HANDOFF DELAY REDUCTION IN NEMO BASED VANET (HDR-NV) FOR ENHANCED PERFORMANCE

BY

SHAIKH MOHAMMAD EHSANUR RAHMAN

A thesis submitted in fulfilment of the requirement for the degree of Master of Science (Computer and Information

Engineering)

Kulliyyah of Engineering International Islamic University Malaysia

JULY 2018

ii

ABSTRACT

Vehicular Ad hoc networks (VANETs) comprise of vehicle-to-vehicle and vehicle-to-infrastructure communications and can be considered the most suitable technology to enable Intelligent Transport System (ITS) application to bestow the user mobility, safety and productivity with human comfort. In vehicular environment, vehicle’s fast movement introduces handoff. Handoff is the process of switching access points of mobile nodes during their movement towards the road direction. As a delay sensitive ITS application, during the VANET operation, handoff delays and packet losses are very crucial. During handoff, when mobile node (vehicle) is acquiring new care of address (CoA), packets directed toward that node are lost; because it’s old identity is no more valid. So in high speed dynamic vehicular environment the number of frequent handoffs would produce delay beyond the normal limit. A complete handoff including both MAC layer, for switching between APs, and network layer, for new CoA registration and configuration, produce adaptation delay which has diverse impact to ITS application. Therefore, to resolve the issues in performance enhancement of handoff delay and packet losses during handoff in VANET environment is very important. A domain based Handoff Delay Reduction in NEMO based VANET (HDR-NV) scheme is proposed in this thesis. Number of vehicles moving towards the road, construct a domain where network mobility-basic support protocol (NEMO-BSP) is applied. A vehicle is selected as master router (MR) and connected to the road side unit (RSU) to the internet and other vehicles in the domain work as localization router (LRs) and communicate through MR. Three performance matrices: handoff latency, packet loss and inter-frame delay have been measured to evaluate the scheme. Simulation test was performed in network simulator (NS)3 and MATLAB SIMULINK to evaluate the performance. From the simulated result, it was observed that the overall achievement of handoff latency is reduced from standard 1100 ms to 653 ms and packet losses reduced by 60%. Evaluation and comparison have made with benchmark papers. During highlighting the development of scheme to reduce handoff delay and packet loss in this thesis, a significant reduced number of handoffs are identified as well.

iii

ملخص البحث المخصصة للمركبات من اتصال مركبة الى (VANET) تتألف شبكات الاتصالات

مركبة و من مركبة الى المحطة الرئیسیة. تعتبر ھذه التكنولوجیا من أنسب الطرق

وذلك لقدرتھا على التحرك والانتاجیة إضافة إلى السلامة ( ITS) لنظام النقل الذكي

وراحة الانسان. أثناء الحركة السریعة للمركبات على الطریق تتم عملیة التبدیل بین

خلال ھذه العملیة .Handoff نقاط الوصول ونقاط التحرك وتسمى ھذه العملیة

ینتج عن ھذا التاخیر (VANET)أثناء عملیة ( (ITS یحدث تأخیر لحساس النظام

خسائر كبیرة اثناء تسلیم الرسائل والامتعة. أثناء التسلیم وخلال نقطة انتقال المركبة

مع فقدان العنوان القدیم الموجھة الى نقطة ) (CoA تتحصل على عنوان رعایة جدید

یات الانتقال الجدیدة. لذلك في بیئة المركبات الدینامیكیة عالیة السرعة فإن عدد عمل

التسلیم المتكررة ینتج عنھا تأخیراً یتجاوز الحد الطبیعي. عملیة التحویل الكاملة

و طبقة الشبكة بالاضافة إلى عملیة ((APs و مفتاح MAC والمتكونة من طبقة

في بیئة شبكة . ITS تسجیل عنوان الرعایة الجدید ینتج عنھ تأخیر یؤثر على أداء

لمھم جداً إیجاد الحلول للمشاكل المتعلقة بجودة من ا VANET النقل عبر الانترنت

الاداء من تأخیر التسلیم وفقدان الحزمة أثناء عملیة التسلیم. یقدم ھذا البحث مقترحاً

-NEMO VANET (HDR لتقلیل زمن تأخیر التسلیم المستند إلى نطاق النظام

NV). الاساسیة للشبكةتتم ھذه العملیة من خلال تطبیق بروتوكول لدعم عملیة التنقل

(NEMO-BSP) بناء على تحرك عدد المركبات نحو الطریق. یتم أختیار مركبة

بینما تعمل المركبات (RSU) ومتصلة بالانترنت مع (MR)تعمل كموجھ رئیسي

وتتواصل مع بعض من خلال الوحدة (LRs)الاخرى في نفس المجال كموجھ عام

(MR) مصفوفات لتقییم مخطط الاداء وھي المتصلة بالانترنت. تم قیاس ثلاثة

مصفوفات زمن الانتقال وفقدان الحزمة والتأخیر بین عملیات التبدیل. تم استخدام

وبرنامج الماتلاب Network Simulator (NS)3 برنامج محاكي الشبكة

MATLAB SIMULINK لتقییم أداء النظام المقترح. من نتائج المحاكاة لوحظ

مللي ثانیة، كذلك 653مللي ثانیة إلى 1100انخفض من ان زمن الاستجابة قد

%. تم مقارنة النتائج مع نتائج سابقة لأوراق 60انخفضت خسائر الحزمة بنسبة

بحثیة قیاسیة. أیضاً في ھذا البحث تم تحدید عدد كبیر من عملیات التسلیم أثناء تطویر

.وبناء النظام من أجل الحد من زمن تأخیر وفقدان الحزمة

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APPROVAL PAGE

I certify that I have supervised and read this study and that in my opinion; it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a thesis for the degree of Master of Science (Computer and Information Engineering).

…………………………………. Farhat Anwar Supervisor

………………………………….. Aisha Hassan Abdalla Hashim Co-Supervisor

I certify that I have supervised and read this study and that in my opinion; it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a thesis for the degree of Master of Science (Computer and Information Engineering).

………………………………….. Mohamed Hadi Habaebi Internal Examiner

………………………………….. Sabira Khatun External Examiner

This thesis was submitted to the Department of Electrical and Computer Engineering and is accepted as a fulfillment of the requirement for the degree of Master of Science (Computer and Information Engineering).

………………………………….. Mohamed Hadi Habaebi Head, Department of Electrical and Computer Engineering.

This thesis was submitted to the Kulliyyah of Electrical and Computer Engineering and is accepted as a fulfillment of the requirement for the degree of Master of Science (Computer and Information Engineering).

………………………………….. Erry Yulian Triblas Adesta Dean, Kulliyyah of Engineering.

v

DECLARATION

I hereby declare that this thesis is the result of my own investigations, except where

otherwise stated. I also declare that it has not been previously or concurrently

submitted as a whole for any other degrees at IIUM or other institutions.

Shaikh Mohammad Ehsanur Rahman

Signature ........................................................... Date .........................................

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INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA

DECLARATION OF COPYRIGHT AND AFFIRMATION OF FAIR USE OF UNPUBLISHED RESEARCH

HANDOFF DELAY REDUCTION IN NEMO BASED VANET (HDR-NV) FOR ENHANCED PERFORMANCE

I declare that the copyright holders of this thesis are jointly owned by the student and IIUM.

Copyright © 2018 Shaikh Mohammad Ehsanur Rahman and International Islamic University

Malaysia. All rights reserved.

No part of this unpublished research may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without prior written permission of the copyright holder except as provided below

1. Any material contained in or derived from this unpublished research may be used by others in their writing with due acknowledgement.

2. IIUM or its library will have the right to make and transmit copies (print

or electronic) for institutional and academic purposes.

3. The IIUM library will have the right to make, store in a retrieved system and supply copies of this unpublished research if requested by other universities and research libraries.

By signing this form, I acknowledged that I have read and understand the IIUM Intellectual Property Right and Commercialization policy.

Affirmed by Shaikh Mohammad Ehsanur Rahman ……..…………………….. ……………………….. Signature Date

vii

This Thesis is especially dedicated to all of –

“my beloved parents, my siblings and my family members for their inspiration, encouragement, guidance, facilitating and praying for me to

be where I am today”.

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ACKNOWLEDGEMENTS

Praise to Allah SWT., the Almighty for bestowing His Grace and Mercy, Solawat and Salam to our beloved prophet (P.B.U.M).

At the very outset, all my prayers and thankfulness to Almighty Allah for abilities in granting me the opportunity with His Great Blessings to carry out and accomplish this thesis successfully throughout the years of my achievement for seeking the knowledge.

I wish to express my deepest gratitude to my supervisor, Dr. Farhat Anwar for permitting me to carry out this thesis with his guidance. I take immense pleasure in expressing my heartfelt gratitude to my co-supervisor, Dr. Aisha Hassan Abdalla Hashim as for her inspiration, guidance and valuable assistance in helping me to complete my research on time.

I extend my thankfulness to all my friends Golam Mostofa, Md. Rubaiyet Hasan, Md. Tawfiqur Rahman, Mosharrof Hossain Masud. Their encouragement and help made me confident to fulfilling my desire and overcoming every difficulty encountered.

Last but not least, I am very grateful to my parents specially remembering my loved mother late Tahmina Khatun and my always mental supporter my father Shaikh Shahjahan for their understanding and their love, encouragement to work hard and my wife Sinthia Hossain and my special gift my son Huzaifa bin Ehsan are my enthusiastic inspiration to continue pursuing my masters. I owe my every achievement to all of them.

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TABLE OF CONTENTS

Abstract .................................................................................................................... ii Abstract in Arabic .................................................................................................... iii Approval Page .......................................................................................................... iv Declaration .............................................................................................................. v Copyright page ......................................................................................................... vi Dedication ............................................................................................................... vii Acknowledgement ................................................................................................... viii Tables of Contents ................................................................................................... ix List of Tables ........................................................................................................... xi List of Figures .......................................................................................................... xii List of Abbreviations ............................................................................................... xiv CHAPTER ONE: INTRODUCTION ................................................................. 1

1.1 Overview ................................................................................................. 1

1.2 Background ............................................................................................. 1 1.3 NEMO Basic Support Protocol .............................................................. 3 1.4 NEMO based VANET ............................................................................ 4 1.5 Problem Statement .................................................................................. 6 1.6 Research Objectives ................................................................................ 6 1.7 Research Methodology ........................................................................... 7 1.8 Research Scopes ..................................................................................... 9 1.9 Thesis Organization ................................................................................ 9

CHAPTER TWO: LITERATURE REVIEW ..................................................... 11

2.1 Introdution .............................................................................................. 11 2.2 Fast Handoff Scheme (FHS)………………… ...................................... 12

2.2.1 Vehicular fast handover scheme………………………………… 12 2.2.2 Fast Mobility Management............................................................ 13 2.2.3 Fast Location-Based Handoff Scheme ......................................... 15

2.3 Fast Authentication Method (FAM) ....................................................... 17 2.3.1 A Fast and Efficient Handover Authentication ............................. 17 2.3.2 A lightweight identity authentication protocol .............................. 19

2.4 Processing of IP Address (PIPA) ............................................................ 20 2.4.1 IP Address Passing for VANETs .................................................. 20 2.4.2 VANET Optimized IP Address Allocation ................................... 22

2.5 NEMO in VANET (VANEMO) ............................................................. 24 2.5.1 Delay-Sensitive Urban Vehicular Networks ................................ 24 2.5.2 The Integration Approach for NN-VANETs ................................. 26

2.6 Cluster Base Handoff (CBH) .................................................................. 28 2.6.1 Reducing Handoff Latency for Cluster based VANET ................. 29 2.6.2 A Cluster Based MAC Protocol for VANETs .............................. 31

2.7 Other type of Handoff in VANET (OHV) .............................................. 33 2.7.1 Network Mobility Protocol for Vehicular Ad Hoc Networks ....... 33 2.7.2 Multihoming Based NEMO for VANETs………………………..36 2.7.3 Neighboring vehicle-assisted fast handoff……………………….37

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2.8 Critical Review ....................................................................................... 38 2.9 Chapter Summary ................................................................................... 40

CHAPTER THREE: RESEARCH METHODOLOGY ................................... 42

3.1 Introduction ............................................................................................. 42 3.2 Methodology ........................................................................................... 42 3.3 The Proposed HDR-NV ......................................................................... 43

3.3.1 Domain Formation Algorithm ....................................................... 45 3.3.2 Design of Proposed HDR-NV ....................................................... 49 3.3.3 Hand off between PAAP and NCAP ............................................. 50

3.4 Operation of the Proposed HDR-NV ...................................................... 52 3.5 Handoff Analysis .................................................................................... 54 3.6 Analytical Model of The Proposed Design............................................. 54 3.7 Simulation Model of The Proposed Design ............................................ 57

3.7.1 Simulation Setup ........................................................................... 57 3.8 Performance Evaluation .......................................................................... 64 3.9 Chapter Summary ................................................................................... 65

CHAPTER FOUR: RESULT AND DISCUSSION ........................................... 66

4.1 Introduction ............................................................................................. 66 4.2 Analytical Result VS Simulation Result ................................................. 66 4.3 Comparison and Discussion ................................................................... 80 4.4 Chapter Summary ................................................................................... 81

CHAPTER FIVE: CONCLUSION AND RECOMMENDATION ................... 82

5.1 Conclusions ............................................................................................. 82 5.2 Summary of Findings.............................................................................. 83 5.3 Future work ............................................................................................. 84

REFERENCES ....................................................................................................... 85 APPENDIX – I ...................................................................................................... 91 APPENDIX – II ..................................................................................................... 92 APPENDIX – III ................................................................................................... 95 APPENDIX – IV .................................................................................................. 102

xi

LIST OF TABLES Table 2.1 Summary of literature review 38

" 4.1 Simulation Proposed Parameters 67

" 4.3 Simulated results comparison for benchmarking 81

xii

LIST OF FIGURES

Figure 1.1 NEMO based VANET 5

" 1.2 Flowchart of Research Activities 8

" 2.1 Architecture of VFHS 12

" 2.2 Extension of HMIPv6 and mobility model 14

" 2.3 Design of a fast location-based handoff scheme 16

" 2.4 Initial full authentication of FEHA 18

" 2.5 Initial and renewal phases of LIAP protocol 19

" 2.6 IP passing diagram between vehicle A and vehicle B 21

" 2.7 Network Architecture for VANET optimized IP allocation 23

" 2.8 Architecture of Delay-Sensitive Urban Vehicular Networks 25

" 2.9 Nested NEMO based VANET 27 " 2.10 Nested NEMO Centric approach integration 27

" 2.11 Cluster based VANET environment 29

" 2.12 CMAC Protocol Model and Clustering Scheme 31

" 2.13 System Architecture network mobility of VANET. 34

" 2.14.a Mobility Architecture of BUS Vehicles 35

" 2.14.b Mobility Architecture of Bus with car Vehicles 35

" 3.1 Proposed HDR-NV scheme architecture 44

" 3.2 Domain formation in VANET environment 46

" 3.3 Domain formation Algorithm 47

" 3.4 Domain Head (MR) Selection 48

" 3.5 Hand over between PAAP and NCAP 50

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" 3.6 Exchange of message during handoff 51

" 3.7.a HDR-NV operational illustration (Part-A) 52

" 3.7.b HDR-NV is operational illustration (Part-B) 53 " 3.8 Netanim in NS3 on Ubuntu 14.04 OS. 58

" 3.9 Base Model of NS3 60

" 3.10 Details of Vehicle node model 62

" 4.1 The RSSI Value versus Vehicles (MNs) speed 67

" 4.2 Handoff latency in respect of vehicle’s speed & data rate 68

" 4.3 Packet loss in different speed and data rate 69

" 4.4 Handoff delay with data rate 70

" 4.5 Data packet latency in respect of time. 71

" 4.6 Inter-frame delay 72

" 4.7 Handoff Latency on vehicles velocity. 73

" 4.8 Handoff Latency based on background data rate 73

" 4.9 Packet losses during vehicle’s movement 74

" 4.10 Packet losses based on background data rate 75

" 4.11 Packet losses with speed and data rate 75

" 4.12 Total Signaling Cost on number of mobile network node (vnn) 76

" 4.13 Signaling Cost based on Hope distance between MR & HA. 77 " 4.14 Handoff delay benchmarking based on vehicles speed. 78 " 4.15 Packet losses benchmarking on vehicles speed. 79

xiv

LIST OF ABBREVIATIONS

AAA Authentication, authorization, and accounting

AP Access Point

ARP Address resolution protocol

AU Application unit

BA Binding acknowledgement

BMR Bus Mobile router

BU Binding update

BV Broken Vehicle

CBH Cluster Based Handoff

CDC Collective Degree of Connectivity

CLC Cumulative Local Connectivity

CMR Car Mobile router

CN Correspondent node

CoA Care of Address

DH Domain Head

DSSP Dynamic Session Secret Process

FAM Fast Authentication method

FMIPv6 Fast Mobile Internet Protocol version 6.

GARP Gratuitous Address regulation protocol

HA Home agent

HDR-NV Handoff Delay Reduction in NEMO based VANET

HMIPv6 Hierarchical MIP

ITS Intelligent Transport System

ITS Intelligent Transport Systems

LCoA Local Care of Address

LFN Local fixed node

LIAP Lightweight Identity Authentication Protocol

LMN Local mobile node

LR Localization Router

MAC Madia Access Controller

MANET Mobile Ad hoc Network

MAP Mobile anchor point

MG Mobile gateway

xv

MIPv6 Mobile internet protocol version 6

MMR Mobile Multihop Relay

MNN Mobile network node

MNP Mobile network prefix

MR Mobile Router

MSP Mobile service provider

NAR Next access router

NCAP New Candidate Access Point

NEMO BS Network Mobility Basic support

NN-VANET Nested NEMO-VANET

NTM Network topology message

OBU On board unit

OSV Oncoming Side Vehicle

PAR Previous access router

PIPA Processing of IP Address

PMIPv6 Proxy MIPv6

RSA Rivest–Shamir–Adleman

RSU Road side unit

RV Relay Vehicle

V2I Vehicle to Infrastructure

V2V Vehicle to Vehicle

VANEMO NEMO based VANET

VANET Vehicular Ad hoc Network

VANET Vehicular Adhoc Network

VD Vehicle Domain

VFHS vehicular fast hand system

VMN Visiting mobile node

1

CHAPTER ONE

INTRODUCTION

1.1 OVERVIEW

Vehicular Ad hoc networks (VANETs) can be considered as the most suitable

technology to provide vehicles with communication abilities to enhance the realization

of Intelligent Transport System (ITS). ITS is an intelligent transport system that

applies advancement in technology of transportation section to improve user mobility,

safety, productivity and minimize the adverse impact on the environment.

As an ITS, VANET consist of vehicle to vehicle and vehicle to infrastructure

communication. In VANET, vehicles form an infrastructure oriented network with

their fixed access points and an ad hoc network with the other vehicles. Hand off takes

place when the mobile node is not able to receive packet properly from its current

access router due to weak signal quality where vehicle notices that the signals from

previous access router continue to diminish and it is entering network area of other

access router. When receiving signal strength goes below certain threshold then the

handoff need to be carried out. Once this is done, then the connection between node

and old Access router is removed. This process is repeated for entire travel duration of

mobile node. This scenario needs to keep up with the speed with which mobile node

moves.

1.2 BACKGROUND

High speed of vehicles introduces more frequent handoff. During movement on the

street, vehicle’s changing point of attachment from one Access Point (AP) to another

(AP) is called Handoff process. In terms of conventional wireless networks, because

2

of the limited transmission radio range of antennas, the mobile vehicle needs to

associate with various access points to continue the communication while moving

towards the road. Vehicles are required to switch the access point as a consequence.

To continue the connection with the road side infrastructure network, vehicles have to

change its association with the RSU backbone connected to the internet.

During hand off, when mobile node is acquiring new care of address, packets

directed towards that node are lost because its old identity is no more valid. Both the

handoffs at MAC layer and network layer comprise together a complete handoff

process. Handoff during MAC layer, the vehicle node connects with new access point

and a wireless link is established at physical layer between vehicle node and access

point. To accomplish a complete handoff at layer 2, various handoff protocols are

used on different wireless technologies. A new care of address (CoA) will be

configured and routing table will be updated during handoff at network layer. Hence,

reducing the handoff delay and overhead is the key concern.

A key difference of VANETs – when contrasted with different flavor of ad-

hoc networks, is their abnormal state of node portability (because of vehicles' fast

movement) creating frequently break down of connections among nodes. Nodes'

mobility in VANET is commonly confined as Vehicles move based on given topology

of the streets. Furthermore, VANET nodes have no substantial memory and

processing abilities. All these mentioned properties of VANETs protocol are

significant for deployment of ITS application. But vehicle’s frequent movements

increase the switching with network point of attachments which made the

consideration of employing NEMO BS protocol in VANET to enhance ITS

application.

3

1.3 NEMO Basic Support Protocol:

The NEMO Basic Support protocol has been standardized in RFC 3963 (V.

Devarapalli, R. Wakikawa, et. al, 2005) to support network mobility. The protocol

maintains the session continuity for all the mobile network nodes (MNNs), even when

the Mobile Router (MR) dynamically changes its point of attachment to the Internet. It

also provides connectivity for all (MNNs) as it moves.

A Mobile Network is a network segment or subnet that can move and attach to

arbitrary points in the routing infrastructure. A Mobile Network can only be accessed

via specific gateways called Mobile Routers (MR) that manages its movement. Mobile

Networks have at least one Mobile Router serving them. When the Mobile Router

moves away from the home link and attaches to a new access router, it acquires a

Care-of Address from the visited link. The Mobile Router can act either as a Mobile

Host or as a Mobile Router at any time. Mobile Router does not distribute the Mobile

Network routes to the infrastructure at its point of attachment (i.e., in the visited

network).

NEMO signalling messages such as binding update (BU) and binding

acknowledgement (BA) are extended Mobile IPv6 messages. The BU and BA

messages have an additional mobile router flag (R) to signal the MR. There are two

modes for NEMO: explicit and implicit. In the explicit mode, one or more mobile

network prefix (MNP) options should be included in a BU message. In the implicit

mode, instead of including MNP options, the home agent (HA) has to make a decision

about the MNP owned by the MR and set up a forwarding mechanism for the mobile

network, such as a dynamic routing protocol. When the MR moves to a foreign link

away from the home link, the MR sends the BU message to its HA with a new care of

address (CoA), which is the IPv6 address of the MR at its current Internet attachment

4

point. The BU message also includes the MNP option and an R flag. Upon receipt of

the BU, the HA updates the MR’s information and replies by sending a BA message.

If the packets are sent to an MNN from a correspondent node (CN), the HA intercepts

the packets and encapsulates them in a bi-directional tunnel to the MR. After that, the

MR de-capsulate the packets and forwards them to the MNN. Reverse traffic must be

tunneled to the HA before it is routed to the CN. The NEMO Basic Support protocol

specifies bi-directional tunneling so that only MRs and HAs need to be aware of the

network mobility. NEMO based VANET tries to resolve these issues of hand off

latency and packet loss by selecting front and rear vehicles which helps in carrying off

hand over process.

1.4 NEMO based VANET

NEMO-based VANET is a vehicular ad hoc network (VANET) with network mobility

(NEMO) protocol (VANEMO) in order to support mobile network nodes (MNNs) that

are temporarily located in one vehicle and connected through a public hotspot with an

Internet access (Asa Baldessari, R., et al. 2008).

5

Figure.1.1: NEMO based VANET

In VANEMO as shown in Figure.1.1: vehicle which moves on highway along with the

road directions are embedded with mobile routers with multiple interfaces. Interface

that handles infrastructure communications and interface that is used for inter vehicle

communication. Router that provides connectivity to the mobile network is called a

Mobile Router (MR). Devices belonging to the mobile network – that obtain

connectivity through the MR – are called Mobile Network Nodes (MNNs) and there

are different types: Local Fixed Node (LFN), that is a node that has no mobility

specific software; Local Mobile Node (LMN), that is a node that implements the

Mobile IP protocol and whose home network is located in the mobile network; and

Visiting Mobile Node (VMN), a node that implements the Mobile IP protocol, has its

home network outside the mobile network, and it is visiting the mobile network

(Azzedine Boukerche, Zhenxia Zhang et. al. 2011)

6

1.5 PROBLEM STATEMENT

When the vehicle node moves from one access point to another, it is unable to

receive/send packet from corresponding node until it configures a new CoA and

complete the association process. The time required to complete the handoff process is

known as handoff latency. In a high dynamicity of vehicular environments, the

completion of a full handoff process may lead to delays beyond the normal limits.

Vehicle’s last packet received from existing access router to first packet at new access

router to the internet may drop as a consequence.Because of this handoff latency, the

vehicle node became unreachable from the network. As a real time ITS application

such as accident detection, prevention, sudden breaking, platooning etc. are extremely

sensitive to the unreachability of vehicle node during handoff. Even in vehicular to

vehicular condition multicast/telecast to transmit movement related data over different

nodes to a gathering recipient are quite unsteady.

On the other hand, high speed of vehicles network introduces more frequent handoff

for the mobile node during the movement towards the road direction. Frequent

number of handoffs may severely affect the functionality and performance of any ITS

application which is very significant in the problem of NEMO based VANET

performance. Thus the enhancement of performance of NEMO based VANET is

essential in terms of reducing delay and reduction of number of handoff.

1.6 RESEARCH OBJECTIVES

The main objective of this research is to develop an enhanced handoff reduction

scheme using NEMO based VANET to meet the requirements of time sensitive ITS

application. The objective in details are follows:

7

1. To investigate issues of handoff latency in Vehicular network

environment.

2. To develop a new Cluster based efficient handoff scheme for NEMO

based VANET.

3. To validate the proposed scheme and benchmark with current standard

vehicular handoff process on simulation.

1.7 METHODOLOGY

The research has been organized through the flowchart of the research activities as

depicted in the Figure 1.2. Review of the former works done through different

methods, have been summarized to compare and evaluate in the literature review. To

intensify the attention on the proposed topic, both advantages and shortcoming of

every individual method are deeply evaluated. The following steps have been

considered to design and develop the proposed Handoff Delay Reduction in NEMO

based VANET (HDR-NV) solution with the knowledge and understanding. After

designing the proposed scheme, it has been simulated for performance optimization

which has been done by using NS3.

Finally, to justify the proposed HDR-NV solution, simulated results have been

analyzed. The proposed design has been compared with Chaurasia, et. al. 2015 for

benchmarking. This has been further elaborated in Chapter Three.

8

Figure 1.2: Flowchart of the research activities.

9

1.8 RESEARCH SCOPE

The performance of HDR-NV system that depends on Cluster formation, Handoff

minimization and associated wireless technology to build up both RSU and mobile

router will be analyzed. This research will only highlight the development of the

scheme to reduce the number of handoff during vehicle’s switching between access

points while it moves. The scopes of the research work as follows:

1) To reduce the number of handoff, this research work involves developing

and test verification of the proposed scheme.

2) To improve the fast cluster formation in respect of dynamic vehicular

environment to enhance its performance.

3) To minimize the handoff latency through adopting multiple paths to RSU

in VANET infrastructure during switching between access points (APs)

1.9 THESIS ORGANIZATION

The thesis has been organized as follows:

Chapter One Explanation on diverse handoff process in VANET system which

follows the sequence of overview, problem statement, research objectives, research

methodology, and thesis outline have been described. VANET and NEMO based

VANET basics, theoretical background of the handoff process in Vehicular Adhoc

Network, using network mobility NEMO protocol have been analyzed in this chapter

two. Also literature views on various handoff systems have been presented. In chapter

three, it describes the proposed designed scheme’s development through the

introduction and demonstration of research methodology. In this chapter the next step

is to optimize the HDR-NV schemes as well as numerical analysis with performance