Really well done. Easy to read, affordable book on wireless basics. The following table lists a few frequency allocations for common cellular and PCS services around the world. Today's mobiles can't tune themselves automatically to the frequencies they find, they need the right hardware, not just software, to use different frequencies. Dual mode phones, by comparison, are those few that operate in, say, a digital CDMA operating system, but use a non digital system like AMPS when no PCS signal is found.
Sprint makes such a phone.
It makes more sense to build radios which can accommodate different frequencies and protocols since common frequencies and a common radio system have never been agreed to. And the future promises us even more operating systems and far more different frequency allocations. But I am getting ahead of myself. Back to frequencies. Mobile to base Base to mobile Base to mobile Mobile to base 2.