Kim and Prasad's contribution to 4G is to explain it in sufficient detail that you can usefully consider possible future applications. You might be working for an existing cellphone provider, for example. Or you might be an individual or company looking to get into the service business for 4G.

4G is essentially a network of networks. It is still a somewhat hazy view of where to go, beyond the current 2G and 3G deployments. Seamless nomadic usage and ubiquitous access are key characteristics. Along with bandwidth of 50-100 Mbps. All by 2010, at least in Asia, by one schedule. While another schedule has this deployed in Europe by 2015. The reader will be struck by the US being at some later unspecified date. While you may be used to the US leading in other technological fields, in the wireless sphere, it is an also-ran by a wide margin.

Mobile IP is suggested by the text as one of the needed technologies. The discussion reveals that it runs best using IPv6, not the current IPv4. Using it under IPv4 is very cumbersome. If you have been following IPv6, you might think its deployment has been slow. A large demand for Mobile IP could be one of the key drivers for an accelerated rollout. (Finally!)

The book suggests that Digital Rights Management will be an important consideration for 4G; more so than under 3G. Its take on DRM is brief. What it does not say is that DRM is intrinsically very hard. Some companies, like music publishers, might have to use DRM to protect their assets on the new phones. But if you are considering a new 4G business to be in, perhaps look for something that does not depend on DRM. A service approach, like multiplayer games. Where the entire issue of DRM is moot.

For SMS and MMS, there could have been more discussion of the problems of spam and phishing. Spam already exists as a considerable problem in SMS in China. While, in general, if MMS takes off, its ability to show images and hyperlinks means it becomes an HTML equivalent. Which increases the attraction of spam and phishing.