Wireless and Mobile Device Security, 2nd Edition

Introduction to Cellular (Mobile Communication)

One of the greatest accomplishments of the 20th century was the rollout of the public switched telephone network (PSTN)—not only because of the technology itself but also because of its ubiquitous reach. With the PSTN, nearly every home in the developed world (and a high percentage of homes even in some undeveloped areas) had a wired communication channel that connected it to the rest of the world, providing a lifeline in times of trouble. The system even provided its own power, keeping the communication channel open when the lights went out. Just imagine the scope and cost of running and maintaining a wired connection in the United States alone, with approximately 125 million homes and 20 million ...