Mobile Communication by ANBARASAN

According to the Revised Syllabus of

ANNA UNIVERSITY- Tiruchirapalli EC1451-MOBILE AND WIRELESS COMMUNICATION For VIII th Semester Electronics and communication Engineering

ByMrs S.Deva Priya,M.Tech, (PhD).,

HOD/ECE,Jayaram college of Engineering and Technology,

Trichy.

Mr.R.Anbarasan B.E.,Engineer/Project-Trainer,

Embedded plus solutions,Trichy.

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EC1451- MOBILE AND WIRELESS COMMUNICATION. For VIII th-Semester ECE. As per ANNA UNIVERSITY- TIRUCHIRAPPALLI Syllabus.

UNIT I-PRINCIPLES OF WIRELESS COMMMUNICATIONS. (10)Hrs.

Digital modulation techniques – Linear modulation techniques – Spread spectrum modulation –Performance of modulation – Multiple access techniques – TDMA – FHMA – CDMA – SDMA –Overview of cellular networks – Cellular concept – Handoff strategies – Path loss – Fading and Doppler effect.

UNIT II -WIRELESS PROTOCOLS. (11) Hrs.

Issues and challenges of wireless networks – Location management –Resource management –Routing –Power management – Security –Wireless media access techniques – ALOHA– CSMA–Wireless LAN –MAN– IEEE 802.11 (a–b–e–f–g–h–i) – Bluetooth. Wireless routing protocols –Mobile IP- IPv4-IPv6 – Wireless TCP–Protocols for 3G and 4G cellular networks – IMT-2000 –UMTS –CDMA2000–Mobility management and handover Technologies – All-IP based cellular Networks.

UNIT III -TYPES OF WIRELESS NETWORKS. (9) Hrs.

Mobile networks – Ad-hoc networks – Ad-hoc routing – Sensor networks – Peer-Peer networks. Mobile routing protocols –DSR,AODV–Reactive routing–LAR- Mobility models – Entity based – Group mobility – Random way – Point mobility model.

UNIT IV- ISSUES AND CHALLENGES. (9) Hrs.

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Issues and challenges of mobile networks –Security issues –Authentication in mobile applications –Privacy issues –Power management–Energy awareness computing. Mobile IP and Ad-hoc networks– VoIP applications.

UNIT V- SIMULATION. (6) Hrs.

Study of various network simulators (GloMoSim-NS2-Opnet) – Designing and evaluating the performance of various transport and routing protocols of mobile and wireless networks using Network simulator (any one). Total: 45 Hours.

Preface The mobile phone industry is going through turbulent times. Motorola teams up with Microsoft, which is working hard to increase its share of the mobile phone market. Vodafone Group, one of the largest cellular operators in the world, announces that in the future it plans to purchase an increasing share of the mobile phones it resells from other suppliers than Nokia, in order to have a bigger say in the design of the handsets and their user interfaces and also to reduce the dominance of Nokia in the mobile communications industry in Europe. At the same time, Nokia goes through “the biggest reshuffle of senior management for five years” (“Nokia chases growth”, 2003), in order to face the challenges of the new multimedia-driven mobile services industry, where the focus will be on imaging, gaming, and entertainment services. NTT DoCoMo’s decision to start to use Symbian operating system in its 3G handsets is big news in the industry, whereas in the past nobody knew — or even cared — which operating system cellular operators and handset makers were using in their mobile phones. Consumer needs are also changing: instead of the simple voice calls of the past, “consumers now want network access in order to support diversified contents, applications and the so-called three A’s: Anywhere, Anytime, Anything communications”. Mobile business is shifting from voice-based services towards a media-like consumption of content. In the 1990s, thanks to the successful deployment of the digital mobile telephony standard, GSM, the European industry enjoyed stronger growth than the United States. As a result of this development, European customers enjoyed more and better services, and European manufacturers and operators M

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became the leaders of the industry. But these were “times when the word ‘crisis’ was out of the telecom’s vocabulary” (Blanco, 2003). Unit 1 describes Wireless technology now reaches or is capable of reaching virtually every location on the face of the earth. Hundreds of millions of people exchange information every day using laptops, personal digital assistants (PDAs), pagers, cellular phones, and other wireless communication devices. Success of outdoor and indoor wireless communication networks has led to numerous applications in sectors ranging from industries and enterprises to homes and universities Unit 2 describes that Some of the most remarkable growth has occurred in the deployment of wireless LANs (WLANs) where IEEE 802.11 based wireless networks have been used to provide connectivity not only as hotspots but also to substantial portions of a city. At the same time, we are also witnessing a significant trend in the emergence of small and low-cost computation and communication devices. While these tiny devices, called sensor nodes, are tightly constrained in terms of energy, storage capacity, and data processing capability, they have the potential to serve as a catalyst for a major change in how we communicate and interact with the environment. At the time we were working on third-generation (3G) wireless systems at Lucent Technologies. ITU-R had defined four 3G systems, and published a set of standards in 1999. The standards specify air interfaces based upon both wideband CDMA (W-CDMA) and wideband TDMA. However, since W-CDMA is the preferred interface, we have chosen to deal with W-CDMA and more specifically cdma2000 and UMTS FDD. Technologies used in 3G and necessary background material required to understand and, in some instances, develop a 3G system are presented. The treatment of topics is neither too detailed nor too brief, and our expectation is that a wide spectrum of readers—systems engineers, engineering managers, people who are new in this area but want to understand the system, and even designers—will find the book useful. Unit 3 and 4 describes that whereas today’s expensive wireless infrastructure depends on centrally deployed hub-and spoke networks, mobile ad hoc networks consist of devices that are autonomously self organizing in networks. In ad hoc networks, the devices themselves are the network, and this allows seamless communication, at low cost, in a self-organized fashion and with easy M

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deployment. The large degree of freedom and the self-organizing capabilities make mobile ad hoc networks completely different from any other networking solution. For the first time, users have the opportunity to create their own network, which can be deployed easily and cheaply. . Ad hoc networks are a key step in the evolution of wireless networks. They inherit the traditional problems of wireless and mobile communications, such as bandwidth optimization, power control and transmission quality enhancement. In addition, the multi hop nature and the lack of fixed infrastructure brings new research problems such as network configuration, device discovery and topology maintenance, as well as ad hoc addressing and self-routing. Many different approaches and protocols have been proposed and there are multiple standardization efforts within the Internet Engineering Task Force and the Internet Research Task Force, as well as academic and industrial projects. Unit5 describes about how network simulation is very useful in any of deputed companies or colleges and to know about their planned network models.GLOMOSIM ,NS2 and OPNET are explained here with sample coding .Readers are requested to download the simulation software and simulate the coding described here to know about this. This books covers revised syllabus of Anna University –Trichy with three model question papers and Part-A ,Part-B questions.

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Acknowledgements

We are thankful to Er.N.Subramanian M.E, chairman of Jayaram college of Engineering and Technology, Oxford Engineering college and Shri Angalamman college of Engineering and technology, who provided me necessary support and encouragement to write this book in successful manner. We would like to express our gratitude to our principal Dr.N.Kannan M.E,M.S,PhD, Jayaram college of Engineering & Technology, who provided valuable support and encouragement to publish this book successful manner. Mrs. S.Devapriya Mr. R.Anbarasan

I dedicate this book to my father P.Ramamoorthy, mother R.Vijaya, and family members for encouragement me to release this book with victory. Mr. R.Anbarasan

Finally, I would like to express my most sincere gratitude to Dr.N.Manivannan PhD,Managing Director,Techland Automatation, Trichy. Mr.A.RocheAdailkala Raj, Asst Professor, Jayaram college of Engineering and Technology Mr.R.Sarath Babu Asst professor, Jayaram college of Engineering and Technology, B.Sudharsan, S.Suresh, N.Anandaraj and B.Prabhakaran and all my close friends because without their constant support and encouragement, I could not have undertaken this work and completed it on time. M

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Mr.R.Anbarasan

Table of Contents

Unit 1: Principles of Wireless Communication 1.1 Introduction….………….…………………………………………………..…1 1.1.1The Evolution of Wireless Networks………………………………...….11.2 Digital Modulation Techniques…………………………………………….....5 1.2.1 Overview of Communication Systems……………………………….....5 1.2.2 Linear Modulation Techniques………………………….…………...….7 1.2.2.1 BPSK………………………………………………………...….7 1.2.2.2Differential Phase Shift Keying (DPSK)…………………..…...11 1.2.2.3Quadrature Phase Shift Keying (QPSK)……....……......………131.3 Spread Spectrum Modulation Techniques…………………………………. 16 1.3.1Direct Sequence Spread Spectrum (DS-SS)………………...…………20 1.3.2Frequency Hopped Spread Spectrum (FH-SS)……………...…………221.4 Performance of Modulation………………………………………………….26 1.4.1Performance of Direct Sequence Spread Spectrum……….…...……….26 1.4.2 Performance of Frequency Hopping Spread Spectrum………...……...28 1.4.3 Performance of Digital Modulation in Slow, Flat Fading Channels......291.5 Multiple Access Techniques….……………………………………………...30 1.5.1 Time Division Multiple Access (TDMA)………….………………….31 1.5.1.1 Efficiency of TDMA…………………………………………..33 1.5.1.2 Number of channels in TDMA system………………………...33 1.5.2 Frequency Division Multiple Access (FDMA)……………………….351.6 Spread Spectrum Multiple Access (SSMA)………………………...………..37 1.6.1 FHMA…………………………………………………………………38 1.6.2 DSMA or CDMA……………………………………………………..38 1.6.2.1 Practical example……………………......……………………..40M

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1.7 Space Division Multiple Access (SDMA)………………………………...….431.8 Mobile wireless networks……….……………………………………...…….45 1.8.1The cellular concept……………………………………………………..46 1.8.2 Cell Fundamentals………………………………………………………47 1.8.3Frequency Reuse……………..…………………………………………48

1.8.4 Channel Assignment Strategies…...……………………………………501.8.4.1Fixed channel assignment strategy (FCAS) ……..……………..50

1.8.4.2 Dynamic channel assignment strategy (DCAS)………………...50 1.8.5 Handoff Strategies………………………………………………………51 1.8.6 Practical Handoff Considerations……………………………………….54 1.8.6.1 Umbrella Cell Approach…...…………………………………….54 1.8.6.2 Cell Dragging. …………..……………………………………….541.8.7 Cell selection in idle mode….……….…………………………………….551.8.8 Interference……………………………………………………………...…56 1.8.8.1 Co-channel Interference and System Capacity……………………...561.9 Free space propagation model………………………………………………57 1.10 Fading…………...…………………………………………………………..58 1.10.1 Factors Influencing Small-Scale Fading…………………………….6o 1.10.1 Factors Influencing Small-Scale Fading…………………………….61 1.10.3 Types of Small scale Fading…………………………………………611.12 Doppler Shift………………………………………………………………...61Important Problems with Solutions………..…………………………………...……63

Summary…………….……………………..……………………………………69Problems for Practice….…………………..………………………………….…71

Unit 2:Wireless Protocols2.1 Introduction…………………………………………………………………..76 2.1.1Wireless Service Requirements…………………………………………762.2 Location management…...…………………………………………………….77 2.2.1Location update Algorithm………………………………………………78 2.2.2Paging Schemes………………………………………………………….79 2.2.3Location management Dissemination…………………………………...802.3 Radio resources and Power management……………………………...……...81 2.3.1Power Control……………………………………………………………82

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2.3.1.1 Open And Closed Loop Power Control………………………….82 2.3.1.2 Centralized Power Control………………………………………83 2.3.1.3 Distributed Power Control……………………………………….83 2.3.2 Power Saving Mechanism………………………………………………832.4 Security in Wireless Networks………………………………………………..84 2.4.1 Security Mechanism……………………………………………………84 2.4.1.1 Secret Key Algorithm...………………………………………...85 2.4.1.2 Public Key Algorithm…………………………………………..862.5 Wireless Media Access………………………………………………………..89 2.5.1 ALOHA………………………………………………………………...90 2.5.2 CSMA…………………………………………………………………..912.6 WLAN………………………………………………………………………...93 2.6.1Metropolitan Area Network……………………………………………..952.7 IEEE802.11 (a,b,e,f,g,h,i)………………………………………...…………..98

2.7.1 Problems in IEEE 802.11……………………………………………1062.8 Bluetooth…………………………………………………………………….108 2.8.1 Overall Architecture………………………………………………….108 2.8.2Definitions of the Terms Used in Bluetooth………………….………110 2.8.3.Protocol Stack……………………………………………………….1102.9 Mobile IP…………………………………………………………………….113 2.9.1Internet Protocol version 4 (IPv4)……………………………………114 2.9.1.1 Internet Addresses...…………………………………………..116 2.9.2Internet Protocol version 6 (IPv6)…………………………………...118 2.9.2.1 The transition from IPv4 to IPv6….…………………………1202.10 TCP/IP Suite……………………………...………………………………...121 2.10.1 Indirect TCP (I-TCP) …………...………………………………….122 2.10.2 Snooping TCP…………...………………………………………….124 2.10.3 Mobile TCP (M-TCP).…………...………………………………...1252.11 IMT-2000………………………………………………………...………....1262.12 Universal Mobile Telecommunication System (UMTS) …………………..130 2.12.1 UMTS System Architecture………………………………………..1312.13 CDMA 2000. ……………………………………………………………...133 2.13.1 CDMA 2000 Architecture…………………………………………..133 2.13.2 The Protocol Stack…………………………………………………134

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2.14 Mobility Management…………………………………………...…………137 2.14.1 Hand Off Management………………………………………………137 2.14.2 Generic Handoff Management Process……………………………...1392.15 Handoff Techniques……………………………………………………..…1412.16 All-IP Based Cellular Network……………………………………………..1422.17 Protocols for 3G…………………………………………………………….1442.18 Protocols for 4G…………………………………………………………….148 2.18.1 Problems with the Current System………………………………….148 2.18.2 4G Hardware………………………………………………………..149 2.18.3 Implementation of Packets………………………………………….151Important Problems with Solutions…………………………………………….151Summary…………………………………….…………………………………..155Problems for Practice.………………………..………………………………………...157

Unit3: Types of wireless networks.3.1 Introduction………………………………………………………………….1613.2 Review of Wireless Network Evolution…………………..…………………161

3.2.1 Wireless Communication Characteristics……………………………161 3.2.2 Types of Wireless Networks…………………………………………163 3.2.3 4G Wireless Architecture and Capabilities…………………………166 3.2.4 Deployment of Mobile WiMAX (complete 4G) ...……….…………168 3.2.5 Wi-Fi vs. WiMAX…………………………………...………………1693.3 Mobile Ad-hoc Networks (MANET)..…………………………………..…170 3.3.1 Characteristics………………………………………………………...173 3.3.2 Applications…………………………………………………………..1743.4 Ad-Hoc Routing………………………………………………………..........1753.5 Sensor Networks……………………………………………………………..179

3.5.1 Wireless Sensor Network Model………….………………………..179 3.5.2 IEEE 1451 and smart sensors ………………………………………181 3.5.3 Virtual Sensor…………………………………………………….…1823.6 Peer to Peer networks……………………………………………………….182 3.6.1 Working Principle…………………………...………………………..183 3.6.2 Applications…………………………………….…………………….184

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3.7 Routing Protocols………………………………...…………………………185 3.7.1 Proactive Approaches …………………..……………………………186

3.7.1.1 DSDV…………………………………………………………187 3.7.1.2 Optimized Link State Routing (OLSR) ……………....………189 3.7.2 Reactive Approaches…………………………………………………191 3.7.2.1Dynamic source routing (DSR) ………………………………191 3.7.2.2 AODV………...………………………………………………193 3.7.3 Geographical Approaches………….…………………………………198 3.7.3.1 Local Aided Routing (LAR) …………………………………198 3.7.4 Hybrid Approaches…………………..………………………………201

3.7.4.1 Zone Routing Protocol………………..………………………2013.8 Mobility Model………………………………………………………………205 3.8.1 Group Mobility Model…………………………..……………………205 3.8.1.1 Reference Point Group Mobility Model (RPGM)……..……205 3.8.1.2 Reference Velocity Group Mobility Model(RVGM)………..207 3.8.2Random Waypoint Model……………………………………….……208 3.8.2.1Random Waypoint on the Border (RWPB)…...……….…….210 3.8.2.2Markovian Waypoint Model (MWP)………………………..210Important Problems with Solutions…………………………………………….211Summary….……………………………………………………………………..211

Unit 4:Issues and challenges4.1 Introduction……………………………….…………………………………2144.2 Security Issues…………………………….…………………………………214 4.2.1 Purpose of Security……........…………………………..………….215 4.2.2 Wireless Security Protocols………………………………………..215

4.2.3 Security Issues in Mobile IP……..………………………………..218 4.2.4 Security Threats of WLAN……….………………………………….219

4.2.5 Required Features for a Secured Wireless……....………………………. ……………………………………Communications System....220

4.3 Authentication in Mobile Application……………….………………………221 4.3.1 Categories of authentication…….………….……………………..222 4.3.2.Biometrics……………………………..………………………….225

4.4 Privacy Issues……………………….………………………………………228

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4.4.1 Privacy Requirements…………….…………………………………229 4.4.2 Theft Resistance Requirements……...………………………………230 4.4.3 Methods of Providing Privacy and Security in Wireless Systems.….2324.5 Voice Over Internet Protocol (VoIP) Applications……………….…………233 4.5.1VoIP Traffic over 802.11 Wireless Links……………………………233 4.5.2Characteristics…………………………………………..……………2364.6 Energy Awareness Computing……………………………...………………2374.7 Mobile IP……………………………………………………………………238 4.7.1 Entities and terminology……...………………………………………239 4.7.2 IP packet delivery………………….…………………………………240 4.7.3 Agent discovery………………………………………………………241 4.7.4 Registration………………………………/.…………………………244 4.7.5 Mobile IP Public Key–Based Authentication………………………..246 4.8 Summary of Security in Current Wireless Systems…………………...……2484.9 Ad-hoc networks Issues……………………………………………..………249Summary….……………………………………………………………………..250

Unit 5:Simulation5.1 Introduction………………………...……………………..…………………253 5.2.1 Simulation steps……………………………………………………..…253 5.2.2 Classification of simulation tools…………………………………….2545.2 Study of GloMoSim……………………………………...…………………256

5.2.1 Network architecture…………………………………………………257 5.2.2The Visualization Tool…..……………………………………………258

5.2.3 Setting Up An Scenario………..……………………………………2595.2.4 GloMoSim Models……………...……………………………………264 5.2.4.1 Free space propagation model………………………………..265 5.2.4.2 Reflection (Two-Ray) Model …………………..…………….2655.2.5 Coding’s in GloMoSim………………………………………………2665.2.6 Structure of GloMoSim………………………………………………2685.2.7 Routing Protocols in GloMoSim….…………………………………2715.2.8 How to add a new Protocol………….………………………………2735.2.9 Installation of GloMoSim……….……………………………………274

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5.2.10 Simulation Examples…………..……………………………………2755.3 Study of Network Simulator-2 (NS2) …...……..……………………………281

5.3.1 Architectural Overview ……….………………………………………283 5.3.2 How to set up NS2? …...………………………………………………286

5.3.4Protocols/Models supported by NS2………...…………………………2875.3.5NS2 Models………………………………….…………………………2875.3.6Researches based on NS2………………………………………………2875.3.7 NS2 Components...……………………….……………………………287

5.3.8 Performance Analysis…………………………………………………287 5.3.8.1 Performance Metrics………………………………………….288 5.3.8.2 Performance Results…………………………………………..289

5.3.9Applications……………………………….……………………………290 5.3.9 A Simple Example in OTcl……………………………………………290

5.4 Study of OPNET………………….…………………………………………2925.4.1 OPNET Architecture……….…………………………………………2935.4.2 The structure of OPNET……...………………………………………2945.4.3 Various Tools of OPNET…......………………………………………2945.4.4The Network Domain Mobility…..….…………………………………2955.4.5 Simulation tool……………….…...……………………………………2955.4.6External System Domain (ESD) ….........………………………………2955.4.7 OPNET Products………..……….……………………………………297

5.5 Comparisson of various Network simulators………………………………..298Summary….……………………………………………………………………..298Anna university Important Part A and Part B questions and Answers………..300Model Question paper 1…………………………………………………………330Model Question paper 2…………………………………………………………332Model Question paper 3…………………………………………………………334Anna university Trichy APR/MAY 2011-Question paper with solutions…….337Anna university Trichy NOV/DEC 2011-Question paper with solutions……340APPENDIX A………….………………………………………………………343APPENDIX B………….………………………………………………………347APPENDIX C………….………………………………………………………350APPENDIX D………….………………………………………………………354APPENDIX E………….………………………………………………………358

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UNIT 1: PRINCIPLES OF WIRELESS COMMUNICATION

Introduction.Digital Modulation Techniques.Spread Spectrum Modulation Techniques.Performance of Direct Sequence Spread Spectrum.Multiple Access Techniques.Spread Spectrum Multiple Access (SSMA).Space Division Multiple Access (SDMA).The Cellular Concept.Handoff Strategies.Path Loss.Fading.Doppler Shift.

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Unit1: Principles of Wireless Communication. 1.1 Introduction:

During the past three decades, the world has seen significant changes in the telecommunications industry. There have been some remarkable aspects to the rapid growth in wireless communications, as seen by the large expansion in mobile systems. Many practical communication systems use a network which allows for full connectivity between devices without requiring a permanent physical link to exist between two devices. The dominant technology for voice communications is circuit switching. As the name implies, it creates a series of links between network nodes, with a channel on each physical link being allocated to the specific connection. In this manner a dedicated link is established between the two devices. Wireless systems consist of wireless wide-area networks (WWAN) [i.e., cellular systems] ,Wireless Local Area Networks(WLAN), and Wireless Personal Area Networks (WPAN). Wireless transmission plays a vital role in communication networks.

1.1.1 The Evolution of Wireless Networks:To date, there have been four distinct generations of mobile cellular networks. The first three generations of mobile networks are conventionally defined by air interfaces and transport technologies.

Figure 1.1 shows the generations, their transport technologies, and applications. 1G: Basic mobile telephony service 2G: Mobile telephony service for mass users with improved ciphering and efficient utilization of the radio spectrum 2.5G: Mobile Internet services 3G: Enhanced 2.5G services plus global roaming, and emerging newM

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applications.

1.8.6.1 Umbrella Cell Approach: When attempting to design for a wide range of mobile velocities. several problems arises. High speed vehicles pass through the coverage region of a cell within a fraction of seconds, whereas pedestrian users may never need a handoff during a call. If high speed users are constantly being passed between very small cells, the MSC can quickly become burdened which happens particularly with the addition of microcells to provide larger capacity.

Fig 1.35: Umbrella cell approach.

While minimizing handoff intervention from the MSC, several approaches have been devised to handle the simultaneous traffic of high speed and low speed users. In practice it is difficult for cellular service providers to obtain new physical cell site locations in urban areas even though the cellular concept clearly provides additional capacity through the addition of cell sites. It is possible to provide "large" and "small" cells which are co-located at a single location, by using different antenna heights and different power levels. A technique is used to provide large area coverage to high speed users while providing small area coverage to users traveling at low speeds is called the umbrella cell approach.

1.8.6.2 Cell Dragging:Another handoff problem in microcell systems is known as cell dragging. When there is a line-of-sight (LOS) radio path between the base station and subscriber in

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urban environment, then the cell dragging results from pedestrian users that provide a very strong signal to the base station. The average signal strength does not decay rapidly, when the user travels away from the base station at a very slow speed, Even when the user has traveled well beyond the designed range of the cell, the received signal at the base station may be above the handoff threshold, thus a handoff may not be made. This creates a potential interference and traffic management problem, since the user has meanwhile traveled deep within a neighboring cell.By adjusting , handoff thresholds and radio coverage parameters ,we can solve the cell dragging problem. Soft Handoff is defined as the ability to select between the instantaneous received signals from a variety of base stations. In Hard handoff ,Unlike channelized wireless systems that assign different radio channels during a handoff , spread spectrum mobiles share the same channel in every cell.

The mobile in a call:When the mobile is in a call, the network has excellent information about it. It knows exactly in what cell it is because it is transmitting and receiving from the mobile in that cell. It has a channel to the mobile, so it can ask it for any information that it might require. When the mobile is in a call, this is noted in the location registers. If another call comes in for the mobile during this time, the note in the location register quickly informs the network of this fact. In GSM there is a facility known as “call waiting” where users engaged on a call can be told that they have another incoming call. If the user has subscribed to this facility, then the network directs the call to the correct cell and sends a message to the user on the channel that they are currently using that they have another phone call. They can then chose whether they wish to accept it.

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UNIT2: WIRELESS PROTOCOLS

Introduction.Location Management.Radio Resources and Power Management.Security in Wireless Networks.Wireless Media Access.WLAN.IEEE802.11.Bluetooth.Mobile IP.TCP/IP Suite.IMT-2000.UMTS.CDMA 2000.Mobility Management.

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Handoff Technique. All-IP Based Cellular Network.Protocols for 3G And 4G.

Unit 2: Wireless Protocols2.1 Introduction: The demand for ubiquitous personal communications is driving the development of new networking techniques that accommodate mobile voice and data users who move throughout the buildings, cities, or countries. To provide wireless communication’s within a particular geographic region , an integrated network of the base stations must be deployed to provide sufficient radio coverage to all mobile user.

2.9 Wireless TCP:The transmission control protocol (TCP) is designed to provide a reliable connection between communicating hosts. TCP is a connection-oriented protocol. Before sending data a connection must be made with the remote host. The connection set up consists of three messages and is therefore called a three-way handshake. When packets are received at the destination an acknowledgement is sent back to the source. If the acknowledgement is not received within a certain time (retransmit timeout) the packet is sent again. In wired networks, random bit error rate is negligible. In a wireless network, packet losses occur due to handoff or fading and can be random. When TCP responds to packet losses by invoking congestion control or an avoidance algorithm, a degraded end-to-end performance in wireless network results. All wireless networks face a high bit error rate. Several approaches have been suggested to improve end-to-end TCP performance over wireless links . They can be classified into three categories.

o End-to-end TCP protocols,M

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o Link-layer protocols.o Split TCP connection protocol.

The end-to-end solution is used to improve TCP performance. Several schemes that have been used with the goal to improve TCP’s performance in wireless and mobile environment are:

o Indirect TCP (I-TCP).(See figure 2.29).o Snooping TCP .(See figure 2.31).o Mobile TCP (M-TCP).o Fast retransmit/fast recovery.o Transmission/time-out freezing.o Selective retransmission.

The following characteristics have been considered in deploying Wireless TCP over 2.5/3G wireless links:

o Data rates.o Latency.o Jitter.o Packet loss.

Based on these characteristics, the following configuration parameters for TCP in a wireless environment have been suggested: Large window size: TCP should use large enough window sizes based on the bandwidth delay experienced in wireless systems. Limit transmit: This is an extension of fast retransmission/fast recovery and is useful when small amounts of data are to be transmitted. Large maximum segment size:(MSS): The larger the MSS the faster TCP increases the congestion window. Selective ACK (SACK): SACK allows the selective retransmission of packets. 2.9.1 Indirect TCP (I-TCP):Two competing configuration led to the development of indirect TCP.

1). TCP performs poorly together with wireless links. 2).TCP within the fixed network cannot be changed.Mobile host connected through a wireless link and an access point (AP) to the ‘wired’ internet. The correspondent node could also use wireless access. Standard TCP is used between the fixed computer and the access point. No computer in the internet recognizes any changes to TCP.

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UNIT 3: TYPES OF WIRELESS NETWORKS.

Introduction.Mobile Ad-hoc Networks.Routing.Sensor Networks.Peer to Peer Networks.Routing Protocols.Local Aided Routing (LAR).Mobility Model.Group Mobility Model.Random Waypoint Model.

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Unit 3: Types of Wireless Networks.

3.1 Introduction: Mobile ad hoc networks (MANETs) are envisioned to become key components in the 4G architecture. Ad hoc networking capabilities are expected to become an important part of overall next-generation wireless network functionalities. In general, mobile ad hoc networks are formed dynamically by an autonomous system of mobile nodes that are connected via wireless links without using an existing network infrastructure or centralized administration. With the expected tremendous growth rate of wireless applications, especially in the hands of independent end users, businesses, and communities, it will be beneficial to have more adaptive, self-organizing technologies that robustly operate and adapt to changes (minor or severe).Within a network region, Mobile ad hoc networking (MANET) is one area of evolving technology that can support the operation of more adaptive wireless networks. An ad- hoc network is a collection of mobile nodes that dynamically forma temporary network, without the use of the existing infrastructure .Before knowing about Ad-hoc networks we have to know about wireless networks.1Dynamic source routing (DSR): It includes two parameters,1.Route discovery: If there is no known route between two nodes, it discovers a route to a destination, When a node wants to share something to destination. 2.Route maintenance:

o Node finds an alternative route ,when node detects problems with existing current route,

o If a node is sending packets through a route continuously, it has to make sure that the route is existing correctly with no breakage.

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o It manages the route. All periodic routing updates are eliminated by DSR and works as follows. If a node needs to discover a route, it broadcasts a route request with a unique identifier and the destination address as parameters. Any node that receives a route request does the following.

o It drops the request packet, if the node has already received the request.

o The request has reached its target, if the node recognizes its own address as the destination.

o Otherwise, the node appends its own address to a list of traversed hops in the packet and broadcasts this updated route request.

Applying route discovery to the example in Figure 3.7 for a route from N1 to N3 at time t1 results in the following Table3.5.

Broadcast Node Request Message ReceiverN1 Request(N1,id=42,target=N3) N2,N4N2 Request((N1,N2),id=42,target=N3) N3,N5N4 Request((N1,N4),id=42,target=N3) N1,N2,N5N5 Request((N1,N2N5,id=42,target=N3) N3,N4 Table 3.5:DSR for Node 1.Node Dropped NodeN4 N5’s BroadcastN1,N2,N5 N4’s Broadcast Table 3.6 Dropping’s in DSR.

Table 3.6 shows , N3 recognizes itself as target.N3 recognizes (N1, N2, and N5) as an alternate, but longer route.N3 now has to return the path (N1, N2, and N3) to N1. This is simple by assuming that symmetric links working in both directions. N3 can forward the information using the list in reverse order.The assumption of bi-directional links holds for many ad-hoc networks. If links are not bi-directional, this gets more complicated. This Algorithm has to be applied to reverse direction if the target does not maintain a current path to the source of the route request.(see Tab 3.7).N5 and N3 drops the request packet, N1 recognizes itself as target.

Broadcast Node Request Message Receiver

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N3 Request((N3,id=17,target=N1) N5N5 Request((N3,id=17,target=N1) N3,N4N4 Request((N3,N5,N4),id=17,target=N1) N5,N2,N1N2 Request((N3,N5,N4,N2,id=17,target=N1) N3,N5,N2

Table 3.7 DSR in Reverse path. Now N3 holds the list for a path from N1 to N3,ie., (N1, N2, N3), N1 knows the path from N3 to N1, (N3, N5, N4, and N1). But N1 still does not know how to send data to N3. The only solution is to send the list (N1, N2, N3) with the broadcasts initiated by N3 in the reverse direction.The basic algorithm for route discovery can be optimized in many ways, 1). Each route request could contain a counter to avoid too many broadcasts, Every node increments the counter by one for every rebroadcasting the request 2). From recent requests, a node can cache path fragments. These fragments can now be used to answer other route requests much faster. 3). While forwarding other packets, a node can also update this cache from packet headers 4).If a node overhears transmissions from other nodes, it can also use this information for shortening routes.

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UNIT 4: ISSUES AND CHALLENGES.

Introduction.Security issues.Authentication in Mobile Application.Privacy issues.Voice Over Internet Protocol (VOIP) Applications.Energy Awareness Computing.Mobile IP.

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Unit 4: Issues and Challenges.

4.1Introduction: The evolution towards a common, flexible, and seamless IP-based core network that will connect heterogeneous networks gives rise to several issues at the network layer. The need for ensured QoS is the key of this evolution. Communications on shared media can be intercepted by any user of the media. When the media are shared, anyone with access to the media can listen to or transmit on the media. Thus, communications are no longer private,All users of the network can overhear any information that an originator sends to the network and can resend the information to place a fraudulent call. The Participants of the phone call may not know that their privacy is compromised. When the media are shared, privacy and authentication are lost unless some method is established to regain it. Cryptography provides the means to regain control over privacy and authentication. 4.2 Security Issues: Wireless networks differ from their wired counter-parts in that they are virtually impossible to physically secure. In a physically secure enterprise, it is difficult for an external attacker to enter the office and covertly connect a laptop to the network. With wireless, the signals are broadcast over the air, and can be easily intercepted by an attacker who is within range of the signals. This makes the wireless security problem more challenging and interesting.

An ideal example that clearly signifies the need for wireless security is that of war drive .It involves an attacker driving around, using a standard wireless NIC(Network interface card) and a custom antenna, to detect available wireless networks.

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Types of biometrics: Several types of biometrics are used for authentication or identification. The name of the system refers to the biometric used, i.e., a voice scan refers to a system using the voice of a client for authentication. We cite:

a).Fingerprint-scan.b).Facial scan.c).Voice authentication.d).Hand geometry.e).Iris scan.f).Retinal scan.g).Signature scan and Keystroke scan.

Keystroke scan identifies the rhythm of a user's typing. It measures how long a key is held down and how much space is between keystrokes. Several other biometrics are in research to use in authentication or identification, such as DNA, ear shape and body odour.Applied Biometrics (www.appliedbiometrics.com) offers the PIN print Pilot, a fingerprint scanner that can simply be attached to Windows-CE handheld computers. This device has the possibility to lock out any authorized users via fingerprint identification. It is also possible to lock an application with this device. This standalone unit contains all algorithms and electronics required for fingerprint capture/compare including a database to store 16 fingerprints. Accessing fingerprint templates in a remote database via a network is also possible. A special version of this device is available for the Palm OS as well. They also demonstrated a special version of a small fingerprint scanner specifically for use in mobile telephones at the Consumer Electronics Show (CES 2000).Performance: The performance of biometric systems depends on several issues. We identify two generally recognized aspects:

1).False Rejection Ratio (FRR): FRR indicates the ratio of authentication Sequences that result in a reject of a valid user. This figure should be as low as possible.(see figure 4.6).

2)False Acceptance Ratio(FAR): False Acceptance Ratio(FAR) % indicates the ratio of authentication sequences that result in an acceptance of an imposter. This figure should be as low as possible too.

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UNIT 5: SIMULATION.

Introduction.Study Of GLOMOSIM . Study of Network Simulator 2 (NS2).OPNET.

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Unit 5: Simulation.5.1Introduction:The modern information society will continue to emerge, and demand for wireless communication services will grow. Future generation wireless networks are considered necessary for the support of emerging services with their increasing requirements. Future generation wireless networks are characterized by a distributed, dynamic, self-organizing architecture . Typical examples include Ad-Hoc/Mesh Networks, Sensor Networks, Cognitive Radio Networks, etc Simulation Modeling is becoming an increasingly popular method for network performance analysis. Thus, the study of a complex system always requires a discrete event simulation package, which can compute the time that would be associated with real events in a real-life situation.

Study Of GloMoSim(Global Mobile Information System Simulator): GloMoSim is a scalable simulation environment for large wireless and wired communication networks. GloMoSim uses a parallel discrete-event simulation capability provided by PARSEC. The scalability of the simulator to very large networks will be achieved primarily by exploiting parallelism on state of the art parallel computers. For instance, we have been successful in running a detailed simulation of a large wireless network with 10,000 mobile radios. Using parallel execution, it was possible to reduce the execution time sufficiently such that a model with 10,000 wireless nodes could be simulated on a 6 processor symmetric multiprocessor in less time than a network with half as many nodes using purely sequential execution.

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The Node Aggregation Technique (NAT) is introduced in to GloMoSim to give significant benefits to simulate on performance. Node aggregation technique(NAT) implies that the number of nodes in the system can be increased , while it maintaining the same number of entities in the simulation.

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