Children's LiteratureAlthough the text focuses on "Present Knowledge" and "Future Trends," this book begins with a whirlwind tour of the history of telecommunications, from the telegraph to the fax machine. Following this is a rather in-depth and technical discussion of the different types of telecommunications systems and signals, which is helpfully illustrated by a variety of charts and diagrams, but may be beyond many general readers. Of more interest may be the sections explaining how a cellular phone network works, as well as the structure of the Internet. One problematic feature of this book (as with any title that purports to discuss future directions in technology) is that some of the items (such as multifunction hand-held devices) that the text presents as cutting-edge and futuristic are already becoming commonplace. In addition to a variety of line drawings of various telecommunications networks, color photographs depicting telecommunications devices illustrate the text. Part of the "21st Century Science" series. 2004, Smart Apple Media, Ages 9 to 12.