i
PERFORMANCE ANALYSIS OF OLSR PROTOCOL IN MANET
CONSIDERING DIFFERENT MOBILITY SPEED AND NETWORK
DENSITY
KOAY YONG CETT
BACHELOR OF COMPUTER SCIENCE (COMPUTER NETWOR
SECURITY) WITH HONOURS FACULTY OF INFORMATICS AND
COMPUTING UNIVERSITY SULTAN ZAINAL ABIDIN
2019
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DECLARATION
I declare that the project report entitled Quality Analysis of the OLSR Protocol in
MANET Considering Different Mobility Speed and Network Density is based on the
results of my own investigations using information from knowledgeable sources with
the exception of quotations and quotations properly acknowledged. I also claim that no
student of the University of Sultan Zainal Abidin has previously submitted it.
Signature: ………………………
Name: Koay Yong Cett
Date:
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APPROVAL
This project report, entitled Performance Analysis of OLSR Protocol in MANET
Considering Different Mobility Speed and Network Density, was prepared and
presented by Koay Yong Cett (Matric Number: BTBL17046228) and found acceptable
in terms of content, quality and partial compliance with the Bachelor's degree in
Computer Science (Network Security) requirement in University of Sultan Zainal
Abidin.
Signature: ………………………………
Supervisor: Dr. Nor Aida Binti Mahiddin
Date:
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ACKNOWLEDGEMENT
First and foremost, I am grateful to my beloved God for blessing me and encouraging
me to finish the OLSR Protocol Performance Analysis this final year in MANET
Considering Different Movement Speed and Network Density study. I would also like
to convey my gratitude and appreciation to my lecturer, Dr. Nor Aida Binti Mahiddin,
for giving me a chance to do work and lead me through study and project experience. I
was profoundly influenced by her passion, honesty, and inspiration. She showed me
how to carry out the research and explain the conclusions of the study as nicely as
possible. Under his leadership, it was a great privilege and joy to be supervised. I am
also extremely indebted to my parents for their determination, encouragement, care and
willingness to educate and prepare me for my coming years. I would also like to thank
my classmates for the encouragement, support and feedback that I have provided
throughout this process.
Lastly, I am very much thankful to the Faculty of Informatics and Computing for the
chance given to me to explore and discover new knowledge. I would really like to thank
all the lecturer for aiding me with assistance and guidance to complete the project for
the final year.
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ABSTRAK
Rangkaian Ad Hoc Mudah Alih (MANET) merupakan rangkaian yang dicipta secara
dinamik oleh banyak nodyang bebas atau autonomi yang disambungkan melalui
sambungan tanpa wayar. MANET adalah rangkaian ad hoc mudah alih dan tidak
bergantung kepada infrastruktur yang sedia ada seperti router di rangkaian berwayar
atau titik akses dalam rangkaian tanpa wayar. Nod mudah alih dalam rangkaian ini
bergerak secara rawak dan topologi sering berubah. Protokol routing MANET
memainkan peranan penting untuk memastikan komunikasi yang boleh dipercayai dan
stabil antara nod mudah alih. Dalam routing MANET, protokol menggambarkan
komunikasi antara nod mudah alih dan mendorong mereka untuk memilih laluan yang
terbaik antara sumber dan destinasi. Pada umumnya, terdapat 3 jenis protokol
penghalaan: proaktif, reaktif dan hibrid. Projek ini akan memberi tumpuan kepada
OLSR yang merupakan protokol penghalaan proaktif. OLSR ialah ‘optimized link- state
routing protocol’ di mana penyebaran paket dalam rangkaian dilakukan dengan teknik
relasi pelbagai titik (MPR). Kertas kerja ini menilai prestasi protokol pelayaran OLSR
pada kelajuan mobiliti dan ketumpatan rangkaian yang berbeza. Metrik prestasi yang
dipertimbangkan dalam kajian ini diukur berdasarkan keupayaan purata, nisbah
penghantaran paket dan kelewatan purata. Simulator Rangkaian (NS) versi 2.35 dan
patch luaran UM-OLSR digunakan untuk merangsang dan menilai prestasi protokol
OLSR.
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ABSTRACT
Mobile Ad Hoc Network (MANET) is generated by an autonomous mobile node
network linked via wireless links in a dynamic manner. MANET is a network of self-
organization and does not relied on pre-existing infrastructure including the wired
network routers or wireless network access points. The mobile nodes in this network
are shifting randomly, and topology is often evolving. MANET routing protocols play
a vital role in making connectivity between mobile nodes reliable and stable Protocols
logically conclude interaction between mobile nodes in MANET routing and urge them
to pick the best pathway between origin and destination. There are 3 types of routing
protocols are generally available: constructive, reactive and hybrid. This project will
focus on OLSR which is a proactive routing protocol. OLSR defined as an optimized
version link state routing where the diffusion of packet in the network is performed with
multi point relay (MPR) technique. This paper examines OLSR routing protocol
performance on varying speed of mobility and network density. The performance
metrics considered in this study is measured based on average throughput, packet
delivery ratio and average delay. Network Simulator (NS) version 2.35 and external
patch UM-OLSR is utilised to stimulate and test the performance of OLSR protocols.
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CONTENTS
DECLARATION ........................................................................................................... i
APPROVAL ................................................................................................................. ii
ACKNOWLEDGEMENT .......................................................................................... iii
ABSTRAK ................................................................................................................... iv
ABSTRACT .................................................................................................................. v
CONTENTS ................................................................................................................. vi
LIST OF TABLES .................................................................................................... viii
LIST OF FIGURES .................................................................................................... ix
LIST OF ABBREVIATIONS ..................................................................................... x
LIST OF APPENDICES ............................................................................................ xi
CHAPTER 1 ................................................................................................................. 1
INTRODUCTION ........................................................................................................ 1
1.1 Background ......................................................................................................... 1
1.1.1 Mobile ad hoc network (MANET) ............................................................. 1
1.1.2 Classification of the Routing Protocols ................................................ 3
1.1.3 Optimized Link State Routing (OLSR) Protocol ................................ 5
1.2 Problem Statement ........................................................................................ 9
1.3 Objectives ....................................................................................................... 9
1.4 Scopes ........................................................................................................... 10
1.5 Limitation of Works .................................................................................... 10
1.6 Summary ...................................................................................................... 11
CHAPTER 2 ............................................................................................................... 12
LITERATURE REVIEW ......................................................................................... 12
2.1 Introduction ...................................................................................................... 12
2.2 Related Works .................................................................................................. 13
2.3 Summary ........................................................................................................... 19
CHAPTER 3 ............................................................................................................... 20
METHODOLOGY .................................................................................................... 20
3.1 Introduction ...................................................................................................... 20
3.2 Research of Methodology ................................................................................ 20
3.3 Simulation ......................................................................................................... 22
3.4 Project Framework .......................................................................................... 24
3.5 Project Flowchart of the Route Selection Technique .................................... 27
vii
REFERENCES ........................................................................................................... 29
APPENDIX ................................................................................................................. 32
viii
LIST OF TABLES
TABLE TITLE PAGE
2.1 Comparison of Parameter Metrics 13
3.1 Comparison of Network Simulator 22
3.2 Table in the cache of the nodes 26
ix
LIST OF FIGURES
FIGURE TITLE PAGE
1.1 Classification of Routing Protocol in MANET 3
1.2 Hello Message Format 6
1.3 Format of an OLSR Packet 6
1.4 Classical Flooding and Flooding with MPR 8
3.1 Research Methodology 21
3.2 NS2.35 installed in Ubuntu 16.04 23
3.3 UM-OLSR is patched into NS2.35 23
3.4 Framework of OLSR Routing Protocol 24
3.5 Routing Selection Technique (MPR) 27
x
LIST OF ABBREVIATIONS
MANET Mobile Ad-Hoc Network
OLSR Optimized Link State Routing
AODV Ad-Hoc On-Demand Distance Vector
TORA Temporally Ordered Routing Algorithm
ZRP Zone Routing Protocol
DSR Dynamic Source Routing
DSDV Destination-Sequenced Distance-Vector
GRP Gathering based Routing Protocol
GPSR Greedy Perimeter Stateless Routing
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LIST OF APPENDICES
APPENDIX TITLE PAGE
1 Gantt Chart 1: Activities and milestones FYP1 32
1
CHAPTER 1
INTRODUCTION
1.1 Background
1.1.1 Mobile ad hoc network (MANET)
The term MANET originate from the name of an Internet engineering task force
(IETF) work group founded in 1998 with the purpose of standardizing the routing
protocols based on Internet protocol technology for ad hoc networks, mobile, etc.
MANET can be described as a wireless network that is self-organized and self-
configured. It is dynamically generated by an autonomous system of mobile nodes
linked by wireless connections that can be implemented without any external
infrastructure support or centralized administration like centralized base station (BS) or
access point (AP). It is a temporary network that is able to setup anytime and anywhere
as an alternative way for the situation where the infrastructure is poor and insufficient.
For instance, MANET is the primarily selected network to be used in disastrous areas
that could have destroyed existing and local infrastructure, causing a huge breakdown
in communication.
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MANET essentially consists of multiple nodes or computers like tablets, cell
phones and video cameras. All of these machines are linked so that they can
communicate with each other via a wireless connection. In addition, All MANET
mobile nodes may connect or leave the network at any time without any limitations or
requirements. Then the nodes able to move randomly and organize themselves. Thus,
the network's topology may change vigorously and unforeseeable. Besides, each
network node can be used as a recipient, transmitter or intermediate node that functions
as a router that transmits data to other mobile nodes. The nodes are highly mobile in
real situations and rely on batteries to function depending on the MANET application
types [1].
Routing protocols are required in routing, a method of conveying information
across the network from a point of origin to the exact destination. The routing in
MANET is based on a easy approach that allow the re-emission of the data message by
each node for the ease of propagation within network. The key issues of routing protocol
lie in the choice of the best pathway. To find the correct route between two or mode
nodes in the network, the routing protocols are used. In a specific manner, these
protocols help nodes to make decision on finding the optimal path to route the packets
in network. It is also used to create and sustain an up-to-date routing table that allows
the node to choose the optimal route between the origin node and the target node for
communication. A few routing protocols were suggested to address the problems of
highly mobile nodes and frequent topology shifts in the MANET network [2].
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1.1.2 Classification of the Routing Protocols
Figure 1.1: Classification of Routing Protocols In MANET
Classification of Routing Protocols is divided into 3 types:
I. Proactive Protocols
It is also defined as table-driven protocols which uses mapping tables to retain
any node's route and path in the network. This builds the network's routing protocols by
constantly sending out the topological information data packets to each node in the
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network. Thus, with the newest routing information, the routing information of each
node is updated regularly. When new nodes are attached or removed from the network,
control messages are sent to neighbouring nodes and routing tables are modified. This
type of protocol typically utilizes link state algorithms that flood the network with
details about their neighbours [3].
II. Reactive Protocols
It is also called on-demand protocols and initiates a path exploration mechanism
only when the origin node has the information packets to be transmitted to the
destination to find the path between the communicating nodes. Once the path is
established, route maintenance will be done to maintain this route until it is no longer
necessary or the data packets arrive at the destination node. Series of action have been
taken to maintain the new route and avoid any looping such as a sequence number is
used [3].
III. Hybrid Protocols
It is a derivative of the approach of mixing proactive and reactive protocol. It
provides some benefits of both the above listed protocols by establishing an immediate
reactive vicinity up to a certain distance that is interconnected with the proactive
connections. A reactive scan is activated if an application needs to send packets to a
node outside this region. With this, the routes in the coverage zone of a node are
available immediately. Initially, the routing tables are used as proactive routing
protocols with the root nodes. If the node found that no data about the pathway to the
5
destination of origin node, pathway detection is initiated as reactive routing protocols
[4].
1.1.3 Optimized Link State Routing (OLSR) Protocol
OLSR is the equivalent implementation of the routing protocol for the classical
link-state. In contrast to the distance vector routing protocol, this routing protocols are
not subjected to routing loops and have no issues in term of scalability [3]. The
transmission of topological information between nodes leads to the creation of a
significant amount of traffic due to the flooding mechanism of the classical connection
state routing protocols. It is undesirable attribute of the MANET due to inadequate
resources. New procedure is implemented by the OLSR in the network to reduce the
volume of traffic involved. All nodes of OLSR are allowed to receive the data packet
of the topological information and only minimum number of nodes known as Multipoint
Relays (MPRs) are able to transmit the messages across the network. MPRs of certain
node are minimum number of its neighbour that are necessary to communicate will all
its other neighbours within two hops [7]. Thus, it guarantees the data messages of
topological information of network will be received by every node in network.
Two principal mechanism is found in OLSR protocol which is neighbourhood
detection and one for topology management. For this mechanism, 4 types of control
messages used are HELLO, TC, MID, and HNA [1]. Neighbour sensing is performed
by using HELLO packets. It has 3 different function in OLSR protocol. The messages
are sent to its neighbours at one hop and two hops. In addition, it is also used in the
declaration of local node as MPRs. [5] The HELLO message format is shown in Figure
2. The HELLO message is also part of the body of OLSR message that are shown in
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Figure3. The HELLO data packet is sent in data field of OLSR packet with Message
Type and TTL both set at 1.
Figure 1.2: HELLO message format [9].
Figure 1.3: Format of an OLSR packet [9].
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The dissemination of topological packet is performed by the spreading of TC
packets using optimized diffusion or MPRs. The TC message packet contain a list of
links in the neighbourhood of node in the network [6]. The OLSR protocol also take
into the consideration of all interfaces that are linked to the node with MID messages.
Thus, the nodes are able to use all available routes independent of the type of each hop
in an efficient way. One of the interface addresses in the network will be chosen to be
the main address and uses as a reference in control messages. Furthermore, HNA
messages are used for the declaration of subnetworks and host outside of MANET. The
subnetworks and hosts are made reachable by a node acting as a gateway [1].
The main goal of MPRs is to lower down the number of redundant or unneeded
transmission during the normal diffusion of the message. MPRs is specifically useful in
the transmission of control messages over the network. The classical diffusion
mechanism applied in link state protocol is optimized by the MPRs. A group of MPRs
is selected by a given node based on the knowledge of the neighbourhood at two hops.
In MANET network with topology that changes in a random manner, the MPRs needed
to be recalculated every time the two-hop neighbour set experience changes. For this
reason, the status of MPRs is set for a limited period in the neighbourhood [8]. The
improvement in diffusion methods of the packets with MPR technique is shown in the
Figure 4. In the first part of the diagram, central node diffuses the control packets to
eight other nodes using the classical the classical flooding technique. On the next
illustration, the relay technique is used and four nodes is selected to relay the message.
Thus, With the choice of MPRs, the number of unnecessary transmissions is minimized.
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Figure 1.4: Classical flooding and Flooding with MPR technique [1].
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1.2 Problem Statements
The nodes relocate in an arbitrary and unpredictive way due to the multi-hop
behaviour of ad hoc networks. This non-specific and volatile node motion causes the
connection to split and reform continuously. The performance of the mobile ad hoc
network is depending on the interconnection between any two nodes transferring the
message that contain the topological information. The mobility speed and network
density of the nodes mat affect the duration required to forward the messages from its
source to destination. Thus, it is important to utilise the routing protocol so that the
nodes in the network can maintain the information packet needed for transferring
packets from source to destination.
1.3 Objectives
The main goal of this thesis is to solve the problem statement proposed by
analyse the effect of different mobility speed and network density. Thus, this project is
mainly focus on the following objectives:
o To study the OLSR in MANET.
o To apply the OLSR routing protocol in MANET by using NS2 stimulation tools.
o To analyse and evaluate the performance of OLSR by using different node
mobility speed and network density.
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1.4 Scopes
The scope in this thesis is to evaluate the performance of OLSR routing protocol
in MANET environment. In addition, the other scope is to study the simulation tools
needed for this routing protocols.
1.5 Limitation of Works
The MANET could not be implemented in real-life experiment because:
1. Costly
The coverage area for the application of MANET such as in a disastrous
environment is large. Then, the amount of labour and mobile devices needed for the
network is very high. Thus, the expenditures for setting up the real-world environment
for MANET will be enormous.
2. Time for configuration is long
The configuration of MANET in real world is time consuming due to the
coverage area required is wide. For instance, disaster area like tsunami is huge and it
will take a few days to set up and build this environment for real-life simulation.
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1.6 Summary
This chapter covered the context, MANET presentation, problem statement,
project goal, scale and limitation. Because of the existence of MANET, it is promising
in terms of education to establish this research project as a commitment to MANET's
field.
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CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
In this chapter, few research papers related to the project are selected as a
literature review. Data and information are collected to give a better view of how the
process works and how it benefits from the project.
As described in chapter 1, it is understandably stated about the definition of
routing protocol in MANET. In the multi hop nature of MANET, the nodes
communicate with each other node using the wireless link. Every node can be viewed
as a host as well as a router that transmits topological information data packets to other
nodes in the network. The foremost difficulty in the application of multi hop mobile ad
hoc networks is the evolution of the routing protocol that can perform best in finding
pathway between the origin and targeted destination in MANET. Since MANET is less
a network system and the nodes are constantly breaking and rebuilding, its existence
makes it difficult to control the network. The implementation of the routing protocol is
therefore used to boost the MANET's performance.
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2.2 Related Works
Figure 2.1: Comparison of Metrics Parameter.
Ad hoc routing protocol is considered as the convention and typical term to
describe the protocol that help to make the decision on which paths to route the packets
between the source and destination of computing devices in MANET. In ad hoc
networks, nodes do not possess the knowledge about the topology of their networks.
Due to the nature of limited resources and random movement of nodes, routing can be
a problem in MANET. Thus, routing protocol is proposed to solve the situation and find
the optimal pathway from the origin to target node.
In a research paper “Performance Analysis of AODV, OLSR and GPSR
MANET Routing Protocols with Respect to Network Size and Density” [10] from
Muthana Najim Abdulleh and Salman Yussof. In this paper, they perform a routing
protocol evaluation comparison with the specific number of nodes and the grid size of
the stimulated area. Routing protocol assessment was conducted by network simulation
14
and efficiency is defined in terms of throughput, average end-to-end delay, packet
delivery fraction and normalized routing load. The stimulation is executed for 2
scenarios and the differences between these 2 scenarios was in term of stimulation
parameter examined. They set the number of nodes for the simulation in the first
example at 30, 50, 70, 90, 110, 130, 150 nodes. In the second scenario, they focus on
the network density and set the map size into 500×500, 750×750, 1000×1000,
1250×1250, 1500×1500 and 1750×1750 in term of metre. The result from the
simulation shows that GPSR outperform OLSR and AODV in the most of the tests.
Furthermore, the simulation findings also demonstrate that the increase in the number
of nodes influences the normalized routing load, while the change in the map scale of
the stimulated region has a significant effect on throughput, end-to-end delay and packet
delivery fraction.
In a research paper from K.Natarajan and G.Mahadevan titled “Mobility based
Performance Analysis of MANET Routing Protocols” [11] make a performance
analysis on how the speed in mobility can influence the routing performance of
protocols. The routing protocols that chosen for the performance analysis is Ad hoc on
demand distance vector routing (AODV), Destination Sequenced Distance Vector
(DSDV), Dynamic Source Routing (DSR), Location-Aided Routing (LAR), Optimised
Link State Routing Protocol (OLSR), Fisheye State Routing (FSR) and Zone Routing
Protocol (ZRP). The network stimulation is split into 3 different scenario which is low
mobility where node speed is 10m/s to 15m/s, medium mobility with node speed is set
to 15m/s to 20m/s and high mobility where node speed is 20m/s to 30m/s. The pause
time is kept constant at 10s. The simulation outcome reveals that LAR and AODV work
better than other protocols, where both transmit approximately 50 to 60 percent data
15
packets, regardless of speed, successfully. Besides, the DSR shows that 53% and 95%
higher delay than AODV and DSDV protocols.
In addition to that, Lakshman Naik L, R. U. Khan and R. B. Mishra in “Analysis
of Node Velocity Effects in MANET Routing Protocols using Network Simulator
(NS3)” [7] analysed the performance of various ad hoc routing protocols with different
node speed. The purpose of this paper is to discuss the effect of mobility speed of the
nodes on different routing protocol. The routing protocol that are chosen for the
performance analysis is AODV, DSDR and OLSR. They run the network simulation
with 3 different node speed which is 10m/s, 20m/s and 30m/s. The simulation has been
carried out by keeping 10 number of source/sink connections fixed. As for the result,
the throughput of the OLSR protocol is high as compared to AODV and DSDV during
node speed variation. Although OLSR has a slight degradation as node speed increases
but it is still better comparing to AODV and DSDV. In addition, packet delivery ratio
of OLSR is higher when comparing to AODV and DSDV. However, OLSR slightly
degrades as node speed increases. In End to end delay, the performance of OLSR is
superior when comparing to the AODV and DSDV. However, OLSR also experience a
slightly degradation as node speed increases. Moreover, the packet loss results reveal
that the performance of OLSR is better than AODV and DSDV, but it slightly degrades
as node speed increases. Lastly, they infer that performance of OLSR is better when it
is compared to AODV and DSDV in all the metrics they analysed.
16
On other hand, Gouri M. Patil, Ajay Kumar and A. D. Shaligram in
“Performance Comparison of MANET Routing Protocols (OLSR, AODV, DSR, GRP
and TORA) Considering Different Network Area Size” [12] make a comparative
performance analysis of various ad hoc routing protocol by considering different
network area size. The routing protocols that have been evaluated are OLSR, AODV,
DSR, GRP (Gathering based Routing Protocol) and TORA (Temporally Ordered
Routing Algorithm). The simulation of the various routing protocol is performed for
network area size of 500 X 500 square meters, 1000 X 1000 square meters and 2000 X
2000 square meters with 50 number of nodes is kept consistent. The results show that
the TORA is the best choice when network load is an important factor. The DSR is the
second-best choice continued with AODV, OLSR and GRP for extensible network area
size up to 2000x2000 square meters. Besides, if end-to-end is important factor in the
application scenario, the GRP provides better performance if network area size is up to
1000 x1000 square meters. While, OLSR is the first choice for 2000x2000 squares
meters. In addition, AODV have the maximum throughput in 3 scenarios with different
network area size.
This recent paper by D. Kumar and S.C. Gupta had conducted “Transmission
Range, Density & Speed based Performance Analysis of Ad Hoc Networks” [13]. The
purpose of this paper is to study the effect of various transmission range, node density
and speed on three routing protocols which is OLSR (proactive), DSR (reactive) and
ZRP (hybrid). These 3 routing protocols represent the three groups in the mobile ad hoc
network which is proactive, reactive and hybrid routing protocols respectively. The
network simulation is executed based on 3 scenarios in term of node density,
transmission range and node speed where the simulation area is kept constant at 1000 x
17
1000 square meter. The first scenario is modelled by using specific the number of nodes
in the fixed area which is 25, 50, 75 and 100 nodes. The second scenario is modelled
by considering different the range of transmission. The transmission range used in this
scenario is 50, 150, 250, 350 and 450 m. As for the third scenario, the speed is set to
0m/s, 4m/s, 8m/s, 12 m/s, 16m/s and 20 m/s in a fixed simulation area. The simulation
result shows DSR performs better than OLSR and ZRP in the performance metrics end
to end delay. In packet delivery ratio, DSR outperforms OLSR and ZRP in all the case.
Lastly, they concluded that DSR is much more better performing protocol followed by
OLSR and ZRP based on the performance metrics used in the simulation.
Moreover, Ashutosh Sharma and Rajiv Kumar conducted a paper “Performance
Comparison and Detailed Study of AODV, DSDV, DSR, TORA and OLSR Routing
Protocols in Ad Hoc Networks” [14] that generates a performance analysis of various
number of ad hoc routing protocols in mobile ad hoc networks. Comparison between
different routing protocols have been done by using different performance metrics like
the average throughput, average packet data ratio and average delay. The results show
that AODV is outperform the other routing protocols in the average throughput. In
addition, OLSR perform best in the scenario of average packet delivery ratio due to the
OLSR perform route selection in acyclic path. Besides, TORA is effective in
performing in dense network by broadcasting the message to all nodes. Lastly, DSR
produces the least delay in the network. They concluded the reactive protocols perform
well in term of average delay and throughput.
18
Lastly, Ako Muhammad Abdullah, Emre Ozen and Husnu Bayramoglu (2019)
conducted “Investigating the Impact of Mobility Models on MANET Routing Protocols”
[15]. In this paper, the authors investigate few mobility models such as Fast Car Model
(FCM), Slow Car Model (SCM), Race Walking Model (RWM) and Human Walking
Model (HWM). These mobility models are designed by the authors with different speed
applied to analyse the performance of AODV, OLSR and GRP protocols with ten pause
time values. Different performance metrics are used to compare the performance
between mobility models with different routing protocol used. For instance, data drop
rate, media access delay, network load, retransmission attempts and throughput. In this
simulation, they show that the performances of these protocols are different from one
model to another. Thus, the results from one model cannot serve as a basis for another
mobility models. From the result of simulation, they deduced that the OLSR protocols
provides better performance than two other routing protocols. In addition, The OLSR
protocol is the most suitable and efficient network routing protocol allowing low delay
and retransmission attempts and higher performance in terms of data transfer from the
source node to the destination node. They also found that the AODV protocol performed
much better compared to OLSR and GRP in respect of data drop rate and network load
in all the configuration of models. AODV network load was a bit high in HWM model
when compared to GRP protocol. In addition, the GRP protocol also yields a much more
lower media access delay and higher throughput than AODV in all scenarios. According
to the results of simulation, they also concluded that they type of application plays a
vital role in determining which protocol should be utilised in the network. For example,
the OLSR protocol is ideal for offering real-time support.
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2.3 Summary
This chapter manifest and conclude the methods and parameters that were
implemented in the research paper that are related to the evaluation and routing selection
scheme in MANET. This study is crucial to obtain the concept and theory needed to
conduct a successful project.
20
CHAPTER 3
METHODOLOGY
3.1 Introduction
This Chapter discuss the methods and alternatives ways that have been utilised
from the beginning till the end of the following project. The simulation of the project
will also be discussed. The network simulation tools used is NS2 Simulator. In addition,
this chapter will also review the research of methodology and flowchart of the project.
It can provide a better understanding in term of visualization in the implementation of
the project.
3.2 Research of Methodology
In the research of methodology, the planning and scheduling of the project is
crucial for the development of the project. Based on the figure below, there are few
phases of the methodology mentioned. The first phase is related to identifying the
problems regarding the field of research. For this project, the problems of MANET are
identified in this phase. The problem statement is identified based on the related
research paper for a better understanding about MANET and the problems occurred on
MANET. The second phase is designing and developing. The main purpose of the
following phase is to find the suitable method to be implemented in the project. For this
21
project, different mobility speed and network density are used on the OLSR routing
protocol. Next phase in the methodology is the simulation of project. In the following
phase, the simulation that will be used in this project is discussed. The stimulation tool
used for this project will be used for this project is Network Simulator 2 (NS2). In
addition, the last phase is evaluating the performance. The performance metrics of this
project need to be evaluated and analysed. The performance metrics that will be
evaluated are packet delivery ratio, average delay and average throughput.
Figure 3.1: Research Methodology [16].
22
3.3 Simulation
Table 3.1: Comparison of Network Simulator [17]
The simulation of the project is performed with NS2 due to the constraints in
real-life experiment which consume a lot of time and cost. NS2 is used to stimulate the
OLSR routing protocol in current project. NS2 is one of the simulation types utilised in
the network stimulation such as MANET and VANET. This offers emulation for both
wired and wireless networks for routing and multicast protocols. Network Simulator is
authorized under GNU (General Public License) version 2 and is widely referred to as
NS2. Therefore, NS2 is an even-driven, object-oriented and discrete simulator. It is
written in combination of C++ and Octl/tcl programming language. In NS2, C++ is
utilised for thorough protocol implementation and Octl is utilised for the configuration.
The compiled C++ objects are made available to Otcl interpreter in the NS2. This
provides the C++ objects to be managed from the simulator Otcl level. The NS2 is used
for this project because it has the advantages of large number of available models [18].
In addition, UM-OLSR is an OLSR implementation for ns2 network simulator. Thus,
23
UM-OLSR will be used for the simulation of OLSR routing protocol of MANET in this
project.
Figure 3.2: NS2.35 installed in ubuntu 16.04.
Figure 3.3: UM-OLSR is patched into NS2.35.
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3.4 Project Framework
Figure 3.4: Framework of OLSR Routing Protocol.
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The OLSR protocol consists of two principal mechanisms which is
neighbourhood detection and neighbourhood sensing for topology management. For
both of this mechanism, OLSR protocol uses 4 types of control messages which are
HELLO, TC, MID, and HNA. In addition, neighbourhood sensing is carried out by the
OLSR protocol using the HELLO packets [1]. The distribution of topological
information is performed by the dispersal of TC packet using optimised diffusion or
MPRs. The TC messages contain a list of links in the neighbourhood of the mobile
nodes for the packet management of the OLSR protocol [19]. Besides, the OLSR
protocol takes into account all interfaces kinked to mobile unit by using the MID
messages. Therefore, the noes of the network can utilise all of the available routes
independent of the type of interfaces used at each hop. The OLSR node select one of its
interface address as main address, which it then can be used as a reference in control
messages. Moreover, HNA messages in the OLSR protocol are used to declare
subnetworks and hosts which is outside of the MANET that is reachable by a node
acting as gateway [1].
In neighbourhood sensing, OLSR protocol as a derivative of the classical link-
state protocols maintains a variety of information tables. The tables are updated every
time control messages are received and every time it is sent out. The nodes store a
variety of different tables in the cache:
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Information tables Explanation
MPR selector set It contains all the local nodes that are selected as MPRs in the
network.
Neighbour Set All the neighbour at one hop distance are saved in the
following table. It is updated dynamically through link set
data. The information involved the symmetric and
asymmetric link neighbours is also stored at this table.
Two-hop neighbour
set
It contains information which is accessible via one hop paths
and this also include the node that inquiry about the
information itself.
In addition, this table may contain similar information of the
same nodes that are appeared in the neighbour set table.
Table 3.2: Table in the cache of the nodes [1].
Furthermore, the HELLO messages have three different roles in OLSR protocol.
The messages are sent to the neighbour at one hop distance for link sensing and
neighbour sensing and to neighbour at two hops away for the two-hop sensing. Lastly,
it functions as an MPR selector sensing which declare the MPRs in the network [1].
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3.5 Project Flowchart of the Route Selection Technique
Figure 3.5: Routing Selection Technique (MPR) [19]
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OLSR is also known as proactive and table-driven routing protocol. The link
state routing protocols are not subjected to routing loops. In addition, Link state routing
protocol possess no problem in term of scalability. However, link state routing protocol
generates a large amount of traffic during the exchange of topological data in mobile
nodes. Large amount of traffic is an undesirable attribute in MANET due to limited
resources available in MANET [19]. The OLSR protocol implemented a new procedure
or technique to greatly reduce the volume of traffic involved in the process of
exchanging topological data between nodes. In the OLSR protocol, all of the nodes are
authorized and allowed to receive the topological data message. Nevertheless, only a
small number of nodes known as multipoint relays (MPRs) are able to transmit all these
messages across the network. In explanation, The MPRs of the given node are the
minimum number of its immediate neighbours which have the necessities to contact all
its neighbour in two hops. Thus, the MPRs guarantees that the data message of the
network topology will be received by every node in the network.
3.6 Summary
The following chapter clarifies and shows the concept of the research
methodology, framework, and flowchart of the project. It provides a better
understanding for the implementation of the simulator that we selected in this project.
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REFERENCES
1. Frikha, M. (2011). Ad hoc networks: routing, QoS and optimization. London:
ISTE.
2. Sarkar, S. K., Basavaraju, T. G., & Puttamadappa, C. (2016). Ad Hoc Mobile
Wireless Networks Principles, Protocols, and Applications, Second Edition.
Baton Rouge: CRC Press.
3. Ismail, R., Zulkifli, C. Z., & Samsudin, K. (2016). Routing Protocols for Mobile
Ad-Hoc Network: A Qualitative Comparative Analysis. Jurnal Teknologi, 78(8).
doi: 10.11113/jt.v78.6025
4. Bai, Y., Mai, Y., & Wang, N. (2017). Performance comparison and evaluation
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Telecommunications Symposium (WTS). doi: 10.1109/wts.2017.7943538
5. Arora, D., Millman, E., & Neville, S. W. (2012). Assessing the Expected
Performance of the OLSR Routing Protocol for Denser Urban Core Ad Hoc
Network Deployments. 2012 IEEE 26th International Conference on Advanced
Information Networking and Applications. doi: 10.1109/aina.2012.93
6. E., Z., & Atef, M. (2017). Performance Evaluation of AODV, DSR and OLSR
in MANET using Opnet Simulator. International Journal of Computer
Applications, 163(11), 23–30. doi: 10.5120/ijca2017913775
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Routing Protocols using Network Simulator (NS3). International Journal of
Computer Applications, 144(4), 1–5. doi: 10.5120/ijca2016910225
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8. Abdullah, A. M., Ozen, E., & Bayramoglu, H. (2019). Investigating the Impact
of Mobility Models on MANET Routing Protocols. International Journal of
Advanced Computer Science and Applications, 10(2). doi:
10.14569/ijacsa.2019.0100204
9. Optimized Link State Routing Protocol (OLSR). (n.d.). Retrieved from
https://tools.ietf.org/html/rfc3626#section-19.
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and GPSR MANET Routing Protocols with Respect to Network Size and
Density. Research Journal of Applied Sciences, Engineering and
Technology, 11(4), 400–406. doi: 10.19026/rjaset.11.1794
11. Natarajan, K., & Mahadevan, G. (2017). Mobility based performance analysis
of MANET routing protocols. International Journal of Computer
Applications, 163(10), 37–43. doi: 10.5120/ijca2017913759
12. Performance Comparison of MANET Routing Protocols (OLSR, AODV, DSR,
GRP and TORA) Considering Different Network Area Size. (n.d.). International
Journal of Engineering and Management Research, 6(3), 475–484.
13. Transmission Range, Density & Speed based Performance Analysis of Ad Hoc
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14. Sharma, A., & Kumar, R. (2016). Performance comparison and detailed study
of AODV, DSDV, DSR, TORA and OLSR routing protocols in ad hoc
networks. 2016 Fourth International Conference on Parallel, Distributed and
Grid Computing (PDGC). doi: 10.1109/pdgc.2016.7913218
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15. Abdullah, A. M., Ozen, E., & Bayramoglu, H. (2019). Investigating the Impact
of Mobility Models on MANET Routing Protocols. International Journal of
Advanced Computer Science and Applications, 10(2). doi:
10.14569/ijacsa.2019.0100204
16. Asri, U. S. (2018). An Enhancement of Gateway Selection Scheme in Mobile
Ad-Hoc Network (MANET).
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(n.d.). International Journal of P2P Network Trends and Technology
(IJPTT), 4(3), 22–26.
18. (n.d.). Retrieved December 21, 2019, from https://www.isi.edu/nsnam/ns/.
19. Moad, D., Djahel, S., & Nait-Abdesselam, F. (2012). Improving the quality of
service routing in OLSR protocol. 2012 International Conference on
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APPENDIX
GANTT CHART FINAL YEAR PROJECT 1
Activity/Week 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Topic
Discussion
Project Title
Proposal
Introduction
Literature
Review
Presentation
Methodology
Draft Report
Submit Draft
Report
Final
Preparation
and
Presentation
Final Report
FYP 1
Gantt Chart 1: Activities and milestones of FYP 1
33