Wireless Personal and Local Area Networks

Preface xi

Structure of the book xii

1 Introduction 1

1.1 Definition and restriction 1

1.2 Overview of advantages and disadvantages 1

1.3 Applications overview 3

1.4 Market events 6

1.5 Organizations and governing bodies 12

2 Basics 17

2.1 History of wireless vs. wired 17

2.2 Technical communication models and classification 20

2.3 Demands on transfer networks 26

2.4 Properties of electromagnetic waves 28

2.5 Digital modulation technology 33

2.6 Channel access 38

2.7 Spread spectrum techniques 39

2.8 Orthogonal frequency division multiplex procedure 43

2.9 Antennae

2.10 Special features of wireless networks 47

2.11 Frequency allocations 48

3 Applications, devices and standards 51

3.1 Application scenarios 51

3.2 Device types 53

3.3 Standards 54

4 IEEE802.11 57

4.1 The standard 57

4.2 Architectures 59

4.3 Channel access 61

4.4 The Physical layer and bit transfer 81

4.5 Other services 86

4.6 Security 86

4.7 Extensions to the standard 88

5 Bluetooth 95

5.1 The standard 95

5.2 Architectures 99

5.3 Channel access 99

5.4 Controlling states 104

5.5 Bit transfer 108

5.6 Security 110

5.7 System implementation 110

6 DECT 113

6.1 The standard 113

6.2 Architectures 113

6.3 Channel access 114

6.4 Bit transfer 115

6.5 Application profiles 115

7 HomeRF 117

7.1 The standard 117

7.2 Architectures 117

7.3 Channel access 119

7.4 Bit transfer 121

8 HiperLAN/2 123

8.1 The standard 123

8.2 Architectures 125

8.3 Channel access 127

8.4 Bit transfer 130

8.5 Other services 132

8.6 The HiperLAN/2 standard versus IEEE802.1 a 132

9 Operating an IEEE802.11b-complaint WLAN 133

9.1 Introduction 133

9.2 Mobile stations 133

9.3 Access points 136

9.4 Extended networks 141

9.5 Network analysis 143

9.6 Examples from real life 148

10 Various aspects of WLAN technology 153

10.1 Security

10.2 Sources of interference 161

10.3 Selecting a spread spectrum technique 163

10.4 Aspects of EMT interference 165

10.5 WLANs and TCP/IP 167

10.6 Deciding factors 167

10.7 Future prospects 169

Appendix 171

A.1 Maxwellian equations 171

A.2 Physical basis of direct sequence spread spectrum process 171

A.3 Directional antennae 174

B Bibliography 179

B.1 English-language publications 179

B.2 German-language publications 182

C Abbreviations 185