Why mobile networks are developed in phases like 1G after 2 years 2G and then like wise every 2 years next G? What is stopping us from deploying 10G right now?
First the "G" thing does not exist at the technical and organizational level in telecoms.
The "G" thing is a marketing invention.<p>You should look at the standard body 3GPP, a consortium of standard bodies, it has releases, not generations and releases come every year or so:<p><a href="http://www.3gpp.org/specifications/releases" rel="nofollow">http://www.3gpp.org/specifications/releases</a><p>Releases are proposals that are realistic, not only technologically but also economically and that make sense in the telecom ecosystem.
For example as you say, one can dream of a 300GHz, 256 antennas phone transmitting data at 3,200 GBits/sec, but actually no phone CPU or hardware would be fast enough to keep up with such a wild beast (they already have difficulties to cope with the current gigabit/sec rates).<p>In addition the higher frequency you go to escape the spectrum regulation, the greater attenuation there is in the medium, so at 300GHz you can may expect a path of only a few meters.