Given the explosion of new wireless communications techniques and the host of wireless network technologies and applications currently available or on the drawing board, it is safe to say that we are in the midst of a wireless networking revolution. Industry adoption of next-generation specifications will provide a substantial boost to the market for wireless multimedia networking, prompting growth in excess of 50 million wireless network devices by 2010, according to a market study by Parks Associates.
A compilation of critical content from , key MK titles published in recent years on wireless networking and communications. Individual chapters are organized as one complete reference that allows it to be used as a 360 degree view from our best- selling authors for those interested in new and developing aspects of wireless network technology.
- Chapters contributed by recognized experts in the field cover theory and practice of wireless network technology, allowing the reader to develop a new level of knowledge and technical expertise.
- Up-to-date coverage of wireless networking issues facilitates learning and lets the reader remain current and fully informed from multiple viewpoints.
- Presents methods of analysis and problem-solving techniques, enhancing the reader's grasp of the material and ability to implement practical solutions.
Wireless Networking Complete is a compilation of critical content from key Morgan Kaufmann titles published in recent years on wireless networking and communications. Individual chapters are organized into one complete reference giving a 360-degree view from our bestselling authors. From wireless application protocols, to Mesh Networks and Ad Hoc Sensor Networks, to security and survivability of wireless systems - all of the elements of wireless networking are united in a single volume. The book covers both methods of analysis and problem-solving techniques, enhancing the reader's grasp of the material and ability to implement practical solutions. This book is essential for anyone interested in new and developing aspects of wireless network technology. Chapters contributed by recognized experts in the field cover theory and practice of wireless network technology, allowing the reader to develop a new level of knowledge and technical expertise Up-to-date coverage of wireless networking issues facilitates learning and lets the reader remain current and fully informed from multiple viewpoints Presents methods of analysis and problem-solving techniques, enhancing the reader's grasp of the material and ability to implement practical solutions
Front Cover 1
Wireless Networking Complete 6
Copyright Page 7
Contents 8
About This Book 16
About the Authors 18
Chapter 1 Supporting Wireless Technologies 22
1.1. The Frequency Spectrum 22
1.1.1 Public Media Broadcasting 25
1.1.2 Cellular Communication 25
1.1.3 Wireless Data Communication 26
1.1.4 Other Fixed or Mobile Wireless Communications 27
1.2. Wireless Communication Primer 27
1.2.1 Signal Propagation 27
1.2.2 Modulation 30
1.2.3 Multiplexing 32
1.3. Spread Spectrum 33
1.3.1 Direct-Sequence Spread Spectrum 34
1.3.2 Frequency-Hopping Spread Spectrum 34
1.3.3 Orthogonal Frequency-Division Multiplexing 35
1.4. Global System for Mobile and General Packet Radio Service 36
1.4.1 Global System for Mobile 36
1.4.2 General Packet Radio Service 41
1.5. Code-Division Multiple Access 45
1.5.1 Code-Division Multiple Access Concept 45
1.5.2 IS-95 46
1.5.3 Software Handoff 47
1.5.4 Road to 4G 48
1.6. GSM Versus CDMA 49
1.7. 3G Cellular Systems 50
1.7.1. UMTS/WCDMA Versus cdma2000 51
1.7.2. UMTS/WCDMA 51
1.7.3. cdma2000 52
1.7.4. 4G Cellular Systems 54
1.8. 2G Mobile Wireless Services 55
1.8.1 WAP and iMode 55
1.8.2 Short Message Service 56
1.9. Wireless Technologies Landscape 57
1.10. 802.11 Wireless LANs 58
1.10.1 Architecture and Protocols 59
1.10.2 Frame Format 62
1.10.3 Beacon Frame 64
1.10.4 Roaming in a Wireless LAN 64
1.10.5 IEEE 802.11 Family 66
1.10.6 Security in Wireless LANs 68
1.11. Bluetooth 68
1.11.1 Architecture and Protocols 68
1.11.2 Bluetooth Overview 68
1.11.3 Bluetooth Architecture 69
1.11.4 Radio and Baseband 70
1.11.5 L2CAP and Frame Format 72
1.11.6 RFCOMM 73
1.11.7 SDP 73
1.11.8 Bluetooth Evolution 74
1.12. Ultra-Wideband 74
1.12.1 UWB Standards 76
1.12.2 UWB Applications 76
1.13. Radio-Frequency Identification 77
1.13.1 RFID System 77
1.13.2 RFID Applications 79
1.14. Wireless Metropolitan Area Networks 81
1.14.1 Wireless Broadband: IEEE 802.16 82
1.14.2 WiMax 83
1.15. Satellite 85
1.15.1 Satellite Communication 85
1.15.2 Satellite Systems 85
1.16. Wireless Sensor Networks 86
1.16.1 WSN Applications 87
1.16.2 Wireless Sensor Node 88
1.16.3 Self-Organized Networks 89
1.16.4 ZigBee 90
1.17. Standardization in the Wireless World 91
1.17.1 Cellular Standard Groups 92
1.17.2 IEEE Standards 92
1.17.3 Standards War 94
1.18. Summary 94
Further Reading 95
Chapter 2 Wireless Networks 98
2.1 Bluetooth (802.15.1) 100
2.2 Wi-Fi (802.11) 102
2.2.1 Physical Properties 102
2.2.2 Collision Avoidance 103
2.2.3 Distribution System 104
2.2.4 Frame Format 106
2.3 WiMAX (802.16) 107
2.4 Cell Phone Technologies 108
Further Reading 111
Chapter 3 An Overview of Wireless Systems 114
3.1 Introduction 114
3.2 First- and Second-Generation Cellular Systems 115
3.3 Cellular Communications from 1G to 3G 118
3.4 Road Map for Higher Data Rate Capability in 3G 121
3.5 Wireless 4G Systems 124
3.6 Future Wireless Networks 127
3.7 Standardization Activities for Cellular Systems 128
3.8 Summary 130
Problems 130
References 130
Chapter 4 Wireless Application Protocol 132
4.1 Introduction 132
4.2 WAP and the World Wide Web (WWW) 132
4.3 Introduction to Wireless Application Protocol 133
4.4 The WAP Programming Model 134
4.4.1 The WWW Model 135
4.4.2 The WAP Model 135
4.5 WAP Architecture 137
4.5.1 Wireless Application Environment 138
4.5.2 Wireless Telephony Application 139
4.5.3 Wireless Session Protocol 140
4.5.4 Wireless Transaction Protocol 141
4.5.5 Wireless Transport Layer Security 142
4.5.6 Wireless Datagram Protocol 142
4.5.7 Optimal WAP Bearers 143
4.6 Traditional WAP Networking Environment 144
4.7 WAP Advantages and Disadvantages 145
4.8 Applications of WAP 147
4.9 imode 148
4.10 imode Versus WAP 149
4.11 Summary 150
Problems 150
References 151
Chapter 5 Wireless Local Area Networks 152
5.1 Introduction 152
5.2 WLAN Equipment 155
5.3 WLAN Topologies 156
5.4 WLAN Technologies 157
5.4.1 IR Technology 157
5.4.2 UHF Narrowband Technology 158
5.4.3 Spread Spectrum Technology 159
5.5 IEEE 802.11 WLAN 160
5.5.1. IEEE 802.11 Architecture 160
5.5.2. 802.11 Physical Layer (PHY) 162
5.5.3. IEEE 802.11 Data Link Layer 174
5.5.4. IEEE 802.11 Medium Access Control 174
5.5.5. IEEE 802.11 MAC Sublayer 180
5.6 Joining an Existing Basic Service Set 182
5.7 Security of IEEE 802.11 Systems 184
5.8 Power Management 185
5.9 IEEE 802.11b—High-Rate DSSS 185
5.10 IEEE 802.11n 186
5.11 Other WLAN Standards 189
5.11.1 HIPERLAN Family of Standards 189
5.11.2 Multimedia Access Communication—High-Speed Wireless Access Network 194
5.12 Performance of a Bluetooth Piconet in the Presence of IEEE 802.11 WLANs 196
5.12.1 Packet Error Rate (PER) from N Neighboring Bluetooth Piconets 197
5.12.2 PER from M Neighboring IEEE 802.11 WLANs 198
5.12.3 Aggregated Throughput 198
5.13 Interference Between Bluetooth and IEEE 802.11 199
5.14 IEEE 802.16 202
5.15 World Interoperability for MicroAccess, Inc. (WiMAX) 204
5.15.1 WiMAX PHY 207
5.15.2 WiMAX Media Access Control (MAC) 208
5.15.3 Spectrum Allocation for WiMAX 209
5.16 Summary 210
Problems 210
References 212
Chapter 6 Fourth-Generation Systems and New Wireless Technologies 214
6.1. Introduction 214
6.2. 4G Vision 216
6.3. 4G Features and Challenges 216
6.4. Applications of 4G 218
6.5. 4G Technologies 221
6.5.1 Multicarrier Modulation 221
6.5.2 Smart Antenna Techniques 222
6.5.3 OFDM–MIMO Systems 226
6.5.4 Adaptive Modulation and Coding with Time-Slot Scheduler 226
6.5.5 Bell Labs Layered Space Time (BLAST) System 227
6.5.6 Software-Defined Radio 230
6.5.7 Cognitive Radio 232
6.6. Summary 233
Problems 233
References 234
Chapter 7 Mesh Networks: Optimal Routing and Scheduling 236
7.1 Overview 236
7.2 Network Topology and Link Activation Constraints 237
7.2.1 Link Activation Constraints 237
7.3 Link Scheduling and Schedulable Region 240
7.3.1 Stability of Queues 243
7.3.2 Link Flows and Link Stability Region 247
7.4 Routing and Scheduling a Given Flow Vector 250
7.5 Discussion 256
7.6 Maximum Weight Scheduling 257
7.6.1 Multicommodity Flow Criteria 259
7.6.2 Lyapunov Stability of a Network of Queues 259
7.6.3 The Algorithm and Its Analysis 260
7.6.4 Discussion 266
7.7 Routing and Scheduling for Elastic Traffic 266
7.7.1 Fair Allocation for Single Hop Flows 270
7.7.2 Fair Allocation for Multihop Flows 273
7.8 Discussion 278
7.9 Notes on the Literature 280
Problems 281
References 282
Chapter 8 Ad Hoc Wireless Sensor Networks 284
8.1 Overview 286
8.2 Communication Coverage 286
8.3 Discussion 287
8.4 Sensing Coverage 288
8.5 Discussion 294
8.6 Localization 295
8.6.1 Convex Position Estimation 297
8.7 Discussion 300
8.7.1 Routing 300
8.7.2 Attribute-Based Routing 305
8.8 Function Computation 307
8.9 Discussion 314
8.10 Scheduling 315
8.10.1 S-MAC 316
8.10.2 IEEE 802.15.4 (Zigbee) 318
8.11 Notes on the Literature 319
Problems 320
References 321
Chapter 9 Sensor Network Platforms and Tools 324
9.1 Sensor Node Hardware 325
9.1.1 Berkeley Motes 326
9.2 Sensor Network Programming Challenges 328
9.3 Node-Level Software Platforms 330
9.3.1 Operating System: TinyOS 331
9.3.2 Imperative Language: nesC 334
9.3.3 Dataflow-Style Language: TinyGALS 340
9.4 Node-Level Simulators 345
9.4.1 The ns-2 Simulator and Its Sensor Network Extensions 347
9.4.2 The Simulator TOSSIM 348
9.5 Programming Beyond Individual Nodes: State-Centric Programming 349
9.5.1 Collaboration Groups 350
9.5.2 PIECES: A State-Centric Design Framework 353
9.5.3 Multitarget Tracking Problem Revisited 356
9.6 Summary 361
References 361
Chapter 10 Mobile IP 366
10.1 The Requirements of Mobile IP 366
10.2 Extending the Protocols 368
10.3 Reverse Tunneling 370
10.4 Security Concerns 372
Further Reading 372
Chapter 11 Mobile IPv6 374
11.1 Introduction 374
11.2 Mobile IPv6 Overview 375
11.2.1 Types of Nodes 376
11.2.2 Basic Operation of Mobile IPv6 377
11.3 Header Extension 381
11.3.1 Alignment Requirements 382
11.3.2 Home Address Option 382
11.3.3 Type 2 Routing Header 383
11.3.4 Mobility Header 385
11.3.5 Mobility Options 393
11.3.6 Neighbor Discovery Messages 396
11.3.7 ICMPv6 Messages 398
11.4 Procedure of Mobile IPv6 402
11.4.1 Protocol Constants and Variables 402
11.4.2 Home Registration 402
11.4.3 Bi-Directional Tunneling 406
11.4.4 Intercepting Packets for a Mobile Node 408
11.4.5 Returning Home 408
11.5 Route Optimization 411
11.5.1 Return Routability 412
11.5.2 Sending Initial Messages 412
11.5.3 Responding to Initial Messages 413
11.5.4 Computing a Shared Secret 415
11.5.5 Verifying Message 416
11.5.6 Security Considerations 417
11.5.7 De-Register Binding for Correspondent Nodes 418
11.5.8 Backward Compatibility 418
11.6 Movement Detection 420
11.7 Dynamic Home Agent Address Discovery 420
11.8 Mobile Prefix Solicitation/Advertisement 421
11.9 Relationship with IPsec 425
References 427
Chapter 12 Security and Survivability of Wireless Systems 428
12.1 Introduction 428
12.2 Background 429
12.3 Current Security Approaches in Wireless Networks 432
12.4 Current Survivability Approaches in Wireless Networks 433
12.5 Framework for Wireless Network Survivability and Security 434
12.6 Interaction Between Survivability and Security in Wireless Networks 438
12.6.1 Extending the Framework to Include Interactions Between Security and Survivability 439
12.6.2 Case Study I: Idle Handoffs 442
12.6.3 Case Study II: Key Management in Heterogeneous Sensor Networks 443
12.7 Conclusion 450
References 451
Index 454
A 454
B 455
C 455
D 456
E 456
F 457
G 457
H 457
I 458
J 459
K 459
L 459
M 459
N 461
O 461
P 461
Q 462
R 462
S 462
T 464
U 464
V 464
W 464
X 466
Z 466
Supporting Wireless Technologies
Pei Zheng
Lionel M. Ni
This chapter provides extensive coverage of existing mobile wireless technologies. Much of the emphasis is on the highly anticipated 3G cellular networks and widely deployed wireless local area networks (LANs), as the next-generation smart phones are likely to offer at least these two types of connectivity. Other wireless technologies that either have already been commercialized or are undergoing active research and standardization are introduced as well. Because standardization plays a crucial role in developing a new technology and a market, throughout the discussion standards organizations and industry forums or consortiums of some technologies are introduced. In addition, the last section of this chapter presents a list of standards in the wireless arena.
1.1 The Frequency Spectrum
The fundamental principle of wireless communication is electromagnetic wave transmission between a transmitter and a receiver. Signals are characterized by their frequencies in use. Multiple signals or noises of the same frequency will cause interference at the receiver. To avoid interference, various wireless technologies use distinct frequency bands with well-controlled signal power which are portions of the so-called frequency spectrum. As a scarce public resource, the frequency spectrum is strictly regulated by governments of countries around the world. In the United States, the Federal Communications Commission (FCC) has the responsibility of regulating civil broadcast and electronic communications, including the use of the frequency spectrum, and the National Telecommunications and Information Administration (NITA) administers the frequency use of the federal government. In Europe, the frequency spectrum is managed on a national basis, and the European Union (EU) members coordinate via the European Conference of Post and Telecommunications Administrations (ECPT) and the Electronic Communications Committee (ECC). Worldwide unified regulation of wireless communication is understandably difficult to achieve for various technological, economic, and political reasons. To this end, the International Telecommunications Union (ITU) has been formed as an international organization of the United Nation. The ITU allows governments and private sectors to coordinate development of telecommunication systems, services, and standards. In almost all countries, portions of the frequency spectrum have been designated as “unlicensed,” meaning that a government license is not required for wireless systems operating at these bands. In effect, wireless system manufacturers and service providers are required to obtain an exclusive license for a frequency band from regulatory bodies or resort to the use of the unlicensed spectrum. In either case, the emitted power of the wireless systems must comply with the power constraints associated with the regulations in question. In addition, frequency allocations of a country may change over time. (For the latest information regarding frequency allocation in the United States, see http://www.ntia.doc.gov/osmhome/allochrt.html.)
A radio signal is characterized by wavelength and frequency. In vacuum, the product of wavelength and frequency is the speed of light (about 3 × 108 m/sec); in general, a higher frequency means shorter wavelength. For example, visible light is in the frequency band of 4.3 × 1014 to 7.5 × 1014 Hz, with wavelengths ranging from 0.35 to 0.9 μm. Frequency modulation (FM) radio broadcasts operate within the frequency range of 30 to 300 MHz at wavelengths between 10 and 1 m.
The frequency spectrum can be divided into the following categories: very low frequency (VLF), low frequency (LF), medium frequency (MF), high frequency (HF), very high frequency (VHF), ultra-high frequency (UHF), super-high frequency (SHF), extremely high frequency (EHF), infrared, visible light, ultraviolet, X-ray, gamma-ray, and cosmic ray, each of which represents a frequency band. Figure 1.1 shows the frequency spectrum up to the visible light band. Notice that in the context of electronic communication, there are two categories of transmission medium: guided medium (e.g., copper coaxial cable and twisted pair) and unguided medium (for wireless communication in the air). The guided medium carries signals or waves between a transmitter and a receiver, whereas the unguided medium typically carries wireless signals between an antenna and a receiver (which may also be an antenna). Nevertheless, each medium operates at a specific frequency band of various bandwidth determined by its physical characteristics. For example, coaxial cable uses many portions of frequencies between 1 KHz and 1 GHz for different purposes: television channels 2, 3, and 4 operate at frequencies from 54 to 72 MHz; channels 5 and 6 from 76 to 88 MHz; and channels 7 to 13 from 174 to 216 MHz. The optical fiber uses visible or infrared light as the carrier and operates at frequencies between 100 and 1000 THz.
Figure 1.1 The frequency spectrum (refer to the text for the exact frequency band allocated to each system).
Wireless communication operates at frequencies in the so-called radio spectrum, which is further divided into VLF, LF, MF, HF, VHF, UHF, SHF, and EHF. In addition, infrared data association (IrDA) is also used for short-range wireless communication. The following text discusses frequency bands at which existing mobile wireless technologies operate; notice that very often the frequency regulations enforce emitted power restrictions to avoid interference among wireless devices operating at the same frequency band.
1.1.1 Public Media Broadcasting
• Amplitude modulation (AM) radio: AM radio stations operate at a frequency band between 520 and 1605.5 KHz.
• FM radio: It uses the frequency band between 87.5 and 108 MHz.
• Shortwave (SW) radio: SW radio uses frequencies between 5.9 and 26.1 MHz within the HF band. The transmission of shortwave radio over a long distance is made possible by ionosphere reflection. HAM amateur radio, a popular activity enjoyed by over three million fans worldwide, relies on the HF band to communicate across the world.
• Conventional analog television: A quite small slice of VHF (30–300 MHz) and UHF (300–3000 MHz) has been allocated for analog television broadcasting. In the United States, each channel occupies a 6-MHz band. The first VHF channel, channel 2, operates at 54–60 MHz, whereas the last UHF channel, channel 69, operates at 800–806 MHz.
• Cable television: The frequency bands of channels 2–13 are exactly the same for both conventional television and cable television. Beyond those channels, cable television requires frequencies from 120 to 552 MHz for channels 13–78.
• Digital cable television: Channels 79 and above are reserved for digital cable broadcasting at frequencies between 552 and 750 MHz.
• Digital audio broadcasting (DAB): DAB is a standard developed by the EU for CD-quality audio transmission at frequencies from 174 to 240 MHz and from 1452 to 1492 MHz. In the United States, a technique called in-band on-channel (IBOC) is used to transmit digital audio and analog radio signals simultaneously with the same frequency band. The resulting services are generally marketed as high-definition radio.
• Direct broadcast satellite (DBS): The upper portion of the microwave Ku band (10.9–12.75 GHz) is used for direct satellite-to-receiver video and audio broadcasting. See Section 1.13 for more details regarding satellite communication.
• Satellite radio: Frequencies from 2320 to 2345 MHz have been allotted for satellite radio services in the United States. See Section 1.13 for more details regarding satellite communication.
1.1.2 Cellular Communication
• Global system for mobile (GSM): The two frequency bands used by GSM are 890–960 MHz and 1710–1880 MHz. They are sometimes referred to as the 900-MHz band and the 1800-MHz band.
• Code-division multiple access (CDMA): The IS-95 standard defines the use of the 800- and 1900-MHz bands for CDMA cellular systems.
• 3G wideband CDMA (WCDMA)/universal mobile telecommunications system (UMTS): Three frequency bands are allocated for 3G UMTS services: 1900–1980 MHz, 2020–2025 MHz, and 2110–2190 MHz.
• 3G CDMA 2000: This system reuses existing CDMA frequency bands.
1.1.3 Wireless Data Communication
• Wireless LANs: IEEE 802.11b operates at 902–928 MHz and 2400–2483 MHz, and the industrial, scientific, and medical (ISM) radio bands operate at 2.4 GHz in the United States. The IEEE 802.11b operates at 2400–2483 MHz in Europe, and at 2400–2497 MHz in Japan. IEEE 802.11a and HiperLAN2 use 5150–5350 MHz and 5725–5825 MHz, and the unlicensed national information infrastructure (U-NII) band operates at 5.8 GHz in the United States. They operate at 5150–5350 MHz and 5470–5725 MHz in Europe, and at 5150–5250 MHz in Japan. Section 1.10 discusses wireless LANs in more detail.
• Bluetooth:...
| Erscheint lt. Verlag | 4.8.2009 |
|---|---|
| Sprache | englisch |
| Themenwelt | Mathematik / Informatik ► Informatik ► Netzwerke |
| Technik ► Elektrotechnik / Energietechnik | |
| Technik ► Nachrichtentechnik | |
| ISBN-10 | 0-12-378570-7 / 0123785707 |
| ISBN-13 | 978-0-12-378570-1 / 9780123785701 |
| Haben Sie eine Frage zum Produkt? |
PDF (Adobe DRM)Größe: 3,2 MB
Kopierschutz: Adobe-DRM
Adobe-DRM ist ein Kopierschutz, der das eBook vor Mißbrauch schützen soll. Dabei wird das eBook bereits beim Download auf Ihre persönliche Adobe-ID autorisiert. Lesen können Sie das eBook dann nur auf den Geräten, welche ebenfalls auf Ihre Adobe-ID registriert sind.
Details zum Adobe-DRM
Dateiformat: PDF (Portable Document Format)
Mit einem festen Seitenlayout eignet sich die PDF besonders für Fachbücher mit Spalten, Tabellen und Abbildungen. Eine PDF kann auf fast allen Geräten angezeigt werden, ist aber für kleine Displays (Smartphone, eReader) nur eingeschränkt geeignet.
Systemvoraussetzungen:
PC/Mac: Mit einem PC oder Mac können Sie dieses eBook lesen. Sie benötigen eine
eReader: Dieses eBook kann mit (fast) allen eBook-Readern gelesen werden. Mit dem amazon-Kindle ist es aber nicht kompatibel.
Smartphone/Tablet: Egal ob Apple oder Android, dieses eBook können Sie lesen. Sie benötigen eine
Geräteliste und zusätzliche Hinweise
Zusätzliches Feature: Online Lesen
Dieses eBook können Sie zusätzlich zum Download auch online im Webbrowser lesen.
Buying eBooks from abroad
For tax law reasons we can sell eBooks just within Germany and Switzerland. Regrettably we cannot fulfill eBook-orders from other countries.
EPUB (Adobe DRM)Größe: 8,8 MB
Kopierschutz: Adobe-DRM
Adobe-DRM ist ein Kopierschutz, der das eBook vor Mißbrauch schützen soll. Dabei wird das eBook bereits beim Download auf Ihre persönliche Adobe-ID autorisiert. Lesen können Sie das eBook dann nur auf den Geräten, welche ebenfalls auf Ihre Adobe-ID registriert sind.
Details zum Adobe-DRM
Dateiformat: EPUB (Electronic Publication)
EPUB ist ein offener Standard für eBooks und eignet sich besonders zur Darstellung von Belletristik und Sachbüchern. Der Fließtext wird dynamisch an die Display- und Schriftgröße angepasst. Auch für mobile Lesegeräte ist EPUB daher gut geeignet.
Systemvoraussetzungen:
PC/Mac: Mit einem PC oder Mac können Sie dieses eBook lesen. Sie benötigen eine
eReader: Dieses eBook kann mit (fast) allen eBook-Readern gelesen werden. Mit dem amazon-Kindle ist es aber nicht kompatibel.
Smartphone/Tablet: Egal ob Apple oder Android, dieses eBook können Sie lesen. Sie benötigen eine
Geräteliste und zusätzliche Hinweise
Zusätzliches Feature: Online Lesen
Dieses eBook können Sie zusätzlich zum Download auch online im Webbrowser lesen.
Buying eBooks from abroad
For tax law reasons we can sell eBooks just within Germany and Switzerland. Regrettably we cannot fulfill eBook-orders from other countries.
aus dem Bereich
