oftware-Defined Radios 347 SDRs for Handsets, USB Modems, and Tablet Computers 348 Contents The Microcell Technology of Picocells and Femtocells 350 Picocells 350 Picocell Technology with Centralized Management Capability and Multisite Distribution 351 Using Distributed Antenna Systems for In-Building Coverage 351 Deploying Femtocells for Improved Coverage 352 Handheld Devices and Tablet Computers 353 Multiband Handsets versus Multi-mode Handsets 353 Managing Security and Billing for Mobile Devices in Enterprises 354 Killing Lost or Stolen Portable Computers by Using the Global Positioning System 356 The Driving Force of Smartphones 356 Tablet Computers and the Increasing Amount of Traffic They Generate 359 Applications and Services 360 Applications on Smartphones and Tablet Computers 360 Mobile Banking Transactions and Payments 362 Machine-to-Machine Communications-between Devices with Embedded Radios 363 Using Prepaid Mobile Services 364 Wi-Fi Standards, Architecture, and Use in Cellular Networks 365 The 802.11 Standard, WLAN, and Wi-Fi 366 The 802.11 Standards 366 WLAN Architecture in Enterprises 368 Managing Security on WLANs 374 Using Wi-Fi to Offload Traffic from Congested Mobile Networks 375 Wireless Internet Service Providers 376 Satellites 376 Satellite Networks 377 Satellite Telephones 377 New, High-Frequency Satellite Service for Airplanes and Internet Access 377 Summary 378 Appendix 379 8 Mobile Carriers Worldwide Introduction 388 The Largest Mobile Carriers Worldwide 390 Contents The Asian Market 392 China India Latin America Brazil 402 Sub-Saharan Africa 405 Kenya Nigeria Europe 412 The Role of the European Union 413 Expansion in Eastern Europe, Asia, and Africa 415 The Russian Federation 417 Summary 421 Glossary Index Preface Innovations in mobile networks and the Internet have eliminated barriers to com- munications created by geographic distances. People in different countries easily and often inexpensively communicate with one another via mobile devices, computers, and landline phones. Students 