Most people consider mobility to be one of their most cherished abilities and rights. In fact, what do we take away from those who have been deemed injurious to their fellow humans? Mobility. The freedom afforded by mobility is very precious.
One area in which we like to exercise our freedom of mobility is at work, and the mobile workforce is growing all the time. Market researchers and industry analysts expect the number of mobile workers to continue to grow worldwide. Given this trend, a company's performance and productivity will increasingly depend on understanding, managing, controlling, and securing technologies and tools that enable its mobile workers. Included in this mix of solutions are both remote and mobile network access, enabling connectivity to enterprise networks, applications, and data while away from the office, using a variety of devices, including notebooks, PDAs, and emerging mobile devices. Without reliable and secure mobile access to enterprise networks, mobile workers will not be able to be productive.
Another area in which we want to use our freedom to be mobile is with the Internet. The mobile Internet is already a reality in many places, and it will become more prevalent everywhere in the near future, as more and more Internet-ready mobile phones and other wireless devices make their way into people's pockets, accessories, and clothing. According to Ray Kurzweil, in his brilliant book The Age of Spiritual Machines, wireless is predicted to become the dominant form of access to the Internet by 2009. Mobile entertainment is yet another application area, with interest and services growing daily. These trends, as well as the trend toward machine-to-machine communications, sensor-based networks, and portable computing in the form of wearables, contribute to our avid interest in wireless communications and systems.
We used to think of wireline facilities as the default and of wireless as something extra that needed to be justified. Wireless was traditionally justified only in situations such as when wire could not be physically applied (e.g., in a jungle, in a desert, on a mountaintop); when wire could not be economically justified (e.g., when the expense of burying cable was too great); when time was an issue (the time to deploy a cable system can range from 9 to 18 months, while wireless systems can be deployed in 3 to 6 months); and of course, when mobility was a requirement. We are now beginning to see mixed-media approaches (including both wireline and wireless solutions), depending on the situation. For example, we may want to bring fiber as close as possible to an end node, but to engage in a more mobile lifestyle, we might use a wireless link for the last few meters.
This chapter discusses the history of wireless communication, wireless communications regulations issues, and technical issues facing wireless communications, including wireless impairments, antennas, bandwidth, signal modulation, and spectrum utilization. Chapter 14, "Wireless WANs," discusses the impressive range of standards and generations in the brief history of wireless wide area networks (WWANs). Chapter 15, "WMANs, WLANs, and WPANs," explores the various options in wireless metropolitan area networks (WMANs), wireless local area networks (WLANs), and wireless personal area networks (WPANs). Chapter 16, "Emerging Wireless Applications," delves into the emerging applications propelling the need for high-speed mobile communications.
Part I: Communications Fundamentals
Telecommunications Technology Fundamentals
Traditional Transmission Media
Establishing Communications Channels
Part II: Data Networking and the Internet
Data Communications Basics
Local Area Networking
Wide Area Networking
The Internet and IP Infrastructures
Part III: The New Generation of Networks
Broadband Access Alternatives
Part IV: Wireless Communications
Wireless Communications Basics
WMANs, WLANs, and WPANs
Emerging Wireless Applications