind of infrastructure. At present, researchers are improving their

studies to implement MANET for disasters like earthquakes, floods, etc.

2.1 Statistical data of Earthquakes

In this section, for the background works our thesis, we have collected the real statistics

of some earthquakes from the year 1964 to 2011 occurred in different places. According

to this real data, we designed our experimental parameters for our designed IMANET

scenarios.

Table 2.1 Statistics of earthquakes

According to the Table 2.1 the great Alaska earthquake occurred on 27th March-

1964, with a magnitude of 9.2 and is one of the largest earthquake causing extensive

damage over 800 km area and being a least densely populated area, only 200 people

were effected among the total population of 226167 [7]. In January, Haitian capital

Port-au-Prince was hit with a 7.0 magnitude, damaging 15km area and yet it had taken

over 150000 lives among the total population 897859 [8]. The Alaska earth quake was

affected in a large area with a high magnitude, but less people were affected whereas

Year Place Magnitude Time scale Area

Effected(km)

People

Effected

1964 Alaska 9.2 Nearly 4min 800km 200

2000 MadhyaPradesh,

India

4.4 1min 70km 1000

2007 Lima and Pisco in

Peru

7.7 and 8.8 3min 150km and

745km

2000

2008 Tibet 6.6 15min 100km 100,000

2008 China 7.9 3-5min 360km 75,000

2010 Port-au-Prince 7.0 7-8min 15km 150,00

2010 NorthernSumatra,

Indonesia

7.7 3-4min 200km 310,000

2010 central part of

Chile

8.8 2min 20sec 500km 1.8million

2011 Northeastern Japan 9.0 2-3min 500km 800000

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the earthquake in Port-au-Prince was small and yet it took a lot of lives. Apart from

these two, the statistics of some other earthquakes are given in the Table 2.1.

2.2 Densities of Earthquakes

For the countries mentioned in Table 2.1, we have drawn the statistics of people using

electronic communication devices in Table 2.2, which is one of the important factors to

design the network for a disaster scenario. According to theses statistics we also

calculated the density of the electronic devices used in the coverage area. However this

might be an over estimation since most of the devices cannot work as MANET node

today but expected to be changed in few years. In our experiment we also considered

the electronic devices density similar to the studied real time scenarios in background

chapter. For these statistics, we have considered the square area and calculated the

density within the area as the number of electronic devices used per square kilometer by

applying the following formula.

Density = Population of effected area*percentage of electronic/Area effected;

Table 2.2 Densities of people using communication devices

2.3 Comparison of real densities and experimental densities

By analyzing all these calculations of all real time network scenarios in different areas,

it is observed that the least density value is 0.273 in Alaska, medium density value is

8.72 in Northern Sumatra, and the high density value is 98.13 in China. Comparing

these real densities in Table 2.2 with the experimental densities in Table 2.3 have good

similarities as the experimental densities fall in the real scenarios statistics.

The statistics of the density of our designed network scenarios is demonstrated in Table

2.3.

Table 2.3 Statistics of the densities of our designed network scenarios

Area Effected Population of

the effected area

Use Electronic

devices (%)

Density

800km*800km 2,69057 65 0.273

70km*70km 11,9805 40 9.78

150km*150km &

745km*745km

60,7392 37.5 0.280

100km*100km 24,649 40 0.98

360km*360km 1,3824746 92 96.45

15km*15km 15,000 53 35.33

200km*200km 1,163921 30 8.72

500km*500km 5,579726 51 11.38

500km*500km 800,000 95 3.04

Network Area Density

10 nodes 25 nodes 100 nodes

1km*1km 10 25 100

3km*3km 1.11 2.7 11.11

10km*10km 0.1 0.25 1

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3. Classification of Wireless Networks

In this chapter, we give a brief discussion on the classification of wireless networks

such as infrastructure wireless networks and ad hoc networks and also further classify

the ad hoc networks.

3.1 Infrastructure Wireless networks and Ad-hoc networks

The wireless networks have become tremendously popular in the computing industry.

The reason of their popularity is that the information can be accessed regardless of the

user‟s geographical location [9]. There are two types of wireless networks namely

infrastructure and Ad hoc networks.

The Infrastructure wireless networks are also known as cellular networks having

fixed base stations. The mobile unit connects and communicates with each other within

these networks [10]. In infrastructure wireless networks a Wireless Access Point (WAP)

exists between the sender and receiver. Among multiple access points, the node selects

an access point having better signal strength. The typical application of infrastructure

wireless network is office Wireless Local Area Network (WLAN). The Figure 3.1

represents a wireless network with infrastructure.

Figure 3.1 A Wireless Network in Infrastructure Mode

The Ad hoc networks are the networks without any pre-structure. This type of

network does not have any predefined infrastructure [10]. From the Figure 3.2, the Ad-

hoc networks have no fixed routers as in wired networks, and no base station or access

point as in wireless networks. Every node of this network participates in routing by

forwarding the data to other nodes.

Figure 3.2 A Wireless Network in Ad hoc Mode

Notebook

PC

Desktop

PC

PDA

Wireless

Access Point

Notebook

PC

Desktop PC

PDA

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3.2 Types of Ad-hoc Networks

The most popular types of Ad hoc networks are Mobile Ad hoc Networks (MANET),

Wireless Mesh Networks (WMN) and Wireless Sensor Networks (WSN).

In MANET, all the nodes are randomly moving without any dedicated physical

medium. The structure does not follow a fixed topology; it may change at any time

depending on network characteristics and node mobility. In such dynamic networks,

routing is a challenging and complex issue. The applications of Ad-hoc networks are in

emergency search, rescue operations, meetings and conferences where people can easily

and quickly share information. The research is being improved to setup a MANET in

catastrophic failure situations, such as earthquakes, floods, etc.

In WMN, the nodes in the network are divided into wireless mesh routers and

wireless mesh clients. The nodes that act as mesh routers are responsible for

transmitting the data to and fro from the mesh clients. If one node fails in this network

architecture, a new path is automatically established by its neighbor node maintaining

the network connectivity. The WMN is mainly applicable in automatic electric meters,

military forces, supports VoIP, etc.

The WSN consists of sensing devices known as sensors. These sensors have the

capability to sense its surrounding environment, gather the information and

communicate among each other. The WSN differs from other networks that exhibit poor

performance as the network size increases whereas WSNs are much stronger and

perform better as the number of nodes increase in the network. The WSN have some

limitations, such as low bandwidth, short communication range, more memory space

and frequently changes network topology. The application areas are monitoring air and

water pollution, agriculture, detecting forest fires, medical and health care, etc.

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4 Routing and Routing protocols

Routing is the core problem in both wired networks and ad-hoc networks. Discovering

the optimum route is a challenging task and till now several routing protocols are

developed to overcome the problem.

4.1 Overview of Routing

Routing is the process of selecting an optimum path in a network, along which the

network traffics are sent. Routing is the key issue in wireless networks for delivering the

data from one node to another node. In wireless networks, no dedicated channel exists

between the sender and receiver; multiple paths exist between the source and

destination instead of single channel.

Types of Routing:

1. Dynamic Routing

2. Static Routing

In dynamic routing, the decisions are based on the pre-defined scenarios. The router

performs the routing. In this routing, the routing table is maintained to route the traffic.

This routing is flexible, reduces traffic overload and multiple paths are used to transfer

the data packet from source to destination [11].

In static routing the decisions are based on the administrators. These administrators

manually forward the packets to the desired destinations. In this routing, no routing

tables are used, instead the routing is performed manually, as per the administrators

instruction [11].

There are two routing techniques named Link State and Distance Vector, these

algorithms are used by the routing protocols to calculate the routes between nodes.

The link state routing algorithm also known as the Shortest Path First (SPF)

algorithm and follow the Dijkstra‟s technique. This routing algorithm can be used by

both table-driven and on-demand routing protocols. In link state routing, every node

maintains the link-state information of the entire network and based on this information

the route decision has made [12]. The link state routers directly meet the other nodes by

continuously exchanging HELLO messages. It minimizes the broadcast overhead and

maintains reliable communication. The OSPF routing protocol is an example of wired

network, which uses the Link State algorithm. The OLSR (Optimized Link State

Routing) routing protocol is an example of Mobile Ad hoc Network which is also using

the Link State algorithm.

The distance vector routing can also be used by both table-driven and on-demand

routing protocols. In distance vector, each node maintains a routing table with the

details including the destination IP address, distance to it and next node in the path. The

router periodically broadcasts the information to neighbor nodes and updates the routing

tables with received information from the neighbor nodes [13]. Thus, always the

updated routing table is maintained. The distance vector uses the Bellman-Ford

algorithm to calculate the paths [13]. The Distance Vector reduces the computational

complexity. The Routing Information Protocol (RIP) is an example of wired networks

which are designed by the Distance Vector algorithm. The MANETs routing protocols

TORA, AODV are also designed by the Distance Vector algorithm.

4.2 Routing Protocols

Routing is used to discover and maintain the routes between the source and destination.

It is complex task in wired networks to overcome this problem many routing protocols

8

are developed. The routing protocol establishes communication between the routers and

transfers the data packets. The main function of the routing protocol is determining the

best path to deliver the network traffic. In the case of ad hoc networks, the routing

protocols play a very major role as all the nodes are randomly mobile and the topology

changes frequently. In such dynamic structures it is difficult to find the best route and

thus protocols play an important role in Ad-hoc networks communications.

4.2.1 Routing Protocols for Wired Networks

The following are the examples of routing protocols in wired networks.

1. Open Shortest Path First

2. Routing Information Protocol

The Open Shortest Path First (OSPF) is a routing protocol developed by the Interior

Gateway Protocol (IGP) working group for Internet Protocol (IP) networks. This

protocol identifies the changes in the network topology, updates very quickly and

maintains a loop-free router structure. This protocol computes the shortest-path using

the Dijkstra‟s algorithm.

The Routing Information Protocol (RIP) is a distance vector routing protocol. This

protocol stops the routing loops in the network by implementing the Hop Count i.e. it

limits the number of routers through which the data packets are passed from source to

destination. The hop limit may also limit the network size. The maximum numbers of

hops allowed in RIP are 15, if the hop count exceeds to 15 then it is considered as an

infinite distance.

4.2.2 Routing Protocols for Ad-hoc Networks

The routing protocols play an important role in ad hoc networks. The following are the

major types of protocols in ad hoc networks.

1. Proactive Routing Protocol (Table-driven)

2. Reactive Routing Protocol (On-demand)

3. Position Based Routing Protocol

In Proactive, each node maintains a routing table with the updated routing

information of all the neighbor nodes. When a source node needs to transmit data from

source to destination, it searches the routing table to find the destination node match

[14]. The proactive routing protocols have both advantages and disadvantages. One of

the main advantages is that the nodes can easily find routing information from the

routing table and it‟s easy to establish a session. The disadvantages are: low bandwidth

and wastage of memory i.e. nodes handle too much updated routing information which

slows its restructure process at the times of link failures.

In Reactive, the routes are discovered only when the source node needs to transmit

the data packet to the destination node, so the packet overhead will be minimized [14].

The reactive routing protocols have both advantages and disadvantages. One of the

advantages is efficient bandwidth. High latency and network congestion are the main

constraints of this protocol as it uses several acknowledgement query packets and

flooding techniques during the selection of new route for sending the data.

The Position Based Routing protocol was recently developed. The routing is based

on geographical position of the destination node. Every node needs to know its own

9

position and also the position of its very neighboring node in order to forward the data

packet. In position based routing [15], the mobile nodes calculate the position using

GPS (Global Positioning System) technology. The advantages are: having better

scalability forming better routes and also minimizes the packet overhead. The

disadvantages are: problem of inaccuracy of node positions which increases the load of

the network.

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5. Overview of MANET

MANET is a wireless ad hoc network. In MANETs, the nodes act as clients and servers.

These mobile nodes move randomly without any fixed topology. The absence of the

infrastructure and dynamic topology has created challenges in today‟s communication

world. In MANETs every node has the routing ability of forwarding the data to their

neighbor nodes. In a MANET, devices can be directly and indirectly connected with

each other. The devices establish indirect connection via other devices. The Figure 5.1

illustrates the indirect connection between the devices.

Figure 5.1 Indirect connections between the devices

The device X and device Z are connected indirectly by relaying on the device Y. The

device X sends a message to device Y with the address of the destination device Z. The

device Y after receiving the message deletes the address and delivers the message to the

destination device Z. In this chapter, we discuss the properties, limitations, applications,

types of MANETs followed by system model of IMANETs.

5.1 Properties of MANET

The MANETs are self-configuring and self-management networks establishing wireless

connection. The following are some of the features of MANETs [16].

1. The MANETs are formed without any pre-existing structure.

2. As the nodes are mobile, the communication can be created anytime and anywhere.

3. The mobile nodes open up alternative paths automatically.

4. Every node acts as a router forwarding the packet to its neighbor nodes. And thus,

mobile nodes play a vital role in communication.

5. The very important and challenging task of MANET is providing service and

information to the peoples when infrastructure networks are destroyed, e.g. during the

times of natural disasters.

So, MANETs have many interesting aspects that make it important for present

communication world. The features like self-organizing, flexibility and low-cost are

favorable to deploy the MANET network easily. The property, non-preexisting structure

of the MANETs is still under research which will be very beneficial to the humans.

5.2 Limitations of MANET

Unfortunately, MANET network is limited by some restraints.

1. The MANETs are not efficient in large network area due to the random mobility

nature of nodes and dynamic network topology.

2. The MANETs have limited physical security, attacked by many security threats

which minimize the network performance.

3. Limited bandwidth.

11

4. Limited resources and power in mobile nodes.

In spite of advantages, there are some restraints that minimize the network

performance. The expensive routing in MANETs is one of the main restraints i.e. as the

nodes are randomly moving, it is difficult to form best routes and due to which the

network cannot be configured successfully.

5.3 MANET Applications

The self-configuring, low cost of deployment, flexibility and infrastructure independent

features of MANET originates many services as follows:

1. In emergency services like rescue operations, medical services etc.

2. In military operations, when the soldiers roam in the battle field can communicate

easily with one another.

3. The most challenging application of MANET is in the catastrophic failures such as

earthquakes, floods, fire explosions, etc. In these situations, when the infrastructure

network collapse, MANETs play a key role in helping the effected people. The people

can communicate easily with each other and the rescue teams can be activated

immediately.

4. In business and educational conferences, meetings and web applications, etc.

5. In maintaining the records of weather conditions, checking air/water pollution, etc.

6. In traffic management, avoiding road accidents, maintaining traffic signals, etc

MANET comprises a wide variety of effective applications like disaster-recovery,

military, conferences etc. These are very general and important situations; especially the

role of MANETs in disaster prone area or rural areas, help the people to communicate

with each other without extra cost. The researchers are still working on successful

implementation of MANETs.

5.4 Types of MANET

The MANET is further classified into 3 types

1. VANET

2. INVANET

3. IMANET.

The VANET (Vehicle Ad-hoc Network) is mainly used for vehicles, dealing with

vehicular devices. The main purpose of VANET is to provide safety. The vehicles

having the VANET devices can communicate with each other by sending and receiving

messages. The examples of VANET are automatic parking system, traffic signal system,

etc.

The INVANET (Intelligence Vehicle Ad-hoc Networks) works under artificial

intelligence mechanism. These types of networks establish communications between

Vehicle-Vehicle (V2V) and Vehicle-Road side (V2R). The main purpose of an

INVANET is; in road side emergency situations, such as the accidents between the

vehicles, other road accidents, etc. If the vehicle having an INVANET device is met

with an accident, then an alarm is automatically generated from the vehicle [17].

The IMANET is combination of wired network (e.g. internet) and MANET. The

wireless communication infrastructures are being developed to make the users access

the internet services and information anytime and anywhere [18]. The growing interest

12

in accessing the internet leads to integrate the MANET with internet. The integration of

MANET with internet is known as an IMANET.

5.5 The System Design of an IMANET

The system design of an IMANET is an extended developing architecture of MANET

which directs to connectivity and accessibility of Mobile Nodes (MNs). The MN can

connect to the internet and can also communicate with other MNs through Wi-Fi (e.g.

IEEE 802.11). The Figure 5.2 illustrates the system design of an IMANET [18]. In

Figure 5.2, we can see that an IMANET consists of a set of MNs connecting and

communicating with each other through ad hoc routing protocols. Some of the MNs can

directly connect with the internet and turn into Access Points (APs) serving as relays to

the rest of the MNs. Thus, an AP acts as gateway for the internet accessing information.

The APs are connected with the routers. Some of the APs are connected to fixed routers

while others can have a satellite connection to the internet. The MNs can move

anywhere and can communicate with MNs in the network. The MN which moves out of

bound of one AP can access the internet through the relays of another AP. The MNs

located nearby an AP can connect directly to that AP whereas the MNs located far from

an AP have to go through several routes to reach that AP [18].

LEO or GEO satellite

IMANET

Fixed network

Fig: AN IMANET Model [x]

Figure 5.2 System design of IMANET [18]

However all the MNs cannot be connected directly with the internet due to the

following limitations of IMANETs:

1. Limited accessibility i.e. all the Mobile Terminals (MNs) cannot access the wired

internet.

2. Lack of wireless bandwidth due to the mobility of MNs, a set of MNs can be

separated from the rest of the MNs and get disconnected from the internet.

3. Longer message latency.

4. The network performance metrics limit the selection of multiple gateways to the

internet.

An Aggregate Caching mechanism has been proposed to address these limitations.

5.5.1 An Aggregate Caching Mechanism

In Aggregate Caching mechanism scheme, the local cache of each MN forms a unified

aggregate cache that reduces the communication latency and improves the information

accessibility. As MNs are forming aggregate cache, the cache of the data item not only

depends on the MN itself, but also on the neighboring MNs [18]. Therefore, an

MN

AP

Fixed router

13

Information Search and Cache Management are proposed in an Aggregate Caching

mechanism.

An Information Search algorithm called Simple Search (SS) is proposed to

determine the data item from the local cache of MNs or APs. A Simple Search

algorithm in an IMANET broadcasts using four control messages; request, Ack, confirm

and reply. This algorithm can be implemented on the top of the existing routing

protocols for MANET [18].

The concept of Cache Management is to employ the cache efficiency by avoiding

the replications of data items. It allows two methods for efficient caching:

1. Cache admission control

2. Cache replacement policy

The Cache admission control [18] is triggered when a MN receives requested data

item and decides whether the MN can or cannot accept the data item for caching. The

decision to cache a data item depends on the distance of other MNs or APs which have

the requested data item.

The method Cache replacement policy is triggered when the MN wants to cache a

data item, but the cache is full and thus selects the data item as a victim. Two elements

are proposed in selecting a victim [18]:

1. The distance (δ), measured by the number of hops away from the APs or MNs which

has the requested data item. The data item with the least δ value is selected as a victim.

2. The elapsed time (τ) caching the last updated δ.

The main goal of our thesis is to analyze the performance of routing protocols and the

possibility to get coverage in a disaster area. Although we are interested in the

performance of the network and the effect of routing, we can see that the caching

mechanism is not affecting the routing. We therefore do not elaborate on this scheme

further in the report.

5.6 Devices supporting MANET networks

The MANETs are purely peer-to-peer networks. The random movement of nodes and

dynamic nature of the network makes the MANET system complex. The MANET

meets many technical challenges in evolving applications and operating systems, to

make the system easy to develop, easy to deploy and easy to use [19].The MANET is a

virtual network and we configure the nodes with the features of electronic devices and

deploy these nodes in the network. For example we can configure a fixed node with the

features of fixed devices like desktop or we can configure some other mobile nodes

with the features of mobile devices like using the phones in trains, buses, etc. And then,

all these nodes can be deployed in the network. Along with the nodes we use

application configuration, mobile configuration, profile configuration, etc to design the

MANET scenario.

In the following section, we explore the support of MANET in today‟s

communication devices like mobile phones, laptops etc. We briefly discuss the

operating systems and software‟s that can be applicable for MANETs at present. For

example, the Ad-hoc Support Library (ASL) is a user space library implementing on-

demand ad hoc routing protocols in Linux [19]. The mobility support of IPv6 for Linux

detects a mobile device and forwards the packet to where the device is currently located

[20].

Most of the devices like laptops, PDAs, smart phones, etc are built up by Linux

platform that supports a MANET. Qolyester is a c++ execution of OLSR protocol for

MANET networks.

The CoCo Node software is Apple‟s Application Programming Interface (API), which

runs on PCs, laptops, mobile phones, smart phones and PDAs. This CoCo‟s MANET

14

provides services irrespective of the size and location of the network. This application is

completely disaster-proof, maintaining the IP applications running without

infrastructure and routes the network traffic in rapidly changing mobile environments.

The CoCo Node supports all existing IP applications [21].

The Android-Gingerbread supports ad hoc networks, acting as wireless base-stations

for other devices. When other devices connect to the mobile (acting as base-station) an

uplink can be provided via USB---> PC---> any internet [22].

The Internet Engineering Task Force (IETF) is currently working on MANETs. The

implementation study is conducted at Ericsson Mobile Data Design (ERV) in

Gothenburg proved that it is possible to set up and run the MANET [23]. The ERV

implemented several mobile ad hoc routing protocols in current operating systems. A

well-developed implementation was built on AODV routing protocol in Linux using

ASL (Ad-hoc Support Library).

The MANET is not yet implemented successfully and is still under research, so at

present most people cannot configure MANET network directly in their electronic

communication devices like mobile phones, laptops, etc.

Figure 5.3 MANET configuration

The mobile devices such as PDAs, smart phones, etc can be connected with each other

in a MANET. From the Figure 5.3, a middle ware establishes connection between

different kinds of mobile devices using wireless interfaces like Bluetooth, Wi-Fi, etc.

The QT toolkit is one such middleware that was developed by Trolltech and it

implements the MANET for mobile devices [24]. The middle ware developed with QT

can be easily activated in different devices with different operating systems; it can be

developed on desktop PC and then can be moved to an embedded system through cross-

compiling. The wireless interface searches, connects and communicates with the

neighboring mobile devices. The service manager has four modules namely device

discovery, profile exchange, participant management and messaging service. It helps to

configure the MANET network automatically without the user interference [24].

At present we can easily configure normal wireless network (Wi-Fi) in general

devices like mobiles, iphones and laptops.

Application layer

Device Discovery

Participant Manager

Contents Exchange

Profile Exchange

Messaging Service

Service Deriving

Wireless interface (Bluetooth, Wi-Fi etc)

QT

Operating System (Linux, Windows)

15

Normally Wi-Fi setup in laptops with windows 7 and vista is possible by following

steps:

Connecting to available networks:

click on internet access icon located on the right hand down corner of the system bar,

there appears all currently available connections ->click on the connection you want to -

> tap connect -> give the security key.

Creating a new connection:

start menu ->control panel ->network and sharing center ->set up a new network

connection ->manually connect to a wireless network and next ->give network name,

security type (WEP), security key and check the ”start this connection automatically”

and next.

Wireless Ad hoc network setup in laptops by following steps:

By configuring ad hoc networks, one device can connect and communicate with other

device directly in a peer-to-peer fashion without the need of access points or routers.

Click on windows control panel->network and internet->network and sharing center-

>click setup a new connection or network->select setup a wireless ad hoc (computer-to-

computer) network and click next->give network name, security key, choose security

type (WPA2-personal).

The Swedish company Terranet designed an ad hoc mesh network in mobiles. They

found a solution to connect the mobile devices without infrastructure network. They

have developed chip that can be built in a mobile phone [25]. This solution might be

very beneficial to people in disaster and other emergency situations. The Terranet‟s

innovation will be tested in 2012. The CoCo communications have developed some

MANET enabled devices like Motorola MC75, Motorola ES400, AMREL RF8, etc and

these can be deployed in most difficult environments [21].

The above discussions show that the research is still going on in analyzing the

possibilities to set up a MANET in the present electronic communication devices and to

deploy it in real applications. The MANET network cannot be easily configured by

oneself like normal wireless setup; it has to be designed by the manufacturers or

administrators. There are two important challenges: the technical challenge which we

have already discussed above and the other is an administrative challenge. In

administrative, the issues like who will decide to set up an ad hoc network in such an

area? Deciding the network name, security settings etc? How will this information be

distributed? Can the devices connect automatically in such situations? Who will pay for

the service etc? However, it takes some more time to solve all these issues and

successfully implement the MANET.

16

6. MANET Routing Protocols

Routing protocols in Ad hoc networks have become an interesting issue due to the fact

that the existing routing protocols supports only the fixed infrastructure and are not

suitable for MANET. The routing protocols are necessary to maintain the network. The

Figure 6.1 shows a classification of MANET routing protocols.

This paper focus on the comparative performance analysis of MANET routing

protocols-OLSR protocol which is proactive/table driven type, TORA and AODV are

reactive/on demand type of routing protocols and GRP. In this chapter, we present the

theoretical concepts of the standardized MANET routing protocols, such as OLSR,

TORA, AODV and GRP.

Figure 6.1 Classification of MANET routing protocols

6.1 OLSR (Optimized Link State Routing)

The optimized link state routing protocol is a well-known pro-active routing protocol.

OLSR is an optimization of pure Link State algorithm in ad hoc networks. Hop by Hop

routing is used in forwarding packets. The nodes in the network use the topology

information from the HELLO protocol and Topology Control (TC) messages in order to

discover their neighbor nodes.

Asymmetric

Asymmetric

Symmetric

Figure 6.2 HELLO message in MANET using OLSR

In OLSR, every node uses the updated information to route a packet. Each node in the

network selects a set of nodes in its neighborhood which retransmits its packets. This

set of selected neighbor nodes is called the Multi Point Rely (MPR) of that node [26].

The MPR is used to reduce the overhead in network. So in OLSR, packets are not

MANET

Proactive Reactive

Link

State Distance

Vector

Link State

Distance

Vector

OLSR

GSR

TBRPF

DSDV

WRP

DSR AODV

TORA

ABR

Position Based

GRID

PNR

GRP

MFR

Node X Node Y

17

broadcasted by all the nodes in the network, instead only the nodes selected as MPR

forward the traffic reducing the size of control message [27]. Every node in the network

maintains an updated routing table. The OLSR uses MPR nodes and the routing

overhead is higher than the other routing protocols. The OLSR is mainly suitable for

large and dense networks. The smaller set of Multi Point Rely provides more optimal

routes.

In OLSR, a HELLO message is periodically broadcasted to their neighbors at a pre-

determined interval. These messages determine the status of the links. For example, if

node X and node Y are neighbors, node X sends HELLO message to node Y. If node Y

receives the message, then the link is said to be Asymmetric. Similarly, it is the same

for the HELLO messages sent by node Y to node X. If two way communications is

established, then the link is said to be Symmetric as shown in Figure 6.2.

These HELLO messages contain all the information about their neighbors. Every node

in the network maintains a routing table with information of multiple hop neighbors.

When the symmetric connections are made, a node chooses a minimal number of MPR

nodes that broadcast Topology Control (TC) messages. The TC messages contain the

information of selected MPR nodes [26, 27]. The HELLO and Topology Control (TC)

are used to discover and disseminate the information throughout the MANET.

6.2 TORA (Temporally Ordered Routing Algorithm)

The Temporally Ordered Routing Algorithm (TORA) is a reactive routing protocol that

establishes quick routes. A key concept in its design is that it decouples the generation

of potentially far-reaching control message propagation from the rate of topological

changes [9]. TORA possess the following attributes:

Loop-free routes

Provide minimal routing functionality

Minimize algorithm reaction

Multiple routing

(-,-,-,-,B)

Source(-,-,-,-,A) (-,-,-,-,C)

(-,-,-,-,E) (-,-,-,-,D)

(-,-,-,-,F)

(0,0,0,0,H)

(0,0,0,0,G ) Destination

Figure 6.3 Route discovery procedure in TORA (Query Message)

TORA is mainly used in MANETs to enhance scalability. The basic functionality of

TORA protocol consists of creating routes, maintaining routes and clearing routes. The

protocol models the network structure as a graph. TORA establishes scaled routes

between the source and destination using the Directed Acyclic Graph (DAG) built in the

destination node. The links in the network can be directed or undirected from source

node to destination node.

18

TORA builds optimized routes using four messages [28]. It starts with a Query

message followed by an Updated message, then Clear message finally Optimization

message. This operation is performed by each node to send various parameters between

the source node and destination node. The parameters include time to break the link (t),

the originator id (oid), reflection indication bit (r), frequency sequence (d) and the nodes

id (i). The first, three parameters are called the reference parameters and the last two are

offset for the respective reference level.

Each node maintains a metric ‟height‟. The links between the nodes are directed based

on the heights [9]. At the beginning, the height of all the nodes is set to NULL i.e. (-,-,-

,-,i) and the destination is set to (0,0,0,0,dest). As the network topology changes, the

heights of the nodes also change.

TORA is a source initiated protocol providing multiple routes for any desired

source/destination pair [29].The source node sends a query message to the destination

node with the id of that intended destination. When a query packet reaches the

destination node, a response known as an update is sent on the reverse path. The height

value of the neighbor node is set to an update message. In Figure 6.3, source node A

sends a query message to destination node H. The neighboring nodes forward the

message to one another and finally the packet is reached to the destination node by its

one hop neighbors G and H.

(-,-,-,3,B) (-,-,-,2,C)

Source(-,-,-,3,A)

(-,-,-,2,F) (-,-,-,1,D)

(-,-,-,2,E)

(0,0,0,0,H)

(-,-,-,1,G) Destination

Figure 6.4 Height of each node updated as a result of UDP message (Update Message)

The source node is represented by A and the destination node is represented by H. A

query message is broadcasted across the network by source node A. Only one-hop

neighbors of the destination reply to the query. In this case, node D and node G are one

hop away from the destination, represented by green color. Therefore, these nodes will

send an updated message in reverse path with the height value set as shown in Figure

6.4.

The main disadvantage of this algorithm is that it is highly dependent on the number

of nodes activated at initial set up [30]. The other disadvantage is that the response to

demand for traffic is dependent on the number of nodes (or rate of change of traffic) in

the networks.

6.3 AODV (Ad hoc On-demand Distance Vector)

AODV is another reactive type routing protocol. In AODV, every node maintains a

routing table. It creates routes in broadcast fashion, where source node broadcasts route

request packet (RREQ) to its neighbor node.

19

The RREQ packet contains the destination IP address and destination sequence

number. The neighbor node accepting the RREQ constructs the reverse path with route

reply packet (RREP). In Figure 6.5, the RREQ message is broadcasted from source

node A to destination node D. The source node „A‟ broadcasts the RREQ message to its

neighbor nodes; the neighbor nodes suited with the RREQ message sends a RREP

incrementing the hop count by one. The neighbor node checks if it suits the RREQ

message, if so then it broadcasts RREP to source node A or if not it broadcasts the

RREQ message in the network again with incremented hop count. When a link failure

occurs, it generates a route error (RERR) message.

The advantage of AODV is that this routing is followed in on-demand fashion by

using the destination sequence number. The disadvantages of this protocol is that it

requires more time to establish a connection, and multiple RREPs are responded to

single RREQ leads to heavy traffic overhead.

b

RREQ (D)

RREQ (D)

RREP (D) RREP (D)

a d

RREQ (D) RREQ (D)

c

Figure 6.5 RREQ and RREP messages in AODV

6.4 GRP (Geographic Routing Protocol)

Geographic Routing Protocol (GRP) is a kind of position-based protocol [31], and each

node is identified by the location. The node positions will be marked by GPS and will

optimize the flooding by dividing into quadrants. A HELLO message is periodically

broadcasted between the nodes to identify their positions and their neighbors. In GRP,

by means of route locking a node can return its packets to the last node when it cannot

keep on sending the packet to the next node.

6.4.1 GRP Routing Lookup

There are two kinds of GRP routing lookup. One is that source and destination are lying

at the same quadrant. In this case, the source node finds the closest neighbor node and

forwards the packet. The packets are broadcasted to the neighbor nodes until the final

destination receives the data packet. The other is that source and destination are at

different quadrants, but belong to the same quadrant at a higher level. The source node

then finds the neighbor node that is closest to the entry point of the destination node‟s

quadrant, and this process is repeated till the packet reaches to the destination.

6.4.2 GRP Flooding

Flooding takes place when the node crosses a quadrant or when the node moves longer

distance than user specified area.

20

6.4.3 GRP Routing Table

In GRP every node maintains one or more routing tables with the updated information

of its neighbor nodes. For different quadrants, the highest level neighboring quadrant

information is maintained.

6.4.4 HELLO Protocol in GRP

HELLO messages are periodically broadcasted in order to keep the information about

the neighbor nodes. Local connectivity is testified through the HELLO messages which

are received from the neighbor nodes. If HELLO message is not received in a specified

period then the message expires and called as “Neighbor expiry time”.

6.4.5 GRP Quadrant

GRP divides ad hoc network into many quadrants to minimize the flooding. The

position of the nodes can be easily identified. Every 4 quadrants in a square form a

higher level quadrant [31]. For example: Aa1, Aa2, Aa3 and Aa4 are four individual

quadrants at level 1, but they belong to quadrant Aa at level 2. Aa, Ab, Ac and Ad are

four individual quadrants at level 2 belonging to quadrant A at level 3. The Figure 6.6

shows the quadrants in GRP.

level 3

Ab

level 2

Ab Ad Bb Bd

Aa Ac Ba Bc

Ab4 Ab3 Ad4Ad3

Ab1 Ab2 Ad1Ad2 level 1

Aa4Aa3 Ac4 Ac3 Ba4 Ba3

Aa1 Aa2 Ac1 Ac2Ba1 Ba2

Size of the quadrant

Figure 6.6 Concept of Quadrants in GRP routing protocol

6.4.6 GRP Routing Backtrack

The backtracking mechanism is used when the routes are blocked, so packets return to

the previous hop and then again a new route is defined. It can occur when the packets

send from source to destination is occupied by default routes.

A B

21

7. Experimental Environment Setup

In this chapter, we will discuss the different networking simulation tools, detailed study

about the environment of OPNET modeler and we have designed our experimental

network model of IMANET with configuration procedures explaining the configuration

of a MANET.

7.1 Network Simulation Tools

It is a challenging task to design an efficient network with high performance. A number

of network simulation tools have been introduced for measuring the performance of the

network. For examples, some commonly used network simulators are given bellow:

The GloMoSim (Global Mobile Information System Simulator) is a scalable

simulation environment for the wireless networks [32]. It is built on Parsec compiler

(Parallel Simulation Environment for Complex Systems) by a C-based simulation

language. Therefore, due to the coding it takes many time frames. For working on

GloMoSim software users need to have a good knowledge about Parsec.

The Packet Tracer, a network simulator is created by Cisco Systems [33]. This tool

supports only the wireless networks. The main purpose of this software is to provide

real time simulation environment. However, ad hoc network feature is not supported by

it. This software doesn‟t support the network modeling, and it is not a free tool for

general use.

The QualNet is a network simulation tool used for analysis of wireless network

environments. This tool is best suited for heterogeneous (wired and wireless) large scale

networks. It is a commercial simulator [34]. C++ programming language is used to

design networks on it. The extension of QualNet is sQualnet which deals with sensor

networks.

The NS2 is the second version of NS (Network Simulator). This simulation software

is based on two programming languages, C++ and OTcl. This tool supports real time

environment and it is not very user-friendly software. It does not support visual and

graphical features [35]. The combination of C++ and OTcl maximizes the performance

of the tool. Therefore, it is widely used by the developers.

The NS-3 is the third version of NS. This tool is also written in C++ and Python

scripting. This software focuses on the real time applications. As it is a recently

developed simulator and is still under development. It requires specialized people to

interact with the users and to maintain the system [36].

The OPNET (Optimized Network Engineering Tool) is one of the popular simulation

software for designing networks and to analysis the network performance [35]. The

reason of its popularity is, it has attractive GUI (Graphical User Interface) and visual

features. The OPNET provides free Academic Edition (IT Guru) for students.

7.2 Detailed View of OPNET Simulator

In this thesis, we have used OPNET 14.5 to design the IMANET scenarios and to

evaluate the performance of state-of-art protocols.

7.2.1 OPNET Simulator for MANET

We designed number of network scenarios of an IMANET to evaluate the performance

of different MANET routing protocols such as OLSR, TORA, and AODV in OPNET

simulator. Although initially, OPNET is developed for military uses only, but now-a-

day‟s it is used in verities of networks like Wi-Fi, UMTS, WiMAX etc [37, 38]. There

are number of reasons for using OPNET modeler such as, it is very user-friendly tool

that provides attractive and intuitive GUI and visual features. The Graphical

22

environment is used to create the routing protocols models intuitively and it also

supports broad range of wireless networks with modeling simulation and analysis. It is

reliable, robust and efficient and also possible to simulate heterogeneous networks with

different protocols. Another advantage of this simulator is that the users need not have

the knowledge of any programming language to use the OPNET.

7.2.2 Workflow of OPNET

The working procedure of OPNET is generally divided into four sections. Figure 7.1

illustrates the basic workflow of OPNET.

Figure 7.1 A general Workflow of OPNET

First, users need to design the network in OPNET based on the experimental model.

For example, in our thesis, we implemented the IMANET scenarios in OPNET 14.5

modeler.

Secondly, after designing or implementing the network model in OPNET, you apply

the statistics on the designed model. The Table 7.3 represents the list of parameters that

we applied to design our network.

Thirdly, test the network scenarios by selecting the run option for a specific time to

collect simulation results and statistical values of simulation results.

Finally, you analyze the performance of network scenarios based on the collected

experimental results.

7.3 Description of Experimental Parameters

The Table 7.3 gives the list of simulation parameters that we used to design our network.

The simulators are the simulation network software. Some examples of network

simulators are GloMoSim, Qualnet, NS 2/3, Packet Tracer, OPNET etc. The OPNET

14.5 is used as a simulator in our thesis.

The Network Scale is a scenario. OPNET supports following network scales such as

world, enterprise, campus, office etc. In our thesis, we have selected campus network

scale, but this is not fixed. The areas of network scale can also vary in simulations.

The Network Area is the region in which users design the network. For example,

selecting campus network scale, we selected three different network areas; 1km*1km,

3km*3km and 10km*10km.

In a wireless network no dedicated path exists between source and destination nodes

similar to wired networks, instead multiple paths exist among nodes in wireless network.

In such situations, finding an optimum path is an important issue. Network Protocols

Design network model

Specify statistics

Run simulations

Analyze results

23

helps to find the optimum paths. In this thesis we study three routing protocols; OLSR,

TORA and AODV.

Network

Parameters

Variation in the

number of node

Variation in the network area

Terrain Size (m2) 1km*1km, 3km*3km,

10km*10km

1km*1km, 3km*3km,

10km*10km

MAC Protocol IEEE-802.11b (Direct

Sequence)

IEEE-802.11b (Direct Sequence)

Traffics HTTP, voice HTTP, voice

Routing Protocols AODV, TORA, and

OLSR

AODV, TORA, and OLSR

Bandwidth 11Mbps 11Mbps

Pause time 100s 100s

Node Placement Random Random

Transmission

Range

300m 300m

Network Address IPv4 IPv4

Mobility Model Random-Waypoint Random-Waypoint

No. of nodes 10, 25, 100 nodes 10, 25, 100 nodes

Network Metrics Throughput, Network

Load, Media Access

Delay, page download

response time, MOS

Throughput, Network Load,

Media Access Delay, page

download response time, MOS

Table 7.3 List of Experimental Parameters

There are different network traffics applications such as database, email, FTP (File

Transfer Protocol), TCP (Transmission Control Protocol), HTTP (Hyper Text Transfer

Protocol), voice, print, video conferencing that can be used to test the performance of

the designed networks. The http traffic is data sent and received over the protocol

between an end device and the web server. The http traffic analyzer captures all http

traffic between an end device and the Internet; It provides various information about

this traffic in real-time. And now a day‟s communication widely means of voice

communication. Therefore, in our thesis to complete our empirical study we considered

two important traffics, HTTP and voice.

There are two types of nodes such as, fixed nodes and mobile nodes. In our study we

designed an IMANET that consists of a MANET (infrastructure less) and a backbone

network. To implement the MANET scenarios we selected 10, 25 and 100 mobile nodes

and 3 fixed gateway nodes.

There are a number of network types available for wireless networks, such as Wi-Fi

(IEEE 802.11), Bluetooth, Zigbee, Microwave etc. As OPNET 14.5 supports the Wi-Fi

(IEEE 802.11), in this thesis, the designed network scenarios follow the Wi-Fi IEEE-

802.11b (Direct Sequence) with maximum data rate 11Mbps and packet size 512 byes.

The Data Rate is a physical characteristic and it depends on the type of the network.

Usually data rate depends on the technology or type of the network.

In a MANET, Multiple paths exist between source and destination nodes with the

random mobility of the nodes. The time period is calculated when the node stops for a

while before taking a random destination, it is known as Pause Time. The stability of

24

networks depends on the value of it. Higher pause time stands for stable network and

vice versa.

In the designed network the issues like: How the nodes move, how we calculate

routing path from one node to other node, how we calculate displacement; all these

depend on the propagation model. There are a number of propagation models tested in

different simulators such as Trajectory Model, random way point model, Okumura

Model, Hata Models for Urban, Suburban and Open Areas, COST Hata Model, etc. In

our experiment, these IMANET scenarios are designed for providing different services

for the affected peoples in a disaster area. Within the affected area peoples can move

with random speeds and random directions. The characteristics of random way point

model are similar to the behavior of these scenarios, where mobile devices can move in

random motion and with random directions. Therefore, we used Default Random Way

Point Model in our designed network scenarios.

This is the speed of the nodes within the network terrain. This parameter varies

depending on the network scenarios. Normally within the affected area, peoples can

move in different ways, such as walk, bus, train, car etc. In order to design a real type

scenario by considering all moving peoples we considered uniform 0-20 (m/s) speed for

the mobile nodes in our designed IMANET scenarios.

The network metrics are the parameters used to observe the performance of the

designed networks. There are a number of network metrics considered depending on the

network traffic or applications. For HTTP and voice traffics, we considered throughput,

network load, media access delay, Mean Opinion Score and page download response.

Here, by observing the throughput and network load we can get overall performance of

the designed network scenarios. Download page response is a key concern of HTTP

traffic, and by a numeric value, MOS we can get the idea of quality of voice in the

designed scenarios.

The output or the average rate of successful message delivery is known as

throughput. It is measured in bit/sec.

The network load is the maximum handling capacity of the mobile nodes i.e., the

amount of data (traffic) being carried by the network.

The latency or delay time i.e., the time taken to carry the data packet between two

nodes somewhere along the path.

The quality of voice for a communication system is measured based on a numerical

value, Mean Opinion Score (MOS). It is given as a number from 1 to 5. Different

values stand for a specific quality of voice, 5 stands for perfect quality of voice, 4 is for

fair, 3 is for annoying quality, 2 is for very annoying and 1 is for impossible to

communicate.

The simulation time is the time taken during the process of simulations. We observed

that if we run the simulation for a long time, millions of simulations evens need to

consider for measuring the average QoS parameters of HTTP and voice traffics, as

nodes are considered as in random motions with random directions. Therefore, to get

correct simulation results from our designed IMANET scenarios, we run the scenarios

for 300 seconds only.

7.4 Design the IMANET scenario in OPNET

In the model design, first we have to run the OPNET 14.5 modeler and select an empty

blank scenario from the start-up wizard, there appears the workspace. In the workspace,

we can design our IMANET backbone network selecting a global scenario as illustrated

in Figure7.2. The backbone network is connected with a MANET scenario through the

different MANET gateways. To configure MANET scenarios, we need to configure

different parameters like application configuration, profile configuration, mobility

25

configuration, MANET Gateway, mobile nodes. For example, a scenario of a MANET

with 25 nodes is demonstrated in Figure 7.3. For our experiment, we generated HTTP

traffic from the HTTP server which is connected with a router of the backbone network

for an IMANET scenario. The details of configurations for overall scenarios of

IMANET are presented in Appendix A to F.

In order to configure a MANET gateway in OPNET 14.5, we need to connect it with a

MANET and a wired Network/LAN. Therefore, we connected a MANET gateway with

a MANET via Wi-Fi (IEEE-802.11b) and with a wired LAN by connecting an Ascend

router via a 10baseT physical link. In Figure 7.2, router 0, router 3 and router 4 are

directly connected with MANET Gateway, MANET Gateway1 and MANET Gateway2,

respectively (see Figure 7.3).

In Figure 7.3, all mobile nodes can communicate with each other‟s (if in range of each

other). They can communicate with a MANET gateway directly if the nodes come close

enough of it or via different neighboring mobile nodes. For selecting optimum route

these mobile nodes use some MANET routing protocols. The mobile nodes can receive

the HTTP and voice traffics which are generated from the server and the server is

connected with a MANET scenario through router and MANET gateways. To analyze

the performance of the state-of-art protocols with respect to different network metrics

we applied the HTTP and voice traffics and collected the experimental results.

Step by step setup of the IMANET scenario:

1. A MANET is a network without fixed topology as nodes are considered to be

mobile. In our network, we considered 10, 25 and 100 mobile nodes to form a

MANET in different areas 1km*1km, 3km*3km and 10km*10km.

2. In order to form an IMANET scenario, we formed a backbone network with

different routers. MANET Gateways are used as intermediary devices to link the

MANET and the backbone network.

3. All mobile nodes in the MANET can communicate with MANET gateways to

connect with a server which is connected in the backbone network.

4. The mobile nodes can communicate with MANET gateways directly if it gets

close enough or via the neighbor nodes. The MANET routing protocols finds an

optimal route to communicate with the MANET gateways and to connect with a

server.

5. Employing HTTP and voice traffics for different routing protocols, we collected

the simulation results varying the number of nodes and areas in order to measure

the performance of routing protocols for our designed IMANET scenarios.

7.5 Data Entities

The data elements are used to design the network scenarios in work space. The different

entities are available in the object palette. For designing the network scenarios, we have

used application, profile, mobility configuration, nodes and server as data entities.

7.5.1 Application configuration

The application configuration in OPNET modeler supports a variety of network

traffics/applications such as FTP, HTTP, TCP, voice, video streaming, etc. According

to the requirements you can choose or configure traffics for every new project. In our

network scenarios for 10, 25 and 100 nodes respectively, we defined two applications in

the application configuration namely HTTP with high load and voice with PCM Quality

Speech. By right clicking on the application configuration on the workspace, we can

26

create a new application with a new name and also can configure the different

parameters for each individual application.

Figure 7.2 A backbone network of an IMANET

7.5.2 Profile configuration

For individual application traffic we need to configure the profile. For our network

scenarios, we have generated two profiles; HTTP with high load and voice with PCM

quality in the application configuration. In order to configure the profile configuration,

we have selected the edit attribute and set the profile name, adjust the number of rows,

we can also set other parameters like operation mode: to run the application randomly

or sequentially one after the other, start time: the starting time of the profile, duration:

default set to the end of simulation, and repeatability; i.e. how often we like to run our

profile during the time it is set for.

7.5.3 Mobility configuration

The mobility configuration specifies the type of mobility model set to the nodes in the

network. In the network scenarios, we have selected random way point for these mobile

nodes. The mobile nodes follow the path of this model to transmit the data packet from

source to destination. We configure the mobility type by selecting edit attribute option

where we set the following attributes: start time, speed, stop time, pause time, etc. The

mobility of the nodes is controlled by these attributes.

7.5.4 Server

The WLAN server normally provides the different services, such as FTP, HTTP, voice,

video etc. for the end users. In our experimental study, server generates the HTTP and

27

voice traffic and it is located outside the MANET. It is connected with a fixed router,

Router-1 as illustrated in Figure 7.2. In order to do that we configured the HTTP and

voice traffics in the server, as the client nodes are relying on the HTTP and voice

profiles.

Figure 7.3 A scenario of IMANET with MANET Gateways

7.5.5 Nodes

In order to design the IMANET scenarios, we configured scenarios in different areas for

10, 25 and 100 nodes. These mobile nodes support maximum data rate 11Mbps. We can

configure the mobile nodes for the following attributes: speed, start time, end time and

pause time, etc. In this network, we set the random way point mobility model for the

mobile nodes. We have employed three routing protocols namely OLSR, TORA and

AODV to configure the scenarios with different number of mobile nodes. In the

workspace, by right clicking on mobility configuration, we can set the different

parameters of mobility configuration. We can select the MANET routing protocols by

configuring the all mobile nodes.

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8. Experimental Results and Analysis

In this chapter, we collect the simulation results from the designed network scenarios to

analyze the performance of the MANET routing protocols OLSR, AODV and TORA by

varying different network parameters.

8.1 Impact of the number of nodes on the QoS parameters of HTTP traffic for

different protocols

In this section, the experimental results demonstrate the comparison among OLSR,

AODV and TORA protocols by varying the number of node for different network areas.

For examples, the simulation results in section 8.1.1, 8.1.2 and 8.1.3 exhibit the

different QoS parameters of HTTP traffic for different number of nodes such as, 10, 25

and 100 in different network sizes- 1km*1km, 3km*3km and 10km*10km, respectively.

8.1.1 Scenario 1(a) QoS of HTTP traffic for 10, 25 and 100 nodes in an area of

1km*1km

(a) (b)

(c) (d)

Figure 8.1 QoS parameters of HTTP traffic for different protocols (10, 25 and 100 nodes in 1km*1km

area): (a) media access delay (sec), (b) network load (bit/sec), (c) page response time (sec), (d) throughput

In scenario 1(a), the media access delay graph illustrates that TORA shows

comparatively higher values with the increment of the number of node, and OLSR

shows almost steady characteristic curve for the different amount of node as depicted in

Figure 8.1(a). For example, in 10 nodes scenario the average media access delay of

29

OLSR, AODV and TORA are approximately 0.001sec, and 0.003sec, respectively.

However, for 100 nodes the average value of OLSR, AODV and TORA experienced

0.001sec, 0.009sec and 0.0108sec, respectively. In Figure 8.1(b), the network load

graph illustrates that at 10 and 25 nodes all three protocols show almost equal amount

of network load which is comparatively very lower than the average value of larger

amount of node. However, in 100 nodes scenario, AODV shows slightly higher network

load than other two protocols. It is usually causes for route break due the move way of

source node. To re-establish the broken routes it uses query messages to the upstream

node [39]. But in multi-hop scenarios with high mobile nodes upstream links may also

broken down, in this case node backwards a error message to the source and again

reinitiate the new route which causes additional network load in the scenario. The page

response time graph shows that the variation of amount of node does not much

influence on characteristic curve of TORA and OLSR as depicted in Figure 8.1(c). But

the average value of AODV increases with the increment of node. Similar to the

network load graph, different protocols show almost average equal amount of

throughput for lower amount of node. But for 100 nodes scenario, OLSR shows

significantly higher throughput than other two protocols. It uses routing tables to

establish a new route which is faster in route establishment and causes less network

congestion in a small area scenario.

8.1.2 Scenario 1(b) QoS of HTTP traffic for 10, 25 and 100 nodes in an area of

3km*3km

The scenario 1(b) gives a detail comparison of QoS parameters of different protocols for

various amount of node within a fixed 3km*3km area. In Figure 8.2(a), the media

access delay graph illustrates that the average value of 25 node scenario is

comparatively higher than the values of 10 and 100 nodes scenarios for different

protocols. And OLSR shows comparatively lower media access delay for different

amount of node compare to other state-of-art protocols. The Page response time also

shows characteristics curve almost similar to the media access delay as depicted in

Figure 8.2(c). The network load graph exhibits that all three protocols show average

equal amount of network load at 10 and 25 nodes scenarios.

(a) (b)

30

(c) (d)



However, OLSR shows comparatively greater network load than other two protocols at

100 nodes scenario. In Figure 8.2(d), the throughput graph shows similar characteristic

graph of network load. But, OLSR shows comparatively higher throughput at 25 and

100 nodes scenarios.

We observe the following differences in Figures 8.1 and 8.2. In Figure 8.1 for 100

nodes scenario, the network load of AODV higher than others. However, in Figure 8.2

it shows very low network load compare to others. However, OLSR shows

comparatively higher value of it. AODV illustrates comparatively higher average page

response value In Figure 8.1. But in Figure 8.2, TORA shows higher average value of it.

However, in both Figures OLSR shows lower page response time. The average

throughputs of different protocols in Figure 8.2 fall down compare to Figure 8.1. But in

both Figures, OLSR always shows higher throughput than others.

8.1.3 Scenario 1(c) QoS of HTTP traffic for 10, 25 and 100 nodes in an area of

10km*10km

(a) (b)

31

(c) (d)



In section 8.1.3, scenario 1(c) presents the different QoS parameters of HTTP traffic for

various amount of node within a fixed area 10km*10km. Figure 8.3(a) illustrates that

OLSR shows very few media access delay for the scenarios with different amount of

node. However, TORA shows very higher media access delay at greater number of node.

The different protocols show almost equal amount of network load at 10 and 25 nodes

scenarios as depicted in Figure 8.3(b). But, OLSR shows significantly higher average

network load compare to other two protocols. The Figure 8.3(c) shows that page

response time of TORA is experienced very few in the scenarios with various amount of

node. On the other hand, AODV illustrates very high and steady page response time in

the observed scenarios. At 10 and 25 nodes scenarios, similar to the network load graph

we observe almost equal amount of the average for different protocols. However, for

100 nodes scenario the throughput of OLSR is significantly higher than other two

protocols as depicted in Figure 8.3(d).

8.2 Impact of the number of nodes on the QoS parameters of voice traffic for

different protocols

The experimental results illustrate the comparison of QoS parameters of voice traffic

among OLSR, AODV and TORA protocols by varying the number of nodes for

different network areas. The simulation results presented in the sections 8.2.1, 8.2.2 and

8.2.3 show the different QoS parameters of voice traffic for different number of nodes

such as, 10, 25 and 100 in different network sizes-1km*1km, 3km*3km and

10km*10km, respectively.

8.2.1 Scenario 2(a) of Voice traffic for 10, 25 and 100 nodes in an area of 1km*1km

The scenario 2(a) presents the QoS parameters of voice traffic in different amount of

nodes scenarios within a fixed 1km*1km area. The Figure 8.4(a) illustrates that

different protocols exhibit almost equal amount of media access delay at 10 and 25

nodes scenarios. However, at 100 nodes scenario, AODV and TORA show higher

average values of it compare to the average value of OLSR.

32

(a) (b)

(c) (d)

Figure 8.4 QoS parameters of voice traffic for different protocols (10, 25 and 100 nodes in 1km*1km

area): (a) media access delay (sec), (b) network load (bit/sec), (c) MOS value, (d) throughput

In Figure 8.4(b), the network load graph illustrates almost similar characteristic graph

of media access delay graph. For example, very few and almost equal amount of

average network loads show in 10 and 25 nodes scenarios. But at 100 nodes scenario,

TORA and OLSR shows much higher values of it compare to the average value of

AODV. The MOS graph presents that different protocols shows almost equal amount of

average value of MOS at 10 and 25 nodes scenarios, which is slightly higher than the

average value of it at 100 nodes scenario as illustrated in Figure 8.4(c). The Figure 8.4(d)

demonstrates that the variation of number of node does not influence much on the

average throughout of TORA and AODV by maintaining steady characteristic curve.

However, at 100 nodes scenario, OLSR shows significantly higher throughput than the

other two protocols.

8.2.2 Scenario 2(b) of Voice traffic for 10, 25 and 100 nodes in an area of 3km*3km

The scenario 2(b) demonstrates the different graphs of QoS parameters of voice traffic

for various amounts of node within a fixed 3km*3km area. The Figure 8.5(a) illustrates

that different protocols show almost equal amount of media access delay. But, with the

increment of number of node, the media access delay of different protocols also

33

increase. Among three protocols, AODV exhibits higher media access delay at 25 and

100 nodes scenarios. On the other hand, at the lower amount of node, for example 10

and 25 nodes scenarios the different protocols show almost equal amount of network

load and at 100 nodes scenario, TORA shows slightly higher average value of it than

OLSR as depicted in Figure 8.5(b). At lower amount of node, different protocols

illustrate almost equal amount of average MOS value as shown in Figure 8.5(c). But at

100 nodes scenario, TORA shows very low MOS value compare to other two protocols.

The throughput graph shows that the variation of the number of node does not much

influence on the average value of it at 10 and 25 nodes scenarios of different protocols

as demonstrates in Figure 8.5(d). But at 100 nodes scenario, OLSR shows very higher

throughput than others.

(a) (b)

(c) (d)



8.2.3 Scenario 2(c) of Voice traffic for 10, 25 and 100 nodes in an area of

10km*10km

The different QoS parameters of voice traffic for different protocols are presented in

scenario 2(c) by varying the number of node within a fixed area 10km*10km. In Figure

8.6(a), although all three protocols show approximately equal amount of media access

delay in the scenario of 10 nodes, AODV shows comparatively higher average value of

it at 25 and 100 nodes scenarios. Figure 8.6(b) illustrates that the scenarios of low

amount of node, for example 10 and 25 nodes, different protocols demonstrate almost

34

equal amount of network load. But at 100 nodes scenario, OLSR exhibits large amount

of network load compare to other two protocols.

(a) (b)

(c) (d)



The variation of the number of node does not much influence on the MOS value of

AODV and TORA. But it affects on the MOS value of TORA as presented in Figure

8.6(c). Similar to the MOS graph throughput graph also demonstrates that the variation

of the number of node does not affect on the average throughput of AODV and TORA.

However, it influences on the throughput of OLSR as shown in Figure 8.6(d). For

example, at 10 and 25 nodes scenarios OLSR shows almost equal amount of throughput

of AODV and TORA, but at 100 nodes scenario the OLSR demonstrates much higher

throughput than other two protocols.

We observe the following points in the Figures 8.4, 8.5 and 8.6. Similar to the HTTP

traffic, OLSR shows lower media access delay and it also demonstrates higher

throughput in all scenarios compare to others. As voice traffic is heavier traffic than

HTTP it causes heavy congestion in the network. Therefore, we observe the average

lower throughputs for different protocols in these figures compare to HTTP traffic

scenarios.

35

8.3 Impact of network area on the QoS parameters of HTTP traffic for different

protocols

In our experimental study, we also observed the impact of variation of network area on

different routing protocol for a fixed number of nodes. In appendix G, H and I we can

see the QoS of parameters of HTTP traffic in various network areas such as, 1km*1km,

3km*3km and 10km*10km for a fixed 10, 25 and 100 nodes, respectively.

Similar to the variation of number of node, the variations of network sizes also causes

the impact on the QoS parameters of HTTP traffic for different routing protocols. In

appendix G, we see that the QoS parameters, media access delay and throughput

decrease with the increase of node in TORA. And, the variation of network area much

influences on the QoS of parameters of HTTP for TORA. However, for various network

sizes, OLSR shows better performance by demonstrating lower media access delay and

greater throughput than other protocols. In appendix H, for 25 nodes scenarios, the QoS

parameters of HTTP traffic degrade for different protocols with the increase in network

sizes. In appendix I, for a large number of nodes (100 nodes), the variation of network

size strongly influences on the QoS parameters of different routing protocols. The QoS

of parameters sharply reduce with the increase in network area. Although, OLSR shows

better throughout in an area 1km*1km than others, but for 3km*3km and 10km*10km

areas the throughput of all protocols is very poor and all protocols show much lower

throughput than other scenarios.

8.4 Impact of network area on the QoS parameters of Voice traffic for different

protocols

We also observed the impact of variation of network area on the QoS parameters of

voice traffic for a fixed amount node. The simulation results are also illustrated at the

end of the report in Appendix J-L. The simulations demonstrate that the variation of

network sizes also influences the QoS parameters of voice traffic for different routing

protocols. In appendix J, for 10 nodes scenario, the simulation results illustrate that the

throughput of OLSR fall down sharply with the increment of network area. The media

access delays of all protocols also increase with the increment of network area.

However, no significant influence is observed on different protocols for the variation of

network size. And, the QoS parameters of 25 and 100 nodes for different protocols in

various areas are presented in appendix K and L, respectively. In appendix K, the media

access delay of AODV is much influenced by the variation of network size and it shows

increasing trend with the increment of network size. The network load graphs of various

protocols are also increasing with the increment of network sizes. However, the

throughput and MOS value does not influence much on the variation of network size. In

appendix L, the variation of network sizes also influences on different QoS parameters

of voice traffic for different protocols. The media access delay graph shows that in a

large area AODV protocol shows lower delay than others and the other two protocols

maintain almost similar values of delay for various areas. The network load of OLSR

protocol gradually increases with the increment of network sizes. Although AODV

maintains a steady curve of network load, TORA shows a decreasing trend with the

increment of network sizes. And in a large network area, all protocols show higher

MOS value than other scenarios. The throughput of different protocols is gradually

decreasing with the increment of network areas.

8.5 Theoritical Explanation of Simulation Results

In chapter 6 we explained how the different protocols work and in Chapter 7 we

presented the result of the simulations. In this section we will discuss the results of the

simulations and compare their expected behavior from the theoretical presentation.

36

OLSR is a proactive routing protocol and to perform its routing operations each node

uses one or more routing tables. Routing of proactive is faster than reactive. Therefore,

for a small network and less number of nodes, OLSR may show better performance than

other protocols. But in highly mobile MANET scenarios, for a large number of nodes

and large network size scenario OLSR protocol will not perform well. And in our

empirical study, OLSR shows similar behavior as we get in theoretical study. Although,

in small network OLSR shows greater throughput than others, but for a large network

size the value of it degrades.

TORA is a reactive protocol and it uses different strategies to ensure loop free route. It

uses different query packets instead of routing table to perform its routing operations. It

also considers multiple routes in parallel to find the optimum route. By theoretical study

it is clear that TORA is designed for scalable networks. But in our empirical study, for

larger network it shows poor QoS in case of both HTTP and voice traffics and it might

be due to high mobility of nodes in our scenarios.

AODV, reactive routing protocol uses some unique strategies such as destination

sequence number rather than other reactive protocol to perform its routing operation.

AODV requires more route establish time as it doesn‟t establish multiple routes for

finding the best route. If any existing route fails it again initiates whole route query

process as routing information is not maintained. In our experimental scenarios, we

consider highly mobile scenarios and so, the considered scenarios are unstable.

Therefore, AODV does not demonstrate the high QoS of HTTP and voice traffic in our

network scenarios.

GRP is a GPS based geographic routing protocol. To find out the position of a node

within the network area, it considers different level of quadrants. It uses table driven

approach and as well as query packets to find out the optimum route. Presently

researchers are trying to test it in different MANET scenarios. But in our experiment,

we cannot simulate it as some devices, such as MANET gateways do not support the

GRP.

37

9. Conclusion and Future Work

9.1 Conclusion

In this thesis, to reach the research goal, first we implemented an IMANET in a network

simulator OPNET and then the designed network models are demonstrated in Figures 7.2

and 7.3. Secondly, we designed different network scenarios in OPNET 14.5 by varying

the amount of nodes and sizes of networks to observe the impact of number of nodes and

network size on different routing protocols. Thirdly, we measured the average QoS

parameters of HTTP and voice traffics from our designed IMANET scenarios.

The scenarios 1 and 2 demonstrated the impact of the number of nodes for different

routing protocols in QoS parameters of HTTP and voice traffics. A detailed analysis on

the performance of the three protocols is presented in sections 8.3 and 8.4 in the report.

We analyze all these works and conclude the following points.

Different routing protocols demonstrate various performances by showing dissimilar

QoS parameters for various numbers of nodes and for various network areas. It is

observed that in a fixed small and medium network area for numerous nodes, although

OLSR shows higher network load, it shows better performance than other two protocols

by demonstrating lower media access delay, page response time and greater throughput.

However, in a large network, although TORA illustrates lower page response time but

yet, OLSR protocol demonstrates comparatively better performance than other protocols.

And in all scenarios for various nodes, TORA protocol demonstrates poor performance.

According to the simulation results demonstrated in appendix G to L, we observe that

the variation of network sizes are also affected on the QoS parameters of HTTP and

voice traffics for different routing protocols similar to the variation of number of nodes.

For a fixed less number of nodes, comparing to other two protocols the performance of

TORA is much influenced by the variation of network area. The performance of OLSR

is comparatively better than other protocols as it shows lower media access and greater

throughput. For a fixed 25 nodes scenario, the throughput of different routing protocols

decrease with the increase of network area. However, for a fixed 100 nodes scenario, the

QoS of parameters falls down with the increment of network area.

9.2 Proposed Solutions to the Research Questions

Working on this thesis, six (research) questions have been revealed in different chapters

as follows.

Q.1 A detail survey of different disaster scenarios is presented in chapter 2. As the

existing communication system is based on infrastructure, it might completely fail during

the disaster situations and so there is a need for MANETs. In MANET, all the devices

are considered as mobile and can communicate without using infrastructure network

topology. If the existing electronic devices can configure both infrastructure as well as

ad-hoc networks, then the MANET is a viable solution to the communication demands

that exist in a disaster area.

Q.2 Nodes are considered as highly mobile in wireless MANETs. Therefore, finding an

optimum route between any two nodes in such dynamic unstable network is a complex

task and an efficiency of designed MANET scenarios in a disaster area depends on the

efficiency of routing protocols. The classification and the working principle of widely

used MANET protocols is presented in the chapter 4.

Q.3 In Table driven protocols, each node maintains one or more routing tables. In order

to find out a new route it collects the route information of destination node from the table

and then forwards the packet toward the route. However, maintaining updated routing

tables for number of nodes in a MANET is not a simple issue. To overcome the

38

limitation of table driven approach, reactive protocols are developed. The reactive

protocols use different query packets instead of maintaining up-to-date routing table. But

it takes more routing time than table driven approach. Among these two approaches, on

demand approach is more effective in MANETs.

Q.4 Different parameters like number of nodes, pause time, node mobility model,

network size, data rate, packet size etc effect the performance of MANET routing

protocols. Normally, the number of nodes in a scenario depends on the application of

selected area. Pause time is an important parameter by which we can design the

different types of networks depending on the applications. For the designing unstable

network (example, Vehicle networks) we need to set the pause time very short and a

long pause time sets for the designing of stable networks (example, Sensor network).

Data rate and packet size depend on the communication environment. For example, in

IEEE 802.11b (Wi-Fi) the data rate is 11Mbps and packet size is 192μs. In our

experimental study keeping all other network parameters constant, we vary the number

of nodes and network area. We observed that the variation in number of nodes had more

influence on the QoS parameters of different routing protocols rather than network area.

Q.5 A model of IMANET scenario in OPNET is demonstrated in chapter 7 and the

details of configuration procedure of IMANET in OPNET are illustrated in Appendix

A-L. To analyze the performance of different routing protocols we measure the

different QoS parameters of HTTP and voice traffics such as media access delay,

network load, page response, MOS and throughput.

Q.6 The theoretical study of different routing protocols is illustrated in chapter 4 and the

figures in chapter 8 demonstrate the QoS parameters of HTTP and voice traffics of

different MANET routing protocols. Based on the theoretical as well as empirical study

we conclude that the OLSR shows comparatively better QoS for both HTTP and voice

traffics. However, for a large network the throughput of OLSR fall down. The protocol

TORA shows comparatively poor QoS in different scenarios and the performance of

TORA is much influenced by varying the network area. However, AODV shows

medium QoS parameters in our considered scenarios.

9.3 Future Works

During the course of the thesis, we noticed some constraints which we did not find at the

start. Initially, we fixed our goal to evaluate performance of MANET routing protocols

along with GRP in our designed network scenarios. Although OPNET simulator has

many advantages, we also observed some limitations; in our designed IMANET model

we used few MANET gateways, but these devices do not support the GRP routing

protocol. Therefore, we failed to evaluate it in our scenarios.

As OPNET has less flexibility to design network, we designed scenarios with IEEE

802.11b with maximum bandwidth 11Mbps and the transmission range of each mobile

node is always fixed 300m. To design more efficient scenarios we should configure

more flexible networks.

For better understanding, observation of the traffic flow is also an important part in

designing a network model. As OPNET does not support the traffic flow with

visualization we fail to do it.

A wide number of routing protocols are proposed for MANETs, but till now no routing

protocol ensured the reliable multimedia communication in MANET environments.

All these findings may help future researches to continue their research in the

development of IMANET as well as other Ad-hoc networks.

39

REFERENCES

[1] D.O. Jörg, Performance Comparison of MANET Routing Protocols in Different

Network Sizes, Comp. Science Project, Institute of Comp. Science and Networks and

Distributed Sys, University of Berne, Switzer land (2003)

[2] A. Jamali, N. Naja and D.E. Ouadghiri, Comparative analysis of ad hoc networks

routing protocols for multimedia streaming, International Conference on Multimedia

Computing and Systems, pp. 381-385 (2009)

[3] H. Ashtiani, M. Nikpour and H. Moradipour, A Comprehensive Evaluation of

Routing Protocols for Ordinary and Large-Scale Wireless MANETs, International

Conference on Networking, Architecture, and Storage, pp. 167-170 (2009)

[4] N. Qasim, F. Said and H. Aghvami, Mobile Ad-Hoc Networks Simulations Using

Routing Protocols for Performance Comparisons, Proceedings of the World Congress

on Engineering, Vol. 1, pp.1-6 (2008)

[5] K. N. Palanisamy, Modular Implementation of Temporally Ordered Routing

Algorithm, Masters thesis, Bharathidasan University (1992)

[online]: http://systems.cs.colorado.edu/Networking/ToraClick/nandesh-thesis.pdf.

[6] N. Aschenbruck, M. Gerharz, M. Frank and P. Martini, Modelling Voice

Communication in Disaster area Scenarios, 31st IEEE Conference on Local Computer

Networks, pp. 211-220 (2006)

[7] [online] http://www.drgeorgepc.com/Earthquake1964Alaska.html

[8] I. Huang, K. Fangk, Reducing the digital divide of the electronic government of the

921 reconstruction areas in Taiwan, Proceedings of Technology Management for Global

Economic Growth, pp. 1-8 (2010)

[9] H. Ehsan, Z.A. Uzmi, Performance comparison of ad hoc wireless network routing

protocols, 8th International Conference of Multitopic, pp. 457-465 (2004)

[10] E.M. Royer, C. Keong, A review of current routing protocols for ad hoc mobile

wireless networks, International Conference on Personal Communications, vol. 6, pp.

46-55 (1999)

[11] Routing protocols and concepts, Introduction to dynamic routing protocols, CCNA

exploration companion guide, pp. 148-177, (2008)

[12] C. Km, Y.B. Koy, N.H. Vaidya, Link-state routing protocol for multi-channel

multi-interface wireless networks, International Conference on Military

Communications, pp. 1-7 (2008)

[13] R.V. Boppana, S.P. Konduru, An adaptive distance vector routing algorithm for

mobile ad hoc networks, 20th Annual Joint Conference of the IEEE Computer and

Communications Societies, vol. 3, pp. 1753-1762 (2001)

[14] N. Gupta and R. Gupta, Routing protocols in Mobile Ad-Hoc Networks,

International Conference an Emerging Trend in Robotics and Communication

Technologies, (2010)

[15] M. Abdoos, K. Faez, M. Sabaei, Position Based Routing with More Reliability in

Mobile Ad Hoc Network, World Academy Of Science, Engineering and Technology, pp.

1-4 (2009)

[16] V. Kumar, Simulation and Comparison of AODV and DSR Routing Protocols in

MANETs, Master Thesis, Thapar University (2009)

[17] M.H. Baig, H.S. Kiani, Performance Evaluation of MANET using MPLS, Master

Thesis, Blekinge Institute of Technology (2010)

[18] S. Lim, W.C. Lee, G. Cao and R.C. Das, A Novel Caching Scheme for Internet

based Mobile Ad Hoc Networks, Computer Communications and Networks, 12th

International Conference, pp. 38-43 (2003)

[19] [online]: http://www.yongguangzhang.net/research/wireless.html [Accessed: Dec

40

15, 2011]

[20] [online]: http://tuxmobil.org/manet_linux.html [Accessed: Dec 15, 2011]

[21] [online]: http://www.cococorp.com/product_coco_node.html [Accessed: Dec 21,

2011]

[22][online]:http://groups.google.com/group/androidplatform/browse_thread/thread/

f7ca397f4865de2a [Accessed: Dec 21, 2011]

[23] T. Larsson, N. Hedman, Routing Protocols in Wireless Ad-hoc Networks- A

Simulation Study, Master’s thesis, Lulea University Of Technology (1998)

[online]: http://www.ietf.org/proceedings/44/slides/manet-thesis-99mar.pdf

[24] C.B. Park, B.S. Park, H. Choi, Service management middleware for mobile devices

in a MANET environment, 13th International Symposiumon Consumer Electronics, pp.

584-585 (2009)

[25] http://terranet.se/ [Accessed: Jan 25, 2012]

[26] M.A. Rahman, F. Anwar, J. Naeem, M.S.M. Abedin, A simulation based

performance comparison of routing protocol on Mobile Ad-hoc Network (proactive,

reactive and hybrid), International Conference on Computer and Communication

Engineering, pp. 1-5 (2010)

[27] C.Mbarushimana, A. Shahrabi, Comparative Study of Reactive and Proactive

Routing Protocols Performance in Mobile Ad Hoc Networks, 21st International

Conference on Advanced Information Networking and Applications Workshops, vol. 2,

pp. 679-684 (2007)

[28] J.M. Kim, I.S. Han, J.B. Kwan, H.B. Ryou, A Novel Approach to Search a Node in

MANET, International Conference on Information Science and Security, pp. 44-48

(2008)

[29] A. Jamali, N. Naja, D.E Ouadghiri, Comparative analysis of ad hoc networks

routing protocols for multimedia streaming, International Conference on Multimedia

Computing and Systems, pp. 381-385 (2009)

[30] S.R. Chaudhry, A.A. Khwildi, Y. Casey, H. Aldelou, A Performance Comparison

of Multi On-Demand Routing in Wireless Ad Hoc Networks, Wireless And Mobile

Computing, Networking and Communications, IEEE International Conference, vol. 3,

pp. 9-16 (2005)

[31] L. Zhiyuan, Geographic Routing Protocol and Simulation, 2nd International

Workshop on Computer Science and Engineering, vol. 2, pp. 404-407 (2009)

[32] [online]: http://pcl.cs.ucla.edu/projects/glomosim/ [Accessed: Jan 29, 2012]

[33] [online]: http://digeset.ucol.mx/cisco-regional/retooling/5_packettracer4.1.pdf

[Accessed: Jan 29, 2012]

[34] [online]: http://www.eurecom.fr/~chenj/SimulatorManual-3.1.pdf [Accessed: Jan

29. 2012]

[35] [online]: http://www.cs.wustl.edu/~jain/cse567-08/ftp/simtools/index.html

[Accessed: Feb 2. 2012]

[36] Y.R. Kumar, S. Chittamuru, A Case Study on MANET Routing Protocols

Performance over TCP and HTTP, Master Thesis, Blekinge Institute of Technology

(2010)

[37] J. Prokkola, OPNET-Network Simulator, Simulations and Tools for

Telecommunications, Master Thesis, University of Oulu (2008)

[38] [online]: http://www.opnet.com/university_program/research_with_opnet/

[Accessed: Feb 17, 2012]

[39] S. Tang, B. Zhang, A robust AODV protocol with local update, Joint Conference

of the 10th Asia-Pacific Conference on Multi-Dimensional Mobile Communications,

vol. 1, pp. 418-422 (2004).

41

APPENDIX

A. HTTP Server Configuration

(a) (b)

(c)

42

B. Backbone Network Configuration

(a) (b)

(c)

43

C. Application Configuration

(a) (b)

D. Profile Configuration

(a) b)

44

E. MANET Gateway Configuration

(a) (b)

F. Mobility Configuration

(a) (b)

G. Scenario of HTTP for 10 nodes in different areas 1km*1km, 3km*3km,

10km*10km

(a) (b)

45

(c) (d)

QoS parameters of HTTP traffic different protocols (10 nodes in 1km*1km, 3km*3km and 10km*10km

areas): (a) Media Access Delay (sec), (b) Network Load (bits/sec), (c) Page response time(sec), (d)

Throughput.

H. Scenario of HTTP for 25 nodes in different areas 1km*1km, 3km*3km,

10km*10km

(a) (b)

(c) (d)


areas): (a) Media Access Delay (sec), (b) Network Load (bit/sec), (c) Page response time(sec), (d)

Throughput.

46

I. Scenario of HTTP for 100 nodes in different areas 1km*1km, 3km*3km,

10km*10km

(a) (b)

(c) (d)


areas): (a) Media Access Delay (sec), (b) Network Load (bit/sec), (c) Page response time(sec), (d)

Throughput.

J. Scenario of Voice traffic for 10 nodes in different areas 1km*1km, 3km*3km,

10km*10km

(a) (b)

47

(c) (d)

QoS parameters of voice traffic different protocols (10 nodes in 1km*1km, 3km*3km and 10km*10km

areas): (a) Media Access Delay (sec), (b) Network Load (bit/sec), (c) MOS Value, (d) Throughput

K. Scenario of Voice traffic for 25 nodes in different areas 1km*1km, 3km*3km,

10km*10km

(a) (b)

(c) (d)



48

L. Scenario of Voice traffic for 100 nodes in different areas 1km*1km, 3km*3km,

10km*10km

(a) (b)

(c) (d)



49

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