Preface

With the explosive growth of the Internet, more and more people got connected. The world suddenly became much smaller, because the distance between people from different parts of the world no longer prevented them from collaborating. In the 90s, there was a frenzied race to get people and corporations connected. Today, Internet access is a necessity; even novice users have trouble finding value in a computer that doesn't have email, a web browser, or instant messenger (IM).

While Internet access becomes as important as telephone or cable service, even more demanding users are appearing who are not satisfied in just getting connected. They want flexible ways to get connected wherever they take their notebook computers.

When wireless networking became affordable, early adopters installed it in their homes and offices, and it also quickly became a part of life in other places: many Starbucks Coffee and Borders bookstores now include wireless hotspots, mobile users are reading and sending email over cellular networks, and students are learning with notebook computers equipped with wireless network cards.

Today, wireless devices come in all shapes and sizes. In fact, wireless technology is not something new: remote control cars and TV remote controls have been in use for some time. Wireless technologies have penetrated our lives for so long that we take them for granted. In the case of a TV remote controller, infrared technology (which uses light) carries signals across the room. For the remote control car, radio waves transmit information from the controller to the car.