What comes after 3G? Given that many telecoms are still struggling to deploy some version of 3G, Glisic offers a longer termed perspective.
Mobility is a key idea; since we are talking about wireless networks after all. There is an extrapolation from current cellphone usage. In one direction, it is to smaller length scales. So that you might have a personal area network of a few meters range, within which might be devices accessible in a wireless manner by your phone. Another idea is that the phone can be used across more regions. With seamless hand off between different providers. Of course, there remains an immense amount of behind the scenes details to be resolved amongst these providers. Not all of these are technological. Crucial issues involved a viable business model for them to rationally offer these fancy new services. (Whatever those might all turn out to be.)
Readers interested in Glisic's account might also want to venture into a related book on the same subject, 4G Roadmap and Emerging Communication Technologies (Universal Personal Communications). Both authors offer considerable overlap in their discussions.