REQUIREMENT FOR THE DEGREE OF MASTER OF INFORMATION ...... offers all the functionality of other routing protocols, plus: Variable-Length Subnet.
i
EVALUATION OF THE QUALITY OF SERVICE PARAMETERS FOR ROUTING PROTOCOLS IN AD-HOC NETWORKS
ZEYAD GHALEB AQLAN AL-MEKHLAFI
UNIVERSITI KEBANGSAAN MALAYSIA
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EVALUATION OF THE QUALITY OF SERVICE PARAMETERS FOR ROUTING PROTOCOLS IN AD-HOC NETWORKS
ZEYAD GHALEB AQLAN AL-MEKHLAFI
THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE DEGREE OF MASTER OF INFORMATION TECHNOLOGY
FACULTY OF INFORMATION SCIENCE AND TECHNOLOGY UNIVERSITI KEBANGSAAN MALAYSIA BANGI 2011
ii
PENILAIAN KUALITI PERKHIDMATAN PARAMETER UNTUK PENGHALAAN PROTOKOL RANGKAIAN AD-HOC
ZEYAD GHALEB AQLAN AL-MEKHLAFI
TESIS YANG DIKEMUKAKAN UNTUK MEMENUHI SEBAHAGIAN DARIPADA SYARAT MEMPEROLEH IJAZAH SARJANA TEKNOLOGI MAKLUMAT
FAKULTI TEKNOLOGI DAN SAINS MAKLUMAT UNIVERSITI KEBANGSAAN MALAYSIA BANGI 2011
iii
DECLARATION I hereby declare that the work in this thesis is my own except for quotations and summaries which have been duly acknowledged.
25 of May 201125 of May 2011
ZEYAD GHALEB AL-MEKHLAFI P50202
iv
ACKNOWLEDGEMENT
I thank Allah (God) for granting me the guidance, patience, health, and determination in successfully accomplishing and completing this work. I would like to express my gratitude and sincere appreciation to my thesis advisor Assoc. Prof. Dr. Rosilah Hassan for her time, patience, and extensive guidance throughout my research. I am also deeply grateful to Ahmed Shamsan Almshreqy for his time, help, and guidance especially during my graduate studies. I am also very thankful to Mohammed Saif for his encouragement, suggestions and valuable advice. I would also like to thank the Higher Education Ministry of Yemen for sponsoring me throughout my graduate studies. Finally, I am deeply grateful to my parents and sister for their encouragement and support in pursuing my graduate studies. I am also deeply grateful to my wife and my two daughters for their patience, understanding, and encouragement throughout the difficult times. My sincere thanks also to my friends especially Dr. Adnan, Nassr Alshawafy, Adel Alofairi, and Ahmed Madfa as well as all other’s person who had a role in making this thesis possible.
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ABSTRAK
Sejak kebelakangan ini, rangkaian Ad-Hoc telah menarik perhatian ramai penyelidik khususnya dalam penghalaan protokol-protokol sama ada Proaktif atau Reaktif. Oleh kerana itu strategi untuk meneruskan data paket dari sumber ke destinasi adalah sasaran utama penghalaan protokol-protokol. Oleh yang demikian perbezaan antara protokol-protokol adalah berdasarkan pada pencarian, penyelenggaraan dan pemulihan pusat penghalaan. Masalah yang mungkin dalam rangkaian Ad-Hoc adalah bagaimana hendak menentukan penghalaan protokol optimum yang memenuhi keperluan aplikasi berdasarkan beberapa kriteria. Kajian ini membentangkan mengenai penilaian penghalaan protokol proaktif Open Shortest Path First (OSPF), Routing Information Protocol (RIP) dan penghalaan protokol reaktif Ad-Hoc OnDemand Distance Vector Routing (AODV), Dynamic Source Routing (DSR) berdasarkan simulasi QualNet. Selain itu, prestasi dari penghalaan protokol akan dapat dikenalpasti berdasarkan pelambatan, throughput dan pemilihan matriks. Penyelidikan ini menunjukkan maklumat routing protocol (RIP) mempunyai prestasi penilaian yang lebih baik berbanding dengan OSPF, AODV dan DSR di kedua-dua senario sementara AODV menyajikan hasil sedikit lebih baik daripada RIP.
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ABSTRACT
In the recent years, the Ad-Hoc networks have gained a lot of research attention especially in routing protocols, which include Proactive and Reactive routing. Therefore, the strategy of forwarding the data packets from the source to the destination is the ultimate target of routing protocols. Hence, the differences among these protocols are based on searching, maintenance and recovering the route path. A potential problem in Ad-Hoc networks is how to investigate the best routing protocol that satisfies the needs of application regarding some criteria. This work presented the evaluation of Proactive routing protocols; Open Shortest Path First (OSPF), Routing Information Protocol (RIP) and Reactive routing protocols; Ad-Hoc On-Demand Distance Vector Routing (AODV), Dynamic Source Routing (DSR) based on the QualNet simulation. Moreover, the performance of those routing protocols was realized based on the throughput, delay, average jitter and energy consumption metrics. This research showed that RIP has best evaluation performance compared to OSPF, AODV and DSR in both scenarios while AODV presents slightly better findings than RIP.
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TABLE OF CONTENTS Page DECLARATION
iii
ACKNOWLEDGEMENT
iv
ABSTRAK
v
ABSTRACT
vi
TABLE OF CONTENTS
vii
LIST OF FIGURES
x
LIST OF TABLES
xi
LIST OF ABREVIATIONS
xii
CHAPTER I
INTRODUCTION
1.1 1.2 1.3 1.4 1.5 1.6 1.7
Introduction Problem Statement Research Objectives Significance of Research Research Scope Research Methodology Organization Of The Thesis
CHAPTER II
LITERATURE REVIEW
2.1
Introduction
10
2.2
Mobile Ad-Hoc Network 2.2.1 History of MANET 2.2.2 Characteristic of MANET 2.2.3 Problems in MANET 2.2.4 Applications of MANET
12 14 15 15 17
2.3
Routing Protocols 2.3.1 Distance Vector Routing 2.3.2 Link State Routing
19 20 20
2.4
Classification Of Routing Protocols 2.4.1 Unicast Routing Protocols 2.4.2 Multicast Routing Protocols 2.4.3 Broadcast Routing Protocols
22 22 22 24
2.5
Classification Of Unicast Routing Protocols 2.5.1 Proactive Routing Protocols 2.5.2 Reactive Routing Protocols 2.5.3 Hybrid Routing Protocol-Zone Routing Protocol(ZRP)
22 23 25 29
2.6
The Reason for Selection of QUALNET Protocols
29
1 3 5 5 5 6 8
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2.7
IEEE 802.11 2.7.1 802.11b 2.7.2 802.11g 2.7.3 802.11a 2.7.4 802.11-1997 (802.11 legacies) 2.7.5 802.11n 2.7.6 802.11-2007
31 31 31 32 33 33 33
2.8
Mobility Model (Random Way Point)
33
2.9
Related Works
35
2.10
Discussion
36
2.11
Conclusion
39
CHAPTER III RESEARCH METHODOLOGY 3.1
Introduction
40
3.2
Reasons for Choosing Simulation Methods
41
3.3
Simulation 3.3.1 Network Simulation 3.3.2 Reasons for Choosing QualNet Simulator
41 43 46
3.4
Simulation Details 3.4.1 Components Of QualNet Developer 3.4.2 Simulation Environments 3.4.3 Traffic Generators 3.4.4 Scenario Designer 3.4.5 Wireless Subnet
47 48 53 55 56 57
3.5
Metrics For Evaluation 3.5.1 Average End-to-End Delay 3.5.2 Average Jitter 3.5.3 Throughput 3.5.4 Energy Consumption
57 59 59 59 60
3.6
Analyzing The Results
60
3.7
Conclusion
61
CHAPTER IV
EVALUATION PERFORMANCE RESULTS
4.1
Introduction
62
4.2
Results And Discussions 4.2.1 Effects of the Number of Nodes 4.2.2 Effects of Packet Size Conclusion
62 63 70 76
4.3
ix
CHAPTER V
CONCLUSION AND FUTURE RESEARCH
5.1
Introduction
77
5.2
Conclusions
78
5.3
Future Research
79
REFERENCES
80
x
LIST OF FIGURES
No. Figure
Page
1.1
Scope of Routing Protocols in Ad-Hoc Network
6
2.1
Infrastructure Mode
11
2.2
Ad-Hoc Mode
11
2.3
An Example of MANET
12
2.4
Infrastructureless MANET
13
2.5
Infrastructure-Based MANET
14
2.6
Classification of Routing Protocols in Ad-Hoc Network
21
2.7
AODV Protocol Messaging
27
2.8
Random Way Point Model
34
3.1
Summary of QualNet Simulation
48
3.2
Architect Design Mode in QualNet
49
3.3
Analyzer of QualNet
50
3.4
The File Editor in QualNet
51
3.5
The Visualization and Analysis of a Network Scenario
52
3.6
The Packet Trace Files Generated During the Simulation
53
3.7
Traffic Generators
56
4.1
Average Jitter in OSPF, RIP, AODV and DSR in Number of Nodes Average end-to-end delay in OSPF, RIP, AODV and DSR in Number of Nodes Throughput in OSPF, RIP, AODV and DSR in Number of Nodes Energy consumption in OSPF, RIP, AODV and DSR in Number of Nodes Average Jitter in OSPF, RIP, AODV and DSR in Packet Size
63
Average end-to-end delay in OSPF, RIP, AODV and DSR in Packet Size Throughput in OSPF, RIP, AODV and DSR in Packet Size
72
Energy consumption in OSPF, RIP, AODV and DSR in Packet Size
75
4.2 4.3 4.4 4.5 4.6 4.7 4.8
65 67 69 70
73
xi
LIST OF TABLES
No. Figure
Page
2.1
MANET’s Characteristics
18
3.1
Kind of Simulation
43
3.2
The Review Of The Candidate Network Simulators
46
3.3
Parameters of effect of the number of nodes
54
3.4
Parameters of the effect of packet size
55
4.1
Data Set of Average Jitter (Scenario I)
63
4.2
Data Set of Average End-to-End Delay (Scenario I)
64
4.3
Data Set of Throughput (Scenario I)
66
4.4
Data Set of Energy Consumption of (Idle mode, Transmit mode, Receive mode) (Scenario I)
68
4.5
Data Set of the result of Energy Consumption (Scenario I)
69
4.6
Data Set of Average Jitter (Scenario II)
70
4.7
Data Set of Average End-to-End Delay (Scenario II)
71
4.8
Data Set of Throughput (Scenario II)
73
4.9
Data Set of Energy Consumption of (Idle mode, Transmit mode, Receive mode) (Scenario II)
74
4.10
Data Set of Throughput (Scenario II)
75
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LIST OF ABREVIATIONS ABR ACOR ADSL AODV AS CBR CDMA CHAMP CGSR CPU CSV DoS DFR DHCP DSDV DSR DSRC GloMoSim GPS GSM GUI HetMAN HSRP IEEE IGP InVANET IP IS-IS ITS LAN MAC MAN MANET NS-2 OFDM OMNeT++ OSI OSPF PHY QOS RIP RWP UCLA UDP VANET
Associatively-Based Routing Admission Control enabled On-demand Routing Asymmetric Digital Subscriber Line Ad-Hoc On Demand Distance Vector Autonomous System Constant Bit Rate Code Division Multiple Access Caching and Multipath Routing Protocol Cluster-head Gateway Switch Routing Protocol Central Processing Unit Comma Separated Value Detail-of-Service Direction Forward Routing Dynamic Host Configuring Protocol Destination Sequenced Distance Vector Routing Dynamic Source Routing Dedicated Short Range Communications Global Mobile Information System Simulation Geographical Positioning System Global System for Mobile communication 1. Graphical User Interface Heterogeneous MANeT Hierarchical State Routing Protocol Institute of Electrical and Electronics Engineers Interior Gateway Protocol Intelligent Vehicular Ad-Hoc Networking Internet Protocol Intermediate System to Intermediate System Intelligent Transportation System Local Area Network Media Access Control Metropolitan Area Network Mobile Ad-Hoc Network Network Simulator 2nd Version Orthogonal Frequency-Division Multiplexing Objective Modular Network Test-bed in C++ Open Systems Interconnection Open Shortest Path First Physical Layer Quality of Service Routing Information Protocol Random Waypoint University of California, Los Angeles User Datagram Protocol Vehicular Ad-Hoc Network
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WAP WiMAX WLAN ZRP
Wireless Access Point Worldwide Interoperability for Microwave Access Wireless Local Network Zone Routing Protocol
1
CHAPTER I
INTRODUCTION
1.1
INTRODUCTION
Ad-Hoc Network is a wireless network that consists of mobile nodes and has a dynamic topology with no pre-existed infrastructure. As Ad-Hoc does not need the pricey communication infrastructure of traditional wireless networks and can be easily deployed, it is the workable solution for many applications and environments, such as the military environments, emergency operations (e.g. disaster recover), and civilian environments.
A routing protocol determines the path of a packet from the source to the destination. To forward a packet, the network protocol needs to know the next node in the path as well as the outgoing interface on which to send the packet. A routing protocol computes such routing information. In general, routing protocols can be divided into two categories: proactive routing protocols and on-demand (reactive) routing protocols. A proactive routing protocol discovers the network topology and computes the routing information regardless of whether the network protocol has a packet which needs that information, and they are those protocols which carry out the function of keeping track of routes for all the destinations in the Ad-Hoc network. They are supported to be available in the form of tables. Furthermore, a proactive routing protocol periodically exchanges routing information in the whole network and maintains routes between different nodes dynamically. It has low latency, high overhead and the routes are reliable. An on-demand (reactive) routing protocol tries to discover a path to a destination only when the network protocol receives a packet
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addressed to that destination and it attempts to identify a path to the destination only in case a packet of data sent to the destination is received by the network protocol. This is one advantage of such a kind of protocols because the degree of uncertainty in the node position is found to be high. They are also proven to be more suitable and more distinguished by their better performance in Ad-Hoc networks. A well-known proactive protocol is: Open Shortest Path First (OSPF) that is a dynamic routing protocol used in Internet Protocol (IP) networks. Specifically, it is a link-state routing protocol and falls into the group of interior gateway protocols, operating within a single Autonomous System (AS). Another example is Routing Information Protocol (RIP) which is as dynamic as OPSF, but it is widely used in both local and wide-area networks, and it is categorized as an Interior Gateway Protocol (IGP). It makes use of the distance-vector routing algorithm. Some well-known reactive protocols are: AdHoc On-Demand Distance Vector Routing (AODV) and Dynamic Source Routing (DSR). AODV is a reactive routing protocol which is basically composed of DSR and Dynamic Destination-Sequenced Distance Vector (DSDV) algorithms. It makes good use of the useful characteristics of both algorithms. As it is dynamic, the multi-hop routing which self starts is permitted to be found between participating mobile or moving nodes. DSR is a routing protocol which is still on demand and in which the sender of the data can determine exactly the needed sequence of the nodes to propagate a packet. This packet header includes a number of intermediate nodes for routing. Each node’s function is to maintain the route cache which catches the source route being learned. Many differences among various routing protocols are based on how to route data from the source node to destination node and how the work in searching, maintenance and recovering the path. The decision of choosing the best routing protocol must take to account for some of these issues, i.e. mobility of nodes, type of data, cost of path, application type, number of nodes, type of traffic and Quality of Services (QoS).
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1.2
PROBLEM STATEMENT
One of the primary characteristics of an Ad-Hoc network is that the network topology is constantly changing based on the fact that there are a lot of routing protocols issued to deal with this infrastructureless topology to enhance the propagation of data from source node to destination whereby each of them has different methodology and features. The potential problem in the characterization of Ad-Hoc network is how to select the best Ad-Hoc routing protocols (proactive and reactive) based on some criteria such as QoS (End-to-End Delay, Throughput and Average Jitter and Energy Efficiency). Because of there are many routing protocols in Ad-Hoc network, most of them use different schemes than, based on the user requirements and the application used. This research tries to give some of the criteria to select the best routing protocol that satisfies the objective of QoS. Therefore, this work focuses on the most important factors: a) End-to-End delay: this factor is important for the Ad-Hoc networks due to the fact that some of the real-time applications are very sensitive to the delay which means the data packet sent from the source node should be delivered to the final target node within the specific period time without any delay. Therefore, the routing protocol will be selected based on the shortest path from the source node to the destination node to meet a request of this type of application resulting in receiving the data packet with reasonable delay. b) Average jitter: this factor assesses the variability over time of the packet latency across a network which is associated with the delay. Therefore, the network with constant delay has no jitter. However, the routing protocol that satisfies the constant delay without any variation during the time will be more suitable to be selected for data routing. c) Throughput: the significance of throughput comes from the need to deliver more messages to destination nodes during a specific time, which means that the routing protocols should use some mechanisms to avoid the congestion in some paths. These protocols are more frequently used to prevent the packet
4
drops during the data routing. Hence the reactive routing will get a better chance to be chosen here because it can find the alternative paths to be used rather than congest one resulting in increasing the throughput of reactive routing protocol compared with the proactive routing, which uses the static route which presents more difficulty in starting to search for the alternative paths. Another mechanism that must be taken into account to increase the throughput for routing protocols in order to be chosen is how to deal with the failures of the paths during the data delivery. It means that if the current path used is no more available either by the node failure or by moving from the current position, the routing, which deals with this issue will be the more preferred choice for the user. d) Energy consumption: energy is a very important factor, especially in mobile ad-Hoc networks because it has restricted energy. Therefore, the routing protocol should consider this factor by choosing the paths that consume. Small amount of energy to extend the lifetime of the node and give the chance to the connectivity of the network to be longer. Moreover, the paths which always routed the data packets the nodes participate in this path will deplete their energy very fast and with the time maybe run-out their batteries. Therefore, the routing protocol must look for new paths to avoid using the same path repeatedly, causing consumption of much energy. Again here the reactive protocols will be preferred because of their on-demand property. From the above explanations of these factors we can see the importance of those factors as measurements of the performance of Ad-Hoc networks to meet the requirements of both users and applications due to their significant effects.
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1.3
RESEARCH OBJECTIVES
The main objectives of the research are: 1.
To assess the performance of Proactive routing protocols (OSPF), (RIP) and Reactive routing protocols (AODV), (DSR) which focuses on the quality of service such as End-to-End Delay, Throughput and Average Jitter.
2.
To analyze the energy consumption in both protocols in the Ad-Hoc networks.
1.4
SIGNIFICANCE OF RESEARCH
The significance of the current research is due to the need for discovering the best evaluation performance routing protocol in Ad-Hoc Network and to deal with it as soon as possible, so that it does not affect the services provided by Ad-Hoc Network. The proposed investigation routing protocols could detect the superior level if occur during the diagnosis process. This is important since in Ad-Hoc topology in nature is dynamic. This work can be used as a guideline for the evaluation of routing protocols for selecting purposes or for routing purposes. 1.5
RESEARCH SCOPE
The proposed research deals with the Ad-Hoc networks based on four routing protocols: two proactive routing protocols; OSPF and RIP, and two reactive routing protocols; AODV and DSR. The experiment method used for this research is through Qualnet simulator. QualNet is a network simulation tool that functions as a simulator for wireless and wired packet mode communication networks. QualNet is supplied with models for common network protocols provided in a source form and organized around the OSI stack. It is also supplied with a graphical user interface so that a user can create the model and its specifications. The reason of choosing QualNet simulator is considered as the first commercial simulator, but the cost of the commercial license is very expensive. It assists simulation results to come out fast for thorough exploration of model parameters, and also it is considered as a real-time simulation for
6
man-in-the-loop and hardware-in-the-loop models. Therefore, this research is designed to decide which type of protocol is the better evaluation performance for the wireless Ad-Hoc networks based on some criteria. Figure 1.1 shows the Scope of Routing Protocol in Ad-Hoc Network.
Reactive Routing Protocols AODV and DSR
Proactive Routing Protocols OSPF and RIP
Simulation in Qualnet
The better evaluation performance for Ad-Hoc
Figure 1.1 Scope of Routing Protocols in Ad-Hoc Network 1.6
RESEARCH METHODOLOGY
The research was conducted in two phases. In the first phase, a literature study was carried out. This study concentrated on the mobile Ad-Hoc network. Therefore, the topology of the network changes dynamically and as well as the background was introduced. Besides that the history of MANET which is the life-cycle of Ad-Hoc networks was categorized into three generations. A characteristic of MANET is it has a dynamic topology. Nodes are easily moved, change randomly and rapidly at unpredictable times, and may comprise both bi-directional and unidirectional links. Problems in MANET are due to its special characters and application environment, which may encounter a lot of problems and challenges. Applications of MANET are used in military applications in battlefields with Defense Advanced Research Projects Agency (DARPA) and PRNET project. Routing protocol is the standard use by the
7
routers to exchange data and communicate among each other. It has linked state and distance vector and classified with Unicast routing protocols as well as proactive routing protocols (OSPF), (RIP) and Reactive routing protocols (AODV), (DSR) based on some criteria such as QoS (End-to-End Delay, Throughput, Average Jitter and Energy Efficiency). Due to the many routing protocols in Ad-Hoc network most of them it uses different schemes than other, based on the user requirements and the application used. This research tries to present some of the criteria in order to select the best routing protocol which satisfies the objective of QoS. Therefore, this work focuses on the most important factors; namely, end-to-end delay, average jitter, throughput and energy consumption which reflect the way of chosen the suitable one. Previous work is related to our work was coated in this thesis. In the second phase, an investigation on the qualities of services was carried out in the simulation part of this research using a QualNet V5 simulation tools is considered as the first commercial simulator, and the cost of the commercial license is very expensive. It assists simulation results to come out fast for thorough exploration of model parameters. It is based on GloMoSim which was developed at the University of California, Los Angeles (UCLA). For Complex Systems (PARSEC) for basic operations, GloMoSim makes use of the Parallel Simulation Environment for Complex Systems (PARSEC). Moreover, it can support multiprocessor systems and distributed computing. Its documentation and tutorials are available free on the internet. By using QualNet, users can create the model and its specification through the graphical user interface. Therefore, specifying small to medium networks by using the GUI compared to specify all connections in a special model file manually is done easily and compared to other simulations which its accuracy and performance are so high. In summary, it’s considered as a real-time simulation for man-in-the-loop and hardware-in-the-loop models, that is widely the best used in Ad-Hoc networks. Moreover, the research methodologies that are inspired by pervious related research consist of two main ones, that is to say, formal methods and simulation. We describe the methods below.
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Initially, the formal method technique was used to model MANET system as a geometric entity. We used computational tools to model a network as an undirected diagram where nodes are vertices and communication links are edges. Finally, we used a simulator to evaluate, and test the performance of our protocols. The simulator was used comprehensively in network research to implement, compute, and evaluate protocols. Using the simulator allows us to focus on the research initiative as an alternative to physical implementation details. We used QualNet V5 simulator due to some of its personality that makes it a suitable choice for this work. 1.7
ORGANIZATION OF THE THESIS
The thesis is divided into five chapters. Chapter I, Introduction, provides the study of background information about Ad-Hoc network and routing protocol, presents the problem statement, research objectives, research significant, research scope and research methodology. Chapter II presents a comprehensive literature review of introduction to routing protocols OSPF, RIP, AODV and DSR, overview IEEE 802.11, reasons for selecting those routing protocols, and related works of them. Chapter III discusses the methodology that was used to accomplish the objectives. Particularly, it describes in detail the simulation methods. As there is much simulation software to replicate the proposed work, we provide a brief description for some of them, and select the QualNet simulation in order to replicate and evaluate our protocols. This chapter also provides simulation environments, setup and configurations. Chapter IV analyzes the different results obtained by various simulation runs. Further, it shows and discusses the simulation results.
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Chapter V summarizes the results of the study, draws some conclusions about them and provides suggestions for further research related to the current research.
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CHAPTER II
LITERATURE REVIEW
2.1
INTRODUCTION
Ad-Hoc network is a category of computer networks which communicate by wireless using Ad-Hoc communication links. In Ad-Hoc network, devices can communicate using either infrastructure mode or Ad-Hoc mode. In road and rail network mode, the communication among devices is indirectly by access points as in Figure 2.1. On the other mode the devices communicate directly as illustrated in Figure 2.2. The network of wireless devices, which connected directly, is called MANET (Basagni et al. 2004). Ad-Hoc networks gained a lot of research attention, especially in the routing protocols, which include proactive and reactive routing protocols. Therefore, the strategy of forwarding the data packet from source to destination is the ultimate target of routing protocols. Hence, the differences among this protocol are based on searching, maintenance and recovering the route path. The decision of choosing the best routing protocol must take into account some of the following issues: mobility of nodes, packet size, cost of path, application type, number of nodes, type of traffic and quality of services.
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Mobile Laptop PC
Mobile `
Desktop PC
` Desktop PC Laptop PC
Radio Antenna
` Desktop PC
Mobile Mobile
` Laptop PC Desktop PC
Figure 2.1 Infrastructure Mode
Desktop PC
Desktop PC
Desktop PC
Desktop PC
Figure 2.2 Ad-Hoc Modes
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Furthermore, there are a lot of routing protocols issued to deal with this infrastructureless topology to enhance the propagation of data from the source node to the destination node. Each of them has different methodology and features. 2.2
MOBILE AD-HOC NETWORK
The topology of the network changes dynamically. Therefore, Mobile is a special kind of Ad-Hoc network in somewhere the nodes of a network are mobile (Corson and Macker 1999). Each node in MANET might manage as both host and router. MANET consists of wireless devices such as laptop, PDA, mobile phone and other similar devices (see Figure 2.3).
PDA
Mobile Phone
Laptop PC
Figure 2.3 An Example of MANET In addition, the other similar devices, that are competent of communicate straight with one another without a server acting as a central coordinator or scheduler for the data traffic among devices (Duggi and Fan 2007). That’s created decentralized.
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Wireless network topologies that enable wireless node to communicate with each other, and with fixed network can be classified into the following categories (Duggi 2008);
Infrastructure-based
Infrastructureless In an infrastructure-based network, wireless nodes communicate through
access points or base station connected to the fixed network like the internet. Infrastructureless network on the other hand, does not require access point or other base stations to communicate within the wireless nodes. MANET can be accomplished anywhere and anytime. In most cases, wireless nodes of MANET are small mobile devices that are relatively limited in terms of memory size, energy consumption, and CPU capability. Duggi (2008) referred to MANET as one of the common and increasingly popular infrastructureless network topologies, which consists of a cluster of wireless nodes that dynamically from a network with each other and without utilizing any pre existing fixed network infrastructure. A Figure 2.4 shows infrastructureless MANET and Figure 2.5 depicts the mobile Ad-hoc network with access to the internet (infrastructure-based MANET).
Figure 2.4 Infrastructureless MANET by Badonnel and Festor (2005)
14
Mobile Ad-Hoc Network
Internet
Access Point
Figure 2.5 Infrastructure-Based MANET 2.2.1 History of MANET The subcommittee of IEEE 802.11 had espoused the expression of deploying Ad-Hoc networks in other vicinities of relevance (Singh and Saxena 2009). The notion of profitable Ad-Hoc networks is one that can be reached with laptop computer and other viable communications equipment. Simultaneously, the scheme of an assortment of mobile nodes was recommended at a number of studies conferences in 1990s. The life-cycle of Ad-Hoc networks might be classified into two generations. Current AdHoc network’s modes were reflected on the two generations. The first generation goes back to 1972. At that juncture, they were called Packet Radio Networks (PRNET) (Bakht 2003). The second generation of Ad-Hoc networks came in 1980s, when the Ad-Hoc network modes were additionally improved and implemented as a fraction of the Survivable Adaptive Radio Networks (SURAN) programs.
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2.2.2 Characteristic of MANET Merwe et al. (2007) stated that MANET has energy constrain due to some or all the nodes in the MANET rely on battery power for their energy. Limited physical security is also one of the characteristics in MANET signifying the increased opportunity of spoofing, eavesdropping, and Detail-of-Service (DoS) attacks should be cautiously considered. Existing link security techniques are often applied within wireless networks to reduce security threats. Wireless networks lack in security compared to wired networks. Furthermore, MANET has the dynamic topology. Nodes are easily moved, change quickly and arbitrarily at changeable times, and may comprise both bidirectional and unidirectional links (Bakht 2003). It also has a bandwidth constrain since wireless links will continue to have a significantly lower capacity than fixed cable networks. In addition, the realized throughput of wireless communications after accounting for multiple access, fading noise, and interference effects is often much less than a radio’s maximum transmission rate. They also explained MANET as fully self-organized. The node does not know each other, but they can collaborate to build communication. It can spontaneously approach other nodes to communicate since it depends upon the cooperative and trusting nature of nodes. Fully self-organized MANETs are open in nature, which is similar to the internet. Any user can join the network at random. Additionally, the self-configuration manner in MANET at the same time permits MANET to expand the configuration itself. 2.2.3 Problems in MANET MANET, due to its special characters and application environment, may encounter a lot of problems and challenges. One of the main confronts in MANET is security issue where MANET is prone to physical attacks, Consequently, of node mobility and topology change, at one fell swoop the node played a different role. Routing problem also considered as one of the most often challenges as a result of node movement in an
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is unpredictable way, the use of the wireless links, a high likelihood of network partitioning, undefined geographic coverage area, and unlimited number of participation nodes in the network. Supporting appropriate Quality of Service (QoS) policies in MANET is as well challenging due to the limited bandwidth of the wireless links utilization. A further environmental issue in MANET is the limited resources; for instance, battery power, bandwidth, CPU and storage. Resource is a serious concern in MANET due to the limitation of such a source which brings down the network operation (Chlamtac et al. 2003). Furthermore, there are a number of issues in MANET which require consideration in developing and managing the network. These issues are the extension of MANET’s characteristic itself. One of the major issues in MANET is security (Gil 2008). In view of the fact that MANET is a wireless network, it is normally more prone to physical security threats than fixed hardwired networks. Protecting data transformation in MANET is a critical aspect. Parties within the network want their communication to be the source. MANET is highly dynamic since topology changes, but link breakage happens quite frequently. Accordingly, the solution should be dynamic as well. Any malicious or misbehaving nodes are able to generate massive attacks. Min and Jiliu (2009) classified security attacks into two categories. They;
Active attacks
Passive attacks
A passive attack is not concerned with the operation in MANET, but an active attack will do more destruction with the disruption to network operations. These types of attack can seriously damage basic aspects of security such as integrity, confidentiality and privacy of the node. At present, cryptography mechanism is the solution for this issue. Another issue in MANET is power consumption. Nodes in MANET usually use battery as the energy which needs to be recharged. This often resulted in power failure due to battery exhaustion during execution of a network-related function. Devices may have limited bandwidth and transmission ranges. Limited power consumption will lead to bandwidth constrain and transmission range problems. Bandwidth and
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transmission range are unlikely to improve dramatically with respect to power consumption. 2.2.4 Applications of MANET MANET was originally used in military applications in battlefields with DARPA and PRNET project (Bakht 2003). Military application involved second and third generation mobile Ad-Hoc network. In the battlefields, according to Bakht, the infrastructureless-based network will limit the movement of the military operation. The infrastructureless nature of MANET will help in this kind of operation. Combat operations include some essential requirements, which are networked to deploy ability, network security, end-to-end IP, anti jamming mechanism and high mobile connectivity. Historically, MANET has primarily been used for tactical network application to improve battlefield communications. MANET was extensively used for many critical application and difficult environments where establishing infrastructure networks is impossible, not cost effective or for urgent situations such as military environments, emergence operation (e.g. disaster recovery), and civilian environments (e.g. Conferences). Another application example of MANET is Bluetooth, which is designed to support a personal area network by eliminating the need of wires among various devices. Also MANET may be used for public hotspots like airport, football grounds and train stations (Singh and Saxena 2009). In a military operation, one of the major issues is geographical factor. The current Geographical Positioning System (GPS) is less efficient to support military operations because GPS will expose the troop’s location when they try to acquire GPS coordinates. Furthermore, the current GPS satellite signals cannot penetrate through caves, underground bunkers or inside shielded buildings.
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Table 2.1 MANET’s Characteristics Characteristics Dynamic topology
Description The topology of a network may change as its nodes are moving in different directions with varying speeds.
Constrained Resource
The nodes’ resource (e.g. battery power, CPU, and storage) has limitations.
Constraint and varying bandwidth
The bandwidth is varying and usually low due to wireless link nature and the effect of noise, interference and congestion.
Limited physical security
Due to their wireless link, MANET is exposed to physical security problem.
Thus in this case, MANET can be seen as the solution. MANET can support the built in geographical location by using an extremely accurate form of triangulation. This feature enables soldiers in a military operation to triangulate their position based on mobile enabled vehicles or other devices. Reading also will be faster since the soldiers do not have to wait for multiple satellites to acquire a centralized security. MANET also allows devices to transmit a lower output power to neighbors which will decrease the possibility to be traced by enemies. In commercial applications which is the third generation mobile Ad-Hoc networks, Cavalcanti et al. (2005) stated the integration between MANET and cellular network will establish the great communication services to customers. According to them, there are three types of mobile stations;
Single mode cellular
Single mode WLAN
Dual mode
Single mode cellular mobile station connects to cellular network through a base station. A single-mode WLAN mobile station is communicated through access point or connects to other WLAN equipped terminals in Ad-Hoc mode to form a MANET. The dual mode mobile station can operate in both by base station or access points and MANET modes using MANET. Adoption of multi hops to communicate to cellular
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networks improves the wireless radio coverage and network robustness against propagation resulting from multi path, radio interfaces, fading and obstacles. Bakht (2003) also mentioned MANET’s important role in a disaster-relief environment. Disaster relief environment comprise emergency situations similar to first fighting and search and rescue operations. In this kind of situation, the rescue teams need to communicate with the head quarters to exchange the information about the current status of the situation. MANET makes it easier for them by providing infrastructureless technology so that everything can be set up as soon as possible to assist in search and rescue operations. 2.3
ROUTING PROTOCOLS
Routing protocol is the standard used by the routers to exchange data and communicate among each other. Stalling (2007) in his book stated, routing in MANET is different from routing in other networks. MANET is dynamic. Consequently, it requires dynamic routing protocol to communicate. A MANET may implement different types of routing. According to Karimous and Myoupo (2006), the basic type of Ad-Hoc routing algorithms are;
Single hop
Multi hop They are based on different link layer characteristics and routing protocols. A
multi hop MANET is simpler than a single hop MANET but lacks the functionality and flexibility of a multi hop MANET. When delivering data packets from a source to its destination, which is out of the direct wireless transmission range, the packet should be forwarded via one or more intermediate nodes. Furthermore, in Ad-Hoc network, each node plays a dual role at the same time. It functions as a router and a host in the sense that it obtains some information concerning the network surrounding it and deals with an algorithm which functions to manage the process of sending and receiving the data packets. Such combination of both functions together is known as a routing protocol.
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Whereas, one characteristic of routing protocols is that they are quickly and elegantly adaptable to constant and unpredictable changes taking place in the network. This usually occurs whilst the conversion process in the memory power and the resources of the bandwidth take place. It is indicated that the increasing size of the Ad-Hoc network is due to the fact that they are met with excess of over heading in the routing messaging which is the result of the increasingly growing number of nodes and, which is amplified by higher node mobility. The increasing growth of networks can answer into an excessive increase in the size of the table of the routing and consequently, such increasing networks have to be broadcasted to other nodes, thus, leading to network overhead (Du Plessis 2006). Keshav (1997) pointed out that the routing, which is either derived from a distance vector or link state is employed by most routing protocols. 2.3.1 Distance Vector Routing Distance vector routing is defined by Annamalai (2005) as a decentralized routing algorithm. Each participating node in the routing plays an effective role in exchanging the estimated least-cost path to the other nodes which are directly connected together in the routing network. Since nodes in the distance vector lacked a global view of the network, the process of convergence becomes slow. 2.3.2 Link State Routing Link state routing refers to the process of maintaining a picture of the global network topology carried out by each node through periodically flooding the information in the routing table to its neighbors. Receiving an update packet, each node functions to update its primary view of the network and the link state by the application of the algorithm with a short path to choose the best next hop node suiting each potential destination node in the network (Du Plessis 2006). Therefore, Annamalai (2005) justified that such link state algorithms provide better reliability and assist in offering solutions to issues concerning count-to-infinity and looping, which are associated with distance vector routing protocols.
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Moreover, Link state routing is a global routing algorithm in which each node computes the shortest path to every other node in the network using global knowledge about the network. In the link state routing protocols, each node reliably broadcasts the link state (cost) to its directly connected neighbors. This reliable flooding gives a global topology view to each node. Link situation algorithms recommend superior reliability and solve count-to-infinity and looping issues associated with space vector routing protocols. The widely-used OSPF routing protocol is a link state protocol. 2.4
CLASSIFICATION OF ROUTING PROTOCOLS
Routing protocols are classified into Unicast routing protocols, multicast routing protocols and broadcast routing protocols as highlighted in Figure 2.6.
Figure 2.6 Classification of Routing Protocols in Ad-Hoc Network by Uma and Padmavathi (2009)
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2.4.1 Unicast Routing Protocols Unicast refers to the process of one side to one side communication. For example, one side (sender) transmits data packages to another single destination (receiver). This is assumed to represent the largest category of routing protocols, which are found in the Ad-Hoc networks. 2.4.2 Multicast Routing Protocols Multicast is used to refer to the routing protocols, which appear when each single node (sender) carries out the procedure of sending or forwarding the same message or series of data to many various destinations (receivers). However, since the bandwidth of MANETs is limited and shared among the participating nodes in the network, it is crucial to efficiently utilize the network bandwidth. Multicast can reduce the link bandwidth consumption by sending the same packet to a group of hosts identified by a single destination address and hence is intended for group-oriented computing (De Morais Cordeiro et al. 2003). 2.4.3 Broadcast Routing Protocols Broadcast is the basic mode of transmittal operation through which each message or stream of data is being sent or transmitted on a wireless channel and generally being received by all other sides of communication that are located within the same group of the sender. Simply, the broadcasting operation is implemented by simple flooding, but it is proven to be possible to lead to a storm of problems because it is redundant rebroadcasting. 2.5
CLASSIFICATION OF UNICAST ROUTING PROTOCOLS
There are several Unicast protocols such as proactive routing protocols; flow oriented routing protocols, reactive routing protocols, and adaptive routing protocols.
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2.5.1 Proactive Routing Protocols Proactive routing protocols are those protocols which carry out the function of keeping track of routes for all the destinations in the Ad-Hoc network. They are supported to be available in the form of tables. Furthermore, proactive routing protocol periodically exchanges routing information in the whole network and maintained routes between different nodes dynamically. It has low latency, high overhead and the routes are reliable. This protocol cannot scale well with the increasing of network size. It is stated that one advantage of applying such kinds of protocols is that they facilitate communication to undergo a minimal initial delay in the application procedure. However, its disadvantage is represented by the fact that they require additional control traffic to constantly update the entries of the stale route. There are several Proactive Routing Protocols such as Hierarchical State Routing Protocol (HSR) (Pei et al. 1999), Direction Forward Routing (DFR) (Lee et al. 2006), Cluster head Gateway Switch Routing Protocol (CGSR) (Chiang et al. 1997), OPSF, and RIP. a)
OPSF
OPSF is defined as a protocol which is used in Internet Protocol (IP) networks for it is a dynamic routing protocol. In particular, it functions as a link state routing protocol and found to be into the group of interior gateway protocols. Its operation is within a single Autonomous System (AS). It was first defined by Moy (1998), as OPSF Version 2. Afterward, it was updated by Coltun et al. (2008) and since then, it is known as OPSF Version 3. Furthermore, OSPF is a router protocol utilized within larger AS networks in favour to the RIP, an older routing protocol that is installed in many of today's corporate networks. Like OSPF, RIP is designated by the Internet Engineering Task Force (IETF) (Bradner 1999) as one of the several Interior Gateways Protocols (IGPs) (Rekhter et al. 1990). Using OSPF, a host who finds a change to a routing table or detects a change in the network instantly multicasts the information to all other hosts in the network so that all will have the same routing table information. Unlike the RIP in which the complete routing table is sent, the host using OSPF sends only the part that has changed. With RIP, the routing table is sent to
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a neighbor host every 30 seconds. OSPF multicasts the updated information only when a change has taken place. Rather than simply counting the number of hops, OSPF bases its path descriptions on "link states" that take into account additional network information. OSPF also lets the user assign cost metrics to a given host router so
that
some
paths
are
given
preference.
OSPF
supports
a
variable
network subnet mask so that a network can be subdivided. RIP is supported within OSPF for router-to-end station communication. Since a lot of networks utilizing RIP are already utilized, router producers tend to include RIP support within a router designed primarily for OSPF. i)
Advantages and Disadvantages
Its advantages are represented by being capable of handling large networks, its improved security, and low bandwidth overhead, being based on an area and capable of supporting advanced addressing structures. However, its disadvantages are represented by the fact that its memory is high and its overhead is a processor. Moreover, the complexity of its routing tables which demand a lot of memory and processing power to handle is another disadvantage. The last disadvantage is its difficult nature to set up since it depends on the user’s network. For example, if a user wants to set up OPSF, he/she needs a large network and this will result in making configuration more difficult as described by OSPF Information (2008). b)
RIP
RIP is also defined as a routing protocol which is as dynamic as OPSF, but it is widely used in both local and wide-area networks, and it is categorized as an interior gateway protocol (IGP). It makes use of the distance-vector routing algorithm. This initial definition of RIP was proposed by Hedrick (1988). Since then, RIP has been extended and updated to RIP Version 2 by Malkin (1998). It is indicated that both RIP Versions are still being used today, but they have been technically supported by more advanced techniques such as OSPF, and the OSI protocol IS-IS. Moreover, RIP has been updated to IPv6 networks, which is known as a standard RIP next generation (RIPng). In addition, RIP is an extensively-utilized protocol for association router information
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within a self-contained network such as a corporate Local Area Network (LAN) or an interconnected group of LANs. RIP utilizes a hop tally like a manner to determine network distance. (Further protocols utilize extra sophisticated algorithms that contain timing too). Each host with a router in the network utilizes the routing table information to determine the subsequent host to route a packet to for a specified destination. RIP is considered an effective solution for small homogeneous networks. For larger, more complicated networks, RIP's transmission of the entire routing table every 30 seconds may put a heavy amount of extra traffic in the network. RIP is classified by the IETF as one of several IGPs. Using RIP, a gateway host (with a router) sends its entire routing table (which lists all the other hosts it knows about) to its closest neighbor host every 30 seconds (Hedrick 1988). The neighbor host in turn will pass the information on to its next neighbor and so on until all hosts within the network have the same knowledge of routing paths, a state known as network convergence. i)
Advantages and Disadvantages
The advantages of employing RIP are its easiness to be understood and configured, its guarantee of being supported by all routers, its support to load balancing, and it’s free from the loop. However, it is pointed out that it is not efficient, slow to be used in large networks due to its configuration, supports equal cost, and load balancing. Its congestion raises a problem, and its scalability is limited since it is only measured as 15 hop maximum (Hedrick 1988). 2.5.2 Reactive Routing Protocols Reactive routing protocols to attempt to identify a path to the destination only in case a packet of data sent to the destination is received by the network protocol. This is one advantage of such a kind of protocols because the degree of uncertainty in the node position is found to be high. They are also proven to be more suitable and more distinguished by their better performance in Ad-Hoc networks. However, such protocols are disadvantaged for they take much more time to find the route and they require more flooding, which results into clogging the network. There are several
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Reactive Routing protocols such as Admission Control Enabled on Demand Routing (ACOR) (Kettaf et al. 2006), Caching and Multipath Routing (CHAMP) (Valera et al. 2003), DSR, Associatively Based Routing (ABR) (Toh 1997) and AODV. Moreover, reactive routing protocol needs to exchange routing information to establish routes between nodes that have data traffic. This will lower the overhead compared to proactive routing protocol in a simple network. In large network and high mobility situation, the overhead may be high due to link breakage. AODV and DSR are the famous reactive routing protocols. a)
AODV
AODV is a Reactive routing protocol which is basically composed of DSR and DSDV algorithms. It makes good use of the useful characteristics of both algorithms. As it is dynamic, the multi-hop routing which self starts is permitted to be found between participating mobile or moving nodes. Thus, it is characterized for the availability of the demand routing mechanism of route discovery and route maintenance of DSR. Moreover, the sequencing number of using hop by hop routing and packets periodically updated is found to be available in this kind of protocol. Using such sequence numbers of destination to recognize the latest path is one useful characteristic of these protocols. In addition, the source and intermediate nodes are capable of storing the next hop- information which corresponds to each flow for data packet transmission (Acs et al. 2006; Moghim et al. 2002; Perkins and Royer 1999; Reddy and Reddy 2006). Additionally, reactive routing protocols can be classified into two groups:
Source routing
Hop by hop routing
AODV is a hop by hop routing protocol, which introduces the more dynamic approach to discover and repair route (Amri et al. 2010). It enables multi hop routing between participating mobile nodes to ascertain and maintain an Ad-Hoc network. In AODV, the fact that a node seeks information about the network only when needed can cause low overhead since nodes do not have to maintain unnecessary route
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information, and the use of a sequence number ensures loop freedom. To handle route information AODV uses three various types of the route message: Route Request (RREQ), Route answer (RREP) and Route Error (RERR) (Wang and Cui 2008). Figure 2.7 presents AODV Protocol Messaging.
Figure 2.7 AODV Protocols Messaging by Chakeres and Belding-Royer (2005) Source node broadcasts RREQ when the new route is needed. Each node which maintains the route to the destination sent RREQ will be sent again to the requested destination. The RERR message is sent wherever a link break causes one or more destinations to become unreachable from some of the node’s neighbors. In AODV, the source node and the intermediate nodes store the next hop information corresponding to each flow for data packet transmission. AODV routing is the more traditional sense compared to DSR and this case the connection among Ad-Hoc networks to wired networks. The sequence number applied in AODV provides freshness for the routes and prevents loops. i)
Advantages and Disadvantages
The mainly advantages for AODV can be its adaptability to highly dynamic networks and reduced overhead. Other advantages are related to its capability to delay connection setup and to detect the latest route to the destination. However, some disadvantages were pointed out by Uma and Padmavathi (2009). It demands that it is
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periodically updated, and this result into routes which are inconsistent especially if the source sequence number of the route is very old. b)
DSR
DSR is defined by Johnson et al. (2001) as a routing protocol which is still on demand and in which the sender of the data can determine exactly the needed sequence of the nodes to propagate a packet. This packet header includes a number of intermediate nodes for routing. Each node functions to maintain the route cache which catches the source route being learned. It is stated that “Route Discovery and Route Maintenance” are the two main components of DSR, which together function to determine and maintain routes to random destinations. The purpose of designing such a protocol is to make restrictions to the large consumption of bandwidth caused by control packets in Ad-Hoc wireless networks. This process is done by deleting the messages of the periodic updates required, which usually appears in the table-driven approach (Acs et al. 2006). Moreover, DSR is a self-maintaining routing protocol for wireless networks. The protocol can also purpose with cellular telephone systems and mobile networks with up to about 200 nodes. A dynamic source routing network can organize and configure itself separately of oversight by human administrators. In DSR, every cause resolves the route to be utilized in conveying its packets to picked destinations. There are two main components, called route maintenance and route discovery. Route maintenance ensures that the transmission path remains optimum and loop-free as network conditions change, even if this requires changing the route during a transmission. Route discovery determines the optimum path for a transmission between a given source and destination. Microsoft has expanded a version of DSR known as Link Quality Source Routing (LQSR) (Draves et al. 2004) specifically for use with their Mesh Connectivity Layer (MCL) (Draves et al. 2004) technology. MCL facilitates the interconnection of computers into a wireless mesh network using Wi-Fi or WiMAX (Andrews et al. 2007) services.
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i)
Advantages and Disadvantages
Establishing a route when necessary, making the sender to be able to choose and control routes by making the load of data reduced, including routing, which is free from the loop containing unidirectional links in networks, are all the main advantages of DSR. However, DSR has some disadvantages. First, it may lead to significant overheads because the source route has to be included with each packet. It uses cashing excessively and lacks mechanisms by which it can detect the freshness of the routes which causes delay and reduction. It seems that the route mechanism for maintenance is unable to repair a broken link locally. Therefore, this makes the delay of the connection setup higher than it is found to be in table-driven protocols (Uma and Padmavathi 2009). 2.5.3 Hybrid Routing Protocol-Zone Routing Protocol (ZRP) Instead of proactive and reactive routing protocols, there is also hybrid routing protocol. Zone Routing Protocol (ZRP) (Haas et al. 2002) is a hybrid routing protocol which is the combination of proactive and reactive routing approaches. It divides the network into several routing zones and specifies two totally detached protocols that operate inside and between routing zone. Routes can be found very fast within routing zones, while routes outside the routing zone can be found by querying selected nodes in the network. This protocol uses advantages from proactive and reactive protocols. However, the problem is when the proactive intra-zone routing protocol is not specified, which will lead to the use of the different intra-zone routing protocol. This causes the nodes to support different routing protocols, and this has effects when dealing with clients (Larsson and Hedman 1998). 2.6
THE REASON FOR SELECTION OF QUALNET PROTOCOLS
There have been dynamic routing protocols available and a lot of static but selection of the correct protocol for routing is reliant on a lot of strictures seriously being networked such as scalability, convergence time, CPU necessities and memory, security and the bandwidth requirements, etc. The reasons why OSPF is chosen to be
30
the building ground for the proposed OSPF routing protocol is as follows: OSPF’s capability to divide a routing domain into areas within one AS, every OSPF router animatedly maintains the equal sight of the AS topology. A loop/free is a necessitated attribute due to of the resource’s pricey overhead. OSPF was the first extensively deployed routing protocol that could converge with a network in the low seconds, and guarantee loop-free paths. It has a lot of attributes that agree to the imposition of policies concerning the propagation of routes that it may be suitable to keep local, for load sharing, and for selective route importing further than others. Moreover, OSPF offers all the functionality of other routing protocols, plus: Variable-Length Subnet Mask (VLSM) support, routing updates without the 30-second "hold-down" period required by others and bandwidth optimization, including less frequent routing updates and a choice of metrics. The reasons why RIP is chosen to be understood and configured and is guaranteed of being supported by all routing and support to load balancing. In addition, the good news is that adding RIP routing on a Cisco router is really easy. Those are reasons why AODV is chosen to be planned for mobile Ad-Hoc network with inhabitants of tens to thousands of mobile nodes are: AODV is able to knob low, has relatively high mobility rates and moderate ones, as well as an assortment of data traffic levels. AODV is planned for utilization in networks where the nodes were able to all faith each other, either by utilization of
preconfigured
keys, or because it is known that there are no malicious intruder nodes. AODV has been planned to decrease the dissemination of control traffic and eliminate overhead on data traffic, in order to improve scalability and performance. The reasons why DSR is chosen to be of high-quality professional service are because it is based on an knowledgeable engineering team and quality assurance, clear and concise contracts, protecting customers’ confidential information and intellectual property, complete project documentation transfer, transparent project management and status reporting on a weekly or upon request basis, friendly and flexible professional relationships with the customer team and time-tested isolated communication methods. Moreover, DSR engages in both short-term and enduring associations. In both cases, DSR transfers Intellectual Property (IP) clearly, ensuring client receipt of all worth shaped by DSR.
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2.7
IEEE 802.11
IEEE 802.11, which is also well known as the brand Wi-Fi, indicates or is referred to as a set of Wireless LAN standards, which were developed by working group 11 of the IEEE LAN/MAN Standards Committee (IEEE 802). IEEE 802.11 also belongs to the 2.4, 3.6 and five GHz frequency bands. As stated by IEEE 802.11b (1999), these bands are created and maintained by the IEEE LAN/MAN Standards Committee (IEEE 802). The term 802.11x is also used to refer to the set of amendments made to the standard by IEEE 802.11 (2010). Moreover, the standard IEEE 802.11 has a wide variety of Versions such as 802.11-1997 (802.11 legacies), 802.11a, 802.11b, 802.11g, 802.11-2007, and 802.11n. All types of 802.11 will be discussed in the following sections. 2.7.1 802.11b 802.11b, as a Version of wireless LAN technology, utilizes a maximum raw data rate of 11 Mbps and makes use of the same media access method defined in the original standard. The emergence of 802.11b product on the market was in the early 2000, since 802.11b was made as a direct extension of the modulation technique defined in the original standard. Since then, it is stated that there was a dramatic increase in throughput of 802.11b (compared to the original standard) along with simultaneous substantial price reductions, which consequently led to the rapid increase in the acceptance of 802.11b as the definitive wireless LAN technology. However, the devices of 802.11b still suffer from the interference of other products operating in the 2.4 GHz band. Microwave ovens, Bluetooth (Bluetooth 2005) devices, baby monitors and cordless telephones are devices operating in the 2.4 GHz range by IEEE 802.11b (1999). 2.7.2 802.11g As reported by Flickenger (2006), the ratification of a second modulation standard known as 802.11g was initiated in June 2003. Like 802.11b, 802.11g works in the 2.4 GHz band, but unlike 802.11b, 802.11g makes use of the same OFDM based
32
transmission scheme as 802.11a. Its operation is carried out at a maximum physical layer bit rate of 54 Mbps excluding the forward error correction codes, or about 22 Mbps average throughputs. As compared to 802.11a, the hardware of 802.11g is completely backwards, compatible with 802.11b hardware and therefore, it is hindered with legacy issues that reduce throughput by ~21%. Before its ratification, the 802.11g standard proposed that time witnessed the rapid adoption from consumers starting in January 2003 because consumers we highly desired to gain higher data rates and to reduce the manufacturing costs. By summer 2003, there was a shift in the products of the dual-band 802.11a/b from the merely dual band into a dual-band/tri-mode, thus, supporting b/g in a single mobile adapter card or access point. Details of enhancing the performance of b and g work together dominated much of the lingering technical process. However, in an 802.11g network, the overall rate of the data will be reduced by the activity of 802.11b participants. Like 802.11b, the devices of 802.11g still suffer from the interference of other products operating in the 2.4 GHz band such as wireless keyboards by IEEE 802.11g (2003). 2.7.3 802.11a The 802.11a regularly utilizes the similar data connection layer protocol and border format as the imaginative of five GHz bandwidth, an utmost net data rate of 54 Mbit/s, plus error adjustment code, which yields the practical net attainable throughput in the mid-20 Mbit/s. As the 2.4 GHz band is heavily utilized to the point of being packed, utilizing the comparatively unutilized five GHz band gives 802.11a a important advantage. However, this high carrier frequency also brings a disadvantage: the effective overall range of 802.11a is less than that of 802.11b/g. In theory, 802.11a signals are engrossed more willingly by walls and other solid objects in their path due to their smaller wavelength and, as a result, cannot penetrate to the extent that those of 802.11b. In practice, 802.11b characteristically had a higher variety at low speeds (802.11b will decrease speed to five Mbit/s or even one Mbit/s at low signal strengths). However, at higher speeds, 802.11a often has the similar or superior variety due to less interference.
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2.7.4 802.11-1997 (802.11 legacies) The imaginative version of the standard IEEE 802.11 was discharged in 1997 and elucidated in 1999, but is today out of date. It stipulated two net bit rates of one or two megabits per second (Mbit/s), good thing frontward error adjustment code. It specified three unconventional physical layer technologies: diffused infrared operating at one Mbit/s; frequency-hopping spread spectrum operating at one Mbit/s or two Mbit/s and direct-sequence spread spectrum operating at one Mbit/s or two Mbit/s. The latter two radio technologies utilized microwave broadcast over the Industrial scientific Medical frequency band at 2.4 GHz. Some previously WLAN technologies utilized lower frequencies, for instance, the U.S. 900 MHz ISM band (Craig 1996). 2.7.5 802.11n It is a current alteration which improves upon the previous 802.11 standards by adding Multiple-Input Multiple-Output antennas (MIMO) and many other newer features. The IEEE has approved the amendment and it was published in October 2009 (Corson and Macker 1999). Prior to the final ratification, enterprises was already migrating to 802.11n networks based on the Wi-Fi Alliance’s (Alliance 2003) certification of products conforming to a 2007 draft of the 802.11n proposal (Layuan et al. 2007). 2.7.6 802.11-2007 In 2003, duty collection TGma was endorsed to "roll up" lots of the alterations to the 1999 version of the 802.11 standard. REVma or 802.11ma, as it was called, formed a single manuscript that merged eight alterations (808.11a, b, d, e, g, h, I, j) with the base standard. Upon endorsement on March 8, 2007, 802.11REVma was renamed to the contemporary base standard IEEE 802.11-2007 (Charles et al. 2003). 2.8
MOBILITY MODEL (RANDOM WAY POINT)
In defining mobility model, Audsin et al. (2009) defined it as the key parameter to be considered for analyzing the performance of routing protocol in a simulation environment. This includes description of the mobile user movement pattern, its location; velocity and acceleration change over time. The most commonly used model
34
in MANET research work is a random way point which has an interdependent relationship with the routing performance. In other senses, the routing performance and connectivity are affected by the speed and pause time. For its application, it has been used in the tests for this research because it is often used in Ad-Hoc network simulation and easy to implement. Random way point model is known as a basic model for which various analytical results exist. Such a model is characterized by having several parameters, which are adjustable to suit a particular scenario (Hyytiä et al. 2005). Figure 2.8 illustrates the random way point mobility where A is used to represent the nodes mobility domain and N symbolizes the node movement from the point Ni to point Ni+1. Some of the distinguished characteristics of this model are presented as follows:
N1
N8 N2
A
N6
N7
N3 N4
N5
Figure 2.8 Random Way Point Model MANET might be dissimilar in terms of characteristics, problems, heterogeneity and applications compared to other networks. AODV is one of the popular routing protocols designed for MANET, which can caster the special characteristics of the network. The performance of the simulation experiment is interconnected with the mobility model. RWP mobility model is the very basic and mostly used model, which has been applied in the work.
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2.9
RELATED WORKS
A performance analysis of proactive and reactive routing protocols for Ad-Hoc network’s Dynamic Destination-Sequenced Distance Vector (DSDV), AODV and Dynamic Source Routing (DSR) showed that the performance of AODV was better in a dense environment, except packet loss (Tyagi and Chauhan 2010). Moreover, it was found that both DSR and AODV performed well, and they proved to be better than DSDV. However, it is not clear which protocol is the best for all the scenarios, even though there are rapid growth and development in the field of Ad-Hoc network. Kanakaris et al. (2010) have evaluated four Ad-Hoc network protocols (AODV, DSDV, DSR and TORA) in diverse network scales taking into consideration the mobility factor. Based on this model, the throughput and energy consumption in tiny size networks did not disclose any momentous differences. On the other hand, for medium and huge Ad-Hoc networks the TORA concert proved to be incompetent in this research. Above all, the concert of AODV, DSDV and DSR in tiny size networks was equivalent. Other than in medium and large size networks, the AODV and DSR formed good results and the concert of AODV in terms of throughput is good in all the scenarios that have been investigated. Performance Evaluation of AODV, DSDV and DSR Routing Protocol in Grid Environment is available in (Usop et al. 2009). According to their model, the performance evaluation of AODV, DSR and DSDV were performing very well when mobility is high while the simulation results have shown that the traditional routing protocols like DSR have a dramatic decrease in performance when mobility is high. Manickam et al. (2011) have Performance Comparisons of Routing Protocols in Mobile Ad-Hoc Network for DSDV, AODV and DSR. Based on this model, the DSR outperforms AODV because DSR has less routing overhead when nodes have high mobility considering the throughput, End-to-End delay and packet delivery ratio metrics while DSDV produces low end-to-end delay compared to AODV and DSR.
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Performance evaluation and simulations of routing protocol in Ad-Hoc networks like AODV, DSR, DSDV, and TORA are available in Layuan et al. (2007). According to their model, the performance evaluation of DSR routing load is temperate, in the temperate topology. It has fewer loss ratios, a huge throughput and a lengthy delay, which is appropriate to the medium-scale network environment without higher delay demand. Because DSDV should uphold the entire state of affairs information, when topology changes regularly and network size increases, the increment of routing weight is extremely rapid, and it is not fitted for large-scale and high-speed touching wireless environment. In all the scenarios, AODV exhibits the smallest delay and loss ratio and the greatest throughput, whose scalability, connectivity and the adaptive ability is also of relative strong point. On the other hand, TORA has the lowest routing load and a good scalability; it functions as the underlying protocol for the routing algorithms and provides multicast capacity. Our work in this present study is to use the more widely used traditional mobility models and traffic sources to create observations based on more standardized methodology that can be used to evaluate which proactive routing protocol (OSPF and RIP) or reactive routing protocol (AODV and DSR) is more stable for Ad-Hoc networks based on some criteria in QualNet simulation. 2.10 DISCUSSION There have been dynamic routing protocols available and a lot of static but selection of the correct protocol for routing is reliant on a lot of strictures such as networked scalability, convergence time, CPU necessities and memory, security and the bandwidth requirements. The reasons why OSPF is chosen to be the building ground for the proposed OSPF routing protocol is as follows: OSPF’s capability to divide a routing domain into areas within one AS and every OSPF router animatedly maintains the equal sight of the AS topology. A loop/free is a necessitated attribute due to of the resource’s pricey overhead. OSPF was the first extensively deployed routing protocol that could converge with a network in the low seconds, and guarantee loop-free paths. It has a lot of attributes that agree to the imposition of policies concerning the propagation of routes that it may be suitable to keep local, for load sharing, and for
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selective route importing further than others. Moreover, OSPF offers all the functionality of other routing protocols, plus Variable-Length Subnet Mask (VLSM) support, routing updates without the 30-second "hold-down" period required by others and bandwidth optimization, including less frequent routing updates and a choice of metrics. The reasons why RIP is chosen to be understood and configured and is guaranteed is being supported by all routing and support to load balancing. In addition, the good news is that adding RIP routing on a Cisco router is really easy. The reasons why AODV is chosen to be planned for mobile Ad-Hoc network with inhabitants of tens to thousands of mobile nodes are AODV is able to knob low, has relatively high mobility rates and moderate, as well as an assortment of data traffic levels. AODV is planned for utilization in networks where the nodes were able to all faith each other, either by utilizing of preconfigured keys, or because it is known that there are no malicious intruder nodes. AODV has been planned to decrease the dissemination of control traffic and eliminate overhead on data traffic, in order to improve scalability and performance. The reasons why DSR is chosen to be of highquality professional service is because it is based on a knowledgeable engineering team and quality assurance team, clear and concise contracts, protecting customers’ confidential information and intellectual property, complete project documentation transfer, transparent project management and status reporting on a weekly or upon request basis, friendly and flexible professional relationships with the customer team and time-tested isolated communication methods. Moreover, DSR engages in both short-term and enduring associations. In both cases, DSR transfers Intellectual Property (IP) clearly, ensuring client receipt of all worth shaped by DSR. This research tries to give some of the criteria to select the best routing protocol that satisfies the objective of QoS. Therefore, this work focuses on the most important factors: a) End-to-End delay: this factor is important for the Ad-Hoc networks due to the fact that some of the real-time applications are very sensitive to the delay which means the data packet sent from the source node should be delivered to the final target node within the specific period time without any delay. Therefore, the routing protocol will be selected based on the shortest path from
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the source node to the destination node to meet a request of this type of applications resulting in receiving the data packet with a reasonable delay. b) Average jitter: this factor assesses the variability over time of the packet latency across a network which is associated with the delay. Therefore, the network with constant delay has no jitter. However, the routing protocol that satisfies the constant delay without any variation during the time will be more suitable to be selected for data routing. c) Throughput: the significance of throughput comes from the need to deliver more messages to destination nodes during a specific time, which means that the routing protocols should use some mechanisms to avoid the congestion in some paths, which are more frequently used to prevent the packet drops during the data routing. Hence the reactive routing will get a better chance to be chosen here because it can find the alternative paths to be used rather than congest one resulting in increased throughput of reactive routing protocol compared with the proactive routing, which uses the static route which is more difficult to start searching for the alternative paths. Another mechanism must take into account the increased throughput for routing protocols in order to be chosen is how to deal with the failures of the paths during the data delivery. This means, that if the current path used is no more available either by the node failure or moving from the current position; so the routing, which deals with this issue will be more preferred for the user. d) Energy consumption: energy is a very important factor, especially in mobile ad-Hoc networks because it has restricted energy. Therefore, the routing protocol should consider this factor by choosing the paths that consume. A small amount of energy to extend the lifetime of the node and give the chance to the connectivity of the network to be longer. Moreover, the paths which always route the data packets the nodes participate in this path will deplete their energy very fast and with time may run-out their batteries. Therefore, the routing protocol must look for new paths to avoiding using the same path repeatedly, causing consumption of much energy. Again here the reactive protocols will be more favorable because of their on-demand property.
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From above the explanations of these factors we can see the importance of those factors as measurements of the performance of ad-Hoc networks to meet the requirements of both users and applications due to their significant effect. Finally, this research tried to give some of the advantages to select the Qualnet simulator such as this simulator is considered as the first commercial simulator, and the cost of the commercial license is very expensive. It assists simulation results to come out fast for thorough exploration of model parameters. It’s based on GloMoSim, which was developed at the University of California, Los Angeles (UCLA). For Complex Systems (PARSEC) for basic operations, GloMoSim makes a use of the Parallel Simulation Environment for Complex Systems (PARSEC). Moreover, it can support multiprocessor systems and distributed computing. Its documentation and tutorials are available free on the internet. By using QualNet, users can create the model and its specification through the graphical user interface. Therefore, specifying small to medium networks by using the GUI is easy done compared to specifying all connections in a special model file manually. Compared to other simulations, its accuracy and performance are so high. In brief, it’s considered as a real-time simulation for man-in-the-loop and hardware-in-the-loop models. 2.11 CONCLUSION This chapter introduced the various classifications of Ad-Hoc routing protocols. It detailed the operations of the four routing protocols (OSPF, RIP, AODV, and DSR) that were used in this investigation and discussed the advantages and disadvantages of each of these protocols. It also introduced an overview of simulation and reasons for selecting the QualNet software, IEEE 802.11 and introduced prior and related work in this area of study.
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CHAPTER III
RESEARCH METHODOLOGY
3.1
INTRODUCTION
Simulation methodology is a term of procedures used to conduct a research. Research in a computer network uses too many methods such as experiments to test the theory. The most popular method of experimentation in terms of networking area is simulation. This chapter provides descriptions of the various simulation parameters and analysis used in this study. It also discusses the implementation specifics related to the simulation model and the various components of the simulation environment. This chapter shows the deposit of methods that were used to carry out the research sequentially to achieve current research objectives. Essentially, the research methodologies that are inspired by pervious related research consist of two main methods: that is to say, formal methods and simulation. The methods are described below. Firstly, formal method technique is used to model MANET system as a geometric entity. We used computational tools to model a network as an undirected diagram where nodes are vertices and communication links are edges. Secondly, we used simulator to evaluate and test the performance of our protocols. Simulator methods are used comprehensively in network research to implement, compute, and evaluate protocols. Using the simulator allows us to focus on the research initiative as an alternative of physical implementation details. We used
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QualNet V5 simulator due to some of its personality that make it a suitable choice for this work. 3.2
REASONS FOR CHOOSING SIMULATION METHODS
It is worth noting that simulation and prototyping entail two different styles of execution. A prototype performs completely in parallel while simulation performs the RTL code serially. This leads to differences in debugging. In the prototype, the user utilizes a sense analyzer for visibility, and so can perceive only a limited number of signals which they strong-minded in front of time (by clipping on investigates). The goal does not stop when the logic analyzer activates, so apiece time the user transforms the probes or trigger condition, they have to reset the surroundings and start again from the commencement. On the other hand, for simulation, the user can set a breakpoint and stop simulation to scrutinize the design state, interact with the design, and resume simulation. The user can stop execution “mid-cycle” as it were, with only part of the code executed; the user can see any signal in the design and the contents of any memory location at any time and the user can even back up time (if they save) and re-run. From the explanations of these we can see the simulation method is important for those evaluation methods as the measurements are easy, accurate, flexible, and low cost. 3.3
SIMULATION
According to Craig (1996), a simulator is recognized as a collection of hardware and software, which are used to minimize the behavior of some entity or phenomenon. Simulations may also be used for analysis and verification of the theoretical models which may be so difficult to grasp from a purely conceptual level. In this way, simulation plays a crucial role in both industrial and academic sectors. It is considered as very important, particularly in cases when testing is involved in the high-risk system. Some of its advantages are represented by its capability to save budget, time and even important in providing the safety aspects. The ultimate aim of routing a
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simulation is to gain results and get some insights into the system by analyzing the results (Varga and Hornig 2008). Furthermore, simulation has many benefits over other research methods because it helps the researches to model and represent the real system with the least time and cost comparing to setting up a real system containing computers, routers, and soon. Also simulation allows testing different ideas that is usually difficult or expensive to do in a real system. Further, simulation provides opportunities for examining the effect of different parameters in network performance. Simulation assists on building of complex networks (Dooley 2002). Simulation is used extensively as a research method to study and analyze communication protocols especially in MANET. Simulation became a necessity in MANET as the consequence of two main reasons; firstly, simulation allows the researcher to model and evaluate MANET with many nodes which still either do not exist or very pricey. Secondly, the complex nature of MANET due to many features such as wireless links, node movement, which often impacted the performance of network (Ariza-Quintana et al. 2008). Simulation is used widely in the conceptual phase because it lets the researcher focus on the research idea. There presently exist three main different kinds of simulations (Dooley 2002) as shown in Table 3.1.
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Table 3.1Kind of Simulation Kind of Simulation Discrete event system
System dynamics simulation
Agent-based simulation
Definition The system is modeled as a sequence of events After identifying the main variables that determine the behavior of the system, those variables are associated one to the other through paired differential equations The agents (system components), which have attributes and possibly even complex behaviors, interact with each other and their environment over time toward the achievement of their desired goals
3.3.1 Network Simulation Network simulator is defined as software or hardware, which is usually used to predict the behavior of the network without presenting the actual network. GloMoSim, NS-2, OPNET, OMNeT++ and QualNet are some examples of the many network simulators which are available. a)
GLOMOSIM Simulator
Global Mobile Information System Simulator (GloMoSim) is defined as a scalable simulation library, which is designed at an UCLA computing laboratory for supporting the large-scale network models, up to millions of nodes, by using parallel distributed execution on a diverse set of parallel computers (with both distributed and shared memory). In this sense, it is a library for the C-based parallel discrete-even simulation language PARSEC. For most protocols in GloMoSim, it is enough to write purely C code added with few PARSEC functions (Di Caro 2003). QualNet is recognized as the commercial Version of GloMoSim. Despite the fact that GloMoSim is the only best simulator among the considered ones, which seem to be able to scale up to thousands of nodes, it is stated that model design GUI is not detailed enough to be useful and simulation results reporting are not adequate (Begg et al. 2006).
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b)
OMNeT++ Simulator
As defined by Varga and Hornig (2008), Objective Modular Network Test-bed in C++ (OMNeT++) is known as a component based, modular and open architecture discrete event network simulator, which was invented by Varga and Hornig. It was released in 1991, and since 1997 it has been made available for public. Although OMNeT++ was designed with the aim of making it as general as possible, commonly it is used as a simulator for computer network and queuing network. It is also open-source software, and it is free from the non-profit use where it can be used under the Academic Public License. In designing OMNeT++ simulator, Varga and Hornig were motivated to develop a simulation tool which can be a powerful open source discrete tool for being use by academics, educational and distributed or parallel system. Therefore, in doing so, they were attempting to bridge the gap between the open sources. Research oriented simulation software such as the NS-2 and expensive commercial alternative like OPNET can run under various user interfaces. c)
NS-2 Simulator
Network Simulator 2nd Edition (NS-2) is well known as the second Version of a network simulator tool which is developed by Virtual InterNetwork Test-bed (VINT) project. It is a simulator driven by network, which has gained popularity among networking research community (Lucio et al. 2003). The core simulation and most of the network protocol models are written in C++ and the rest are written in OTcl. The function of the NS-2 is focused on modeling various networks’ protocols for wired, wireless and satellite networks, including TCP, UDP, SCTP and supports Unicast and Multicast. Moreover, it provides infrastructure for simulations related to statistic tracing error models, etc. For wireless part, NS-2 provides Ad-Hoc routing and mobile IP. Although NS-2 is free software, it has been pointed out that some protocol and features are not well documented, and the patching extensions in it are not easy. Furthermore, it lacks clean separation between C++ and OTcl (Begg et al. 2006).
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d)
OPNET Simulator
Optimized Network Engineering Toll (OPNET) is a commercial tool generated from OPNET Technologies Inc. for modeling and simulation of communication network. For its applications, OPNET is used by large companies for managing simulation for hundreds of nodes. To support MANET, the wireless (local, GSM, AND Ad-Hoc) module of OPNET is accompanied by all of the most necessary components in terms of mobility, radio propagation models and protocol to stack, including MAC (802.11) and popular routing algorithms like AODV AND DSR (Di Caro 2003). Although the advantage of OPNET is that it is a powerful discrete-event simulator, it is disadvantaged for demanding a large amount of processing power and being very time-consuming, especially when used in a network with a large number of transmitters and receivers. Furthermore, the expensive cost of the commercial license is another disadvantage of OPNET. e)
QUALNET Simulator
QualNet is defined as a network simulation tool that functions as a simulator for wireless and wired packet mode communication networks. QualNet is supplied with models for common network protocols provided in a source form and are organized around the OSI Stack. It is also supplied with a graphical user interface so that a user can create the model and its specification. Therefore, specifying small to medium networks by using the GUI compared to specifying all connections in a special model file manually is done easily. Moreover, although QualNet is a network simulator which mainly targets at wireless solutions, it also contains support for wired networks. Since the environment and library in the QualNet are very sophisticated, it is very easy to simulate a real network with QualNet. However, simulating a real network with QualNet makes the simulation of logical networks a little bit more difficult and challenging. It is possible to be carried out. Since Java for the GUI is used as the primary element in such a network with QualNet, it is available for Linux as well as for Windows. The simulator itself is designed in a way that suits the specified target system optimized C program as stated by Comparision of Network-Simulator (2009).
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To obtain more information about QualNet basics, there are several other tutorials available for learning QualNet basics at QualNet (2001) and QualNet Tutorial (2007). 3.3.2 Reasons for Choosing QUALNET Simulator Qualnet is based on GloMoSim, which was developed at the University of California, Los Angeles (UCLA). In the light of the review of the candidate network simulators in Table 3.2, we have decided to utilize QualNet as the surrounding for improvement and simulation. None of the reviewed simulators seem to really possess the whole set of characteristics required to simulate our research strategy and objectives analysis. Table 3.2: The review of the candidate network simulators Features Commercial Open source GUI Costs and Licenses Accuracy Documentation and tutorials Ease to use/modify/extend Real-time Performance Support multiprocessor systems
OPNET √ √ √ Lots √
QualNet √ √ √ √ Lots √ √ √ √
NS2, NS3
OMNeT++
√
√ √
√ less
less
√
However, QualNet shows itself as the best concession in stipulations of number of pre-built components, modularity, scalability, and ability. QualNet has been selected as it met most of the requirements such as widespread set of pre-built models, protocols and algorithms, a good level of acceptance from the technical community, an outstanding scalability, a slightly good, extremely modular, software design, an acceptable level of usability, capability and expandability, superior graphical and mathematical tools for experiment building, monitoring and post-processing, good documentation, a possibility of parallel and/or distributed executions, and a possibility to specify a realistic 3D model of the environment. The presence of an extensive set of right executions of models, protocols and algorithms will dramatically shorten our startup time, since we will have to agonize only about the execution of our algorithms and of possible modifications/extensions to existing modules. Also OPNET and NS-2 present this important feature, but not OMNeT++. The scalability up to thousands of
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nodes will go away as the likelihood to perform studies over a wide range of features and scenarios. This scalability possessions and the highly modular nature of the system can in principle accept also statistical-mechanics-like simulations. Among the other considered simulators, only OMNeT++ could enjoy this possibility. In terms of ease to use/modify/extend, QualNet seems to be more than acceptable. In this sense, it is almost certainly comparable to OPNET, while OMNeT++, with its good objectoriented design seems to be the best simulator in this respect. NS-2 scores poorly. The quality of the supplementary tools for design, monitoring, and analysis is in general at an acceptable level in GloMoSim, and definitely good in QualNet. From this point view GloMoSim/QualNet compares favorably and/or at the same level with respect to the other simulators. The research premeditated to start to construct our algorithms and simulation architecture by using QualNet. In spite of the fact that GloMoSim and QualNet have rather similar features and QualNet is not cost-free, we have preferred QualNet over GloMoSim since QualNet's supplementary tools for design and analysis seem to be key-features to speed up algorithms' execution and make easy the in-depth understanding of their behavior. Furthermore, GloMoSim is not anymore supported by its authors, while QualNet, being a commercial product, is shipped with a full online support for any sort of technical and execution issues. 3.4
SIMULATION DETAILS
The objectives of these QualNet Version Five simulations are to evaluate the study of Proactive (OSPF and RIP) and Reactive (AODV and DSR) routing protocols in AdHoc networks. The evaluation metrics used are throughput, end-to-end delay, average jitter and energy consumption. Figure 3.1 shows a flowchart of this research in what it will do in QualNet simulator, and it given the summary of methodology in this research.
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Simulation
QualNet V5
Effects of Number of Nodes
Energy consumption
Implement
Throughput
Effects of Packet Size
Average Jitter
End to End Delay
Evaluation Performance
Figure 3.1: Summary of QualNet Simulation. 3.4.1 Components of QualNet Developer As mentioned by QualNet Developer (2010), this section describes several components such as QualNet Architect: Design Mode, QualNet Analyzer, QualNet File Editor, QualNet Architect: Visual Mode and QualNet Packet Tracer. a)
QualNet Architect: Design Mode
QualNet Architect, known as Design Mode can give users opportunities to set up terrain, network connections, subnets, mobility patterns of wireless users, and other functional parameters of network nodes. By using intuitive, click and drag operations, users are assumed to be able to create network models. By using such models, the
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protocol stacked of any of the nodes can be customized and the application layer traffic and services that run on the network can be specifically identified by users. Figure 3.2 shows Architect design mode in QualNet for the scenario I from AODV in 50 numbers of nodes and show the traffic in green color during growing the scenario I.
Figure 3.2: Architect design mode in QualNet. b)
QualNet Analyzer
QualNet Analyzer is defined as a statistical graphing device which shows the metrics collected during the simulation of a network scenario in a graphical format. The graph display can be customized. All statistics are exportable to spreadsheets in CSV format. Figure 3.3 presents analyzer of QualNet for the scenario in metric value graphical format in CBR client. CBR client shows the total bytes sent, comparison type node.
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Figure 3.3: Analyzer of QualNet. c)
QualNet File Editor
QualNet File Editor is known as a text editing tool by which the contents of the selected file are displayed in a text format and by which the user can edit files. Figure 3.4 illustrates the file editor for the scenario I from AODV in 50 numbers of nodes. It shows QualNet configuration file for the parameters setting such as simulation time.
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Figure 3.4: The file editor in QualNet. d)
QualNet Architect: Visual Mode
QualNet Architect as a visual mode provides the user with opportunities to perform in depth visualization and analysis of a network scenario designed in Design Mode. While simulations are running, it is possible for users to watch packets at various layers flow through the network and view dynamic graphs of critical performance metrics. Real-time statistics are also optional where users can watch dynamic graphs while a network scenario simulation is running. Figure 3.5 presents the visualization and analysis of a network scenario I from AODV in 50 numbers of nodes. This Figure is during the implementation.
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Figure 3.5: The visualization and analysis of a network scenario. e)
QualNet Packet Tracer
QualNet Packet Tracer is stated to provide a visual representation of packet trace files created during the simulation of a network scenario. Trace files are text files presented in XML format containing information about packets as they move up and down the protocol stack. Figure 3.6 shows the packet tracer files generated during the simulation. It presents the packet tracer that moves up and down during the implementation of the action type.
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Figure 3.6: The packet trace files generated during the simulation 3.4.2 Simulation Environments Network simulation Version 5 (QualNet) is a state-of-the-art simulation where there are a lot of heterogeneous networks, and the distributed applications that execute on such networks. This research will generate two scenarios to implement our work. Both scenarios are using an 802.11 MAC. The first scenario affects the number of nodes, and the second scenario affects the packet size. a)
Effects of the Number of Nodes
The simulation was performed using the effects of the number of nodes that determine the parameters and metrics of the simulation such as types of traffic, simulation time, routing protocols, number of nodes, etc. Table 3.2 demonstrates the parameters of the effects of the number of nodes. This research selected these parameters according to Tyagi and Chauhan (2010), except for the routing protocols.
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Table 3.3: Parameters of effect of the number of nodes Parameter Value Number of nodes
50,90,130,170,210
Simulation Time
1200sec(20Min)
Simulation area Routing protocols Mobility Model Transmission Power Transmit Power Consumption Receive Power Consumption Idle Power Consumption Transmission range Transmission Power Item Size PHY Type of traffic Data Rate Speed
800Х1200m OSPF,RIP,AODV and DSR Random Way Point 25dBm 100mW 130mW 120mW 270m 25.0 512bytes 802.11b CBR 11Mbps (10-100) m/s
The scenario I was implemented in this research into five reason experiences with the different number of nodes. The research used physical layer 802.11b due to the performance under ideal conditions, without the overhead. Its range is, in practice, about 100 feet indoors. It's up to 1500 feet in the open. Its cost is low, typical of applications good for homes or small offices, its compatibility only with itself. Its frequency is 2.4 GHz, and it’s supported for QualNet simulation. b)
Effects of Packet Size
The simulation will perform using the effect of packet size and size area that determine the parameters and metrics of the simulation such as data type, size area, routing protocols, item size, etc. Table 3.3 summarizes the parameters of the packet size and size area.
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Table 3.4: Parameters of the effects of packet size Parameter
VALUE
Number of Nodes
7
Simulation Time
3000s
Size area Routing protocols Transmission Power Mobility Model Transmission Power Transmit Power Consumption Receive Power Consumption Idle Power Consumption Transmission range Packet size PHY Type of traffic Packet rate Speed
500Х500m OSPF,RIP,AODV and DSR 25.0 Random Way Point 25dBm 100mW 130mW 120mW 270m 100,200,300,400,500,600 and700 Bytes 802.11b CBR 11Mps (10-100) m/s
The scenario II was implemented in this research into seven reason experiences with different packet size. The research used in physical layer 802.11b due to the performance under ideal conditions, without the overhead. Its range is, in practice, about 100 feet indoors. It's up to 1500 feet in the open. Its cost is low, typical of applications good for homes or small offices, its compatibility only with itself. Its frequency is 2.4 GHz, and it’s supported for QualNet simulation. 3.4.3 Traffic Generators The importance uses of Ad-Hoc are used is to perform the function of deploying a dynamic rapid communication network setup in disaster relief and military operations (Annamalai 2005). Some applications such as video and voice communications are constant in the data rate datagram. To model similar loads, constant bit rate (CBR) traffic was used as the application traffic model running over a User Datagram Protocol (UDP) transport connection. The scripts of the CBR traffic generation are available in QualNet Version 5. Actually, some sensible simulations can be done by selecting Applications CBR from the toolbar in the designer view from QualNet. Through the drag drop, it's possible for users to connect all sensor nodes with the root
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node. But it should put into consideration that it is dragged from sensor node to root node so that there's a unidirectional trace to root node. After the scenario is completely done, it will look like Figure 3.7.
Figure 3.7: Traffic Generators Finally, the traffic generators have to be configured according to the scenarios in the Tables 3.3 and 3.4. 3.4.4 Scenario Designer Scenario designer is defined as a graphical tool or device which provides an intuitive model and one of its usages is to create and design experiments in QualNet. By using this type of model, a user can define the geographical distribution, physical connections and the functional parameters of the network nodes, all just by using the
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intuitive click and drag tools. Moreover, network layer protocols and traffic characteristics for each node can be identified by the user using such a model. 3.4.5 Wireless Subnet Until now, all the nodes only communicate on PHY and MAC layer. Therefore, the default wireless channel model and IEEE 802.11 physical layer (PHY) and MAC were used to supply wireless subnet. Our work is using MAC 802.11 and PHY 802.11b in QualNet. 3.5
METRICS FOR EVALUATION
Corson and Macker (1999) pointed out that evaluation metrics are possible to be made use of in evaluating quantitatively MANET routing protocols. Such a quantitative measurement is useful as a prerequisite for assessing or evaluating the performance of network or even to compare the performance using different routing protocols. This research tries to give some of the criteria to select the best routing protocol that satisfies the objective of QoS. Therefore, this work focuses on the most important factors: a) End-to-End delay: this factor is important for the Ad-Hoc networks due to the fact that some of the real-time applications are very sensitive to the delay which means the data packet sent from the source node should be delivered to the final target node within the specific period time without any delay. Therefore, the routing protocol will be selected based on the shortest path from the source node to the destination node to meet a request of this type of applications resulting is receiving the data packet with reasonable delay. b) Average jitter: this factor assesses the variability over time of the packet latency across a network which is associated with the delay. Therefore, the network with constant delay has no jitter. However, the routing protocol that satisfies the constant delay without any variation during the time will be more suitable to be selected for data routing.
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c) Throughput: the significance of throughput comes from the needs to deliver more messages to destination nodes during a specific time which means that the routing protocols should use some mechanisms to avoid the congestion in some paths, which are more frequently used to prevent the packet drops during the data routing. Hence the reactive routing will get a better chance to be chosen here because it can find the alternative paths to be used rather than congest one resulting in increased throughput of reactive routing protocol compared with the proactive routing, which uses the static route which is more difficult to start searching for the alternative paths. Another mechanism must take into account the increased throughput for routing protocols in order to be chosen is how to deal with the failures of the paths during the data delivery. This means, that if the current path used is no more available either by the node failure or moving from the current position; so the routing, which deals with this issue will be more preferred for the user. e) Energy consumption: energy is a very important factor, especially in mobile ad-Hoc networks because it has restricted energy. Therefore, the routing protocol should consider this factor by choosing the paths that consume. A small amount of energy to extend the lifetime of the node and give the chance to the connectivity of the network to be longer. Moreover, the paths which always route the data packets the nodes participate in this path will deplete their energy very fast and with time may run-out their batteries. Therefore, the routing protocol must look for new paths to avoiding using the same path repeatedly, causing consumption of much energy. Again here the reactive protocols will be more favorable because of their on-demand property.
From the prior explanations of these factors we can see the importance for those factors, as measurements of the performance of Ad-Hoc networks, to meet the requirements of both users and applications due to their significant effect. The evaluation in the current study includes the following performance metrics:-
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3.5.1 Average End-to-End Delay This refers to the interval taking place between the data packet generation time and the time of the arrival of the last bit at the destination, as well as the average amount of time taken by a packet to move from source to destination. The process includes all possible delays which happen due to buffering during route discovery, latency, queuing at the interface queue, retransmission delays at the MAC and propagation and transfer times (Tyagi and Chauhan 2010). 3.5.2 Average Jitter Average Jitter is known as the time variation measured between the arrival of the packets due to the congestion of the network, the drift in timing, or changing of the route (Layuan et al. 2007). Furthermore, in data over IP (CBR), jitter is the variation in the time among caused by network jamming, packets arriving, timing float or route modification. A jitter buffering was able to be utilized to knob jitter. Moreover, Jitter is the excursion in or displacement of a number of aspects of the pulses in a highfrequency digital Unified Communication Resources signal. As the name proposes, jitter can be considered of as wobbly pulses. The divergence can be in stipulations of amplitude, phase timing, or the width of the signal pulse. Another definition is that it is "the period frequency displacement of the signal from its ideal location." Among the sources of jitter are electromagnetic interference (EMI) and crosstalk with other signals. Jitter can cause a show monitor to glimmer; affect the capability of the processing a personal computer to execute as intended; introduce clicks or other undesired effects in audio signals, and loss of broadcasted data between network devices. The quantity of permissible jitters depends greatly on the application. 3.5.3 Throughput It is usually defined as the number of data packets delivered to their destination per unit of time (Mishra et al. 2008). Moreover, throughput is the ratio of the total amount of data that a receiver receives from a sender to the time it takes for the receiver to get the last packet. A low delay in the network translates into higher throughput. Delay is
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one of the factors affecting throughput. Throughput gives the fraction of the channel capacity used for useful transmission and is one of the dimensional parameters of the network. 3.5.4 Energy Consumption Given that mainly wireless nodes in Ad-Hoc networks were not associated to an authority supply and battery substitution might be difficult, optimizing energy consumption in these networks has elevated main concern, in sequence to draw out the network lifetime, through which the network can purpose our work properly. This involves not only energy efficient hardware, but also energy efficient protocols. Consequently, power administration is one of the most taxing problems in Ad-Hoc networking. Studies have given away that the noteworthy consumers of power in a typical laptop are the CPU, memory, display, hard disk, keyboard/mouse, and wireless network interface card. Generally, radios in an Ad-Hoc network node can operate in four separate modes of operation: transmit, receive, idle, and sleep (Feeney 2001; Feeney and Nilsson 2001; Raghunathan et al. 2002). In the idle mode, the radio can switch to receive or transmit mode. Idle is the default mode for Ad-Hoc surroundings. Receive and Transmit modes are for receiving data and transmitting data. Therefore, it’s defined a use of energy as a source of heat or power or as a raw material input to a manufacturing process or like amount of energy consumed in a process or system, or by an organization or society. The result can be gotten by collecting (Idle mode + Transmit mode + Receive mode). 3.6
ANALYZING THE RESULTS
The results of the simulation analyses the statistical data generated during simulation. Inside the subdirectory belonging to the current scenario there should be some files called:
QualNet…..app
QualNet…...config
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QualNet…...display
QualNet…...nodes
QualNet…...stat The important file among those files is called "QualNet....stat"; if not, the
scenario hasn't been run before. Double clicking of the file according to statistic file opens the Analyzer which allows you to browse through the statistics of the different OSI layers. Selected items show informative graphs. The dataset can also be copied to Microsoft Excel to show informative graphs. 3.7
CONCLUSION
This chapter has outlined the research methodology, simulation methodology o and implementation of OSPF, RIP, AODV and DSR of this study. The importance of this chapter was on evaluation metrics and simulation details. It includes a discussion of the various performance metrics of interest for evaluation, and an explanation of the traffic generation used in the simulation study for metrics of evaluation. For the simulation, the detail is to setup the parameter of the scenario. It has provided a discussion of the various simulation considerations, such as protocols simulation codes, analyzing the results and wireless subnet.
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CHAPTER IV
EVALUATION PERFORMANCE RESULTS
4.1
INTRODUCTION
The result is obtained after the experiments have been conducted. There are two experiment results in this study, which are simulation results. The aim of this study is to present the evaluation performance of each chosen routing protocol with respect to the effects of the number of nodes and packet size. The generated files that come out from the simulation scenarios were used with the same set of the number of nodes and packet size in an identical fashion to perform a fair comparison. The evaluation metrics is considered for average jitter, end-to-end delay, throughput, and energy consumption. The tests highlight the evaluation performance of OSPF, RIP, AODV and DSR in Ad-Hoc network. 4.2
RESULTS AND DISCUSSIONS
After the simulation was completed for scenario I and scenario II, the evaluation performance analysis was performed using average jitter, end-to-end delay, throughput, and energy consumption evaluation metrics. Two variables have been considered:
Number of nodes
Packet size
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4.2.1 Effects of the Number of Nodes a)
Average Jitter
Data set effects of the number of nodes are shown in Table 4.1. They were obtained during implement of scenario I by QualNet simulation of average jitter. Table 4.1 Data Set of Average Jitter (Scenario I)
No of Nodes 50 90 130 170 210
AODV 0.0353922 0.0352495 0.0366559 0.0326047 0.0326047
Scenario I Average Jitter(s) DSR 0.0365204 0 0.0248375 0.0143463 0.0224834
OSPF 0.003106 0.0026324 0.0565191 0.0015455 0.0014656
RIP 0.015466 0.036365 0.018677 0.000938 0.01431
Average Jitter (s) 0.06
Average Jitter (s)
0.05 0.04 AODV
0.03
DSR OSPF
0.02
RIP 0.01 0 50
90
130
170
210
No of Nodes
Figure 4.1: Average Jitter in OSPF, RIP, AODV and DSR in number of nodes.
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The four kinds of routing protocols have different jitters with the increased number of nodes, as shown in Figure 4.1. As a whole, OSPF has better jitter than the RIP, AODV and DSR, expected when the number of nodes is 130. In detail, OSPF shows a better jitter then RIP, AODV and DSR when the number of nodes is the bigger than 50 nodes while RIP, AODV and DSR show better jitter than OSPF, when the number of nodes is 130 but when the number of nodes is 90,170,210 nodes, the OSPF is the better jitter then RIP, AODV and DSR. This finding in the current study is possibly due to the accuracy and real time of the QualNet very satisfactory. However, the other study conducted by Layuan et al. (2007) found that the AODV was the best. b)
Average End-to-End Delay
Data set effects of the number of nodes are illustrated in Table 4.2. It was obtained during implement the scenario I by QualNet simulation of average End-to-End Delay. Table 4.2 Data Set of Average End-to-End Delay (Scenario I)
No of Nodes 50 90 130 170 210
Scenario I Average End-to-End Delay(s) AODV DSR OSPF 0.127879 0.127189 0.134225 0.126619 0.126619
0.079186 0.197886 0.207281 0.063845 0.191009
0.008285 0.03342 0.370966 0.019607 0.106076
RIP 0.058514 0.069717 0.052935 0.03455 0.04776
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Average End-to-End Delay (s)
Average End to End Delay (s)
0.4 0.35 0.3 0.25 AODV
0.2
DSR
0.15
OSPF RIP
0.1 0.05 0 50
90
130
170
210
No of Nodes Figure 4.2: Average end-to-end delays in OSPF, RIP, AODV and DSR in number of nodes. Figure 4.2 shows the influence of the number of nodes on network average end-to-end delay for four routing protocols. The average end-to-end delay value increases according to the number of nodes for OSPF. The maximum average end-to-end delay gains simulation with 130 number of nodes from OSPF and the minimum average end-to-end delay gains from the simulation of 50 nodes from OSPF. The average endto-end delay values increase and decrease according to the number of nodes for RIP. The maximum average end-to-end delay gains simulation with 90 nodes from RIP and the minimum average end-to-end delay gains from the simulation of 170 numbers of nodes from RIP. The average end-to-end delay values increase and decrease according to the number of nodes for AODV. The maximum average end-to-end delay gains simulation with 130 numbers of nodes from AODV and the minimum average end-toend delay gains from the simulation of 210 nodes from AODV. The average end-toend delay values increase and decrease according to the number of nodes for DSR. The maximum average end-to-end delay gains simulation with 130 nodes from DSR and the minimum average end-to-end delay gains from the simulation of 170 nodes from DSR. From the graph it is very clear that RIP out performs OSPF, AODV and
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DSR for scenario of varying pause time, varying simulation time, varying speed and varying number of nodes. In the case of OSPF, delay time increases very sharply with increased numbers of nodes. When the number of nodes is 170 delay time decreases very sharply while AODV and DSR have longer delay than OSPF and RIP with an increasing number of nodes. It is important to note here RIP’s end-to-end delay is low compared to OSPF, AODV and DSR. In this study, the RIP’s was the best. However, the other study conducted by Tyagi and Chauhan (2010) found that the AODV was the best. c)
Throughput
Data set effects of the number of nodes are demonstrated in Table 4.3, obtained during implementation of scenario I by QualNet simulation of throughput. Table 4.3 Data Set of Throughput (Scenario I)
No of Nodes 50 90 130 170 210
AODV
Scenario I Throughput(bits/s) DSR
OSPF
RIP
3308.5 3308 3307 27.5 27.5
2312 3 6 14 6
2565.5 2415 2554 6 9.5
2320 2301.75 1532.33 2285 2343.25
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Throughput (bits/s) 3500
Throughput (bits/s)
3000 2500 2000
AODV
1500
DSR OSPF
1000
RIP
500 0 50
90
130
170
210
No of Nodes
Figure 4.3: Throughputs in OSPF, RIP, AODV and DSR in number of nodes.
Figure 4.3 shows the influence of the number of nodes on network throughput for four routing protocols (OSPF, RIP, AODV and DSR). The throughput value increases according to the number of nodes for RIP OSPF and AODV. While in DSR it is increased when the number of nodes rises to 50 after which it starts to decrease very sharply with an increasing number of nodes. In addition, AODV and OSPF increase the throughput value according to the number of nodes expected when the numbers of nodes are 170,210 and decrease very sharply. The maximum throughput gains from simulation with 50, 90 and 130 numbers of nodes from AODV, and the minimum throughput gains from simulation 170 and 210 nodes. The maximum throughput gains from the simulation with 50 nodes from DSR and the minimum throughput gains from simulation (90,130,170,210) nodes. The maximum throughput gains from the simulation with 50 nodes from OSPF and the minimum throughput gains from the simulation (170,210) nodes. The maximum throughput gains from the simulation with 210 nodes from RIP and the minimum throughput gain from simulation 130 numbers of nodes. RIP had higher throughput value compared to OSPF, AODV and DSR. The
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accuracy of AODV was in accordance with Layuan et al. (2007), who reported some improvement in the outcome of AODV. d)
Energy Consumption
In energy consumption the result can be gotten by collecting idle mode + transmit mode + receive mode. We had two Tables to show the energy consumption. The first Table has idle mode, transmit mode and receive mode. The second Table has been collecting idle mode + transmit mode + receive mode. Table 4.4 shows the energy consumption of idle mode, transmit mode and receive mode by Qualnet simulation, while Table 4.5 shows the result of energy consumption collecting (idle mode + transmit mode + receive mode). Table 4.4 Data Set of Energy Consumption of (idle mode, transmit mode, receive mode) (Scenario I) AODV No of Nodes Receive mode Transmit mode Idle mode
50 0.004212 0.005698 39.9961
90 0.96178 0.003518 39.1122
No of Nodes Receive mode Transmit mode Idle mode
50 0.066248 0.020879 39.9387
90 26.4599 0.008001 15.5754
No of Nodes Receive mode Transmit mode Idle mode
50 40.9188 4.68583 2.18705
90 41.1133 3.06968 2.02187
130 2.33353 0.00372 37.8459
170 30.616 0.002043 11.7391
210 42.7732 0.001871 0.517033
130 33.6272 0.013737 8.95939
170 36.8386 0.007616 5.99503
210 29.895 0.007551 12.4046
130 36.4143 6.26578 6.33091
170 43.0805 0.398799 0.229807
210 13.3072 5.45351 7.66781
130 2.96544 0.577919 37.2575
170 3.51517 0.718834 36.7488
210 4.11252 1.01791 36.1947
DSR
OSPF
RIP No of Nodes Receive mode Transmit mode Idle mode
50 2.25513 0.21928 37.9164
90 2.35914 0.398631 37.8188
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Table 4.5 Data Set of the result of Energy Consumption (Scenario I)
No of Nodes 50 90 130 170 210
AODV
Scenario I Energy Consumption DSR
OSPF
RIP
40.00601 40.0775 40.18315 42.35714 43.2921
40.02583 42.0433 42.60033 42.84125 42.30715
47.79168 46.20485 49.01099 43.70911 26.42852
40.39081 40.57657 40.80086 40.9828 41.32513
Energy Consumption (w)
Energy Consumption(w)
60 50 40 AODV
30
DSR OSPF
20
RIP
10 0 50
90
130
170
210
No of Nodes
Figure 4.4: Energy Consumption in OSPF, RIP, AODV and DSR in number of nodes. The Energy consumption increases for four routing protocols with a starting scenario, as shown in Figure. 4.4. OSPF has a longer consumption than RIP, DSR and AODV except when the number of nodes is 210. So RIP, DSR and AODV have better Energy consumption than OSPF. However, RIP has better Energy consumption than DSR and AODV. On the other hand, the other study conducted by Kanakaris et al. (2010) found that the better ones were AODV and DSR.
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4.2.2 Effects of Packet Size a)
Average Jitter
Data set of effects of packet size was presented in Table 4.6, which was obtained during implementation of the scenario II by QualNet simulation of average jitter. Table 4.6 Data Set of Average Jitter (Scenario II)
Packet Size 100 200 300 400 500 600 700
AODV
Scenario II Average Jitter(s) DSR
OSPF
RIP
0.206328 0.168437 0.175319 0.193227 0.180074 0.145902 0.066711
0.956555 1.03527 0.997965 1.04567 1.03995 1.04009 1.05922
0.000565 0.000409 0.00041 0.000147 0.000447 0.000463 0.000285
0.001107 0.000909 0.000897 0.001143 0.000736 0.000409 0.000677
Average Jitter (s) 1.2
Average Jitter (s)
1 0.8 AODV
0.6
DSR OSPF
0.4
RIP 0.2 0 100
200
300
400
500
600
700
Packet Size Figure 4.5: Average end-to-end delays in OSPF, RIP, AODV and DSR in packet size.
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As shown in Figure 4.5 the four kinds of routing protocols have a different jitter with the increased packet size. On the whole, OSPF and RIP have a better jitter than the two other routing protocols while DSR shows a longer jitter than AODV. OSPF and RIP show the best evaluation performance. The findings of the current study are in agreement with Manickam et al. (2011), who found that outperformance of DSR was superior due to having fewer routing overhead and jitter. b)
Average End-to-End Delay
Data set of effects of packet size is shown in Table 4.7, obtained during implementation of the scenario II by QualNet simulation of average End-to-End Delay. Table 4.7 Data Set of Average End-to-End Delay (Scenario II)
Packet Size 100 200 300 400 500 600 700
Scenario II Average End-to-End Delay (s) AODV DSR OSPF 0.342346 0.214737 0.252899 0.306708 0.263188 0.237278 0.085281
6.5376 6.54139 6.43877 6.73125 6.06969 6.41203 6.81644
0.000603 0.000558 0.000529 0.00038 0.000554 0.000617 0.000501
RIP 0.00089 0.00085 0.000777 0.000939 0.000761 0.000566 0.000714
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Average End-to-End Delay (s) 8
Average End-to-End Delay (s)
7 6 5 AODV
4
DSR
3
OSPF RIP
2 1 0 100
200
300
400
500
600
700
Packet Size Figure 4.6: Average end-to-end delays in OSPF, RIP, AODV and DSR in packet size The average end-to-end delay decreases for all routing protocols except DSR with packet size higher than 100 Bytes, as shows in Figure 4.6 DSR has a longer delay than OSPF, RIP and AODV. OSPF and RIP exhibit a shorter delay because they are type of proactive (table-driven) routing protocols. AODV shows a smaller delay than DSR. In our simulation experiment’s environment of increasing packet size, DSR has always a longer delay than AODV. This study is also in the same line with Usop et al. (2009). c)
Throughput
Data set of effects of packet size is shown in Table 4.8, obtained during implementation of the scenario II by QualNet simulation of throughput.
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Table 4.8 Data Set of Throughput (Scenario II)
Packet Size 100 200 300 400 500 600 700
AODV
Scenario II Throughput (bits/s) DSR
OSPF
RIP
0.342346 0.214737 0.252899 0.306708 0.263188 0.237278 0.085281
6.5376 6.54139 6.43877 6.73125 6.06969 6.41203 6.81644
0.000603 0.000558 0.000529 0.00038 0.000554 0.000617 0.000501
0.00089 0.00085 0.000777 0.000939 0.000761 0.000566 0.000714
Throughput (bits/s) 3000
Throughput (bits/s)
2500
2000 AODV
1500
DSR OSPF
1000
RIP
500
0 100
200
300
400
500
600
700
Packet Size Figure 4.7: Throughput in OSPF, RIP, AODV and DSR in packet size As shown in Figure 4.7, shows the influence of the packet size on network throughput for four routing protocols. Overall, the throughput value increases according to the packet size for all routing protocols. Throughput increases quickly for OSPF, RIP, AODV and DSR with increased packet size. The maximum throughput is gained from simulation with 700 Bytes packet size and the minimum throughput is gained from simulation with 100 Bytes packet size. DSR, on the other hand, has a maximum
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throughput value according to increase packet size compared into OSPF, RIP and AODV. So the DSR produces better throughput than other routing protocols. This perhaps is due to the superior accuracy and performance to other. d)
Energy Consumption
In energy consumption the result can be gotten by collecting idle mode + transmit mode + receive mode. We had two Tables to show the energy consumption. The first Table has idle mode, transmit mode and receive mode. The second Table has been collecting idle mode + transmit mode + receive mode. Table 4.9 displays the energy consumption of idle mode, transmit mode and receive mode by Qualnet simulation, while Table 4.10 shows the result of energy consumption collecting (idle mode + transmit mode + receive mode). Table 4.9 Data Set of Energy Consumption of (idle mode, transmit mode, receive mode) (Scenario II) Packet Size Receive mode Transmit mode Idle mode Packet Size Receive mode Transmit mode Idle mode Packet Size Receive mode Transmit mode Idle mode Packet Size Receive mode Transmit mode Idle mode
100
200
0.005903 0.020331 149.981
0.005599 0.019659 149.982
100
200
0.01317 0.045568 149.958
0.015901 0.056014 149.948
100
200
0.023858 0.087242 149.92
0.02384 0.087071 149.92
100
200
0.008079 0.029998 149.973
0.007198 0.027191 149.975
AODV 300 0.006421 0.023004 149.979
DSR 300 0.017571 0.063108 149.942
OSPF 300 0.024151 0.088673 149.919
RIP 300 0.012669 0.046771 149.957
400
500
600
700
0.006697 0.024187 149.978
0.006999 0.025582 149.977
0.006917 0.025612 149.977
0.007311 0.027325 149.975
400
500
600
700
0.016744 0.060627 149.944
0.018613 0.068709 149.937
0.018896 0.069231 149.937
0.0192 0.071318 149.935
400
500
600
700
0.024271 0.089334 149.918
0.024797 0.091235 149.917
0.026166 0.096174 149.912
0.025198 0.09322 149.915
400
500
600
700
0.00829 0.031318 149.972
0.007753 0.029584 149.973
0.010093 0.036045 149.967
0.009364 0.03608 149.967
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Table 4.10 Data Set of Throughput (Scenario II)
Packet Size 100 200 300 400 500 600 700
AODV
Scenario II Throughput (bits/s) DSR
OSPF
RIP
150.0072 150.0073 150.0084 150.0089 150.0096 150.0095 150.0096
150.0167 150.0199 150.0227 150.0214 150.0243 150.0251 150.0255
150.0311 150.0309 150.0318 150.0316 150.033 150.0343 150.0334
150.0111 150.0094 150.0164 150.0116 150.0103 150.0131 150.0124
Energy Consumption (w)
Energy Consumption (w)
150.035 150.03 150.025 150.02 AODV
150.015
DSR
150.01
OSPF
150.005
RIP
150 149.995 149.99 100
200
300
400
500
600
700
Packet Size
Figure 4.8: Energy consumption in OSPF, RIP, AODV and DSR in packet size The four types of routing protocols have different energy consumption with increasing packet size as shown in Figure 4.8. OSPF has longer energy consumption than AODV, RIP and DSR, while AODV and RIP have smaller energy consumption than DSR. DSR shows smaller energy consumption than OSPF with increasing packet size. So the RIP and AODV show the best evaluation performance in energy consumption. This may be due to the energy consumption of OSPF was longer than others.
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4.3
CONCLUSION
This chapter outlined evaluation performance from the simulation results and metrics for the four protocols being investigated in this study. The two scenarios were then introduced, and the relative evaluation performance of the protocols under each usage scenario was explained. This chapter provided a comparison of the evaluation performance of each protocol under the different number of nodes and packet size. The results of the comparisons highlighted the best candidates for certain Ad-Hoc network’s scenarios. The evaluation performance of our protocols was evaluated based on two scenarios: the first scenario effect of the number of nodes and the second scenario is the effect of packet size. A Comparison between our work protocols and other pervious works shows that Routing Information Protocol outperforms other protocols in terms of communications complexity.
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CHAPTER V
CONCLUSION AND FUTURE RESEARCH
5.1
INTRODUCTION
This work investigates the evaluation performance of OSPF, RIP, AODV and DSR routing protocols in how to get the optimum, using two scenarios. Both scenarios (effect of the number of nodes and effect of packet size) are implemented by QualNet simulation. In this chapter, the conclusion and potential future work are presented. The objectives of this research are, firstly, to investigate the focuses on identification of proactive routing protocols and reactive routing protocols, which emphasized the quality of service in Ad-Hoc networks. We achieved this objective in Chapter 2, where an extensive and critical study of the routing protocols problem and many of its protocol are provided. Secondly, to assess the performance of proactive routing protocols (OSPF and RIP) and reactive routing protocols (AODV and DSR) which focuses on the quality of service such as End-to-End Delay, Throughput and Average Jitter. This objective is achieved in Chapter 4, where we proposed the protocols for performance in Ad-Hoc; analyzed the energy consumption in both protocols in the Ad-Hoc networks. Finally, to simulate, implement, and evaluate the proposed protocols. This objective is achieved by using QualNet V5 simulator as shown in Chapter 3 and Chapter 4 as well.
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5.2
CONCLUSIONS
This study’s analyses and investigations were carried out on acquired simulation results of four routing protocols: OSPF, RIP, AODV and DSR. Using simulation, QualNet V5, the evaluation performance of these protocols was compared and recommendations made for the best candidates for different scenarios. The study has introduced some component tools to aid scenario visualizations. The dynamic nature of Ad-Hoc wireless networks requires certain approaches based on the expected mobility scenario. This research found during this study the problems associated with Ad-Hoc networks, more specifically routing on Ad-Hoc networks. It also found how to select the better routing protocols for these problems and to make two diverse scenarios and applied over four protocols, which are OSPF, RIP, AODV and DSR to evaluate performance. As shown in the first scenario of five reasons experiments with the different number of nodes the routing information protocol (RIP) is the best choice for all evaluation performance metrics like throughput, average jitter, end-to-end delay, and energy consumption. In the second scenario of seven reasons experiments with different packet size shows that RIP performs better in Ad-Hoc network than OSPF, AODV and DSR in terms of end-to-end delay, Average jitter but the AODV shows better results regarding the energy consumption because AODV uses small control packets during the route discovery and route maintenance, and it is multi hop scheme rather than single hop. Generally, the routing information protocol has the best evaluation performance compared to OSPF, AODV and DSR in both scenarios.
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5.3
FUTURE RESEARCH
In this study there are limitations regarding the used scenarios derived from effects of the number of nodes and effects of the packet size. In the future work tends to analyze all the routing protocols to measure the performance with the increased number of nodes in large-scale network, packet size in large-scale network and enhance all routing protocols. In our research we used all the nodes we used in the network are homogenous MANET. We are planning in the future to simulate the nodes in the network with the heterogeneous MANET to be more realistic. The future research could include the routing protocols with different scenarios based on mobility speeds and different traffic types such as VBR, VoiceIP and could involve more enhancements and analysis of OSPF, RIP, AODV and DSR routing protocols to increase the number of nodes, increase packet size, include several parameters and test-bed requirements. These can be matched with the characteristic of routing protocols in an Ad-Hoc network by using other simulators like OPNET simulation to make a new protocol in the Ad-Hoc wireless network. The new protocol hopefully helps to improve the evaluation performance of routing protocol in Ad-Hoc network.
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