Cellphone Generations
The present hype is around Third-Generation (3G) phones, which will provide most of the advanced services planned until at least 2010. But it's worth looking at the other generations and the features they offer.
1G
First-generation phones are analog, meaning that they send information as a continuously varying waveform. They can only be used for voice and have highly variable call quality, thanks to interference. Another serious disadvantage is that they are very insecure; snoopers can listen in on calls with a simple radio tuner, or can even charge calls to another person's account. The first-generation AMPS standard is still popular in the U.S., but is seldom used elsewhere.
2G
Second-generation phones convert all speech ...
Get Essential Guide to Wireless Communications Applications, The now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
