n impact far beyond what the developers of the original Internet protocols, fiber-optic networks, and high-speed switches envisioned. Social networks have added a new dimension to how people stay in touch, make business connections, and share photographs and videos. Competition from the Inter- net has caused many "bricks-and-mortar" businesses to shut down or change the way they operate. Innovative Internet businesses continually evolve and offer increas- ingly sophisticated ways to access and store music and movies, documents, and large databases. The development of innovative Internet-based businesses depends in large part on open access to broadband networks. Broadband providers that favor their own services or charge prohibitive fees to start-ups for access could potentially inhibit this growth. Part IV Mobile Networks and Mobile Carriers Worldwide Chapter 7 Mobile and Wi-Fi Networks Chapter 8 Mobile Carriers Worldwide This page intentionally left blank Mobile and Wi-Fi Networks In this chapter: Introduction First-Generation Analog Technologies Finite Spectrum for Wireless Networks Second-, Third-, and Fourth-Generation Digital Networks Fourth-Generation Advanced Mobile Services The Streamlined Infrastructure of Long-Term Evolution Architecture The Microcell Technology of Picocells and Femtocells Handheld Devices and Tablet Computers Applications and Services Wi-Fi Standards, Architecture, and Use in Cellular Networks Satellites Summary Appendix Mobile and Wi-Fi Networks INTRODUCTION obile networks are critical during personal and national emergencies as well as for day-to-day communications. Worldwide, large percentages of populations that don't have access to affordable wireline broadband services are able to access e-mail with low-cost mobile devices. In addition, mobile networks are becoming an integral part of commercial transactions, and businesses that develop new applications and infrastruc- ture for mobile networks contribute to economic growth by generating revenue and creating employment opportunit