This easy-to-read introduction to wireless communications is clearly targeted toward lay readers. I recommend it to those who want to learn the key buzzwords in 5 to 10 minutes.

The article also contains an ample supply of technical details, mainly numbers. If you want to know what frequencies fall in the Ku band, you will find the answer here, along with tens of other numbers. Why authors include such details in introductory articles has always puzzled me. I speculate that people who care to know that the C band is 3.7–4.2 GHz no longer need to read introductory articles. One might imagine that there is no harm in supplying readers with technical details. Alas, no alert reader will trust Fowler’s numbers, since he believes that Sputnik was launched in 1954. If he is off by three years in that regard, why believe him when he says that Iridium satellites weigh 689 kg?

As is always the case in an introductory article, the choice of material is somewhat arbitrary, but this is a necessity. I would prefer, though, to see not only a description of Iridium and GPS, but of the other orbiting initiatives, such as Goldstar or the MEO ICO, which I consider to be the most promising.